JP2011085597A - Inspection method and inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a simplified inspection method in which the need for setting up a prober at a wiring is dispensed with, and to provide an inspection device which uses the inspection method. <P>SOLUTION: Inspection is carried out by making electromotive force generated in a wiring of an element substrate due to electromagnetic induction, and thereby passing a current through the wiring. The inspection method includes impressing a voltage on a circuit or a circuit element in a contactless manner to make the circuit or a circuit element actuate; reading a voltage output from the circuit or circuit element in a contactless manner; and determining the quality of the circuit or a circuit element. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a measurement method for operating a circuit or a circuit element included in a semiconductor device and reading an output of the circuit or the circuit element, and a method for inspecting whether a pixel portion operates normally using the measurement method. In particular, the present invention relates to a non-contact type inspection method and a non-contact type inspection apparatus using the same.

  In recent years, a technique for forming a thin film transistor (TFT) using a semiconductor film (having a thickness of about several to several hundred nm) formed on a substrate having an insulating surface has attracted attention. This is because the demand for an active matrix semiconductor display device which is one of the semiconductor devices has increased. The active matrix semiconductor display device typically includes a liquid crystal display, an OLED (Organic Light Emitting Device) display, and a DMD (Digital Micromirror Device).

  A TFT (crystalline TFT) using a semiconductor film having a crystal structure as an active layer has high mobility. Therefore, an active matrix semiconductor that displays high-definition images by integrating functional circuits on the same substrate. A display device can be realized.

  Incidentally, an active matrix semiconductor display device is completed through various manufacturing processes. For example, in the case of an active matrix liquid crystal display, a pattern forming process for forming a semiconductor film and forming a pattern, a color filter forming process for realizing colorization, an element substrate having an element including a semiconductor, and a counter electrode A cell assembly process for forming a liquid crystal panel by enclosing a liquid crystal between a counter substrate and a liquid crystal panel assembled in the cell assembly process, and driving parts and a backlight for operating the liquid crystal panel are attached, It mainly has a module assembly process to be completed as a liquid crystal display.

  Although there are some differences depending on the type of liquid crystal display, each of the above steps includes an inspection step. If a defective product can be identified at an early stage of the process before it is completed as a product, the subsequent process can be omitted for the panel. Therefore, the inspection process is a very effective means from the viewpoint of cost reduction.

  One inspection process included in the pattern formation process is a defect inspection after pattern formation.

  Defect inspection after pattern formation refers to a location where a malfunction occurs due to variation in the width of a semiconductor film, insulating film or wiring pattern (hereinafter simply referred to as a pattern), dust, or film formation failure after pattern formation. Thus, it is an inspection for detecting a location where the wiring is disconnected or short-circuited, or specifying whether the circuit or circuit element to be inspected normally operates.

  Such defect inspection is mainly divided into an optical inspection method and a probe inspection method.

  The optical inspection method is an inspection method in which a pattern formed on a substrate is read by a CCD or the like and compared with a reference pattern to identify a defective portion (defect). Further, the probe inspection method is an inspection method in which fine pins (probes) are set up on terminals on the substrate side, and pass / fail is determined by the magnitude of current or voltage between the probes. In general, the former is called a non-contact type inspection method, and the latter is called a stylus type inspection method.

Whichever method is used, the quality of the element substrate can be determined.
However, each inspection method has its disadvantages.

  In the optical inspection method, it is difficult to identify the pattern formed in the lower layer when the inspection is performed after the formation of the pattern of the layers is completed. Therefore, the defective portion is detected, and the quality of the circuit or the circuit element is determined. Difficult to judge. However, if the inspection is performed every time the pattern is formed, the inspection process itself becomes complicated, and the time required for the entire manufacturing process becomes longer. In the probe inspection method, since the probe is directly set on the wiring or the probe terminal, the wiring or the probe terminal may be damaged and fine dust may be generated. The dust generated in the inspection process is not preferable because it causes a decrease in the yield of the subsequent process.

  In view of the above problems, an object of the present invention is to establish a simpler inspection method that does not require a probe to be placed on a wiring or a probe terminal, and to provide an inspection apparatus that uses the inspection method.

  The present inventor has thought that even if a probe is not set up, an electromotive force is generated in the wiring of the element substrate by electromagnetic induction, thereby allowing a current to flow through the wiring.

  Specifically, an inspection substrate (inspection substrate) for inspecting the element substrate is separately prepared. The inspection board includes an input primary coil (referred to herein as an input primary coil or a first primary coil) and an output secondary coil (hereinafter referred to as an output secondary coil or Called a second secondary coil). The element substrate to be inspected includes an input secondary coil (hereinafter referred to as an input secondary coil or a first secondary coil) and an output primary coil (hereinafter referred to as an output primary coil). Or a second primary coil).

  Note that the input primary coil, the input secondary coil, the output primary coil, and the output secondary coil can all be formed by patterning a conductive film formed on the substrate. In the present invention, the primary coil for input, the secondary coil for input, the primary coil for output, and the secondary coil for output are not a coil having a magnetic path at the center but a magnetic path. The coil which does not provide is used.

  Then, the primary coil for input included in the inspection substrate and the secondary coil for input included in the element substrate are overlapped at a certain interval, and an AC voltage (alternating current) is applied between the two terminals of the primary coil for input. Voltage), an electromotive force is generated between the two terminals of the input secondary coil.

  The smaller the interval, the better. The input primary coil and the input secondary coil should be as close as possible to control the interval.

  In this specification, a voltage being applied to the coil means that the voltage is applied between two terminals of the coil. Further, in this specification, that a signal is input to the coil means that the voltage of the signal is applied between two terminals of the coil.

  Then, an AC voltage, which is an electromotive force generated in the input secondary coil, is rectified in the element substrate, and then smoothed appropriately, whereby a DC voltage for driving a circuit or a circuit element included in the element substrate is obtained. (Hereinafter referred to as power supply voltage). In addition, a signal having a voltage for driving a circuit or a circuit element included in the element substrate by appropriately shaping an AC voltage waveform, which is an electromotive force generated in the input secondary coil, using a waveform shaping circuit or the like. (Hereinafter referred to as a drive signal).

  Then, the generated drive signal or power supply voltage is supplied to a circuit or a circuit element formed on the element substrate. The circuit or the circuit element performs some operation by the drive signal or the power supply voltage. Then, all the outputs of the circuit or circuit element to be inspected are input to an inspection-dedicated circuit provided on the element substrate.

  If it is possible to specify whether or not the circuit or the circuit element operates normally, the voltage of any part of the circuit or the circuit element is input to the test-dedicated circuit as the output of the circuit or the circuit element. be able to.

  On the other hand, an AC voltage, which is an electromotive force generated in the input secondary coil, is also input to the inspection dedicated circuit. The inspection-dedicated circuit mainly (1) performs signal processing on the output of the circuit or circuit element to be inspected and outputs a signal (operation information signal) having the operation state of the circuit or circuit element to be inspected as information Means for generating; (2) means for amplifying the operation information signal; and (3) means for modulating and outputting the amplitude of the alternating voltage input to the test-dedicated circuit according to the amplified operation information signal. Have. In this specification, a signal having an AC voltage is called an AC signal, and a modulated AC signal is called a modulated signal.

  Note that (2) means for amplifying the operation information signal is not necessarily provided. In the present specification, (3) means for modulating and outputting the amplitude of the AC voltage input to the test-dedicated circuit in accordance with the amplified operation information signal is hereinafter referred to as a modulation circuit.

  The AC modulated signal output from the inspection dedicated circuit is input to one of the two terminals of the output primary coil provided on the element substrate. A constant voltage is applied to the other terminal of the primary coil for output. In this state, the output primary coil included in the element substrate and the output secondary coil included in the inspection substrate are overlapped with a certain distance therebetween, so that the output secondary coil is generated between the two terminals of the output secondary coil. Generate power.

  The smaller the interval, the better. The output primary coil and the output secondary coil should be as close as possible to control the interval.

  A constant voltage is applied to one terminal of the output secondary coil. The voltage value at the other terminal of the output secondary coil is determined by the voltage of the modulated signal. Therefore, it is possible to specify whether or not the circuit or circuit element to be inspected normally operates from the voltage value at the other terminal of the output secondary coil.

  When the frequency of the alternating voltage input to the test dedicated circuit is increased, the frequency of the modulated signal input from the test dedicated circuit to the terminal of the output primary coil also increases. The impedance of the coil is determined by various factors such as the coil design such as the number of turns and the size, and the frequency of the signal input to the coil. Therefore, it is desirable that the frequency value of the AC voltage before modulation input to the test-dedicated circuit is determined in consideration of other factors that influence the impedance value of the coil.

  Depending on the operation state of the circuit or circuit element to be inspected, the operation information signal may contain a direct current component. Even when the operation information signal includes a direct current component, an electromotive force having good / bad information can be obtained by inputting the AC modulated signal generated by the modulation by the operation information signal to the terminal of the output primary coil. Can be generated between the terminals of the output secondary coil.

  Note that the operation state of the pixel is not necessarily classified into a non-defective product and a defective product, but may be classified into a plurality of ranks depending on the operation state.

  Note that the input primary coil and the output secondary coil are not necessarily provided on the same inspection substrate. They may be formed on different substrates.

  In addition, without providing the primary coil for output and the secondary coil for output, the weak electromagnetic wave or electric field generated by driving the circuit or circuit element is monitored, and the normal operation can be performed from among many circuits or circuit elements. It is possible to detect a portion that is not operating.

  In this case, any information contained in the electromagnetic wave or electric field can be monitored and used. Specifically, information included in electromagnetic waves or electric fields can be collected in various dimensions such as frequency, phase, intensity, and time. In the present invention, any information of electromagnetic waves or electric fields is used as long as it is possible to detect a part that is not operating normally from a large number of circuits or circuit elements. It is possible.

  A known method can be used for monitoring weak electromagnetic waves or electric fields generated in circuits or circuit elements.

  The present invention can detect a defective portion and judge the quality of a circuit or a circuit element without directly setting a probe on the wiring by the above-described configuration. Decreasing the process yield can be prevented. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.

  Since the present invention can determine whether the operation of the circuit or circuit element to be inspected is good or not without setting up the probe directly on the wiring or the terminal, the fine dust generated by setting up the probe It is possible to prevent the yield of subsequent processes from being lowered. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.

The top view of an inspection board and an element board. The block diagram of an inspection board and an element board. Coil enlarged view. The perspective view of the test | inspection board | substrate and element board | substrate at the time of a test | inspection. The circuit diagram of a waveform shaping circuit. The circuit diagram of a rectifier circuit. Change over time of the signal that has been rectified from alternating current and becomes a pulsating flow. Change over time of DC signal generated by adding pulsating flow. The circuit diagram of a test-dedicated circuit. The circuit diagram of the circuit only for a test | inspection which has an output pad. The block diagram of the element substrate of a liquid crystal display. The block diagram of the element board | substrate of an OLED display. The top view of a large sized element substrate. The top view of a large sized element substrate. The flowchart which shows the flow of the inspection process of this invention. The top view and sectional drawing of a coil. The block diagram of an inspection apparatus. The circuit diagram of a rectifier circuit.

  FIG. 1A shows a top view of an inspection substrate for performing the inspection of the present invention. FIG. 1B shows a top view of an element substrate to be inspected. Note that in this embodiment mode, the inspection method of the present invention is described using an element substrate included in a liquid crystal display as an example. However, the inspection method of the present invention is not limited to a liquid crystal display and uses a semiconductor. Any semiconductor device formed as described above can be used.

  The inspection board shown in FIG. 1A has an input primary coil forming part 101, an output secondary coil forming part 102, an external input buffer 103, an external output buffer 104, and a connector connecting part on the board 100. 105 is provided. In the present specification, the inspection substrate includes the substrate 100 and all circuits or circuit elements formed on the substrate 100.

  Note that the number and arrangement of the input primary coil forming portions 101 and the output secondary coil forming portions 102 included in the inspection board are not limited to the configuration shown in FIG. The number and arrangement of the input primary coil forming unit 101 and the output secondary coil forming unit 102 can be arbitrarily set by the designer.

  The element substrate illustrated in FIG. 1B is provided over a substrate 110 with a signal line driver circuit 111, a scan line driver circuit 112, a pixel portion 113, a lead-out wiring 114, a connector connection portion 115, a waveform shaping circuit, or a rectifier circuit 116. , An input secondary coil forming section 117, an output primary coil forming section 118, a test dedicated circuit 119, and a coil wiring 120 are provided. Note that in this specification, the element substrate includes the substrate 110 and all circuits or circuit elements formed on the substrate 110. Note that the lead wiring 114 is a wiring for supplying a drive signal and a power supply voltage to the pixel portion and the driver circuit included in the element substrate.

  Note that the number and arrangement of the input secondary coil forming portions 117 and the output primary coil forming portions 118 included in the element substrate are not limited to the configuration illustrated in FIG. The number and arrangement of the input secondary coil forming section 117 and the output primary coil forming section 118 can be arbitrarily set by the designer.

  FPC or TAB or the like is connected to the connector connecting portion 115 in a step after the inspection step. The element substrate is cut at a dotted line A-A ′ after the inspection process so that the coil wiring 120 is physically and electrically separated.

  Next, the operation of the element substrate and the inspection substrate in the inspection process will be described. In order to make it easy to understand the signal flow in the inspection process, the configuration of the element substrate and the inspection substrate shown in FIG. 1 is shown in a block diagram in FIG. 2, and will be described with reference to FIGS.

  In the inspection board 204, an AC signal for inspection is input from the signal source 201 or the AC power source 202 to the external input buffer 103 via the connector connected to the connector connection unit 105. The AC signal for inspection is buffered and amplified in the external input buffer 103 and input to the input primary coil forming unit 101.

  1 and 2, the input AC signal is buffered and amplified in the external input buffer 103 and then input to the input primary coil forming unit 101. However, the present invention is not limited to this configuration. . An AC signal may be directly input to the input primary coil forming unit 101 without providing the external input buffer 103.

  The input primary coil forming unit 101 is formed with a plurality of input primary coils. An AC signal is applied between the two terminals of each input primary coil.

  On the other hand, the input secondary coil forming unit 117 included in the element substrate 205 is formed with a plurality of input secondary coils corresponding to the plurality of input primary coils included in the input primary coil forming unit 101. . When an AC signal is input to the input primary coil, an AC voltage that is an electromotive force is generated between the two terminals of each input secondary coil due to electromagnetic induction.

  The AC voltage generated in the input secondary coil is supplied to the waveform shaping circuit 116a or the rectifier circuit 116b. The waveform shaping circuit 116a or the rectifier circuit 116b shapes or rectifies the AC voltage to generate a drive signal or a power supply voltage.

  The generated drive signal or power supply voltage is input to the lead wiring 114 via the coil wiring 120. The input drive signal, power supply voltage, or the like is supplied to the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113 through the lead wiring 114.

  Note that a plurality of pixels are formed in the pixel portion 113, and a pixel electrode is formed in each pixel. Note that the number of signal line driver circuits and scan line driver circuits is not limited to the numbers illustrated in FIGS.

  Then, the output of each circuit or circuit element included in the signal line driver circuit 111, the scanning line driver circuit 112, and the pixel portion 113 is input to the inspection dedicated circuit 119.

  Note that in the pixel portion 113, for example, the voltage of each terminal of the transistor or the voltage of the pixel electrode can be input to the test-dedicated circuit 119 as an output of a circuit or a circuit element. However, in all the pixels, it is not necessary to input the output of the circuit or the circuit element to the inspection dedicated circuit 119, and the output of the circuit or the circuit element may be input to the inspection dedicated circuit 119 only in an arbitrarily selected pixel. good. Further, a pixel dedicated to inspection (dummy pixel) that is not used for actual display may be provided in the pixel portion 113, and an output of a circuit or a circuit element may be input to the inspection dedicated circuit 119 in the pixel dedicated to inspection. This is not limited to the pixel unit 113, and it is not necessary to input all the circuits or circuit element outputs of the element substrate to the test-dedicated circuit 119, and some of the circuits or circuit elements are selected and the output is dedicated to the test The signal may be input to the circuit 119. Alternatively, a circuit or circuit element dedicated to inspection that is not used for actual driving may be formed, and an output of the circuit or circuit element dedicated to inspection may be input to the circuit dedicated to inspection 119.

  The inspection dedicated circuit 119 performs signal processing on the output of the input circuit or circuit element, and generates a signal (operation information signal) having the operation state of the circuit or circuit element to be inspected as information. Then, the amplitude of the operation information signal is amplified and input to the modulation circuit 121. Note that the operation information signal is not necessarily amplified, and in this case, the operation information signal is directly input to the modulation circuit 121.

  On the other hand, an alternating voltage generated in the input secondary coil is input to the inspection dedicated circuit 119. The AC signal is input to the modulation circuit 121 included in the inspection dedicated circuit 119.

  Then, the test dedicated circuit 119 modulates the amplitude of the AC voltage input in the modulation circuit 121 according to the input operation information signal, and inputs the modulated voltage to the output primary coil forming unit 118 as a modulated signal.

  Specifically, the voltage of the modulated signal input to the output primary coil forming unit 118 is input to one terminal of the plurality of output primary coils included in the output primary coil forming unit 118. . A constant voltage is applied to the other terminal of the plurality of primary coils for output.

  On the other hand, a plurality of output secondary coils corresponding to the plurality of output primary coils included in the output primary coil forming unit 102 are formed in the output secondary coil forming unit 102 included in the inspection board 204. . When an AC voltage is input between the two terminals of the output primary coil, an AC voltage that is an electromotive force is generated between the two terminals of each output secondary coil due to electromagnetic induction. The AC voltage generated between the two terminals of the output secondary coil has the operation state of the circuit or circuit element as information.

  A constant voltage is applied to one terminal of the output secondary coil. The voltage at the other terminal of the output secondary coil is amplified in the external output buffer 104 and input to the inspection unit 203.

  The external output buffer 104 is not necessarily provided, and the voltage at the other terminal of the output secondary coil may be directly input to the inspection unit 203 without being amplified.

  The inspection unit 203 can determine the quality of the circuit or the circuit element from the AC voltage having the operation state of the circuit or the circuit element as information, and can determine the position of the defective portion.

  When the frequency of the alternating voltage input to the test dedicated circuit is increased, the frequency of the modulated signal input from the test dedicated circuit to the terminal of the output primary coil also increases. The impedance of the coil is determined by various factors such as the coil design such as the number of turns and the size, and the frequency of the signal input to the coil. Therefore, it is desirable that the frequency value of the AC voltage before modulation input to the test-dedicated circuit is determined in consideration of other factors that influence the impedance value of the coil.

  Depending on the operation state of the circuit or circuit element to be inspected, the operation information signal may contain a direct current component. Even when the operation information signal includes a direct current component, an electromotive force having good / bad information can be obtained by inputting the AC modulated signal generated by the modulation by the operation information signal to the terminal of the output primary coil. Can be generated between the terminals of the output secondary coil.

  Note that the input primary coil and the output secondary coil are not necessarily provided on the same inspection substrate. They may be formed on different substrates.

  1 and 2, a portion where a plurality of input primary coils are formed is defined as an input primary coil forming portion, and a portion where a plurality of output secondary coils are formed is defined as an output secondary coil. Although it distinguishes as a coil formation part, the test | inspection board | substrate of this invention is not limited to this structure. When a plurality of input primary coils and a plurality of output secondary coils are arranged so as to be mixed, a portion where a plurality of input primary coils are formed and a plurality of output secondary coils are formed. There is no need to distinguish the parts.

  Note that when a drive signal, a power supply voltage, or the like is input to the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113, each circuit included in the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113 or An electromagnetic wave or an electric field is generated in the circuit element. Without providing a primary coil for output and secondary coil for output, it monitors weak electromagnetic waves or electric fields generated by driving a circuit or circuit element, and operates normally from many circuits or circuit elements. It is also possible to detect a missing part.

  The strength of the electric field and electromagnetic wave generated in a circuit or circuit element that is not operating normally differs from the strength of the electric field and electromagnetic wave generated in a circuit or circuit element that is operating normally. Therefore, by monitoring the intensity of the electromagnetic wave and electric field generated in each circuit or circuit element, the inspection unit 203 can determine pass / fail or locate the defective portion.

  When the primary coil for output and the secondary coil for output are not provided, in FIG. 2, the output from the inspection dedicated circuit 119 is input to a predetermined terminal (pad). Then, by measuring the intensity of the electric field or electromagnetic wave in the pad and inputting the measured value to the inspection unit 203, the inspection unit 203 can determine pass / fail or detect the position of the defective portion.

  As a method for monitoring electromagnetic waves and electric fields, any method may be used as long as it has a sensitivity sufficient to determine whether a circuit or a circuit element is good or bad.

  Next, detailed configurations of the input primary coil, the input secondary coil, the output primary coil, and the output secondary coil (hereinafter simply referred to as a coil) will be described.

  FIG. 3 shows an enlarged view of the coil. The coil shown in FIG. 3 (A) is in a state of spiraling in a curved shape, and coil terminals 301 and 302 are formed at both ends of the coil. In addition, the coil shown in FIG. 3B is in a state of spiraling in a rectangular shape, and coil terminals 303 and 304 are formed at both ends of the coil.

  In addition, the coil used by this invention should just form the whole wiring which a coil has on the same plane, and the wiring which a coil has spirals. Therefore, when viewed from a direction perpendicular to the plane on which the coil is formed, the wiring of the coil may be curved or may have a cornered shape.

  Further, the number of turns of the coil, the line width, and the area occupied on the substrate can be appropriately set by the designer.

  Next, FIG. 4A shows a state in which the element substrate and the inspection substrate are overlaid. However, the element substrate shown in FIGS. 1B and 2 has the coil shown in FIG. 3A as an input secondary coil and an output primary coil. 2 shows a case where the inspection board shown in FIG. 2 has the coil shown in FIG. 3A as an input primary coil and an output secondary coil. Reference numeral 206 denotes a connector for connecting the inspection board 204 to a signal source, an AC power source, and an inspection unit.

  As shown in FIG. 4A, the input primary coil forming unit 101 included in the inspection substrate 204 and the input secondary coil forming unit 117 included in the element substrate 205 overlap each other with a certain interval. It should be noted that this interval is preferably as small as possible. The input primary coil forming unit 101 and the input secondary coil forming unit 117 included in the element substrate 205 should be as close as possible to control the interval.

  Further, the output secondary coil forming unit 102 included in the inspection substrate 204 and the output primary coil forming unit 118 included in the element substrate 205 are overlapped with each other with a certain interval. The smaller the interval, the better. The output secondary coil forming unit 102 and the output primary coil forming unit 118 should be as close as possible to control the interval.

  The interval between the inspection substrate 204 and the element substrate 205 may be maintained by fixing both substrates. Alternatively, one of the element substrate 205 and the inspection substrate 204 may be fixed, and a fluid having a constant flow rate or pressure may be used between the inspection substrate 204 and the element substrate 205 to maintain the interval. Note that a gas or a liquid can be typically used as the fluid. In addition, it is also possible to use a fluid such as a viscous gel.

  FIG. 4B shows an enlarged view of a portion where the input primary coil forming unit 101 and the input secondary coil forming unit 117 overlap. Reference numeral 208 denotes an input primary coil, and 207 denotes an input secondary coil.

  The input primary coil 208 and the input secondary coil 207 have the same winding direction of the wiring, but the present invention is not limited to this configuration. The winding direction of the primary coil and the secondary coil may be reversed.

Further, the designer can also set the distance (L _gap ) between the primary coil and the secondary coil as appropriate.

  The output primary coil of the output primary coil forming unit 118 and the output secondary coil of the output secondary coil forming unit 102 are also the input primary coil 208 and the input 2 coil shown in FIG. By superimposing like the next coil 207, it can electromagnetically couple.

  Next, a detailed configuration of the waveform shaping circuit 116a shown in FIG. 2 will be described.

FIG. 5 shows how the signal source 201, the input primary coil forming unit 101, the input secondary coil forming unit 117, and the waveform shaping circuit 116a shown in FIGS. 1 and 2 are connected.
The input primary coil forming unit 101 is provided with a plurality of input primary coils 208. The input secondary coil forming unit 117 is provided with a plurality of input secondary coils 207.

  An AC signal for inspection is input from the signal source 201 to each input primary coil 208. Specifically, the voltage of the AC signal for inspection from the signal source 201 is applied between the two terminals of each input primary coil 208. When an AC signal is input to the input primary coil 208, an AC voltage as an electromotive force is generated in the corresponding input secondary coil 207, and the AC voltage is applied to the waveform shaping circuit 116a.

  The waveform shaping circuit 116a is an electronic circuit used for forming or shaping an amount that changes with time, that is, a waveform such as voltage or current. In FIG. 5, resistors 501 and 502 and a capacitor 503 are included, and an integrated waveform shaping circuit 116a is configured by combining each circuit element. Of course, the waveform shaping circuit is not limited to the configuration shown in FIG. Further, similarly to the power supply circuit, the waveform shaping may be performed using a detection circuit using a diode.

  Specifically, the waveform shaping circuit 116a used in the present invention generates and outputs a clock signal (CLK), a start pulse signal (SP), and a video signal (Video Signals) from the input AC electromotive force.

  Note that the waveform shaping circuit 116a is not limited to the signal described above, and can generate a signal having an arbitrary waveform. The signal generated by the waveform shaping circuit 116a may be any signal that can confirm the operation state of the circuit or the circuit element.

  A signal output from the waveform shaping circuit 116a is input to a circuit in a subsequent stage (in FIG. 1 and FIG. 2, the signal line driver circuit 111, the scanning line driver circuit 112, and the pixel portion 113).

  Next, a detailed configuration of the rectifier circuit 116b illustrated in FIG. 2 will be described.

  FIG. 6 illustrates a connection state of the AC power source 202, the input primary coil forming unit 101, the input secondary coil forming unit 117, and the rectifier circuit 116b illustrated in FIGS. The input primary coil forming unit 101 is provided with a plurality of input primary coils 208. The input secondary coil forming unit 117 is provided with a plurality of input secondary coils 207.

  Each input primary coil 208 receives an AC signal for inspection from the AC power source 202. When an AC signal is input to the input primary coil 208, an AC voltage, which is an electromotive force, is generated in the corresponding input secondary coil 207, and the AC voltage is applied to the rectifier circuit 116b.

  In the present invention, the rectifier circuit means a circuit that generates a DC power supply voltage from a supplied AC voltage. The DC power supply voltage means a voltage that is applied to a circuit or a circuit element and is maintained at a certain height.

  The rectifier circuit 116b illustrated in FIG. 6 includes a diode 601, a capacitor 602, and a resistor 603. The diode 601 rectifies the input AC voltage and converts it into a DC voltage.

FIG. 7A shows the change over time of the AC voltage before rectification in the diode 601. Further, FIG. 7B shows a time change of the voltage after rectification.
As can be seen by comparing the graph of FIG. 7A and the graph of FIG. 7B, after rectification, the voltage takes a value having zero or one polarity every half cycle. It is the voltage of the current.

  The pulsating voltage shown in FIG. 7B is difficult to use as the power supply voltage. Therefore, normally, the pulsating flow is smoothed and converted into a DC voltage by storing electric charge in the capacitor. However, in order to form a large-capacity capacitor that can sufficiently smooth the pulsating flow using a thin film semiconductor, it is necessary to increase the area of the capacitor itself, which is not practical. Therefore, in the present invention, after rectification, the pulsating voltages having different phases are synthesized (added) to smooth the voltages. With the above configuration, the pulsating flow can be sufficiently smoothed even when the capacitance of the capacitor is small, and further, the pulsating flow can be sufficiently smoothed without actively providing a capacitor.

  In FIG. 6, AC signals having different phases are input to the four primary coils, so that four pulsating voltages having different phases are output from the four diodes 601. Then, the four pulsating voltages are added to generate a DC power supply voltage whose height is kept substantially constant, and is output to a subsequent circuit.

  In FIG. 6, the power supply voltage is generated by adding four pulsating signals having different phases output from the four diodes 601, but the present invention is not limited to this configuration. The number of phase divisions is not limited to this, and any number of phase divisions may be used as long as the output from the rectifier circuit can be smoothed so that it can be used as a power supply voltage.

  FIG. 8 shows a time change of the power supply voltage obtained by adding a plurality of rectified signals. FIG. 8A shows an example in which one power supply voltage is generated by adding four pulsating voltages having different phases.

  Since the voltage generated in the rectifier circuit of the present invention is generated by adding a plurality of pulsating currents, ripples that are components other than direct current exist. The ripple corresponds to the difference between the highest voltage and the lowest voltage. The smaller the ripple is, the closer the voltage generated in the rectifier circuit is to direct current and the easier it is to use as the power supply voltage.

  FIG. 8B shows a change in power supply voltage over time, which is obtained by adding eight pulsating voltages having different phases. It can be seen that the ripple is smaller than the time change of the power supply voltage shown in FIG.

  FIG. 8C shows a time change of the power supply voltage obtained by adding 16 pulsating voltages having different phases. It can be seen that the ripple is further reduced as compared with the time change of the power supply voltage shown in FIG.

  Thus, it can be seen that the ripples of the power supply voltage are reduced by adding many different pulsating flows having different phases, and the DC voltage is further increased. Therefore, the greater the number of phase divisions, the easier the power supply voltage output from the rectifier circuit is smoothed. Further, the larger the capacitance of the capacitor 602, the easier the power supply voltage output from the rectifier circuit is smoothed.

  The power supply voltage generated in the rectifier circuit 116b is output from the terminals 610 and 611. Specifically, a voltage close to ground is output from the terminal 610, and a power supply voltage having a positive polarity is output from the terminal 611. The polarity of the output power supply voltage can be reversed by connecting the anode and cathode of the diode in reverse. The anode 602 and the cathode of the diode 602 connected to the terminals 610 and 611 are connected in reverse to the diode 601 connected to the terminals 612 and 613. Thus, a voltage close to ground is output from the terminal 612, and a power supply voltage having a negative polarity is output from the terminal 613.

Various circuits or circuit elements are formed on the element substrate, and the power supply voltage to be supplied to the circuits or circuit elements varies depending on the type or application of each circuit or circuit element. In the rectifier circuit shown in FIG. 6, the height of the voltage input to each terminal can be adjusted by adjusting the amplitude of the input AC signal.
Furthermore, the height of the power supply voltage supplied to the circuit or the circuit element can be changed by changing the terminal connected by the circuit or the circuit element.

  The rectifier circuit used in the present invention is not limited to the half-wave rectifier circuit shown in FIG. The rectifier circuit used in the present invention may be any circuit that can generate a DC power supply voltage from an input AC signal.

  FIG. 18 shows a circuit diagram of a rectifier circuit having a configuration other than that shown in FIG. The rectifier circuit shown in FIG. 18A is a voltage doubler full-wave rectifier circuit 901 and includes two diodes 902 and 903. In addition, the voltage doubler full-wave rectifier circuit illustrated in FIG. Note that the positions and the number of capacitors are not limited to those shown in FIG.

  The cathode of the diode 902 and the anode of the diode 903 are both connected to one of the terminals of the input secondary coil. By providing a plurality of voltage doubler full-wave rectifier circuits 901 and adding the outputs, a DC voltage twice that of the half-wave rectifier circuit shown in FIG. 6 can be obtained.

  The rectifier circuit illustrated in FIG. 18B is a bridge rectifier circuit 911 and includes four diodes 912, 913, 914, and 915. The four diodes 912, 913, 914, and 915 form a bridge circuit. In addition, the bridge rectifier circuit illustrated in FIG. 18B includes a capacitor 916. Note that the positions and the number of capacitors are not limited to those shown in FIG.

  Next, a detailed configuration of the inspection dedicated circuit 119 shown in FIG. 2 will be described.

  FIG. 9 shows the configuration of the inspection dedicated circuit 119. The inspection dedicated circuit 119 has means for performing signal processing on the output of the circuit or circuit element to be inspected and generating a signal (operation information signal) having the operation state of the circuit or circuit element to be inspected as information. is doing. In this embodiment, an A / D conversion circuit 223 and a data formatting unit 224 are used as the above means.

Analog outputs from circuits or circuit elements included in the signal line driver circuit 111, the scan line driver circuit 112, and the pixel portion 113 are converted into digital signals by an A / D conversion circuit 223. The digital signal is input to the data format unit 224.
When the output from the circuit or circuit element is a digital signal instead of an analog signal, the digital signal is directly input to the data formatting unit 224.

  Note that in this embodiment, all signals output from a circuit or circuit element are converted to digital, and the data format unit 224 performs processing using the digital signal. However, the present invention is not limited to this configuration. All signals output from the circuit or circuit element may be converted into analog, and the data format unit 224 may process the analog signal.

  In the data format unit 224, an input digital signal corresponding to a circuit or a circuit element is arithmetically processed to generate an operation information signal. The operation information signal is a signal having the operation state of the circuit or circuit element to be inspected as information. Specifically, the operation information signal may be a signal converted into a serial signal by temporarily storing digital signals input in parallel and sequentially reading them, or a voltage of a digital signal input in parallel. It may be a signal obtained by sequentially outputting in accordance with a predetermined timing. In addition, an operation output from the data formatting unit 224 when the outputs of the circuits or circuit elements to be inspected are all digital signals having the same voltage and when there is a digital signal having even one different voltage. The voltage of the information signal may be changed. In any case, it is only necessary to be able to grasp the quality of the circuit or circuit element to be inspected from the operation information signal, and the position of the defective portion.

  The operation information signal output from the data format unit 224 is amplified in the buffer 222 and input to the modulation circuit 121. Note that the output from the data formatting unit 224 may be directly input to the modulation circuit 121 without providing the buffer 222.

  On the other hand, an AC signal for inspection is input from each AC power source 202 to each input primary coil 208. When an AC signal is input to the input primary coil 208, an AC voltage that is an electromotive force is generated in the corresponding input secondary coil 207, and the AC voltage is applied to the modulation circuit 121.

  The modulation circuit 121 has means for modulating the amplitude of the AC voltage input from the input secondary coil 207 in accordance with the operation information signal input from the data format unit 224 or the buffer 222. In FIG. 9, transistors 220 and 221 are provided as the above means, but the present invention is not limited to this structure. The modulation circuit 121 has any configuration as long as the amplitude of the AC voltage input from the input secondary coil 207 can be modulated according to the operation information signal input from the data format unit 224 or the buffer 222. May be.

In the modulation circuit 121 illustrated in FIG. 9, the output of the buffer 222 is input to the gate electrodes of the transistors 220 and 221. One of the source region and the drain region of the transistor 220 is connected to the first terminal of the input secondary coil 207, and the other is connected to the first terminal of the output primary coil 210.
One of the source region and the drain region of the transistor 221 is connected to the first terminal of the output primary coil 210, and the other is supplied with a constant voltage.
The constant voltage may be a ground voltage.

  With the above configuration, the AC voltage output from the input secondary coil 207 is modulated by the operation information signal and input to the first terminal of the output primary coil 210 as a modulated signal. In the present embodiment, the AC voltage output from the input secondary coil 207 is switched by the operation information signal, and is input to the first terminal of the output primary coil 210 as a modulated signal. .

  Further, the same constant voltage is applied to the second terminals of the input secondary coil 207 and the output primary coil 210, respectively. This voltage may be a ground voltage.

  When the primary coil for output 210 and the secondary coil for output 211 are electromagnetically coupled, an alternating voltage that is an electromotive force is generated between the two terminals of the primary coil for output 211. The AC voltage is input to the inspection unit 203.

  The inspection unit 203 can specify whether or not the circuit or circuit element to be inspected normally operates from the AC voltage input from the output secondary coil 211.

  When the frequency of the alternating voltage input to the test dedicated circuit is increased, the frequency of the modulated signal input from the test dedicated circuit to the terminal of the output primary coil also increases. The impedance of the coil is determined by various factors such as the coil design such as the number of turns and size, and the frequency of the signal input to the coil. Therefore, it is desirable that the frequency value of the AC voltage before modulation input to the test-dedicated circuit is determined in consideration of other factors that influence the impedance value of the coil.

  Depending on the operation state of the circuit or circuit element to be inspected, the operation information signal may contain a direct current component. Even when the operation information signal includes a direct current component, an electromotive force having good / bad information can be obtained by inputting the AC modulated signal generated by the modulation by the operation information signal to the terminal of the output primary coil. Can be generated between the terminals of the output secondary coil.

  In this embodiment mode, an example in which an element substrate has a signal line driver circuit and a scan line driver circuit which are driver circuits has been described; however, the element substrate to be inspected in the present invention is not limited thereto. Even when the element substrate has only the pixel portion, the inspection can be performed using the inspection method of the present invention. Further, even in a single element called TEG or an evaluation circuit in which the single elements are combined, the operation state can be confirmed using the inspection method and inspection apparatus of the present invention.

  In addition, although an inspection method for an element substrate included in a liquid crystal display has been described in this embodiment mode, a semiconductor display device other than a liquid crystal display can also be inspected using the inspection method described in this embodiment mode. . Further, the semiconductor device is not limited to a semiconductor display device, and any semiconductor device that uses the characteristics of a semiconductor formed on a substrate can be inspected using the inspection method of the present invention. Note that the semiconductor device may be a semiconductor device using a semiconductor thin film formed over a glass substrate, or may be a semiconductor device formed on a single crystal silicon substrate.

  However, the number of coils and the design need to be set as appropriate in accordance with the type and standard of the semiconductor device. In addition, the waveform, frequency, and amplitude of the AC signal for inspection input to the input primary coil forming unit must be set as appropriate in accordance with the type and standard of the semiconductor device.

  According to the present invention, it is possible to determine whether or not the probe is directly raised on the wiring by the above-described configuration, so that it is possible to prevent the yield of a subsequent process from being reduced due to fine dust generated by raising the probe. it can. In addition, unlike the optical inspection method, the quality of all pattern forming steps can be determined in one inspection step, so that the inspection step is further simplified.

  Examples of the present invention will be described below.

  In this embodiment, a weak electromagnetic wave or electric field generated by driving a circuit or a circuit element is monitored without providing a primary coil for output and a secondary coil for output, and from among many circuits or circuit elements. An example of detecting a part that is not operating normally will be described.

  FIG. 10 shows the configuration of the element substrate and the inspection substrate of this example. The element substrate 455 illustrated in FIG. 10 includes an inspection dedicated circuit 419. The inspection dedicated circuit 419 has means for performing signal processing on the output of the circuit or circuit element to be inspected and generating a signal (operation information signal) having the operation state of the circuit or circuit element to be inspected as information. is doing. In this embodiment, an A / D conversion circuit 473 and a data format unit 474 are used as the above means.

  In this embodiment, the element substrate 455 includes a signal line driver circuit 411, a scanning line driver circuit 412, and a pixel portion 413. An analog output from a circuit or a circuit element included in the signal line driver circuit 411, the scan line driver circuit 412, and the pixel portion 413 is converted into a digital signal in the A / D conversion circuit 473. The digital signal is input to the data format unit 474. When the output from the circuit or circuit element is a digital signal instead of an analog signal, the digital signal is directly input to the data format unit 474.

  In the present embodiment, all signals output from the circuit or circuit element are converted to digital, and the data format unit 474 processes the digital signal. However, the present invention is not limited to this configuration. A signal output from a circuit or a circuit element may be converted into analog, and the analog signal may be processed in the data format unit 474.

  The data format unit 474 performs arithmetic processing on all digital signals corresponding to the input circuit or circuit element, and generates an operation information signal having the operation state of the circuit or circuit element to be inspected as information.

  The operation information signal output from the data format unit 474 is amplified in the buffer 472 and input to the modulation circuit 421. Note that the output from the data format unit 474 may be directly input to the modulation circuit 421 without providing the buffer 472.

  On the other hand, an AC signal for inspection is input from the AC power supply 452 to each input primary coil 458 included in the inspection board 454. When an AC signal is input to the input primary coil 458, an AC voltage as an electromotive force is generated in the input secondary coil 457 included in the corresponding element substrate 455, and the AC voltage is applied to the modulation circuit 421. Is done.

  The modulation circuit 421 has means for modulating the amplitude of the AC voltage input from the input secondary coil 457 according to the operation information signal input from the data format unit 474 or the buffer 472. In FIG. 9, transistors 470 and 471 are provided as the above means, but the present invention is not limited to this structure. The modulation circuit 421 has any configuration as long as it can modulate the amplitude of the AC voltage input from the input secondary coil 457 according to the operation information signal input from the data format unit 474 or the buffer 472. May be.

  In the modulation circuit 421 illustrated in FIG. 9, the output of the buffer 472 is input to the gate electrodes of the transistors 470 and 471. One of a source region and a drain region of the transistor 470 is connected to a first terminal included in the input secondary coil 457, and the other is connected to an output pad 458 included in the element substrate 455. One of a source region and a drain region of the transistor 471 is connected to the output pad 458, and the other is supplied with a constant voltage. The constant voltage may be a ground voltage.

  A constant voltage is applied to the second terminal of the input secondary coil 457. This voltage may be a ground voltage.

  With the above configuration, the AC voltage output from the input secondary coil 457 is modulated by the operation information signal and input to the output pad 458 as a modulated signal.

  In the output pad 458, a weak electromagnetic wave or electric field is generated. The measurement unit 460 provided separately from the inspection substrate 454 and the element substrate 455 monitors the electromagnetic wave or electric field and inputs the data to the inspection unit 453 as data. The inspection unit 453 can specify whether or not the circuit or circuit element to be inspected normally operates from the data.

  In this case, any information contained in the electromagnetic wave or electric field can be monitored and used. Specifically, information included in electromagnetic waves or electric fields can be collected in various dimensions such as frequency, phase, intensity, and time. In the present invention, any information of electromagnetic waves or electric fields is used as long as it is possible to detect a part that is not operating normally from a large number of circuits or circuit elements. It is possible.

  A known method can be used for monitoring weak electromagnetic waves or electric fields generated in circuits or circuit elements. In this embodiment, an example will be described in which an electric field generated in a circuit or a circuit element in an inspection process is detected using an electro-optic effect. Specifically, in this embodiment, an example in which measurement is performed using a Pockels cell will be described.

  The Pockels cell is one of electro-optic elements using the Pockels effect, which is one of the electro-optic effects. An electro-optical element is an element that utilizes an electro-optical effect in which a refractive index changes when an electric field is applied. Utilizing this property, an AC voltage or a pulse voltage can be applied to the crystal and used for light modulation, shutter, and generation and detection of circularly polarized light.

  The Pockels cell has a first electrode, a second electrode, and a Pockels crystal that is a ferroelectric crystal. A Pockels crystal is sandwiched between the first electrode and the second electrode. The first electrode and the second electrode are formed of a conductive material that transmits light.

  A constant voltage is applied to the first electrode. The first electrode and the second electrode are arranged in parallel with the element substrate so that the second electrode and the output pad 458 overlap. Note that the second electrode may be disposed so as to be in contact with the element substrate 455 or may be disposed at a certain interval. Further, a buffer material may be sandwiched between the second electrode and the element substrate 455.

  Due to the electric field generated from the output pad 458, the refractive index of light changes in the portion overlapping the output pad 458 of the Pockels cell. This refractive index varies depending on the intensity of the electric field emitted from the output pad 458. Therefore, the intensity of the electric field generated from the output pad 458 can be measured by monitoring the refractive index of light in the Pockels cell.

  Specifically, among the light transmitted through the Pockels cell, the light in the direction perpendicular to the element substrate is separated using an optical system such as a polarization beam splitter, and the intensity of the Pockels cell is monitored. The refractive index is calculated, and the magnitude of the voltage applied to the Pockels cell can be determined from the refractive index. And it is possible to detect a defective part from the magnitude | size of the voltage applied to the Pockels cell.

  It should be noted that some arithmetic processing may be performed on the result of the monitoring over a plurality of times to determine whether it is acceptable or not.

  In addition, in the circuit or circuit element to be inspected, the output of the circuit to be inspected is input to the inspection dedicated circuit, and the intensity of the electromagnetic wave or electric field generated in the output pad is measured using an electro-optical element. Therefore, it is not necessary to monitor using the Pockels cell one by one, and the inspection process can be simplified and speeded up.

Note that. As the Pockels crystal, crystals such as NH ₄ H ₂ PO ₄ , BaTiO ₃ , KH ₂ PO ₄ (KHP), KD ₂ PO ₄ (KDP), LiNbO ₃ , and ZnO can be mainly used. However, the Pockels crystals that can be used in this embodiment are not limited to those described above. Any crystal having the Pockels effect may be used.

  In this embodiment, a Pockels cell is used. However, the electro-optic element for sensing the magnitude of the electric field is not limited to this. Any electro-optic element that utilizes the phenomenon that its optical characteristics change when voltage is applied can be used in the inspection method or inspection apparatus of the present invention. Therefore, liquid crystal or the like can be used.

  In this embodiment, when the frequency of the alternating voltage input to the test dedicated circuit is increased, the frequency of the modulated signal input from the test dedicated circuit to the output pad also increases.

  In this embodiment, the driving signal and power supply voltage for inspection will be described in more detail by taking the case of a liquid crystal display and an OLED display as examples.

  Since the number of primary coils and secondary coils varies depending on the structure of the pixel portion of the element substrate and the drive circuit, it is important to set the number according to the standard of each element substrate.

  FIG. 11 shows a configuration of an element substrate of a general liquid crystal display. The element substrate illustrated in FIG. 11 includes a signal line driver circuit 700, a scanning line driver circuit 701, and a pixel portion 702.

  A plurality of signal lines and a plurality of scanning lines are formed in the pixel portion 702, and a region surrounded by the signal lines and the scanning lines corresponds to a pixel. Note that FIG. 11 representatively shows only a pixel having one signal line 703 and one scanning line 704 among a plurality of pixels. Each pixel has a pixel TFT serving as a switching element and a pixel electrode 706 of a liquid crystal cell.

  A gate electrode of the pixel TFT 705 is connected to the scanning line 704. One of the source region and the drain region of the pixel TFT 705 is connected to the signal line 703 and the other is connected to the pixel electrode 706.

  The signal line driver circuit 700 includes a shift register 710, a level shifter 711, and an analog switch 712. A power supply voltage (Power supply) is applied to the shift register 710, the level shifter 711, and the analog switch 712. The shift register 710 is supplied with a clock signal (S-CLK) and a start pulse signal (S-SP) for the signal line driver circuit. Video signals (Video signals) are supplied to the analog switch 712.

  When the clock signal (S-CLK) and the start pulse signal (S-SP) are input to the shift register 710, a sampling signal that determines the sampling timing of the video signal is generated and input to the level shifter 711. The amplitude of the voltage of the sampling signal is increased in the level shifter 711 and input to the analog switch 712. The analog switch 712 samples the input video signal in synchronization with the input sampling signal and inputs it to the signal line 703.

  On the other hand, the scan line driver circuit includes a shift register 721 and a buffer 722. A power supply voltage (Power supply) is supplied to the shift register 721 and the buffer 722. The shift register 721 is supplied with a clock signal (G-CLK) and a start pulse signal (G-SP) for the scanning line driver circuit.

  When a clock signal (G-CLK) and a start pulse signal (G-SP) are input to the shift register 721, a selection signal for determining the timing for selecting a scanning line is generated and input to the buffer 722. The selection signal input to the buffer 722 is buffered and amplified and input to the scanning line 704.

  When the scanning line 704 is selected, the pixel TFT 705 whose gate electrode is connected to the selected scanning line 704 is turned on. Then, the sampled video signal input to the signal line is input to the pixel electrode 706 via the pixel TFT 705 that is turned on.

As described above, when the signal line driver circuit 700, the scanning line driver circuit 701, and the pixel portion 702 are operated, outputs of the respective circuits or circuit elements (End Signals).
Is input to the inspection dedicated circuit 730. In the test-dedicated circuit, an operation information signal is generated from the output of each circuit or circuit element, and a modulated signal is generated by the operation information signal. Then, the AC voltage generated in the output secondary coil when the modulated signal is input to the output primary coil is input to the inspection unit, and the operation of each circuit or circuit element is checked in the inspection unit. The status of is confirmed. Note that, when the signal line driver circuit 700, the scan line driver circuit 701, and the pixel portion 702 are operated, an electric field or an electromagnetic wave generated in each circuit or circuit element is monitored by some means, so that each circuit or The quality of the circuit element can also be determined.

  For example, when the shift register 710 is formed using a plurality of flip-flops, the voltage given to the first flip-flop and stored in the next flip-flop in order is synchronized with S-CLK. Sent and memorized. Thus, a plurality of flip-flops operate in order. In the sampling signal obtained by the operation of each flip-flop, the timings at which the pulses appear are sequentially shifted. If the preceding flip-flop does not operate normally, the succeeding flip-flop also does not operate normally. Therefore, in this case, the sampling signal obtained by operating the flip-flop at the final stage can be used as an output (End Signals). The output when any one of the flip-flops included in the shift register does not operate normally because it has a defective portion is different from the output when all the flip-flops operate normally in the waveform of the voltage.

  In the case of the element substrate shown in FIG. 11, S-CLK, S-SP, G-CLK, G-SP, and a video signal are input to each circuit as drive signals for inspection. Note that the driving signal for inspection is not limited to the signal described above. Any signal related to driving can be used as a driving signal for inspection. For example, in addition to the signals described above, a signal for determining the timing for switching the scanning direction of the scanning line, a signal for switching the input direction of the selection signal to the scanning line, or the like may be input. However, it is important to input a signal that can determine whether the circuit or the circuit element is good or bad in the circuit to be inspected.

  In addition, when not all the circuits included in the element substrate are inspected but a part of the circuits to be inspected, it is possible to determine whether the state of the circuit is good or not. There is no need to input the drive signal. For example, when only the shift register 710 included in the signal line driver circuit 700 is to be inspected, only the inspection drive signals S-CLK and S-SP and the inspection power supply voltage for the shift register 710 are waveformd. It may be generated in the shaping circuit and the rectifier circuit and input to the shift register 710.

Next, FIG. 12 shows a configuration of an element substrate of a general OLED display.
Note that FIG. 11 illustrates an example of a driving circuit of an OLED display that displays an image using a digital video signal. The element substrate illustrated in FIG. 12 includes a signal line driver circuit 800, a scanning line driver circuit 801, and a pixel portion 802.

  A plurality of signal lines, a plurality of scanning lines, and a plurality of power supply lines are formed in the pixel portion 802, and a region surrounded by the signal lines, the scanning lines, and the power supply lines corresponds to a pixel. Note that FIG. 12 representatively shows only a pixel having one signal line 807, one scanning line 809, and one power supply line 808 among the plurality of pixels. Each pixel has a switching TFT 803 serving as a switching element, a driving TFT 804, a storage capacitor 805, and a pixel electrode 806 of an OLED.

A gate electrode of the switching TFT 803 is connected to the scanning line 809.
One of the source region and the drain region of the switching TFT 803 is connected to the signal line 807 and the other is connected to the gate electrode of the driving TFT 804.

  One of a source region and a drain region of the driving TFT 804 is connected to the power supply line 808 and the other is connected to the pixel electrode 806. A storage capacitor 805 is formed by the gate electrode of the driving TFT 804 and the power supply line 808. Note that the storage capacitor 805 is not necessarily formed.

  The signal line driver circuit 800 includes a shift register 810, a first latch 811, and a second latch 812. The shift register 810, the first latch 811 and the second latch 812 are each supplied with a power supply voltage (Power supply). The shift register 810 is supplied with a clock signal (S-CLK) and a start pulse signal (S-SP) for the signal line driver circuit. The first latch 811 is supplied with a latch signal (Latch signals) and a video signal (Video signals) for determining the latch timing.

  When a clock signal (S-CLK) and a start pulse signal (S-SP) are input to the shift register 810, a sampling signal that determines the sampling timing of the video signal is generated and input to the first latch 811.

  Note that the sampling signal from the shift register 810 may be buffered and amplified by a buffer or the like and then input to the first latch 811. Since many circuits or circuit elements are connected to the wiring to which the sampling signal is input, the load capacitance (parasitic capacitance) is large. This buffer is effective in preventing “dullness” of the rise or fall of the timing signal caused by the large load capacity.

  The first latch 811 has a plurality of stages of latches. In the first latch 811, the input video signal is sampled in synchronization with the input sampling signal, and is sequentially stored in the latch of each stage.

  The time until video signal writing is completed in all the latches of the first latch 811 is called a line period. Actually, the line period may include a period in which a horizontal blanking period is added to the line period.

  When one line period ends, a latch signal is input to the second latch 812. At this moment, the video signals written and held in the first latch 811 are sent to the second latch 812 all at once, and are written and held in the latches of all stages of the second latch 812.

  In the first latch 811 which has finished sending the video signal to the second latch 812, the video signal is sequentially written based on the sampling signal from the shift register 810.

  During the second line period, the video signal written and held in the second latch 812 is input to the source signal line.

  On the other hand, the scan line driver circuit includes a shift register 821 and a buffer 822. A power supply voltage (Power supply) is supplied to the shift register 822 and the buffer 822. The shift register 821 is supplied with a clock signal (G-CLK) and a start pulse signal (G-SP) for the scanning line driver circuit.

  When a clock signal (G-CLK) and a start pulse signal (G-SP) are input to the shift register 821, a selection signal for determining the timing for selecting a scanning line is generated and input to the buffer 822. The selection signal input to the buffer 822 is buffered and amplified and input to the scanning line 809.

  When the scanning line 809 is selected, the switching TFT 803 whose gate electrode is connected to the selected scanning line 809 is turned on. Then, the video signal input to the signal line is input to the gate electrode of the driving TFT 804 via the switching TFT 803 that is turned on.

  Switching of the driving TFT 804 is controlled based on 1 or 0 information included in the video signal input to the gate electrode. When the driving TFT 804 is on, the potential of the power supply line is applied to the pixel electrode. When the driving TFT 804 is off, the potential of the power supply line is not applied to the pixel electrode.

As described above, when the signal line driver circuit 800, the scanning line driver circuit 801, and the pixel portion 802 are operated, outputs of each circuit or circuit element (End Signals).
Is input to the inspection dedicated circuit 830. In the test-dedicated circuit, an operation information signal is generated from the output of each circuit or circuit element, and a modulated signal is generated by the operation information signal. Then, the AC voltage generated in the output secondary coil when the modulated signal is input to the output primary coil is input to the inspection unit, and the operation of each circuit or circuit element is checked in the inspection unit. The status of is confirmed. Note that, when the signal line driver circuit 800, the scan line driver circuit 801, and the pixel portion 802 are operated, an electric field or an electromagnetic wave generated in each circuit or circuit element is monitored by some means, so that each circuit or The quality of the circuit element can also be determined.

  In the case of the element substrate shown in FIG. 12, S-CLK, S-SP, G-CLK, G-SP, a latch signal, and a video signal are input to each circuit as drive signals for inspection. Note that the driving signal for inspection is not limited to the signal described above. Any signal related to driving can be used as a driving signal for inspection. For example, in addition to the signals described above, a signal for determining the timing for switching the scanning direction of the scanning line, a signal for switching the input direction of the selection signal to the scanning line, or the like may be input. However, it is important to input a signal that can determine whether the circuit or the circuit element is good or bad in the circuit to be inspected.

  In addition, when not all the circuits included in the element substrate are inspected but only a part of the circuits are to be inspected, only a driving signal for operating only the part of the circuit may be input. It is not necessary to input all the drive signals. For example, when only the shift register 810 included in the signal line driver circuit 800 is to be inspected, only the inspection drive signals S-CLK and S-SP and the inspection power supply voltage for the shift register 810 have waveforms. It may be generated in the shaping circuit and the rectifier circuit and input to the shift register 810.

  When the power supply voltage is generated by adding a plurality of pulsating signals having different phases, the number of primary coils varies depending on the number of pulsating signals to be added.

  The inspection apparatus and inspection method of the present invention are not limited to the element substrate having the structure shown in FIGS. The inspection apparatus and inspection method of the present invention may be any semiconductor device that can generate an operation information signal from the output of each circuit or circuit element by inputting a drive signal and a power supply voltage in a non-contact manner. It can be used for semiconductor devices of types and standards.

  This embodiment can be implemented by freely combining with the first embodiment.

  In this embodiment, when a plurality of display substrates are formed using a large element substrate, cutting of the substrate after completion of the inspection will be described.

  FIG. 13 shows a top view of a large element substrate before cutting according to this embodiment. Reference numeral 1001 denotes a pixel portion, 1002 denotes a scanning line driver circuit, and 1003 denotes a signal line driver circuit. The area indicated by 1004 is used only in the inspection process, such as a plurality of input secondary coils, a plurality of output primary coils, a waveform shaping circuit, a rectifier circuit, and an inspection dedicated circuit. Circuits or circuit elements that are not used are formed.

  In FIG. 13, nine display substrates are formed from one element substrate by cutting the element substrate along a line indicated by a dotted line. Note that, in this embodiment, an example in which nine display substrates are formed from one substrate is shown, but this embodiment is not limited to this number.

  At the time of cutting, the lead-out wiring and the coil wiring are cut and destroyed so as to be physically and electrically separated. In FIG. 13, a region 1004 is provided on a substrate that is not used for display after the element substrate is cut.

  An example different from FIG. 13 will be described with respect to how to cut a large substrate which is an element substrate. Reference numeral 1101 denotes a pixel portion, 1102 denotes a scanning line driver circuit, and 1103 denotes a signal line driver circuit. The area indicated by 1104 is used only during the inspection process, such as a plurality of input secondary coils, a plurality of output primary coils, a waveform shaping circuit, a rectifier circuit, and an inspection dedicated circuit. Circuits or circuit elements that are not used are formed.

  In FIG. 14, nine display substrates are formed from one element substrate by cutting the element substrate along a line indicated by a dotted line. Note that, in this embodiment, an example in which nine display substrates are formed from one substrate is shown, but this embodiment is not limited to this number.

At the time of cutting, the lead-out wiring and the coil wiring are cut and destroyed so as to be physically and electrically separated. In FIG. 14, the region 1104 is provided on the cutting line of the substrate and is cut and destroyed after the inspection is completed.
After the inspection is completed, a circuit or a circuit element formed in the region 1104 is unnecessary, so that there is no problem in the operation of the completed semiconductor device.

  Note that the waveform shaping circuit or the rectifier circuit may be left on the substrate used for the semiconductor device after cutting, or may be formed on the substrate not used for the semiconductor device. Moreover, it may be destroyed after cutting.

  This embodiment can be implemented by freely combining with the configuration of Embodiment 1 or 2.

  In this embodiment, the order of the inspection process of the present invention will be described using a flowchart.

  FIG. 15 shows a flowchart of the inspection process of the present invention. First, after the manufacturing process before the inspection is completed, a power supply voltage or a driving signal for inspection is input to the circuit or circuit element to be inspected.

  Then, a circuit or circuit element to be inspected is operated by inputting a power supply voltage or a driving signal for inspection, and an output thereof is input to the inspection dedicated circuit, and an operation information signal is generated in the inspection dedicated circuit.

  Then, a modulated signal is generated by modulating the amplitude of the AC signal input to the test-dedicated circuit in accordance with the operation information signal, and input to the output primary coil. The primary coil for output and the secondary coil for output are electromagnetically coupled, and the AC voltage generated in the secondary coil for output is input to the inspection unit.

  From the alternating-current signal input to the inspection unit, it is possible to identify the quality of the inspection unit and the position of the defective portion. Specifically, the amplitude of the AC signal input to the inspection unit when using a normally operating circuit element and the AC input to the inspection unit when using a circuit element that is actually inspected are used. Compare the amplitude of the signal. At this time, the amplitude of the AC signal input to the inspection unit may be compared between the same circuit or circuit elements, or the amplitude value derived from the theoretical value calculated by simulation and the actual value may be compared. You may make it compare with the value of the amplitude obtained by the measurement.

  As a result of comparison, when the amplitude of the voltage of the AC signal input to the inspection unit is significantly different, the circuit or circuit element corresponding to the different amplitude is determined as a defective portion.

Therefore, it is possible to simultaneously specify the operation state of the circuit or the circuit element and further the position of the defective portion. At this time, the criteria for determining the quality of the circuit or the circuit element can be appropriately set by a person who implements the present invention, and can be determined to be defective when there is even one defective portion. However, when there is a certain number of defective portions, it can be determined as defective.

  When it is determined to be good, it is considered that the inspection has been completed, and the manufacturing process after the inspection process is started.

  If it is determined to be defective, it is selected whether to remove the product from the process and not complete the product (lotout) or to specify the cause of the defect. When a plurality of products are to be manufactured from one large substrate, a non-defective product and a defective product are selected after cutting the substrate, and the defective product becomes a lot-out.

  When the cause of the defect is specified and it is determined that repair (repair) is possible, after the repair, the inspection process of the present invention is performed again, and the above-described operation can be repeated. On the other hand, if it is determined that repair is impossible, the lot is out.

  This embodiment can be implemented by freely combining with the configurations of the first to third embodiments.

  In this embodiment, the coil used in the present invention and the connection between the terminal and the wiring (coil wiring) of the coil will be described in detail.

  In FIG. 16A, a coil 1601 is formed on the insulating surface, and an interlayer insulating film 1603 is formed on the insulating surface so as to cover the coil 1601. A contact hole is formed in the interlayer insulating film, and a coil wiring 1602 is formed on the interlayer insulating film so as to be connected to the coil 1601 through the contact hole.

  FIG. 16B is a cross-sectional view taken along dashed line C-C ′ in FIG.

In FIG. 16C, a coil wiring 1612 is formed on the insulating surface, and an interlayer insulating film 1613 is formed on the previous insulating surface so as to cover the coil wiring 1612.
A contact hole is formed in the interlayer insulating film, and a coil 1611 is formed on the interlayer insulating film so as to be connected to the coil wiring 1612 via the contact hole.

  FIG. 16D is a cross-sectional view taken along dashed line D-D ′ in FIG.

  Note that the method for manufacturing the coil used in the present invention is not limited to the above-described method. A spiral groove is formed by patterning the insulating film, and a conductive film is formed on the insulating film so as to cover the groove. Thereafter, the conductive film is polished by etching or CMP until the insulating film is exposed, so that the conductive film remains only in the groove. It is also possible to use the conductive film remaining in this groove as a coil.

  The present embodiment can be implemented by freely combining with the configurations of the first to fourth embodiments.

  In the present embodiment, the configuration of an inspection apparatus for performing inspection using the inspection method of the present invention will be described.

  FIG. 17 shows a block diagram of the inspection board of the present invention. The inspection apparatus 1700 of the present invention shown in FIG. 17 has a signal source or AC power source 1702, an input primary coil 1720, and an output secondary coil 1721. Further, the input primary coil 1720 and the input secondary coil 1722 included in the element substrate 1703 and the output secondary coil 1721 and the output primary coil 1723 included in the element substrate 1703 are spaced apart from each other by a certain interval. Means (substrate fixing means 1704) that can be superposed is provided. Furthermore, a unit (inspection unit 1705) for determining pass / fail from the AC voltage generated in the output secondary coil 1721 by the modulated signal generated in the element substrate 1703 is provided.

  In this embodiment, the signal source or AC power source 1702 is regarded as a part of the inspection device 170, but the inspection device of the present invention may not include the signal source or AC power source 1702.

  An AC signal generated in the signal source or AC power supply 1702 is input to an external input buffer 1706 included in the inspection board 1701. The input AC signal is amplified or buffer-amplified in the external input buffer 1706 and input to the input primary coil 1720 included in the inspection board 1701.

  On the other hand, the positions of the inspection substrate 1701 and the element substrate 1703 are determined by the substrate fixing means 1704 so that the input primary coil 1720 and the input secondary coil 1722 overlap each other at a constant interval.

  Then, a power supply voltage or a drive signal generated by an alternating voltage generated in the input secondary coil 1722 is input to a circuit or a circuit element 1712 included in the element substrate 1703. Note that a circuit for generating a power supply voltage or a drive signal included in the element substrate 1703 has already been described in detail in the embodiment of the invention, and thus description thereof is omitted here.

  An output from the circuit or circuit element 1712 is input to a test-dedicated circuit 1730. The inspection dedicated circuit 1730 has a modulation circuit 1731. The inspection dedicated circuit 1730 generates an operation information signal from the output from the circuit or the circuit element 1712 and inputs the operation information signal to the modulation circuit 1731.

  On the other hand, the AC voltage generated in the input secondary coil 1722 is input to the modulation circuit 1731. The modulation circuit 1731 generates a modulated signal by modulating the input AC voltage using an operation information signal. The generated modulated signal is input to the output primary coil 1723.

  On the other hand, the positions of the inspection substrate 1701 and the element substrate 1703 are determined by the substrate fixing means 1704 so that the output primary coil 1723 and the output secondary coil 1721 overlap each other at a constant interval.

  Then, an AC voltage is generated in the output primary coil 1723. The AC voltage is amplified or buffer amplified in the external output buffer 1732 and input to the inspection unit 1705.

  In the inspection unit 1705, the AC voltage input to the inspection unit 1705 is digitized and sent as data (measured value) to the arithmetic unit 1709 included in the inspection unit 1705.

  The arithmetic unit 1709 determines pass / fail based on the input measurement value. As a specific example, when a circuit element that is operating normally is used, an AC signal input to the inspection unit is stored in a memory or the like, and a circuit element that is actually inspected is used. Compare with the amplitude of the AC signal input to the inspection unit. Further, the amplitude of the AC signal input to the inspection unit may be compared between the same circuits or circuit elements, or the amplitude value derived from the theoretical value calculated by simulation and the actual measurement. You may make it compare with the value of the obtained amplitude.

  The above-described comparison method is only an example, and the present invention is not limited to this. It is only necessary to detect a circuit element in which the amplitude of the AC signal input to the inspection unit is significantly different from the amplitude of the AC signal input to the inspection unit when a normal circuit element is used. .

  As a result of comparison, if the amplitude of the voltage of the AC signal input to the inspection unit is significantly different, the circuit or circuit element corresponding to the different amplitude is determined to be defective. Actually, even in the case of a normal circuit, the amplitude of the voltage of the AC signal input to the inspection unit often changes every certain period. In that case, an average value of amplitude may be obtained for each period, and the average value for each period may be compared with that of a normal circuit element. Any method may be used for the comparison.

  Note that when the electric field or electromagnetic wave generated in the circuit or the circuit element is monitored to determine whether it is good or bad, the output primary coil 1723, the output secondary coil 1721, and the external output buffer 1732 need not be provided. In this case, an output pad is provided on the element substrate 1703, and the modulated signal output from the modulation circuit 1723 is input to the output pad.

  Then, a measurement unit is provided in the inspection device, and an electromagnetic wave or an electric field generated in the output pad is monitored in the measurement unit and sent as data to a calculation unit 1709 included in the inspection unit 1705. The arithmetic unit 1709 specifies the operation state of the circuit or the circuit element and further the position of the defective portion based on the input data.

  The present embodiment can be implemented by freely combining with the configurations of the first to fifth embodiments.

Claims (3)

A first AC voltage is applied between two terminals of the first coil provided on the first substrate,
The first coil and the second coil provided on the second substrate are overlapped at a certain interval to generate a second AC voltage between two terminals of the second coil. Let
A power supply voltage or a drive signal is generated from the second AC voltage, and the power supply voltage or the drive signal is input to a modulation circuit included in a test-dedicated circuit and a circuit or a circuit element.
The operation information signal is generated by inputting the output of the circuit or the circuit element to the test-dedicated circuit,
In the modulation circuit, the power supply voltage or the drive signal input according to the operation information signal is modulated to generate a modulated signal,
The modulated signal is input to one of two terminals of a third coil provided on the second substrate,
The third coil and the fourth coil provided on the first substrate are overlapped at a certain interval, and a third AC voltage is applied between two terminals of the fourth coil. Give rise to
An inspection method comprising inspecting a state of the circuit or the circuit element by reading the third AC voltage. In claim 1,
The power supply voltage is generated by rectifying the second AC voltage,
The inspection method, wherein the drive signal is generated by shaping the second AC voltage. In claim 1 or 2,
The inspection method, wherein the circuit or the circuit element is a circuit or a circuit element included in a pixel portion, a scanning line driver circuit, or a signal line driver circuit.

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