KR101178909B1 - Organic light emitting display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device, comprising: a plurality of inner lead bonding pads connected to an input pad and connected to bumps of a driving circuit chip, and a plurality of outs connected to bumps of a driving circuit chip. A lead bonding pad includes a dummy bonding pad connected to a dummy bump of a driving circuit chip, wherein the inner lead bonding pad and the out lead bonding pad have a multilayer structure, and the dummy bonding pad includes a pad portion having a single layer structure. In an organic light emitting display device in which wiring is formed in a multilayer structure of a transparent conductive material and an opaque conductive material to reduce a resistance value, a dummy bonding pad made of only a transparent conductive material is formed between bonding pads on which a driving circuit chip is mounted. Connection between the bump and the bonding pad can be easily visually inspected.

Organic light emitting diode, driving circuit chip, COG, dummy bonding pad, bumper, conductive ball

Description

Organic light emitting display device

1 is a photograph showing indentations of a conductive ball formed on a bonding pad of a conventional organic light emitting display device.

2 is a plan view illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.

3 is a cross-sectional view illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating the organic light emitting display device of FIG. 2.

FIG. 5 is a plan view for explaining a pad unit of FIG. 2; FIG.

6 is a cross-sectional view illustrating a state in which a driving circuit chip is mounted on a pad unit of FIG. 2.

7A and 7B are cross-sectional views for explaining FIG. 6.

8 is a photograph of the conductive ball observed through the dummy bonding pad according to the present invention.

<Explanation of symbols for the main parts of the drawings>

100: organic light emitting device 101: buffer layer

102 semiconductor layer 103 gate insulating film

104a: gate electrode 104b: scan line

104c and 106d: Input pad 105: Interlayer insulating film

106a and 106b: source and drain electrodes

106c: data line 107: planarization layer

108: anode electrode 109: pixel defining film

110: organic thin film layer 111: cathode electrode

140: pad portion 142: inner lead bonding pad

144: out lead bonding pads 146, 148: dummy bonding pads

151: Transparent Challenge 152: Opaque Challenge

200: substrate 210: pixel region

220: non-pixel region 300: encapsulation substrate

320: sealant 400: drive circuit chip

410: scan driver 420: data driver

430: bump 440: dummy bump

500: anisotropic conductive film 520: conductive ball

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device in which a driving circuit chip is mounted in a chip on glass (COG) method.

As the information and communication industry is rapidly developed, the use of display devices is rapidly increasing, and in recent years, display devices capable of satisfying conditions of low power, light weight, thinness, and high resolution are required. In response to these demands, liquid crystal displays or organic light emitting displays using organic light emitting characteristics have been developed.

The organic light emitting display device is a next-generation display device having self-luminous characteristics, and has excellent characteristics in terms of viewing angle, contrast, response speed, power consumption, etc., compared to the liquid crystal display device. It is possible to produce.

The organic light emitting display device is composed of a substrate providing a pixel region and a non-pixel region, and a container or a substrate disposed to face the substrate for encapsulation and bonded to the substrate by a sealant such as epoxy. . In the pixel region of the substrate, a plurality of light emitting elements are formed in a matrix manner between the scan line and the data line to form a pixel. In the non-pixel region, a plurality of light emitting elements are formed. An extended scan line and data line, a power supply voltage supply line for operating the organic light emitting diode, and a scan driver and a data driver for processing a signal supplied from the outside through an input pad and supplying the signal to the scan line and the data line are formed. The scan driver and the data driver include a driving circuit that processes a signal provided from the outside to generate a scan signal and a data signal. The scan driver and the data driver are formed in the manufacturing process of the organic light emitting diode, or are manufactured as separate integrated circuit chips and mounted on a substrate. do.

When manufactured in the form of an integrated circuit chip and mounted on a board, a drive IC chip is mounted in a tape carrier package (TCP) and directly attached to a tape automated bonding (TAB) method connected to a pad of the board or a pad of the board. It may be mounted in a COG (hip on glass) method or the like. Among them, the COG method is widely used in small and medium sized display panels of mobile communication products because the structure is simpler and occupies a smaller area than the TAB method.

In the COG method, an inner lead bonding pad (IBL) pad formed on a substrate through a conductive ball including bumps formed at an input and an output terminal of a driving circuit chip is included in an anisotropic conductive film (ACF). It is a method that is pressed on the Out Lead Bonding (OLB) pad.

A flexible printed circuit (FPC) is connected to the input pad connected to the inner lead bonding pad. When the control signal and the data signal are provided from the outside through the FPC, the driving circuit chip generates the scan signal and the data signal and provides the generated signal to the organic light emitting diode through the scan line and the data line connected to the out-read bonding pads. .

In the conventional organic light emitting display device, a wiring including a scan line, a data line, a power supply voltage supply line, an inner lead bonding pad, and an out lead bonding pad is formed of indium tin oxide (ITO) and chromium (Cr) to reduce resistance. It is formed in a double structure. Therefore, after mounting the driving circuit chip in the COG method, the bumps and bonding pads are correctly connected by the conductive balls by inspecting the indentation (marking caused by pressure) caused by the conductive balls on the back surface of the substrate as shown in FIG. 1. It is difficult to accurately check the connection between the bumps and the bonding pads only by inspection by indentation, which results in a decrease in yield due to a defect.

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic light emitting display device capable of visually and accurately inspecting a connection state between a bump of a driving circuit chip and a bonding pad formed on a substrate.

According to an aspect of the present invention, an organic light emitting display device is connected to an input pad and is connected to a plurality of first bonding pads and organic light emitting diodes connected to bumps of a driving circuit chip. A plurality of second bonding pads connected to the bumps of the chip and a third bonding pad connected to the dummy bumps of the driving circuit chip, wherein the first and second bonding pads have a multi-layered structure and the third bonding pads. The pad has a pad portion formed of a single layer structure.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. no.

2 and 3 are plan views and cross-sectional views for describing an organic light emitting display device according to an exemplary embodiment of the present invention.

The organic light emitting display device according to the present invention is made of a transparent material and faces the substrate 200 to seal the pixel region 210 and the substrate 200 providing the pixel region 210 and the non-pixel region 220. The encapsulation substrate 300 is disposed to be bonded to the substrate 200 by the sealant 320.

In the pixel area 210 of the substrate 200, a plurality of organic light emitting diodes 100 are formed between the scan line 104b and the data line 106c in a matrix manner to form pixels, and the non-pixel area ( In 220, a power supply voltage supply line for operation of the scan line 104b and the data line 106c and the organic light emitting diode 100 extending from the scan line 104b and the data line 106c of the pixel region 210. (Not shown) A scan driver 410 and a data driver 420 are formed to process signals supplied from the outside through the input pads 104c and 106d and to supply them to the scan line 104b and the data line 106c.

In the passive matrix method, the organic light emitting display device 100 is connected between the scan line 104b and the data line 106c in a matrix manner. In the case of the active matrix method, the organic light emitting diode 100 is connected between the scan line 104b and the data line 106c in a matrix manner to control the operation of the organic light emitting diode 100. A thin film transistor (TFT) and a capacitor for holding a signal are further included.

4 illustrates an example of an organic light emitting display device 100 including a thin film transistor, in which a buffer layer 101 is formed on a substrate 200, and a source and drain region and a channel region are provided on the buffer layer 101. The semiconductor layer 102 is formed. The gate insulating film 103 is formed on the entire surface including the semiconductor layer 102, and the gate electrode 104a is formed on the gate insulating film 103 above the channel region. An interlayer insulating layer 105 is formed on the entire surface including the gate electrode 104a, and contact holes are formed in the interlayer insulating layer 105 and the gate insulating layer 103 so that the semiconductor layers 102 of the source and drain regions are exposed. . Source and drain electrodes 106a and 106b are formed on the interlayer insulating layer 105 to be connected to the source and drain regions through contact holes, and the planarization layer 107 is formed on the entire surface including the source and drain electrodes 106a and 106b. Is formed. Via holes are formed in the planarization layer 107 to expose the source or drain electrodes 106a or 106b, and anode electrodes 108 connected to the source or drain electrodes 106a or 106b through the via holes are formed on the planarization layer 107. Is formed. In addition, a pixel defining layer 109 for exposing a predetermined portion of the anode electrode 108 is formed on the planarization layer 107, and the organic thin film layer 110 and the cathode electrode 111 are disposed on the exposed anode electrode 108. ) Is formed. The organic thin film layer 110 may have a structure in which a hole transport layer, an organic light emitting layer, and an electron transport layer are stacked, and further include a hole injection layer and an electron injection layer.

FIG. 5 is a plan view illustrating the pad unit 140 of FIG. 2 in detail, and FIG. 6 illustrates that a driving circuit chip 400 such as the scan driver 410 or the data driver 420 is mounted on the pad unit 140. It is sectional drawing which shows the state.

The pad part 140 is formed in the non-pixel area 220 of the substrate 200 and extends from the scan line 104b or the data line 106c of the pixel area 210. 106c). The pad unit 140 is a first bonding pad connected to the input pads 104c and 106d through which a signal is input from the outside and connected to the bump 430 of the driving circuit chip 400. And a second bonding pad connected to the organic light emitting diode 100 through the scan line 104b or the data line 106c and connected to the bump 430 of the driving circuit chip 400. A third bonding pad is connected to the pad 144 and the dummy bump 440 of the driving circuit chip 400 and is formed between the inner lead bonding pad 142 and the out lead bonding pad 144, respectively. Dummy bonding pads 146 and 148. The inner lead bonding pads 142 and the out lead bonding pads 144 are formed in a line so as to correspond to each other, and the dummy bonding pads 146 and 148 are respectively formed of the inner lead bonding pads 142 and the out lead bonding pads 144. It can be formed between or on both sides.

The scan line 104b, the data line 106c, the inner lead bonding pad 142, and the out lead bonding pad 144 are formed in a multilayer structure of the transparent conductive material 151 and the opaque conductive material 152, and are dummy bonded. The pad 146 is formed in a single layer structure of the transparent conductive material 151. As the transparent conductive material 151, one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO) may be used, and chromium (Cr) may be used as the opaque conductive material 152. , One selected from the group consisting of aluminum (Al), molybdenum (Mo), titanium (Ti), tungsten (W) or gold (Au).

Bumps 430 are formed on an input terminal and an output terminal of the driving circuit chip 400 with a conductive material such as gold (Au) to facilitate connection with a bonding pad. An actual signal is input among the input terminal and the output terminal. Alternatively, a dummy bump 440 is formed at a terminal that is not output. Therefore, the dummy bonding pads 146 and 148 may be formed to correspond to the dummy bumps 440.

An anisotropic conductive film (ACF) 500 including a conductive ball 520 is formed on the pad unit 140 formed as shown in FIG. 5, and the driving circuit chip 400 is formed on the anisotropic conductive film 500. Is placed. In this case, the bump 430 of the driving circuit chip 400 corresponds to the inner lead bonding pad 142 and the out lead bonding pad 144, and the dummy bump 440 corresponds to the dummy bonding pads 146 and 148. . In this state, when the bumps 430 and 440 are pressed in a process such as thermocompression bonding, the conductive balls 520 are broken so that the bumps 430 and 440 of the driving circuit chip 400 are the inner lead bonding pads 142 and the out lead. It is electrically connected to the bonding pads 144 and the dummy bonding pads 146 and 148, respectively.

When the compression is performed as described above, whether the bumps 430 and 440, the inner lead bonding pad 142, and the out lead bonding pad 144 are correctly electrically connected to each other by the conductive balls 520 on the rear surface of the substrate 200. In this case, the inner lead bonding pad 142 and the out lead bonding pad 144 formed of the transparent conductive material 151 and the opaque conductive ball 152 as shown in FIG. 7A can only be observed by indentation. The conductive balls 520 may be directly observed through the dummy bonding pads 146 and 148 formed only of the transparent conductive material 151, as illustrated in FIG. 7B. 8 shows conductive balls 520 as viewed through dummy bonding pads 146 and 148.

Therefore, when the dummy bonding pads 146 and 148 are formed to be uniformly distributed throughout, the connection state between the bump 430, the inner lead bonding pad 142, and the out lead bonding pad 144 may be easily inspected. Therefore, the dummy bonding pads 146 and 148 are formed at both side portions and the center portions of the inner lead bonding pad 142 and the out lead bonding pad 144 so that the connection state is uniform as a whole. It is preferable that the bottoms are arranged so as to be symmetrical with each other.

In the organic light emitting display device configured as described above, an FPC (not shown) in the form of a film is electrically connected to an input pad 106d connected to the inner lead bonding pad 142, and a control signal and a data signal are externally supplied through the FPC. When provided, the driving circuit chip 400 generates a scan signal or a data signal and supplies the scan signal or the data signal to the organic light emitting diode 100 through the scan line 104b or the data line 106c connected to the out read bonding pad 144. Therefore, the organic light emitting display device 100 of the pixel selected by the scan signal emits light corresponding to the data signal.

As described above, the preferred embodiment of the present invention has been disclosed through the detailed description and the drawings. The terms are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

As described above, the present invention provides a dummy bonding pad including only a transparent conductive material between bonding pads on which a driving circuit chip is mounted in an organic light emitting display device in which wiring is formed in a multilayer structure of a transparent conductive material and an opaque conductive material to reduce a resistance value. By forming a, the connection state between the bump and the bonding pad can be easily visually inspected. Therefore, the yield can be improved by detecting and dealing with connection defects before the product is finished.

Claims (9)

A plurality of first bonding pads connected to the input pads and connected to bumps of the driving circuit chip; A plurality of second bonding pads connected to the organic light emitting diodes and connected to bumps of the driving circuit chip; A third bonding pad connected to the dummy bumps of the driving circuit chip, The organic light emitting display device of claim 1, wherein the first and second bonding pads have a multi-layered structure, and the third bonding pad has a single pad structure. The organic light emitting display device of claim 1, wherein the organic light emitting display device and the second bonding pad are connected to a scan line or a data line. The organic light emitting diode of claim 1, wherein the first bonding pad is connected to the bump formed at an input terminal of the driving circuit chip, and the second bonding pad is connected to the bump formed at an output terminal of the driving circuit chip. Display device. The organic light emitting display device of claim 1, wherein the bumps and the dummy bumps are respectively connected to the first to third bonding pads through conductive balls. The organic light emitting display device of claim 1, wherein the third bonding pads are formed between the plurality of first bonding pads and between the plurality of second bonding pads, respectively. The organic light emitting display device of claim 1, wherein the third bonding pads are formed at both side portions and a central portion of the plurality of first and second bonding pads, respectively. The organic light emitting display device of claim 1, wherein the third bonding pads are arranged in a symmetrical structure. The organic light emitting display device of claim 1, wherein the first and second bonding pads are formed of a double layer structure of a transparent conductive material and an opaque conductive material, and the third bonding pads are formed of a single layer structure of the transparent conductive material. The method of claim 8, wherein the transparent conductive material is one selected from the group consisting of ITO, IZO and ITZO, the opaque conductive material is chromium (Cr), aluminum (Al), molybdenum (Mo), titanium (Ti), tungsten An organic light emitting display device which is one selected from the group consisting of (W) and gold (Au).

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