KR20180112655A - Method of testing an object and apparatus for performing the same - Google Patents

Abstract

The height of the object and the surface state are simultaneously obtained by a simple structure composed of one light projecting illumination device.
The inspection apparatus of the present invention comprises a moving device for holding an object, a moving device for moving the object, a light source, a first area for converting the light emitted from the light source into slit light, And a second region for limiting the amount of the light emitted by the light source and transmitting the light emitted from the light source through the light transmitting mask pattern to the object And a detecting device for receiving the reflected light of the measurement light projected onto the object and detecting the height and the surface state of the object based on the reflected light.

Description

≪ Desc / Clms Page number 1 > METHOD OF TESTING AN OBJECT AND APPARATUS FOR PERFORMING THE SAME

The present invention relates to an inspection apparatus and an inspection method.

2. Description of the Related Art As a means for detecting a height after mounting a semiconductor chip in a semiconductor production site, an apparatus that irradiates an object with slit light and uses an image captured by a sensor is generally known (see, for example, Patent Documents 1 to 3). It is possible to improve the manufacturing quality by managing whether or not the mounting is correct by judging whether or not the height is a predetermined value.

In addition, in order to strictly control the amount of film material pushed out on the surface of the chip or the chip mounted on the chip after mounting, observation of the surface by visible light is also an important management item. Since the height measurement unit and the surface observation unit are usually constituted by separate units, there is a problem that the cost of the apparatus is increased. In addition, since the object must be moved on the sensor in order to measure, the moving distance increases, which may be an increase factor of the inspection time.

Patent Document 1 discloses a configuration for projecting slit light to obtain a height. Further, Patent Document 2 discloses a structure for projecting a plurality of slit lights and estimating the height at a relative position. Patent Document 3 discloses a structure for estimating the lower height of the silicon through the silicon by irradiating the infrared slit light.

Patent Document 1: JP-A-07-063518 Patent Document 2: JP-A No. 11-241916 Patent Document 3: JP-A-2007-048841

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inspection apparatus and an inspection method capable of simultaneously obtaining a height and surface state of an object with a simple structure.

According to an aspect of the present invention, there is provided a moving image display apparatus including a moving device for holding an object and moving the object, a light source, a first area for converting the light emitted from the light source into slit light, And a second region that is arranged in a direction of movement of the object with respect to the first region and limits the amount of the light emitted by the light source and transmits the light so that the light swept by the light source passes through the light- And a detection device for receiving the reflected light of the measurement light projected onto the object and detecting the height and surface state of the object based on the reflected light .

According to an aspect of the present invention, in the inspection apparatus, the second region is formed by arranging two or more partial regions having different light transmission characteristics in the moving direction.

According to an aspect of the present invention, in the inspection apparatus, the moving device moves the object at a constant speed.

According to an aspect of the present invention, in the inspection apparatus, the at least two partial regions include a plurality of partial regions different in grayscale or halftone tint.

According to an aspect of the present invention, in the inspection apparatus, the light source is a white light source, and the at least two partial areas include a partial area of a red filter, a partial area of a green filter and a partial area of a blue filter.

According to an aspect of the present invention, in the inspection apparatus, the at least two partial regions include a plurality of partial regions forming polarizers having different polarizing directions.

According to another aspect of the present invention, there is provided a moving apparatus comprising: a moving device for holding an object and moving the object; a light source; a first area for converting light emitted from the light source into slit light; And a second region that is arranged in the direction of movement of the object and limits the amount of light swept by the light source and transmits the light, wherein the light emitted from the light source passes through the light- For detecting the height and the surface state of the object based on the reflected light, and a detecting method for detecting the height and the surface state of the object on the basis of the reflected light, by using a light emitting device for projecting light onto the object, to be.

According to the present invention, it is possible to acquire the object height and the surface state at the same time with a simple structure composed of one light projecting illumination device.

1 is a block diagram showing a basic configuration example of a mounting inspection apparatus according to an embodiment of the present invention.
2 is a perspective view schematically showing a configuration example of the mounting inspection apparatus 10 shown in Fig.
3 is a plan view of the mounting inspection apparatus 10 shown in Fig.
4 is a front view of the mounting inspection apparatus 10 shown in Fig.
5 is a plan view schematically showing a configuration example of the light-transmitting mask pattern 22 shown in Fig.
6 is a plan view schematically showing another example of the configuration of the light-transmitting mask pattern 22 shown in Fig.
7 is a plan view schematically showing another example of the configuration of the light-transmitting mask pattern 22 shown in Fig.
8 is an explanatory view for explaining an example of the operation of the mounting inspection apparatus 10 shown in Fig.
Fig. 9 is a front view schematically showing a modification of the mounting inspection apparatus 10 shown in Fig. 2;
10 is a schematic diagram for explaining an operation example of the mounting inspection apparatus 10 shown in Fig.
11 is a schematic diagram for explaining an operation example of the mounting inspection apparatus 10 shown in Fig.
12 is a schematic diagram for explaining an operation example of the mounting inspection apparatus 10 shown in Fig.
13 is a schematic diagram for explaining an operation example of the mounting inspection apparatus 10 shown in Fig.
14 is a schematic diagram for explaining an operation example of the mounting inspection apparatus 10 shown in Fig.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a block diagram showing a basic configuration example of a mounting inspection apparatus 10 according to an embodiment of the present invention. 2 is a perspective view schematically showing a configuration example of the mounting inspection apparatus 10 shown in Fig. 3 and 4 are a plan view and a front view of the mounting inspection apparatus 10 shown in Fig. 5 is a plan view schematically showing a configuration example of the light-transmitting mask pattern 22 shown in Fig. 9 is a front view schematically showing a modified example of the mounting inspection apparatus 10 shown in Fig. 2 as the mounting inspection apparatus 10a.

A mounting inspection apparatus 10 (inspection apparatus) shown in Fig. 1 includes a moving apparatus 1, a light projecting illumination apparatus 2, a detection apparatus 3, and a control apparatus 4. The control device 4 controls the operation of the mobile device 1, the illumination device 2 and the detection device 3 or mediates the exchange of information between the devices, It is determined whether or not the mounting state of the object 7 is acceptable based on the information. 2, the moving device 1 holds the object 7 on the stage 11 and moves the stage 7 at a constant speed in the moving direction indicated by the arrow 101 so as to move the object 7 . In the example shown in Fig. 2, the object 7 is a printed substrate 71, and a plurality of semiconductor chips 72 are mounted on the printed substrate 71. [ However, the object 7 is not limited to this example. The mobile device 1 transmits coordinate information indicating the movement position of the stage 11 to the detection device 3 via the control device 4. [ The detection device 3 obtains the image capturing timing in synchronization with the coordinate information indicating the movement position of the stage 11.

As shown in Fig. 2 and Fig. 4, the light-projecting illumination device 2 includes a light source 21, a light-transmitting mask pattern 22, and a lens 23, for example. The light source 21 is composed of a visible light laser, an LED (light emitting diode), or the like. The lens 23 can be constructed using, for example, a telecentric lens.

The light-transmitting mask pattern 22 has a light-shielding region 50, a first region 51 and a second region 52, as shown in Fig. 5, for example. The first region 51 and the second region 52 are arranged along the movement direction (arrow 101) of the object 7. The light shielding region 50 shields the light emitted by the light source 21. The first region 51 has a plurality of slits 511 and allows the light emitted from the light source 21 to be converted into a plurality of slit lights by passing the light emitted from the light source 21 to the plurality of slits 511. The slit light generated by the first region 51 is used for height detection by the optical cutting method shown in Patent Documents 1 to 3 and the like. The second area 52 limits the amount of light emitted by the light source 21 to an amount suitable for imaging an image (a normal two-dimensional image) in a range of a predetermined width and transmits the light. A comparatively large amount of light is required as the slit light used in the optical cutting method. On the other hand, a relatively small amount of light smaller than the light amount of the slit light is often suitable for normal image pickup. Therefore, in this embodiment, the amount of light passing through the second region 52 is limited by adjusting the light transmittance (one element of the transmission characteristic) in the second region 52. The projection light device 2 projects the measurement light 200 generated by passing the light emitted from the light source 21 through the projection mask pattern 22 and the lens 23 to the object 7.

In the light-transmitting mask pattern 22 shown in Fig. 5, the second region 52 is formed of a plurality of partial regions 521 to 523 having different light transmission characteristics. These partial regions 521 to 523 are arranged in the moving direction (arrow 101) of the object 7. The partial areas 521 to 523 are formed to be gray scale or halftone, and are different from partial areas having different shades. In this case, the partial regions 521 to 523 are different from the partial regions in which the light transmittance is different. The transmissivity of each of the partial regions 521 to 523 is constant. By varying the transmissivity of each of the partial areas 521 to 523, the light amount of the light projected onto the object 7 can be changed in a constant range. According to this configuration, it is possible to change the light amount of the reflected light 300 from the object 7 only by moving the object 7. The detection device 3 can obtain an image with brightness suitable for detection of a part to be observed, a foreign object, a foreign object, a crack, or the like, although the part, foreign object, have.

On the other hand, the second region 52 may be composed of only one region, or may have two or more partial regions. The first region 51 may have only one slit 511 and is not limited to having a longitudinal direction perpendicular to the movement direction (arrow 101), and may be a vertical direction and a horizontal direction May have a plurality of slits.

The detection device 3 has one or a plurality of imaging devices (cameras) and an image processing device and receives the reflected light 300 of the measurement light 200 projected onto the object 7, The height and the surface state of the object 7 are detected. In the examples shown in Figs. 2 to 4, the detecting device 3 has three imaging devices 31 to 33 arranged vertically with respect to the moving direction (arrow 101). The imaging devices 31 to 33 are, for example, CMOS (Complementary Metal Oxide Semiconductor) sensor cameras or CCD (Charge Coupled Device) sensor cameras, and optical systems are provided with telecentric lenses. On the other hand, the configuration of the mounting inspection apparatus 10 shown in Fig. 1 is not limited to the configuration shown in Figs. 2 to 4, and may be a configuration shown as a mounting inspection apparatus 10a in Fig. 9, for example. In the mounting inspection apparatus 10a shown in Fig. 9, the measurement light 200 from the light-projecting illumination apparatus 2 is directly irradiated onto the object 7 from above. In the mounting inspection apparatus 10a, the imaging units 3-1 and 3-2 of the detection device 3 are arranged before and after the movement direction (arrow 101). The image pickup units 3-1 and 3-2 are each configured to include, for example, the image pickup devices 31 to 33 shown in Fig. According to the mounting inspection apparatus 10a shown in Fig. 9, it is possible to reduce the unmeasurable part (called ochronization). In Fig. 9, the same components as those shown in Figs. 2 to 4 are denoted by the same reference numerals, and a description thereof will be omitted.

The imaging devices 31 to 33 generate three images (two-dimensional images) having different brightness by picking up the reflected light 300 of the measurement light 200 transmitted through the second area 52 shown in Fig. 5 . The detecting device 3 detects the surface state of the object 7 by executing, for example, a known image recognition process based on three images having different brightness. The imaging devices 31 to 33 generate an image 700 as shown in Fig. 8 by picking up the reflected light 300 of the measurement light 200 transmitted through the first area 51 shown in Fig. 5 . 8 is a view for explaining an example of the operation of the detection device 3 and shows an image 700 captured by the image pickup devices 31 to 33 and an image 700 generated by the detection device 3 Dimensional image 701 of the three-dimensional image 7 and the determination results of the three-dimensional image 701. [ The image 700 shows a state in which the slit light 201 is projected on the printed board 71 and the semiconductor chip 72. [ The slit light 201 is the light generated by the slit 511 in the first region 51 shown in FIG. 5 in the measurement light 200. The detection apparatus 3 generates a three-dimensional image 701 by the optical cutting method based on the plurality of images 700, the coordinate information (position information) of the stage 11 (object 7) The three-dimensional image 701 is an image (or map) obtained by adding height information to the image 700 by a predetermined color gradient. The detection device 3 (or the control device 4) compares the mounting state of the semiconductor chip 72 with a predetermined reference based on the three-dimensional image 701, for example, when the inclination angle is small, It is determined that the mounting state of the semiconductor chip 72 is acceptable (OK), and in other cases, it is determined that the semiconductor chip 72 is not acceptable (NG). The detection device 3 corrects the coordinate information of each pixel of the image pickup device and the stage 11 of the image pickup devices 31 to 33 in advance so that the measurement light 200 passing through the first area 51 And the image based on the reflected light 300 of the measurement light 200 passing through the second region 52 can be aligned with each other. Therefore, the detecting device 3 can determine the mounting state by connecting the height information of the object 7 and the detection result of the surface state, for example.

Here, a method of measuring the height of the object 7 by the optical cutting method in the present embodiment will be described with reference to Figs. 10 to 14. Fig. In Figs. 10 to 12, the same or corresponding components as those shown in Figs. 2 to 4 are denoted by the same reference numerals, and a description thereof will be omitted as appropriate. Figs. 10 to 12 schematically show the positional relationship between the light projector 2, the detecting device 3 and the printed board 71, which is an example of the object 7. Fig. The positional relationships shown in Figs. 10 to 12 are the same. 10 to 12, the slit light 200a projected from the light source 21 of the light projector 2 to the object 7 is regularly reflected to be picked up by the detection device 3. [ In this example, the angle of projection θ of the slit light 200a projected from the light-projecting illumination device 2 with respect to the printed substrate 71 and the reflected light 300b of the detection device 3 with respect to the printed substrate 71 The imaging angle? Is the same. That is, the angle formed by the light source 21 and the detecting device 3 with respect to the axis Z in the vertical direction is the same as?. However, the present invention is not limited to the case where the projection angle and the imaging angle are the same. 10 shows a state in which the slit light 200a is projected onto the surface of the print substrate 71 so that the detection device 3 picks up the reflected light 300a on the surface of the print substrate 71. FIG. 11 shows a state in which the slit light 200a is projected onto the surface of the semiconductor chip 72 mounted on the printed substrate 71 so that the detection device 3 picks up the reflected light 300b from the surface of the semiconductor chip 72 . The height of the semiconductor chip 72 is referred to as z. Fig. 12 shows the same state as Fig.

As shown in Fig. 11, when the height of the object 7 is changed, the detection position of the detection device 3 is changed by v. The relationship between the change v in the detection position and the height z is given by the following equation (1). On the other hand, the height (Z-axis value) of the printed board 71 is "0".

12, the position where the slit light 200a is reflected by the semiconductor chip 72 at the height z and the position where the reflected light 300a from the printed substrate 71 of the slit light 200a has a height z The distance a from the passing position is given by the following equation (2).

From equation (1) and equation (2), the change v is found by the following equation.

On the other hand, the reflected light 300b in the detection device 3 has a constant luminance distribution (that is, as band-shaped light having a constant width) as shown in Figs. 13 and 14. 13 is a diagram schematically showing a picked-up image of the reflected light 300b from the semiconductor chip 72 when the imaging surface of the detection device 3 is a U-V coordinate system. The U-axis and the V-axis of the U-V coordinate system are indicated by arrows U and arrows V in Figs. Here, the V-axis direction is perpendicular to the slit direction (the longitudinal direction of the slit light 200a), the U-axis direction is horizontal, and the vertical direction with respect to the drawing. In Fig. 13, the abscissa is the coordinate value of the V-axis, and the ordinate is the coordinate value of the U-axis. 13 shows the brightness of each pixel in terms of gray scale brightness. In this case, the closer to black, the higher the luminance. The coordinate value vbase corresponds to the luminance distribution of the reflected light 300a from the printed substrate 71. [ The coordinate value vbi and the coordinate value vti correspond to the rising edge and the falling edge of the luminance distribution of the reflected light 300b in the U-axis coordinate value ui shown in Fig.

The imaging position of the reflected light 300b is obtained, for example, as an average of the center or half-width of the profile in the V-axis direction perpendicular to the slit direction. 14 shows the luminance distribution of the picked-up image of the reflected light 300b at the coordinate value ui of the U-axis. The horizontal axis is the coordinate value of the V axis (the U axis is constant at the coordinate value ui), and the vertical axis is the luminance value G (the luminance value of each pixel in the U-V coordinate system). As shown in Fig. 14, the average coordinate value vai of the half width of the position of the coordinate value ui is obtained from the coordinate value vbi of the rising edge and the coordinate value vti of the rising edge by the following equation.

Therefore, the three-dimensional height zi is obtained by the following equation based on the equations (3) and (4).

On the other hand, in reality, since the error components due to the lens distortion or the brightness fluctuation of the slit light are overlapped, correction is made by irradiating the object having the known height with slit light and obtaining the average coordinate value vai of the half width.

As described above, the mounting inspection apparatus 10 of the present embodiment can simultaneously obtain the chip height and the image for inspection of the surface state after semiconductor mounting using the optical cutting method. That is, according to the present embodiment, the height and the surface state of the object 7 can be simultaneously acquired and inspected. Therefore, the distance traveled on the sensor is shortened, leading to a shortening of the measuring time. By arranging the halftone or the gray tone, it is possible to perform inspection at once without adjusting the brightness even in an object having a different reflectance.

In this embodiment, the movement of the object 7 by the mobile device 1 is not limited to the constant velocity. The three-dimensional image 701 can be generated by the optical cutting method as described above with reference to Fig. 8 based on the coordinate information of the mobile device 1, even when it is not moved at the constant velocity.

Next, a modified example of the light-transmitting mask pattern 22 shown in Fig. 5 will be described with reference to Fig. The transmissive mask pattern 22a shown in Fig. 6 is a modification of the transmissive mask pattern 22 shown in Fig. In Fig. 6, the same components as those shown in Fig. 5 are denoted by the same reference numerals, and a description thereof will be omitted as appropriate. The light-transmitting mask pattern 22a shown in Fig. 6 is formed in such a manner that the partial area 524 of the red filter, the partial area 525 of the green filter and the part of the blue filter 522, in which the second area 52 is arranged in the moving direction And an area 526. When the light source 21 is a white light source, the detection device 3 converts the reflected light 300 of the measurement light 200 transmitted through each color filter into a partial area (a red color filter, a green filter, 524 to 526), whereby a color image can be generated. On the other hand, each of the partial areas 524 to 526 has a transmittance that transmits the amount of light emitted by the light source 21 in an amount suitable for capturing an image in a range of a predetermined width.

Next, another modified example of the light-transmitting mask pattern 22 shown in Fig. 5 will be described with reference to Fig. The light-transmitting mask pattern 22b shown in Fig. 7 is a modification of the light-transmitting mask pattern 22 shown in Fig. In Fig. 7, the same components as those shown in Fig. 5 are denoted by the same reference numerals, and a description thereof will be omitted as appropriate. The light-transmitting mask pattern 22b shown in Fig. 7 has a plurality of partial regions 527 and partial regions 528, in which the second regions 52 are arranged in the moving direction (arrow 101) . The partial area 527 and the partial area 528 transmit, for example, linearly polarized light in the vertical or horizontal direction. The detection device 3 captures the reflected light 300 of the measurement light 200 transmitted through the partial area 527 and the partial area 528 to limit the measurement light 200 to linearly polarized light in a plurality of predetermined directions So that the surface state of the object 7 can be picked up. In addition, each of the partial areas 527 and 528 has a transmittance that limits the amount of light emitted by the light source 21 to an appropriate amount for capturing an image in a range of a predetermined width.

According to the embodiment or the modification, the moving device 1 holds the object 7, moves the object 7 at a constant speed, and the light-projecting illumination device 2 moves the light source 21 and the light source 21 A first region 51 which is arranged in the direction of movement of the object 7 with respect to the first region 51 and which limits the amount of light emitted by the light source 21, And the measurement light 200 generated by passing light emitted from the light source 21 through the light transmission mask pattern 22 is projected onto the object 7 Therefore, it is possible to acquire the object height and the surface state at the same time with a simple structure composed of one light projecting illumination device.

As described above, some embodiments of the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the present invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and alterations can be made without departing from the gist of the invention. These embodiments and their modifications fall within the scope and spirit of the invention as defined in the appended claims and equivalents thereof as falling within the scope and spirit of the invention.

10: mounting inspection device 1: mobile device
2: Illuminator for projecting light 3: Detector
4: control device 21: light source
22: light-transmitting mask pattern 51: first region
511: slit 52: second region
521 to 528:

Claims (7)

A moving device for holding the object and moving the object;
A second region that is arranged in the direction of movement of the object with respect to the first region and restricts and transmits the amount of the light emitted by the light source; A projection light device for projecting the measurement light generated by passing the light emitted by the light source through the light transmitting mask pattern to the object;
And a detection device that receives reflected light of the measurement light projected onto the object and detects the height and surface state of the object based on the reflected light. The method according to claim 1,
Wherein the second region is formed by arranging two or more partial regions having different light transmission characteristics in the direction of movement. 3. The method according to claim 1 or 2,
And the moving device moves the object at a constant speed. The method according to claim 2 or 3,
Wherein the at least two partial regions include a plurality of partial regions different in grayscale or halftone. The method according to claim 2 or 3,
Wherein the light source is a white light source,
Wherein the at least two partial areas include a partial area of a red filter, a partial area of a green filter and a partial area of a blue filter. The method according to claim 2 or 3,
Wherein the at least two partial regions comprise a plurality of partial regions forming polarizers having different polarizing directions. A moving device for holding the object and moving the object;
A second region that is arranged in the direction of movement of the object with respect to the first region and restricts and transmits the amount of the light emitted by the light source; And a projection illumination device for projecting the measurement light generated by passing the light emitted by the light source through the light-transmitting mask pattern to the object,
Receiving the reflected light of the measurement light projected onto the object by the detection device, and detecting the height and the surface state of the object based on the reflected light.

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