TWI583942B - Check the device and check the method - Google Patents

Description

Inspection device and inspection method

The present invention relates to an inspection apparatus and an inspection method for determining the quality of a film formed on a work using an image.

An appearance inspection of an image using a workpiece is performed on a workpiece such as a substrate used in a solar battery cell or a semiconductor device (see, for example, Patent Document 1). Various methods are used in the visual inspection using images.

For example, the uniformity of the film quality, the film thickness, and the like of the film formed on the workpiece can be determined based on the color of the workpiece after film formation. That is, a hue (HUE) value is calculated for each point of the image based on the intensity of each color obtained from the color image of the workpiece, and a degree profile is plotted for the HUE value to obtain an HUE value distribution profile. Then, the quality is judged based on the height or width of the peak of the obtained HUE value distribution profile. Generally, in the case where the film is not uniform, the peak width of the HUE value distribution profile is widened. Therefore, when the peak width of the power is equal to or smaller than the predetermined width, it is determined that the film is formed normally. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2012-7952

[Problems to be solved by the invention]

The number of peaks of the HUE value distribution profile in the case where the film is normally formed on the workpiece is one, and it is judged to be defective in the case of having a plurality of power peaks. However, when a plurality of power peaks are present in close proximity, the plurality of power peaks overlap and the peak width of the entire HUE value distribution profile is narrowed. In this case, when the quality peak width is used to determine the quality, the quality of the defective product is determined to be good, and the accuracy of the quality determination is lowered.

In view of the above problems, an object of the present invention is to provide an inspection apparatus and an inspection method for accurately determining the quality of a film formed on a workpiece using an image. [Means for solving the problem]

According to an aspect of the present invention, an inspection apparatus includes: (a) an image acquisition device that acquires an inspection image of a film-formed workpiece; and (b) a determination device that calculates a HUE for each point of the inspection image The value is plotted as a HUE value distribution profile, and when the number of peaks of the HUE value distribution profile is one, the workpiece is judged to be good, and when the number of peaks is plural, the workpiece is judged to be defective.

According to another aspect of the present invention, there is provided an inspection method comprising the steps of: (a) acquiring an inspection image of a film-formed workpiece, and (b) calculating an HUE value for each point of the inspection image, and setting the HUE value When the degree map is plotted, the HUE value distribution profile is created, and (c) when the number of peaks of the HUE value distribution profile is one, the workpiece is judged to be good, and when the number of peaks is plural, the workpiece is judged to be defective. [Effects of the Invention]

According to the present invention, it is possible to provide an inspection apparatus and an inspection method for accurately determining the quality of a film formed on a workpiece using an image.

Next, an embodiment of the present invention will be described with reference to the drawings. In the description of the following drawings, the same or similar reference numerals are attached to the same or similar parts. Wherein, the intentional expression is a schematic diagram. In addition, the embodiment described below exemplifies an apparatus or method for embodying the technical idea of the invention, and the embodiment of the invention does not specify the structure, arrangement, and the like of the component parts as follows. Embodiments of the invention may be modified in various ways within the scope of the patent application.

(First Embodiment) The inspection apparatus 1 according to the first embodiment of the present invention shown in Fig. 1 inspects the uniformity of the film formed on the workpiece 100 based on the color of the workpiece 100, and determines whether or not the workpiece 100 is good or bad. The inspection apparatus 1 includes an illumination device 10 that irradiates the film 100 subjected to the film formation process with the inspection light L, and an image acquisition device 20 that images the workpiece 100 irradiated with the inspection light L to acquire an inspection image of the workpiece 100; The device 30 performs the quality determination of the workpiece 100 using the HUE value distribution profile created from the inspection image.

The contour creating unit 31 of the determining device 30 calculates an HUE value for various lights based on the color inspection image acquired by the image acquiring device 20. For example, the contour creating unit 31 calculates an HUE value for each point of the inspection image based on the intensities of the red (R) light, the green (G) light, and the blue (B) light, and creates an HUE value for each color. The HUE value distribution profile drawn by the degree.

The determination unit 32 of the determination device 30 detects the degree peak of the HUE value for the HUE value distribution profile of each color. Then, the number of peaks of the degree of determination is one or more, and when the number of peaks is one, the workpiece 100 is determined to be good, and when the number of peaks is plural, the workpiece 100 is determined to be defective.

Further, the total number of HUE values of the HUE value distribution profile is defined in accordance with the resolution of the image acquisition device 20. For example, in the case where the resolution of the image acquisition device 20 is 2048 pixels × 2048 pixels, the total number of HUE values is 2048 × 2048. For example, a charge coupled device (CCD) camera or a complementary metal oxide semiconductor (CMOS) camera or the like can be employed in the image acquisition device 20. The image data D captured by the image acquisition device 20 is sent to the determination device 30 as an inspection image.

Further, in order to create an HUE value distribution profile for each of the plurality of colors based on the inspection image as described above, the illumination device 10 capable of emitting the inspection light L of the inspection image of the desired color is prepared. For example, a light-emitting diode (LED) that emits red (R) light, green (G) light, and blue (B) light simultaneously or individually can be used for the illumination device 10. The wavelength of the inspection light L is selected in order to easily express the distribution of the film formed on the workpiece 100 as the distribution of the HUE value.

When the quality of the workpiece 100 is determined based on the color, the film is formed in a uniform film of the workpiece 100, and the HUE value is substantially constant over the entire area of the inspection image. Therefore, as shown in FIG. 2, the number of peaks of the HUE value of the HUE value distribution profile of the good product is one, and the width of the power peak is narrow. On the other hand, when the film thickness or film quality of the film formed on the workpiece 100 is not uniform, generally, as shown in FIG. 3, the width W of the power peak of the HUE value in the HUE value distribution profile is widened. Therefore, the predetermined value of the width W of the power peak is set based on the HUE value distribution profile of the good product, and when the width W of the power peak exceeds a predetermined value, the workpiece 100 can be determined to be defective.

However, there are cases where a plurality of power peaks are closely present, the peaks of the plurality of degrees overlap, and the peak width of the entire HUE value distribution profile is narrow. In this case, if the quality W is determined based on the width W of the power peak, the workpiece 100 which is a defective product is erroneously determined to be a good one. For example, as shown in FIG. 4, even when two degree peaks P1 and a number of peaks P2 appear in the HUE value distribution profile, the width W of the entire power peak obtained by superimposing the two power peaks is larger than a predetermined determination value. In the case of a narrow case, the defective product will also be mistakenly judged as a good product.

On the other hand, in the inspection apparatus 1, since the number of peaks of the HUE value in the HUE value distribution profile is plural, the workpiece 100 having the HUE value distribution profile shown in FIG. 4 is correctly determined as a defective product.

As described above, the inspection apparatus 1 according to the first embodiment of the present invention can perform high-precision determination. As a result, the workpiece 100 of the defective product is prevented from entering the subsequent step, and the execution of the useless processing can be suppressed. Therefore, it is possible to reduce the manufacturing cost and improve the quality by the inspection device 1.

Further, the inspection apparatus 1 can perform not only the number of the peaks of the HUE value distribution profile but also the parameters such as the width, the position, and the height of the peak, and the predetermined determination value, thereby comprehensively determining the quality of the workpiece 100. For example, when the number of peaks is one, and the width of the power peak is wider than the determination value, and the height of the power peak is lower than the determination value, and the HUE value of the power peak is not within the range of the determination value, In at least either case, the determination unit 32 determines that the workpiece 100 is a defective product.

(Second Embodiment) As shown in Fig. 5, the inspection apparatus 1 according to the second embodiment of the present invention further includes a division unit 33 that divides the inspection image into a plurality of divided regions. The other configuration is the same as that of the first embodiment shown in Fig. 1 . In the inspection apparatus 1 shown in FIG. 5, an HUE value distribution profile is created for each divided area, and the number of power peaks is detected.

There is a case where an abnormal region such as a film thickness or a film quality of the film formed on the workpiece 100 is partially present in a partial region of the workpiece 100. In this case, the power peak of the HUE value distribution profile due to the abnormal region may not appear as the HUE value distribution profile of the entire inspection image.

For example, as shown in FIG. 6, a case where the abnormal region 210 is generated only in a part of the inspection image 200 of the workpiece 100 is considered. At this time, as shown in FIG. 7, there is a case where the power peak Pf of the HUE value distribution profile resulting from the abnormal region 210 is hidden in the entire power peak Pa. In this case, only the power peak Pa of the entire workpiece 100 is detected, and the power peak Pf due to the abnormal region 210 is not detected. Therefore, in the case where the quality is determined based on the number of peaks of the entire workpiece 100, the number of detected peaks is one, and the workpiece 100 is erroneously determined to be good.

However, according to the inspection apparatus 1 of the second embodiment, the erroneous determination can be prevented. Hereinafter, an inspection method of the inspection apparatus 1 shown in FIG. 5 will be described.

First, the division unit 33 divides the inspection image acquired by the image acquisition device 20 into a plurality of divided regions. For example, the inspection image 200 shown in FIG. 6 is divided into the divided region 201 to the divided region 204 as shown in FIG. 8 .

Then, the contour creating unit 31 calculates an HUE value for each point of the divided region, and creates an HUE value distribution profile for each divided region. That is, an HUE value distribution profile is created for each of the divided regions 201 to 204.

Then, the determination unit 32 detects the peak of the HUE value for the HUE value distribution profile of each divided region, and determines whether the number of peaks is one or more. When the number of peaks of the HUE value distribution profile is one in all the divided regions, the determination unit 32 determines that the workpiece 100 is a good product. On the other hand, when there are a plurality of power peak numbers of the HUE value distribution profile in at least one divided region, the determination unit 32 determines that the workpiece 100 is a defective product. Further, the determination of the quality of the determination unit 32 may be performed simultaneously in all of the divided areas, or may be sequentially performed for each of the divided areas.

In the example shown in FIG. 8, each of the divided peaks 201, the divided regions 202, and the divided regions 204 that do not include the abnormal region is detected as shown in FIG. However, for the divided region 203 including the abnormal region, a plurality of power peaks are detected as shown in FIG. As a result, the workpiece 100 is judged to be defective.

Further, as shown in FIG. 8, it is preferable that the outer edge portions of the divided regions 201 to 204 overlap each other. Thereby, it is possible to reliably detect an abnormality at the boundary of the divided region.

The above exemplarily describes the case where the inspection image is divided into four divided regions, but the number of divided regions is of course not limited to four. The larger the number of divided regions, the smaller the abnormal area or the smaller the unevenness can be detected. On the other hand, the more the number of divided regions, the more inspection time. Therefore, the number of divided regions may be appropriately set in accordance with the area or unevenness of the abnormal region that can be tolerated and the processing time.

As described above, according to the inspection apparatus 1 of the second embodiment, even when the abnormal region exists only partially in a part of the workpiece 100, it is possible to perform high-precision determination. Others are substantially the same as those of the first embodiment, and the repeated description is omitted.

(Other Embodiments) As described above, the present invention is described by the embodiments, but the description and drawings which are a part of the disclosure are not to be construed as limiting the invention. Based on this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

In the above description, an example in which the determination device 30 creates an HUE value distribution profile for each of a plurality of colors based on the inspection image is shown. However, it is also possible to create an HUE value distribution profile for only one color. For example, by forming a HUE value distribution profile only for a color that is easy to appear in film thickness or film quality unevenness, the time required for good or bad determination can be shortened.

As described above, the present invention naturally includes various embodiments and the like not described herein. Therefore, the technical scope of the present invention is defined only by the specific matters of the invention as defined by the scope of the Applicable Patent Application.

1‧‧‧Checking device
10‧‧‧Lighting device
20‧‧‧Image acquisition device
30‧‧‧Determining device
31‧‧‧Contour Production Department
32‧‧‧Decision Department
33‧‧‧ Division
100‧‧‧Workpiece
200‧‧‧Check the image
201～204‧‧‧Divided area
210‧‧‧Abnormal area
D‧‧‧Image data
L‧‧‧Check light
P1, P2‧‧‧degree peaks
Pa‧‧‧ overall peaks
Pf‧‧‧degree peaks due to the distribution of HUE values in anomalous regions
W‧‧‧degree peak width

FIG. 1 is a schematic view showing a configuration of an inspection apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of a HUE value distribution profile of a good product. Fig. 3 is a schematic diagram showing an example of a HUE value distribution profile of a defective product. 4 is a schematic view showing another example of a HUE value distribution profile of a defective product. Fig. 5 is a schematic diagram showing the configuration of an inspection apparatus according to a second embodiment of the present invention. Fig. 6 is a schematic diagram showing an example of an inspection image. Fig. 7 is a schematic diagram showing an HUE value distribution profile of the inspection image shown in Fig. 6. FIG. 8 is a schematic diagram showing an example of dividing an inspection image. FIG. 9 is a schematic diagram showing an HUE value distribution profile of a divided region that does not include an abnormal region. FIG. 10 is a schematic diagram showing an HUE value distribution profile of a divided region including an abnormal region.

1‧‧‧Checking device

10‧‧‧Lighting device

20‧‧‧Image acquisition device

30‧‧‧Determining device

31‧‧‧Contour Production Department

32‧‧‧Decision Department

100‧‧‧Workpiece

D‧‧‧Image data

L‧‧‧Check light

Claims (6)

An inspection apparatus, comprising: an image acquisition device that acquires an inspection image of a film-formed workpiece; and a determination device that calculates a hue value for each point of the inspection image, and calculates a degree of the hue value Performing a chromatographic value distribution profile, and determining that the workpiece is a good product, and the number of peaks in the degree is determined when the width of the peak of the color value distribution profile is within a predetermined value range and the number of peaks is one. In the case of a plurality of cases, it is determined that the workpiece is defective. The inspection apparatus according to claim 1, wherein the determination means creates the hue value distribution profile for each of the plurality of colors based on the inspection image. The inspection apparatus according to claim 1 or 2, wherein the determination means divides the inspection image into a plurality of divided regions, and the hue value distribution contour is created for each of the divided regions And determining, in a case where the number of peaks of the hue value distribution profile is one in all the divided regions, determining that the workpiece is a good product, and the number of peaks of the hue value distribution profile in at least one of the divided regions In the case of a plurality of cases, it is determined that the workpiece is defective. An inspection method comprising the steps of: acquiring an inspection image of a film-formed workpiece; calculating a hue value for each point of the inspection image, and plotting the degree of the hue value to form a hue value a distribution profile; and a width of the peak of the degree of the distribution of the hue value in a range of a prescribed value When the number of peaks is one, it is determined that the workpiece is a good product, and when the number of peaks is plural, it is determined that the workpiece is defective. The inspection method according to claim 4, wherein the hue value distribution profile is separately produced for a plurality of colors based on the inspection image. The inspection method of claim 4 or 5, further comprising the step of dividing the inspection image into a plurality of divided regions, wherein the hue value distribution contour is created for each of the divided regions And determining, in a case where the number of peaks of the hue value distribution profile is one in all the divided regions, determining that the workpiece is a good product, and the number of peaks of the hue value distribution profile in at least one of the divided regions In the case of a plurality of cases, it is determined that the workpiece is defective.