Void inspection method, void inspection program, and void inspection system

Abstract

To provide a void inspection method, a void inspection program and a void inspection system capable of suppressing erroneous detection of a void in a solder ball.SOLUTION: The void inspection method includes a step 260 of generating an extracted void image 160 so that a void region 161 included in a solder ball region 121 is not extracted as the void region 161 regardless of a pixel value in a solder ball image 120 of an outer peripheral part 121a of the solder ball region 121.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a void inspection method, a void inspection program, and a void inspection system. [Background technology]

[0002] BACKGROUND ART Conventionally, an X-ray imaging system that generates an X-ray image of a substrate on which solder balls are arranged is known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses an X-ray imaging system including a fluoroscopic device that generates an X-ray image of a substrate on which solder balls are arranged, and an analysis device that analyzes the generated X-ray image. The X-ray imaging system described in the above-mentioned Patent Document 1 inspects the solder balls for abnormalities such as voids. Electronic components are mounted on the substrate on which the solder balls are arranged described in the above-mentioned Patent Document 1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-29975 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not described in Patent Document 1, when inspecting for voids in solder balls using a conventional X-ray imaging system such as that described in Patent Document 1, because electronic components are mounted on the board on which the solder balls are arranged, the X-ray image of the board will show brightness variations not only due to the voids but also due to the electronic components arranged on the board, which poses the problem of false detection of voids in the solder balls.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a void inspection method, a void inspection program, and a void inspection system that can suppress false detection of voids in solder balls. [Means for solving the problem]

[0007] In order to achieve the above object, a void inspection method in a first aspect of the present invention comprises the steps of generating a solder ball image by extracting a solder ball area from an X-ray image of a substrate on which solder balls are arranged, and generating an extracted void image of a void area contained in the solder ball area such that the outer periphery of the solder ball area is not extracted as a void area regardless of the pixel values ​​in the solder ball image.

[0008] In addition, in order to achieve the above object, the void inspection program in a second aspect of the present invention causes a computer to execute the following controls: control to generate a solder ball image by extracting a solder ball area from an X-ray image of a substrate on which solder balls are arranged; and control to generate an extracted void image of a void area contained in the solder ball area such that the outer periphery of the solder ball area is not extracted as a void area regardless of the pixel values ​​in the solder ball image.

[0009] In addition, in order to achieve the above-mentioned object, a void inspection system in a third aspect of the present invention comprises an X-ray imaging device that takes X-ray images of a substrate on which solder balls are arranged, a void inspection device that performs the following controls: generating an X-ray image of the X-rayed substrate, generating a solder ball image by extracting a solder ball area from the X-ray image, and generating an extracted void image of a void area included in the solder ball area such that the outer periphery of the solder ball area is not extracted as a void area regardless of the pixel values ​​in the solder ball image. [Effects of the Invention]

[0010] As a result of extensive research, the inventors of the present application have found that voids are almost absent in the peripheral portion of a solder ball region. Therefore, in the void inspection method of the first aspect, the void inspection program of the second aspect, and the void inspection system of the third aspect, as described above, an extracted void image is generated so that the peripheral portion of the solder ball region is not extracted as a void region regardless of the pixel values ​​in the solder ball image. As a result, when extracting a void region included in a solder ball region, even if the pixel values ​​of the peripheral portion of the solder ball region satisfy the conditions for extraction as a void region, the peripheral portion of the solder ball region, which is likely not a void in an electronic component, is not extracted as a void region. As a result, erroneous detection of voids in solder balls can be suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing the overall configuration of a void inspection system according to an embodiment of the present invention. [Figure 2] FIG. 2 illustrates a substrate on which solder balls are disposed according to an embodiment of the present invention. [Figure 3] 1A and 1B are diagrams for explaining images generated in a void inspection system according to an embodiment of the present invention. [Figure 4] 10A and 10B are diagrams for explaining generation of a void image by excluding the outer periphery corresponding portion and connected portion of the condition satisfying region from the extracted image in the void inspection system according to the embodiment of the present invention. [Figure 5] FIG. 1 is a diagram showing a flow of a void inspection method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0013] [Void inspection system] The configuration of a void inspection system 100 according to this embodiment will be described with reference to FIGS.

[0014] (Overall configuration of void inspection system) 1, the void inspection system 100 includes an X-ray imaging device 10, a void inspection device 20, and a solder ball inference device 30. The void inspection system 100 is a system that inspects voids in a plurality of solder balls 91 (bumps) (see FIG. 2) arranged on a substrate 90. The X-ray imaging device 10 and the solder ball inference device 30 are each connected to a control unit 21 (described later) of the void inspection device 20 so as to be able to communicate with each other.

[0015] As shown in Fig. 2, a plurality of solder balls 91 and an electronic component 92 are mounted on a substrate 90. The electronic component 92 is electrically connected to the substrate 90 by the plurality of solder balls 91. The plurality of solder balls 91 have approximately the same size. The plurality of solder balls 91 are arranged in a grid pattern on the substrate 90. In other words, the electronic component 92 is connected to the substrate 90 by a BGA (Ball Grid Array). The electronic component 92 is, for example, a chip capacitor.

[0016] (Configuration of X-ray equipment) 1, the X-ray imaging device 10 is an apparatus for X-ray imaging of a substrate 90 on which a plurality of solder balls 91 (see FIG. 2) are arranged. The X-ray imaging device 10 includes an X-ray irradiation unit 11 and an X-ray detection unit 12.

[0017] The X-ray irradiator 11 is configured to irradiate X-rays. The X-ray irradiator 11 includes an X-ray tube that irradiates X-rays when power is supplied from a power supply device (not shown). The X-ray irradiator 11 irradiates X-rays onto a substrate 90 on which a plurality of solder balls 91 (see FIG. 2) are arranged.

[0018] The X-ray detection unit 12 detects the X-rays irradiated from the X-ray irradiation unit 11. The X-ray detection unit 12 outputs an electrical signal corresponding to the detected X-rays. The X-ray detection unit 12 is, for example, an FPD (Flat Panel Detector). The electrical signal output from the X-ray detection unit 12 is input to a control unit 21 (described later) of the void inspection device 20.

[0019] (Configuration of void inspection device) 1, the void inspection device 20 is a device that inspects voids in solder balls 91 (see FIG. 2) arranged on a substrate 90, using an X-ray image 110 (see FIG. 3) of the substrate 90 on which a plurality of solder balls 91 are arranged, which is X-ray photographed by an X-ray imaging device 10. The void inspection device 20 includes a control unit 21 and a memory unit 22.

[0020] The control unit 21 controls a power supply device (not shown) to control the irradiation of X-rays by the X-ray irradiation unit 11. The control unit 21 includes, for example, a processor such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), or an FPGA (Field-Programmable Gate Array) configured for image processing, and a memory such as a ROM (Read Only Memory) or RAM (Random Access Memory).

[0021] The storage unit 22 stores various programs, parameters, etc. executed by the control unit 21. The storage unit 22 includes a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The storage unit 22 stores a void inspection program 40, which will be described later.

[0022] (Configuration of solder ball inference device) 1, the solder ball inference device 30 is a device that infers a portion that is a solder ball region 121 (see FIG. 3) in an X-ray image 110. The solder ball inference device 30 includes a control unit 31 and a storage unit 32.

[0023] The control unit 31 includes, for example, a processor such as a CPU, a GPU, or an FPGA configured for image processing, and memories such as a ROM and a RAM. The control unit 31 uses the learned model 32a, which will be described later and is stored in the storage unit 32, to generate a probability image (inference image) indicating the probability of a portion that is the solder ball region 121 (see FIG. 3) in the X-ray image 110 (see FIG. 3) input from the control unit 21 of the void inspection device 20.

[0024] The storage unit 32 stores various programs, various parameters, etc. that are executed by the control unit 31. The storage unit 32 includes, for example, a non-volatile memory such as an HDD or an SSD. The storage unit 32 stores a learned model 32a that has been previously learned by machine learning using a dataset of a large number of X-ray images 110 for a portion that is the solder ball region 121 (see FIG. 3) in the X-ray image 110 (see FIG. 3).

[0025] (Configuration of the control unit of the void inspection device for inspecting voids in solder balls) As shown in FIG. 1, the control unit 21 includes, as functional blocks, an X-ray image generation unit 21a, a ball image generation unit 21b, an extraction image generation unit 21c, a post-exclusion ball image generation unit 21d, a ball outer peripheral portion image generation unit 21e, a void image generation unit 21f, and an area ratio calculation unit 21g. The X-ray image generation unit 21a, the ball image generation unit 21b, the extraction image generation unit 21c, the post-exclusion ball image generation unit 21d, the ball outer peripheral portion image generation unit 21e, the void image generation unit 21f, and the area ratio calculation unit 21g are configured software-wise as functional blocks realized when the control unit 21 executes the void inspection program 40 stored in the storage unit 22. That is, the void inspection program 40 causes a computer (control unit 21) to execute the control performed by the X-ray image generation unit 21a, the ball image generation unit 21b, the extraction image generation unit 21c, the post-exclusion ball image generation unit 21d, the ball outer peripheral portion image generation unit 21e, the void image generation unit 21f, and the area ratio calculation unit 21g.

[0026] <X-ray image generation unit> As shown in Fig. 3, the X-ray image generating unit 21a (see Fig. 1) generates an X-ray image 110 of the X-rayed board 90 (see Fig. 1). Specifically, as shown in Fig. 1, the X-ray image generating unit 21a generates the X-ray image 110 (see Fig. 3) based on an electrical signal output from the X-ray detection unit 12 of the X-ray imaging device 10.

[0027] <Ball image generation section> As shown in FIG. 3, the ball image generation unit 21b (see FIG. 1) generates a solder ball image 120 by extracting a solder ball region 121 from an X-ray image 110. Specifically, as shown in FIG. 1, the ball image generation unit 21b inputs the X-ray image 110 (see FIG. 3) to the control unit 31 of the solder ball inference device 30. The control unit 31 of the solder ball inference device 30 uses a trained model 32a stored in the storage unit 32 of the solder ball inference device 30 to generate a probability image (inference image) indicating the probability of a portion that is a solder ball region 121 in the X-ray image 110 input from the control unit 21 of the void inspection device 20. The control unit 31 of the solder ball inference device 30 outputs the generated probability image to the control unit 21 of the void inspection device 20. The ball image generation unit 21b generates a solder ball image 120 (see FIG. 3) by binarizing the probability image (inference image) output from the control unit 31 of the solder ball inference device 30. 3, images other than the X-ray image 110 are shown as partially enlarged views of the solder ball region 121. For convenience of illustration, the ratio of the pixel size to the solder ball region 121 is shown larger than the actual ratio in FIG.

[0028] <Extracted image generation section> As shown in FIG. 3, the extraction image generation unit 21c (see FIG. 1) generates an extraction image 130 by extracting a condition satisfying region 131, which is a portion where the pixel values ​​in an image obtained by combining the X-ray image 110 and the solder ball image 120 satisfy the conditions for extraction as a void region 161. Specifically, the extraction image generation unit 21c generates a composite image by adding the pixel values ​​in the X-ray image 110 and the pixel values ​​in the solder ball image 120. Then, the extraction image generation unit 21c extracts the condition satisfying region 131 by binarizing this composite image based on the conditions for extraction as a void region 161. The conditions (pixel values) for extraction as a void region 161 are stored in advance in the storage unit 22.

[0029] <Post-exclusion ball image generation section> 3, the post-exclusion ball image generating unit 21d (see FIG. 1) generates a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 has been excluded. Specifically, the post-exclusion ball image generating unit 21d performs a contraction process to contract the solder ball region 121 so as to change pixels in which at least one of four neighboring pixels, which are four pixels adjacent above, below, left, and right to a pixel of interest in the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, is a non-solder ball region 122 into the non-solder ball region 122, thereby generating a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 has been excluded. Furthermore, the post-exclusion ball image generating unit 21d generates a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 is excluded by performing the contraction process a number of times corresponding to the Manhattan distance, which is set in advance to a value equal to or less than 3% of the diameter of the solder ball region 121. The Manhattan distance is the distance between two points on a two-dimensional coordinate system, measured as the sum of the differences between the coordinates of the two points.

[0030] <Ball Outer Part Image Generation Unit> 3, the ball periphery partial image generating unit 21e (see FIG. 1) generates a solder ball periphery partial image 150 by extracting only the periphery portion 121a of the solder ball region 121 in the solder ball image 120. Specifically, the ball periphery partial image generating unit 21e generates the solder ball periphery partial image 150 by subtracting the solder ball image 120 from the post-exclusion solder ball image 140.

[0031] <Void image generation unit> 3, the void image generating unit 21f (see FIG. 1) generates a void image 160 based on the solder ball image 120 and the extraction image 130, by excluding from the extraction image 130 a periphery corresponding portion 131a (see FIG. 4) of the condition satisfying region 131 that corresponds to the periphery corresponding portion 121a of the solder ball region 121. Specifically, based on the solder ball periphery portion image 150 and the extraction image 130, the void image generating unit 21f generates a void image 160 by excluding from the extraction image 130 the periphery corresponding portion 131a of the solder ball region 121 of the condition satisfying region 131. In other words, the void image generating unit 21f generates the extracted void image 160 such that the void region 161 included in the solder ball region 121 is not extracted as the void region 161 regardless of the pixel value in the solder ball image 120.

[0032] 4, the void image generating unit 21f (see FIG. 1) generates a void image 160 (see FIG. 3) by excluding from the extraction image 130 (see FIG. 3) not only the outer circumferential corresponding portion 131a of the condition satisfying region 131 but also the connected portion 131b connected to the outer circumferential corresponding portion 131a. Specifically, the void image generating unit 21f generates the void image 160 by excluding from the extraction image 130 not only the outer circumferential corresponding portion 131a of the condition satisfying region 131 but also the connected portion 131b connected to the outer circumferential corresponding portion 131a by connecting at least one pixel out of eight neighboring pixels, which are eight pixels adjacent to the periphery of the pixel of interest.

[0033] <Area ratio calculation section> 1, the area ratio calculation unit 21g calculates the area ratio of the void region 161 (see FIG. 3) to the area of ​​the solder ball region 121 (see FIG. 3) based on the solder ball image 120 (see FIG. 3) and the void image 160 (see FIG. 3). Specifically, the area ratio calculation unit 21g calculates the ratio of the area of ​​all the void regions 161 in the void image 160 to the total area of ​​the multiple solder balls 91 in the solder ball image 120.

[0034] [Void inspection method] The void inspection method according to this embodiment will be described with reference to FIGS.

[0035] (Step of generating an X-ray image) As shown in Fig. 5, first, step 210 is performed to generate an X-ray image 110. In step 210, as shown in Fig. 3, an X-ray image 110 of a substrate 90 (see Fig. 2) on which solder balls 91 (see Fig. 2) are arranged is generated, the X-ray image being X-rayed by an X-ray imaging device 10 (see Fig. 1). Step 210 is performed by an X-ray image generating unit 21a (see Fig. 1) of a control unit 21 (see Fig. 1) of a void inspection device 20 (see Fig. 1).

[0036] (Step of generating solder ball images) As shown in Fig. 5, next, step 220 is performed to generate a solder ball image 120. In step 220, as shown in Fig. 3, a solder ball image 120 is generated by extracting a solder ball region 121 from an X-ray image 110 of a substrate 90 (see Fig. 2) on which solder balls 91 (see Fig. 2) are arranged. Step 220 is performed by the ball image generation unit 21b (see Fig. 1) of the control unit 21 (see Fig. 1) of the void inspection device 20 (see Fig. 1).

[0037] (Step of generating an extracted image) As shown in Fig. 5, next, step 230 is performed to generate an extracted image 130. In step 230, as shown in Fig. 3, an extracted image 130 is generated by extracting a condition satisfying region 131, which is a portion where pixel values ​​in an image obtained by combining the X-ray image 110 and the solder ball image 120 satisfy the condition for extraction as a void region 161, as shown in Fig. 3. Step 230 is performed by the extracted image generating unit 21c (see Fig. 1) of the control unit 21 (see Fig. 1) of the void inspection device 20 (see Fig. 1).

[0038] (Step to generate solder ball image after exclusion) As shown in Fig. 5, next, step 240 is performed to generate a post-exclusion solder ball image 140. In step 240, a post-exclusion solder ball image 140 is generated by excluding the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, as shown in Fig. 3. Specifically, in step 240, a contraction process is performed to contract the solder ball region 121 so that pixels in which at least one of four neighboring pixels, which are four pixels adjacent above, below, left, and right to a pixel of interest in the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, are in the non-solder ball region 122, are changed to the non-solder ball region 122, thereby generating a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 is excluded. That is, the contraction process for contracting the solder ball region 121 is performed so as to change pixels (outermost pixels) adjacent to pixels of the non-solder ball region 122 on either the top, bottom, left, or right of the solder ball region 121 in the solder ball image 120 into the non-solder ball region 122. Also, in step 240, the contraction process is performed a number of times corresponding to the Manhattan distance, which is set in advance to a value equal to or less than 3% of the diameter of the solder ball region 121, to generate a post-exclusion solder ball image 140 in which the outer periphery portion 121a of the solder ball region 121 in the solder ball image 120 has been excluded. Step 240 is performed by the post-exclusion ball image generation unit 21d (see FIG. 1) of the control unit 21 (see FIG. 1) of the void inspection device 20 (see FIG. 1).

[0039] (Step of generating an image of the solder ball periphery) As shown in Fig. 5, next, step 250 is performed to generate a solder ball periphery partial image 150. In step 250, as shown in Fig. 3, a solder ball periphery partial image 150 is generated by extracting only the periphery portion 121a of the solder ball region 121 in the solder ball image 120. Specifically, in step 250, the solder ball periphery partial image 150 is generated by subtracting the solder ball image 120 from the post-exclusion solder ball image 140. Step 250 is performed by the ball periphery partial image generating unit 21e (see Fig. 1) of the control unit 21 (see Fig. 1) of the void inspection device 20 (see Fig. 1).

[0040] (Step of generating a void image) As shown in FIG. 5, next, step 260 is performed to generate a void image 160. In step 260, as shown in FIG. 3, based on the solder ball image 120 and the extraction image 130, a void image 160 is generated by excluding from the extraction image 130 a periphery corresponding portion 131a (see FIG. 4) of the condition satisfying region 131 that corresponds to the periphery corresponding portion 121a of the solder ball region 121. Specifically, in step 260, based on the solder ball periphery portion image 150 and the extraction image 130, a void image 160 is generated by excluding from the extraction image 130 the periphery corresponding portion 131a of the solder ball region 121 of the condition satisfying region 131. That is, in step 260, an extracted void image 160 is generated such that the void region 161 included in the solder ball region 121 is not extracted as the void region 161 regardless of the pixel value in the solder ball image 120. Step 260 is performed by the void image generating unit 21f (see FIG. 1) of the control unit 21 (see FIG. 1) of the void inspection device 20 (see FIG. 1).

[0041] In step 260, as shown in Fig. 4, a void image 160 (see Fig. 3) is generated by excluding from extraction image 130 (see Fig. 3) not only circumferential corresponding portion 131a of condition satisfying region 131 but also connected portion 131b connected to circumferential corresponding portion 131a. Specifically, in step 260, void image 160 is generated by excluding from extraction image 130 not only circumferential corresponding portion 131a of condition satisfying region 131 but also connected portion 131b connected to circumferential corresponding portion 131a by connecting at least one pixel out of eight neighboring pixels, which are eight pixels adjacent to the periphery of the pixel of interest. Note that connected portion 131b connected to circumferential corresponding portion 131a of condition satisfying region 131 includes pixels directly adjacent to the pixels of circumferential corresponding portion 131a of condition satisfying region 131, but also pixels indirectly adjacent to the pixels of circumferential corresponding portion 131a of condition satisfying region 131 via pixels directly adjacent to the pixels of circumferential corresponding portion 131a of condition satisfying region 131.

[0042] (Step of calculating the area ratio of the void region) 5, next, step 270 is performed to calculate the area ratio of the void region 161. In step 270, the area ratio of the void region 161 (see FIG. 3) to the area of ​​the solder ball region 121 (see FIG. 3) is calculated based on the solder ball image 120 (see FIG. 3) and the void image 160 (see FIG. 3). Step 270 is performed by the area ratio calculation unit 21g (see FIG. 1) of the control unit 21 (see FIG. 1) of the void inspection device 20 (see FIG. 1).

[0043] [Effects of this embodiment] In this embodiment, the following effects can be obtained.

[0044] (Effect of void inspection method) As described above, the void inspection method of this embodiment includes step 220 of generating a solder ball image 120 in which a solder ball region 121 is extracted from an X-ray image 110 of a substrate 90 on which solder balls 91 are arranged, and step 260 of generating an extracted void image 160 in which a void region 161 included in the solder ball region 121 is not extracted as the void region 161 regardless of the pixel values ​​in the solder ball image 120. As a result, when extracting the void region 161 included in the solder ball region 121, even if the pixel values ​​of the outer periphery 121a of the solder ball region 121 satisfy the condition for extraction as the void region 161, the outer periphery 121a of the solder ball region 121 is not extracted as the void region 161, as this is a portion that is unlikely to be a void in an electronic component or the like. As a result, erroneous detection of voids in the solder balls 91 can be suppressed.

[0045] Furthermore, the void inspection method of this embodiment has the following configuration, which provides further advantages.

[0046] That is, as described above, the void inspection method of this embodiment further includes step 230 of generating an extracted image 130 in which a condition satisfying region 131 is extracted, which is a portion in an image obtained by combining the X-ray image 110 and the solder ball image 120, where the pixel values ​​satisfy the condition for extraction as a void region 161. Then, step 260 of generating a void image 160 is a step of generating a void image 160 in which, based on the solder ball image 120 and the extracted image 130, a periphery corresponding portion 131a of the condition satisfying region 131 is excluded from the extracted image 130, the periphery corresponding portion 131a corresponding to the periphery portion 121a of the solder ball region 121. This makes it possible to generate a void image 160 in which the periphery corresponding portion 131a, which is a portion that is highly unlikely to be a void in an electronic component or the like, is excluded from the extracted image 130. As a result, when extracting a void region 161 contained in a solder ball region 121, even if the pixel values ​​of the peripheral portion 121a of the solder ball region 121 satisfy the conditions for extraction as a void region 161, it is possible to easily realize a configuration in which the peripheral portion 121a of the solder ball region 121, which is an area that is unlikely to be a void of an electronic component or the like, is not extracted as a void region 161.

[0047] As described above, the void inspection method of this embodiment further includes step 250 of generating a solder ball periphery partial image 150 by extracting only the periphery portion 121a of the solder ball region 121 in the solder ball image 120. Step 260 of generating a void image 160 is a step of generating a void image 160 by excluding the periphery corresponding portion 131a of the solder ball region 121 in the condition satisfying region 131 from the extraction image 130, based on the solder ball periphery partial image 150 and the extraction image 130. This makes it possible to easily exclude from the extraction image 130 the periphery corresponding portion 131a of the solder ball region 121 in the condition satisfying region 131, based on the solder ball periphery partial image 150 by extracting only the periphery portion 121a of the solder ball region 121.

[0048] As described above, the void inspection method of this embodiment further includes step 240 of generating a post-exclusion solder ball image 140 by excluding the outer periphery portion 121a of the solder ball region 121 in the solder ball image 120. Step 250 of generating a solder ball outer periphery partial image 150 is a step of generating the solder ball outer periphery partial image 150 by subtracting the solder ball image 120 from the post-exclusion solder ball image 140. This makes it possible to easily generate the solder ball outer periphery partial image 150 by subtracting the solder ball image 120 from the post-exclusion solder ball image 140 by excluding the outer periphery portion 121a of the solder ball region 121 in the solder ball image 120.

[0049] Furthermore, in the void inspection method of this embodiment, as described above, step 240 of generating the post-exclusion solder ball image 140 is a step of generating the post-exclusion solder ball image 140 in which the peripheral portion 121a of the solder ball region 121 in the solder ball image 120 has been excluded, by performing a shrinking process to shrink the solder ball region 121 so that pixels in which at least one of the four neighboring pixels, which are the four pixels adjacent above, below, left, and right of the pixel of interest in the peripheral portion 121a of the solder ball region 121 in the solder ball image 120, are the non-solder ball region 122, are changed into the non-solder ball region 122. As a result, by performing the contraction process for contracting the solder ball region 121 so as to change pixels in which at least one of the four neighboring pixels, which are the four pixels adjacent above, below, left, and right of the pixel of interest in the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, is a non-solder ball region 122, to a non-solder ball region 122, it is possible to prevent the shape of the solder ball region 121 from changing from a round shape to a shape other than a round shape when contracting the solder ball region 121. In other words, it is possible to prevent the round shape of the solder ball region 121 in the post-exclusion solder ball image 140 from differing from the round shape of the solder ball region 121 in the solder ball image 120. As a result, by subtracting the solder ball image 120 from the post-exclusion solder ball image 140, it is possible to generate a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 has been excluded in a balanced manner over the entire periphery.In addition, when the shrinking process for shrinking the solder ball region 121 is performed so as to change a pixel in which at least one of the eight neighboring pixels, which are eight pixels adjacent to the pixel of interest in the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, is a non-solder ball region 122, to a non-solder ball region 122, a pixel in which at least one of the four pixels diagonally adjacent to the pixel of interest is a non-solder ball region 122 will also be changed to a non-solder ball region 122, and as a result, when the solder ball region 121 is shrunk, the shape of the solder ball region 121 is likely to change from round to a shape other than round.

[0050] Furthermore, in the void inspection method of this embodiment, as described above, step 240 of generating the post-exclusion solder ball image 140 is a step of performing the contraction process a number of times corresponding to a preset Manhattan distance to generate the post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 is excluded. Here, the Manhattan distance is the distance between two points on a two-dimensional coordinate system measured as the sum of the differences between the coordinates of the two points. Therefore, it is a distance concept that is easy to use when the distances between two points are equal, such as the distances between a pixel of interest and each of four neighboring pixels, which are the four pixels adjacent to the pixel of interest on the top, bottom, left, and right. As a result, by performing the shrinking process for shrinking the solder ball region 121 a number of times corresponding to a preset Manhattan distance, it is possible to easily perform the shrinking process for shrinking the solder ball region 121 so as to change a pixel in which at least one of the four neighboring pixels, which are the four pixels adjacent to the pixel of interest above, below, left, and right in the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120, is a non-solder ball region 122 into a non-solder ball region 122.

[0051] Furthermore, in the void inspection method of this embodiment, as described above, step 240 of generating the post-exclusion solder ball image 140 is a step of generating the post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 is excluded by performing the contraction process a number of times corresponding to the Manhattan distance set to a value equal to or less than 3% of the diameter of the solder ball region 121. This prevents the number of contraction processes for contracting the solder ball region 121 from becoming excessively large, making it possible to prevent the generation of a post-exclusion solder ball image 140 in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 is excessively excluded.

[0052] Furthermore, in the void inspection method of this embodiment, as described above, step 260 of generating void image 160 is a step of generating void image 160 by excluding, from extraction image 130, periphery corresponding portion 131a of condition satisfying region 131 and connecting portion 131b connected to periphery corresponding portion 131a. This makes it possible to generate void image 160 by excluding, from extraction image 130, periphery corresponding portion 131a and connecting portion 131b connected to periphery corresponding portion 131a, which, like periphery corresponding portion 131a, is a portion that is likely not to be a void in an electronic component or the like. Compared to generating void image 160 by excluding only periphery corresponding portion 131a of condition satisfying region 131 from extraction image 130, erroneous detection of voids in solder ball 91 can be further suppressed. Furthermore, by excluding the connecting portion 131b in addition to the outer periphery corresponding portion 131a from the extraction image 130, it is possible to generate a void image 160 from which portions that are likely not to be voids are sufficiently excluded from the extraction image 130, even when the size of the outer periphery corresponding portion 131a is made relatively small. This allows the size of the outer periphery corresponding portion 131a to be made relatively small. As a result, when generating the void image 160, it is possible to prevent the exclusion of not only portions that are likely not to be voids but also portions that are likely to be voids from the extraction image 130.

[0053] Furthermore, in the void inspection method of this embodiment, as described above, step 260 for generating the void image 160 is a step for generating the void image 160 by excluding from the extracted image 130 the outer periphery corresponding portion 131a of the condition satisfying region 131 and the connected portion 131b connected to the outer periphery corresponding portion 131a by connecting at least any of the eight neighboring pixels, which are eight pixels surrounding the pixel of interest. This allows the size of the connected portion 131b connected to the outer periphery corresponding portion 131a to be larger than when the connected portion 131b is a portion connected to the outer periphery corresponding portion 131a by connecting at least any of the four neighboring pixels, which are four pixels adjacent to the pixel of interest above, below, left, and right. This allows the size of the outer periphery corresponding portion 131a to be smaller than when the connected portion 131b is a portion connected to the outer periphery corresponding portion 131a by connecting at least any of the four neighboring pixels, which are four pixels adjacent to the pixel of interest above, below, left, and right. As a result, when generating the void image 160, it is possible to further prevent not only parts that are likely not to be voids but also parts that are likely to be voids from being excluded from the extracted image 130.

[0054] (Effects of void inspection program) As described above, the void inspection program 40 of this embodiment causes a computer to execute the following controls: control to generate a solder ball image 120 in which a solder ball region 121 is extracted from an X-ray image 110 of a substrate 90 on which solder balls 91 are arranged; and control to generate an extracted void image 160 in which a void region 161 included in the solder ball region 121 is not extracted as the void region 161 regardless of the pixel values ​​in the solder ball image 120. As a result, similar to the above-described void inspection method, when extracting the void region 161 included in the solder ball region 121, even if the pixel values ​​of the outer periphery 121a of the solder ball region 121 satisfy the condition for extraction as the void region 161, the outer periphery 121a of the solder ball region 121 is not extracted as the void region 161, because this portion is unlikely to be a void in an electronic component or the like. As a result, similar to the above-described void inspection method, erroneous detection of voids in the solder balls 91 can be suppressed.

[0055] (Effects of void inspection system) As described above, the void inspection system 100 of this embodiment comprises an X-ray imaging device 10 that takes an X-ray image of a substrate 90 on which solder balls 91 are arranged, a void inspection device 20 that performs the following controls: generating an X-ray image 110 of the X-rayed substrate 90; generating a solder ball image 120 by extracting a solder ball region 121 from the X-ray image 110; and generating an extracted void image 160 for a void region 161 included in the solder ball region 121 such that the peripheral portion 121a of the solder ball region 121 is not extracted as the void region 161 regardless of the pixel value in the solder ball image 120. As a result, similar to the above-described void inspection method and void inspection system, when extracting a void region 161 contained in the solder ball region 121, even if the pixel values ​​of the outer peripheral portion 121a of the solder ball region 121 satisfy the conditions for extraction as the void region 161, the outer peripheral portion 121a of the solder ball region 121, which is a portion that is unlikely to be a void in an electronic component or the like, is not extracted as the void region 161. As a result, similar to the above-described void inspection method and void inspection system, erroneous detection of voids in the solder ball 91 can be suppressed.

[0056] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0057] For example, in the above embodiment, an example was shown in which a solder ball periphery partial image 150 was generated by extracting only the periphery portion 121a of the solder ball region 121 in the solder ball image 120, and a void image 160 was generated by excluding the periphery corresponding portion 131a of the solder ball region 121 of the condition satisfying region 131 from the extraction image 130 based on the solder ball periphery partial image 150 and the extraction image 130, but the present invention is not limited to this. In the present invention, a void image may be generated by excluding the periphery corresponding portion of the solder ball region of the condition satisfying region from the extraction image based on an image other than the solder ball periphery partial image and the extraction image.

[0058] Furthermore, in the above embodiment, an example was shown in which a post-exclusion solder ball image 140 is generated by excluding the outer periphery portion 121a of the solder ball region 121 in the solder ball image 120, and the solder ball outer periphery partial image 150 is generated by subtracting the solder ball image 120 from the post-exclusion solder ball image 140, but the present invention is not limited to this. In the present invention, the solder ball outer periphery partial image may be generated by a method other than subtracting the solder ball image from the post-exclusion solder ball image.

[0059] Furthermore, in the above embodiment, an example was shown in which a post-exclusion solder ball image 140 in which the peripheral portion 121a of the solder ball region 121 in the solder ball image 120 has been generated by performing a contraction process to contract the solder ball region 121 so as to change pixels in which at least one of four neighboring pixels, which are four pixels adjacent above, below, left, and right of a pixel of interest in the peripheral portion 121a of the solder ball region 121 in the solder ball image 120, that are in the non-solder ball region 122, into the non-solder ball region 122, but the present invention is not limited to this. In the present invention, a post-exclusion solder ball image in which the peripheral portion of the solder ball region in the solder ball image has been excluded may be generated by performing a contraction process to contract the solder ball region so as to change pixels in which at least one of eight neighboring pixels, which are eight pixels adjacent around the pixel of interest in the peripheral portion of the solder ball region in the solder ball image, that are in the non-solder ball region, into a non-solder ball region.

[0060] Furthermore, in the above embodiment, an example was shown in which the contraction process was performed a number of times corresponding to a preset Manhattan distance to generate the post-exclusion solder ball image 140 in which the outer periphery 121a of the solder ball region 121 in the solder ball image 120 was excluded, but the present invention is not limited to this. In the present invention, a post-exclusion solder ball image in which the outer periphery of the solder ball region in the solder ball image was excluded may be generated by performing the contraction process a number of times corresponding to a newly set Manhattan distance when generating the post-exclusion solder ball image.

[0061] Furthermore, in the above embodiment, an example was shown in which a post-exclusion solder ball image 140 was generated in which the outer peripheral portion 121a of the solder ball region 121 in the solder ball image 120 was excluded by performing the contraction process a number of times corresponding to the Manhattan distance set to a value equal to or less than 3% of the diameter of the solder ball region 121, but the present invention is not limited to this. In the present invention, a post-exclusion solder ball image in which the outer peripheral portion of the solder ball region in the solder ball image was excluded may also be generated by performing the contraction process a number of times corresponding to the Manhattan distance set to a value greater than 3% of the diameter of the solder ball region.

[0062] In the above embodiment, an example was shown in which void image 160 was generated by excluding, from extraction image 130, outer circumferential corresponding portion 131a of condition satisfying region 131 as well as connected portion 131b connected to the outer circumferential corresponding portion, but the present invention is not limited to this. In the present invention, a post-exclusion void image may be generated by excluding, from the extraction image, only the outer circumferential corresponding portion of the condition satisfying region.

[0063] Furthermore, in the above embodiment, an example was shown in which a void image 160 was generated by excluding from the extracted image 130 the peripheral corresponding portion 131a of the condition satisfying region 131 and the connected portion 131b connected to the peripheral corresponding portion 131a by connecting at least any of the eight neighboring pixels, which are the eight pixels adjacent to the periphery of the pixel of interest, but the present invention is not limited to this. In the present invention, a void image may be generated by excluding from the extracted image the peripheral corresponding portion of the condition satisfying region and the connected portion connected to the peripheral corresponding portion by connecting at least any of the four neighboring pixels, which are the four pixels adjacent above, below, left, and right of the pixel of interest.

[0064] Furthermore, in the above embodiment, an example was shown in which the void inspection system 100 was equipped with the solder ball inference device 30, but the present invention is not limited to this. In the present invention, the void inspection system does not have to be equipped with the solder ball inference device. In that case, the void inspection system may be provided outside the void inspection system, or the control unit of the void inspection device may be configured to also have the functions of the solder ball inference device.

[0065] In the above embodiment, an example was shown in which the void inspection system 100 inspects voids in a plurality of solder balls 91 having approximately the same size, but the present invention is not limited to this. In the present invention, the void inspection system may inspect voids in a plurality of solder balls having different sizes.

[0066] In the above embodiment, an example has been shown in which the void inspection system 100 inspects voids in a plurality of solder balls 91 arranged on a substrate 90, but the present invention is not limited to this. In the present invention, the void inspection system may inspect voids in one solder ball arranged on a substrate.

[0067] Furthermore, in the above embodiment, an example has been shown in which the control unit 31 of the solder ball inference device 30 uses the trained model 32a stored in the memory unit 32 of the solder ball inference device 30 to generate a probability image (inference image) indicating the probability of a portion being a solder ball region 121 in the X-ray image 110 input from the control unit 21 of the void inspection device 20, but the present invention is not limited to this. In the present invention, the control unit of the void inspection device may use the trained model stored in the memory unit of the void inspection device to generate a probability image (inference image) indicating the probability of a portion being a solder ball region in the X-ray image.

[0068] Furthermore, in the above embodiment, an example was shown in which an extracted image 130 is generated by extracting a condition satisfying region 131, which is a portion where the pixel values ​​in an image obtained by combining the X-ray image 110 and the solder ball image 120 satisfy the conditions for extraction as a void region 161, and a void image 160 is generated by excluding from the extracted image 130, based on the solder ball image 120 and the extracted image 130, a periphery corresponding portion 131a of the solder ball region 121 in the condition satisfying region 131, but the present invention is not limited to this. In the present invention, an extracted void image may be generated directly from the solder ball image without generating an extracted image, so that a void region included in the solder ball region is not extracted as a void region regardless of the pixel values ​​in the solder ball image.

[0069] [Aspect] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0070] (Item 1) generating a solder ball image by extracting solder ball regions from an X-ray image of a substrate on which solder balls are arranged; A void inspection method comprising a step of generating an extracted void image of a void area contained in the solder ball area such that the outer periphery of the solder ball area is not extracted as the void area regardless of the pixel values ​​in the solder ball image.

[0071] (Item 2) generating an extracted image by extracting a condition-satisfying region, which is a portion in an image obtained by combining the X-ray image and the solder ball image, where the pixel value satisfies the condition for extraction as the void region; Item 2. A void inspection method according to item 1, wherein the step of generating the void image is a step of generating the void image from the extraction image based on the solder ball image and the extraction image, excluding a peripheral corresponding portion of the condition-satisfying region that corresponds to the peripheral portion of the solder ball region.

[0072] (Item 3) generating a solder ball periphery portion image by extracting only the periphery portion of the solder ball region in the solder ball image; Item 3. A void inspection method according to item 2, wherein the step of generating the void image is a step of generating the void image from the extracted image based on the solder ball outer periphery portion image and the extracted image, excluding the outer periphery corresponding portion of the solder ball region in the condition satisfying region.

[0073] (Item 4) generating a solder ball image after excluding the outer periphery of the solder ball region in the solder ball image; 4. A void inspection method according to item 3, wherein the step of generating the solder ball outer periphery partial image is a step of generating the solder ball outer periphery partial image by subtracting the solder ball image from the excluded solder ball image.

[0074] (Item 5) Item 5. A void inspection method according to item 4, wherein the step of generating the post-exclusion solder ball image is a step of performing a shrinking process to shrink the solder ball area so that at least one of four neighboring pixels, which are four pixels adjacent above, below, left, and right to a pixel of interest in the peripheral part of the solder ball area in the solder ball image, is changed into the non-solder ball area, thereby generating the post-exclusion solder ball image excluding the peripheral part of the solder ball area in the solder ball image.

[0075] (Item 6) 6. A void inspection method according to item 5, wherein the step of generating the post-exclusion solder ball image is a step of generating the post-exclusion solder ball image by performing the shrinking process a number of times corresponding to a preset Manhattan distance, thereby excluding the outer periphery of the solder ball region in the solder ball image.

[0076] (Item 7) Item 7. The void inspection method according to item 6, wherein the step of generating the post-exclusion solder ball image is a step of generating the post-exclusion solder ball image by performing the shrinking process a number of times corresponding to the Manhattan distance set to a value of 3% or less of the diameter of the solder ball area, thereby excluding the outer periphery of the solder ball area in the solder ball image.

[0077] (Item 8) 8. A void inspection method according to any one of items 2 to 7, wherein the step of generating the void image is a step of generating the void image by excluding the outer periphery corresponding portion of the condition-satisfying region from the extracted image as well as the connected portion connected to the outer periphery corresponding portion.

[0078] (Item 9) Item 9. A void inspection method according to Item 8, wherein the step of generating the void image is a step of generating the void image by excluding from the extracted image the peripheral corresponding portion of the condition-satisfying region as well as the connected portion connected to the peripheral corresponding portion by connecting at least any pixel among eight neighboring pixels, which are eight pixels adjacent to the pixel of interest.

[0079] (Item 10) A control for generating a solder ball image by extracting a solder ball area from an X-ray image of a substrate on which the solder balls are arranged; A void inspection program that causes a computer to execute the following: control to generate an extracted void image of a void area included in the solder ball area so that the outer periphery of the solder ball area is not extracted as the void area regardless of the pixel values ​​in the solder ball image.

[0080] (Item 11) an X-ray imaging device for X-raying the substrate on which the solder balls are arranged; A void inspection system comprising a void inspection device that performs the following controls: generating an X-ray image of the substrate photographed with X-rays; generating a solder ball image by extracting a solder ball region from the X-ray image; and generating an extracted void image of the void region included in the solder ball region such that the outer periphery of the solder ball region is not extracted as the void region regardless of the pixel value in the solder ball image. [Explanation of symbols]

[0081] 10 X-ray equipment 20 Void inspection equipment 40 Void Inspection Program 90 PCB 91 Solder balls 100 Void Inspection System 110 X-ray images 121 Solder Ball Area 121a Outer periphery (of the solder ball area) 122 Non-solder ball area 120 Solder Ball Images 130 Extracted Images 131 Condition Satisfaction Region 131a (corresponding to the outer peripheral portion of the solder ball region in the condition satisfying region) 131b Connecting part 140 Solder ball image after removal 150 Solder ball outer periphery image 160 Void Images 161 Void Area

Claims

1. generating a solder ball image by extracting solder ball regions from an X-ray image of a substrate on which solder balls are arranged; A void inspection method comprising a step of generating an extracted void image of a void area contained in the solder ball area such that the outer periphery of the solder ball area is not extracted as the void area regardless of the pixel values ​​in the solder ball image.

2. generating an extracted image by extracting a condition-satisfying region, which is a portion in an image obtained by combining the X-ray image and the solder ball image, where the pixel value satisfies the condition for extraction as the void region; 2. The void inspection method according to claim 1, wherein the step of generating the void image is a step of generating the void image from the extraction image based on the solder ball image and the extraction image, excluding a peripheral corresponding portion of the condition-satisfying area that corresponds to the peripheral portion of the solder ball area.

3. generating a solder ball periphery portion image by extracting only the periphery portion of the solder ball region in the solder ball image; 3. The void inspection method according to claim 2, wherein the step of generating the void image is a step of generating the void image by excluding the outer periphery corresponding portion of the solder ball region in the condition-satisfying region from the extracted image based on the solder ball outer periphery portion image and the extracted image.

4. generating a solder ball image after excluding the outer periphery of the solder ball region in the solder ball image; 4. The void inspection method according to claim 3, wherein the step of generating the solder ball outer periphery partial image is a step of generating the solder ball outer periphery partial image by subtracting the solder ball image from the post-exclusion solder ball image.

5. 5. The void inspection method according to claim 4, wherein the step of generating the post-exclusion solder ball image is a step of performing a shrinking process to shrink the solder ball area so that at least one of four neighboring pixels, which are four pixels adjacent above, below, left, and right to a pixel of interest in the peripheral part of the solder ball area in the solder ball image, is changed into the non-solder ball area, thereby generating the post-exclusion solder ball image excluding the peripheral part of the solder ball area in the solder ball image.

6. 6. The void inspection method according to claim 5, wherein the step of generating the post-exclusion solder ball image is a step of generating the post-exclusion solder ball image by performing the contraction process a number of times corresponding to a predetermined Manhattan distance, thereby excluding the outer peripheral portion of the solder ball region in the solder ball image.

7. 7. The void inspection method according to claim 6, wherein the step of generating the post-exclusion solder ball image is a step of generating the post-exclusion solder ball image by performing the shrinkage process a number of times corresponding to the Manhattan distance, which is set to a value of 3% or less of the diameter of the solder ball area, thereby excluding the outer peripheral portion of the solder ball area in the solder ball image.

8. 3. The void inspection method according to claim 2, wherein the step of generating the void image is a step of generating the void image by excluding the outer periphery corresponding portion of the condition-satisfying region from the extracted image as well as the connected portion connected to the outer periphery corresponding portion.

9. 9. The void inspection method according to claim 8, wherein the step of generating the void image is a step of generating the void image by excluding from the extracted image the peripheral corresponding portion of the condition-satisfying area as well as the connected portion connected to the peripheral corresponding portion by connecting at least any pixel among eight neighboring pixels, which are eight pixels adjacent to the pixel of interest.

10. A control to generate a solder ball image by extracting a solder ball area from an X-ray image of a substrate on which the solder balls are arranged; A void inspection program that causes a computer to execute the following: control to generate an extracted void image of a void area included in the solder ball area so that the outer periphery of the solder ball area is not extracted as the void area regardless of the pixel values ​​in the solder ball image.

11. an X-ray imaging device for X-raying a substrate on which solder balls are arranged; A void inspection system comprising a void inspection device that performs the following controls: generating an X-ray image of the substrate photographed with X-rays; generating a solder ball image by extracting a solder ball region from the X-ray image; and generating an extracted void image of a void region included in the solder ball region such that the outer periphery of the solder ball region is not extracted as the void region regardless of the pixel values ​​in the solder ball image.

Images