JP6115338B2 - Inspection device, inspection method, and inspection program - Google Patents

Description

  The present invention relates to an inspection apparatus, an inspection method, and an inspection program, for example, an inspection apparatus, an inspection method, and an inspection program for inspecting whether or not a terminal and a substrate are bonded.

  An automatic visual inspection device is used to determine the quality of the bonding state between the package terminals and the substrate. In the automatic appearance inspection apparatus, inspection information such as setting of inspection areas and acceptance / rejection determination criteria is created in advance using design information in CAD (Computer Aided Design).

  As an inspection method for components mounted on a substrate, an inspection method for inspecting the presence or absence of terminal floating from a frequency distribution of terminal heights is known (for example, Patent Document 1). Further, as a method for inspecting solder printed on a substrate, a method for inspecting a circumscribed rectangle of a detected connected component as an inspection frame is known (for example, Patent Document 2). As a method for inspecting the appearance of a chip component, it is known that an image is expanded or contracted (for example, Patent Document 3).

JP 2012-53016 A JP 2002-286430 A JP 2002-243655 A

  The inspection using the automatic appearance inspection apparatus is complicated because inspection information is created in advance. When an operator visually inspects, a terminal joint failure may be overlooked.

  The purpose of the inspection apparatus, inspection method, and inspection program is to appropriately determine a bonding failure.

  Image processing in which a plurality of patterns each including a terminal are extracted from an image obtained by bonding a plurality of terminals to a base, the plurality of patterns are subjected to pixel expansion processing, and a concatenated pattern among the plurality of patterns is used as a determination pattern A unit, a measurement unit for measuring the height of a terminal included in the determination pattern for each of the determination patterns, and a determination unit for determining the quality of the joint based on the measured height for each of the determination patterns; An inspection apparatus characterized by comprising:

  Extracting a plurality of patterns each including a terminal from an image obtained by joining a plurality of terminals to electrodes, subjecting the plurality of patterns to pixel expansion processing, and using a connected pattern among the plurality of patterns as a determination pattern; Measuring the height of the terminal included in the determination pattern for each of the determination patterns, and determining whether the bonding is good or not based on the measured height for each of the determination patterns. Use characteristic inspection methods.

  A computer extracts a plurality of patterns each including a terminal from an image obtained by bonding a plurality of terminals to electrodes, performs pixel expansion processing on the plurality of patterns, and determines a connected pattern among the plurality of patterns as a determination pattern An inspection program for measuring the height of a terminal included in the determination pattern for each determination pattern, and determining whether the bonding is good or not based on the measured height for each determination pattern. Use.

  According to this inspection apparatus, inspection method, and inspection program, it is possible to appropriately determine a bonding failure.

FIG. 1A is a plan view of an electronic component, and FIG. 1B is a perspective view for explaining a mounting failure. FIG. 2 is a diagram showing pass / fail of type A and B terminals. FIG. 3 is a perspective view of a substrate on which components are mounted. FIG. 4 is a block diagram illustrating the inspection system used in the first embodiment. FIG. 5A is a block diagram of a computer. FIG. 5B is a functional block diagram of the inspection apparatus according to the first embodiment. FIG. 6 is a flowchart showing processing performed by the computer. FIG. 7 is a flowchart showing the process of step S10. FIG. 8A and FIG. 8B are diagrams showing image processing. FIG. 9A and FIG. 9B are diagrams showing image processing. FIGS. 10A to 10D are diagrams illustrating an example of pixel expansion processing. FIG. 11 is a flowchart showing the process of step S12. FIG. 12A and FIG. 12B are diagrams showing the measurement process. FIG. 13 is a flowchart showing the process of step S14. FIG. 14A is a diagram showing an example of the height measurement result, and FIG. 14B is a diagram showing an example of the height frequency.

  Hereinafter, embodiments will be described with reference to the drawings.

  Examples of electronic components to be inspected and defective examples in the first embodiment will be described. FIG. 1A is a plan view of an electronic component, and FIG. 1B is a perspective view for explaining a mounting failure. With reference to FIG. 1A, the component 30 includes a package 32 and a terminal 34. A plurality of terminals 34 are led out from the side of the package 32. A plurality of terminals 34 are led out per side of the package. In the package 32, the chip is sealed with a resin such as an epoxy resin. The terminal 34 is, for example, a lead, mainly including a metal such as Cu, and is electrically connected to the sealed chip. In the component 30, for example, terminals 34 may be provided on four sides of the package. The component 30 is mounted on the base body 40. The base 40 is, for example, a printed board. An electrode 42 mainly containing a metal such as Cu is formed on the surface of the substrate 40. The terminal 34 is joined to the electrode 42 using a solder 36.

  With reference to FIG. 1B, the component 30 is joined to the base body 40. The terminal 34 is joined to the electrode 42 using a solder 36. The type A terminal 34 is sufficiently bonded to the electrode 42. In the type B terminal 34, the solder 36 is not sufficiently melted. For this reason, the terminal 34 is not sufficiently bonded to the electrode 42. Since the solder 36 is not melted, the type B terminal 34 is raised above the type A terminal 34.

  FIG. 2 is a diagram showing pass / fail of type A and B terminals. Type A is good and type B is bad. When the terminal 34 is observed from above, the solder of the type B looks smaller than the type A, but other differences are small. On the other hand, when the terminal 34 is observed from the side, since the solder 36 between the terminal 34 and the electrode 42 is not sufficiently melted in the type B, the type B terminal 34 is higher than the type A terminal 34.

  Such a difference between Type A and B can be detected by using an automatic visual inspection apparatus. However, the automatic visual inspection apparatus creates and registers inspection information such as setting of inspection areas and pass / fail judgment criteria in advance for each product type. Since this work takes time and labor, for example, it is not suitable for a small quantity and a wide variety. When the operator visually inspects, since the joining state is observed from above, there is a possibility that a slight difference between Type A and B cannot be determined. For this reason, the quality determination of the joining state of the terminal 34 and the base 40 cannot be performed appropriately.

  FIG. 3 is a perspective view of a substrate on which components are mounted. With reference to FIG. 3, a convex portion 41 is formed on the base body 40. The component 30 a is mounted on a portion other than the convex portion 41. The component 30 b is mounted on the convex portion 41. Thereby, the heights of the mounting surfaces on which the components 30a and 30b are mounted are different. When the operator visually inspects, it is possible to recognize that the parts 30 and 30b are parts of the same shape only with different heights. However, when the inspection is performed using the automatic appearance inspection apparatus, if the reference surface having a height for inspection is on the mounting surface of the component 30a, the component 30a is determined as a non-defective product. Since the mounting surface of the component 30b is increased by the thickness of the convex portion 41, it is determined as a defective product. In order to avoid such misjudgment, for example, an inspection area is set, and the part 30b registers the inspection information that the upper surface of the convex portion 41 is the height reference, and the inspection information is displayed during the inspection. Reference and inspect. As described above, in the automatic appearance inspection apparatus, when the mounting surfaces of the components 30a and 30b are different in height, it is difficult to inspect without the inspection information.

  In the first embodiment, even in the above case, the bonding between the terminal 34 and the base body 40 is appropriately inspected.

  FIG. 4 is a block diagram illustrating the inspection system used in the first embodiment. Referring to FIG. 4, the inspection system 50 includes a computer 10, an imaging device 52, a height measuring device 54, a half mirror 56, and illuminators 58 and 59. The computer 10 controls the imaging device 52 and the height measuring device 54. The imaging device 52 is a camera, for example, and images the component 30 and the base body 40 from above. The height measuring device 54 is, for example, a laser-type height measuring device, and measures the heights of arbitrary positions of the component 30 and the base body 40. The half mirror 56 reflects the light 60 from the illuminator 58 to the component 30 and transmits the light 62 from the component 30 to the imaging device 52. The illuminator 58 irradiates the component 30 with light 60 from the coaxial direction via the half mirror 56. The illuminator 59 irradiates the component 30 with light 64 from an oblique direction. A lens may be provided between the imaging device 52 and the component 30. For example, when observing a deep position such as a component mounted on a printed circuit board, it is preferable to use a lens having a deep focal depth. For example, a telecentric lens can be used as a lens having a deep focal depth.

  FIG. 5A is a block diagram of a computer. Referring to FIG. 5A, the computer 10 executes an inspection method and an inspection program. The computer 10 includes a central processing unit (CPU) 11 that is a processor, a display device 12, an input device 13, and an output device 14. The computer 10 further includes a main storage device 15, a hard disk drive (HDD) 16, a storage medium drive 17, a communication interface 18, and an internal bus 19. The display device 12 includes a display panel such as a liquid crystal panel, for example, and displays processing results and the like. The input device 13 is, for example, a keyboard, a mouse, and a touch panel, and inputs processing data and the like. The output device 14 is a printer, for example, and outputs a processing result or the like. The main storage device 15 is a volatile memory such as a DRAM (Dynamic Random Access Memory), for example, and stores data being processed. The HDD 16 stores, for example, data during or after processing. The storage medium drive 17 is used when a program stored in the storage medium 21 is installed. Alternatively, the processed data is stored in the storage medium 39. The communication interface 18 transmits / receives data to / from the imaging device 52 and the height measuring device 54. The internal bus 19 connects each device in the computer 10.

  FIG. 5B is a functional block diagram of the inspection apparatus according to the first embodiment. The inspection apparatus 20 includes an image processing unit 22, a measurement unit 24, and a determination unit 26. The computer 10 functions as an image processing unit 22, a measurement unit 24, and a determination unit 26 in cooperation with software.

  A portable storage medium can be used as the storage medium 21 readable by the computer 10 storing the program. As the portable storage medium, for example, a CD-ROM (Compact Disc Read Only Memory) disc, a DVD (Digital Video Disc) disc, a Blu-ray disc, or a USB (Universal Serial Bus) memory can be used. As the storage medium 21, a flash memory or an HDD may be used.

  FIG. 6 is a flowchart showing processing performed by the computer. Referring to FIG. 6, the image processing unit 22 performs image processing of an image in which a plurality of terminals 34 are bonded to the base body 40, and extracts a determination pattern (step S10). The measurement unit 24 performs height measurement for each determination pattern (step S12). The determination unit determines whether or not the bonding is good from the measured frequency of height (step S14).

  First, the processing of the image processing unit 22 will be described. FIG. 7 is a flowchart showing the process of step S10. FIG. 8A to FIG. 9B are diagrams showing image processing. With the illuminators 58 and 59 turned on, the image processing unit 22 acquires images of the component 30 and the base body 40 from the imaging device 52 (step S20). FIG. 8A shows an image 70 acquired from the imaging device 52. With reference to FIG. 8A, the terminal 34 of the component 30 is joined to the electrode 42 of the base body 40 by solder 36.

  Referring to FIG. 7, next, the image processing unit 22 extracts the pattern 72 (step S22). Referring to FIG. 8B, since the metal pattern 72 has a high reflectance, it reflects light from above. For this reason, the metal pattern 72 turns white in the image 70. By binarizing the image 70, a plurality of metal patterns 72 are extracted. Each of the plurality of metal patterns 72 includes a terminal 34, solder 36 and an electrode 42. Each of the plurality of metal patterns 72 only needs to include at least one terminal 34.

  Referring to FIG. 7, next, the image processing unit 22 performs pixel expansion processing on the pattern 72 (step S24). Referring to FIG. 9A, for example, the image processing unit 22 expands the pattern 72 to such an extent that the patterns 72 along the same side of the component 30 are connected and the patterns 72 along different sides are not connected. Referring to FIG. 7, the connected pattern is extracted as determination pattern 74 (step S26).

  Referring to FIG. 7, the image processing unit 22 performs pixel contraction processing on the pattern 72 (step S28). With reference to FIG. 9B, pixel contraction processing is performed until, for example, one pixel (this is referred to as a representative point) is extracted from the pattern 72. Thereafter, the process ends, and the process proceeds to step S12 in FIG.

  FIGS. 10A to 10D are diagrams illustrating an example of pixel expansion processing. In FIG. 10A to FIG. 10D, the minimum section represents the pixel 80 in the image 70. In the binarization processing of the image 70, a pixel brighter than the threshold is processed as 1, and a pixel darker than the threshold is processed as 0. Referring to FIG. 10A, for example, a filter 82 of 3 × 3 pixels is used. In the filter 82, eight pixels 80b are arranged around the center pixel 80a. The processing of the filter 82 is as follows. When the center pixel 80a of the filter 82 is 0, the pixel in the filter 82 is not changed. When the center pixel 80a of the filter 82 is 1, all the surrounding pixels 80b are set to 1.

  Referring to FIG. 10B, an image of 10 × 10 pixels is assumed. One pixel of the pixels forms the pattern 72. The filter 82 performs the filter process while the center pixel 80a moves from pixel (1,1) to pixel (8,8) pixel by pixel. When the center pixel 80a of the filter 82 is (1, 1), since the center pixel 80a is 0, the pixels in the filter 82 are not changed.

  Referring to FIG. 10C, when the center pixel 80a of the filter 82 is (3, 3), the center pixel 80a is 1, so the pixel in the filter 82 is changed to 1. Referring to FIG. 10D, when the filtering process for all the pixels is completed, the pixel in the range 73 of one pixel around the pattern 72 becomes 1. As a result, the pattern 72 is expanded by one pixel. The number of expansion processes is set in consideration of the distance between the electrodes 42 and the like. For example, the interval between the electrodes 42 is 200 μm, and the size of the pixel 80 is 10 μm × 10 μm. When the pattern 72 is expanded 10 times, the patterns 72 are connected to each other. Therefore, the number of expansion processes is set to 11 times or 12 times. At this time, the patterns 72 of the terminals 34 on different sides of the component 30 (opposite sides in FIG. 9A) are not connected.

  Next, processing of the measurement unit 24 will be described. FIG. 11 is a flowchart showing the process of step S12. FIG. 12A and FIG. 12B are diagrams showing the measurement process. With reference to FIGS. 11 and 12A, the measurement unit 24 extracts a line 78 passing through each terminal 34 for each determination pattern 74 extracted in step S26 (step S30). For example, the measurement unit 24 calculates an approximate line (for example, an approximate line) from the representative point 76 in the determination pattern 74. The approximate straight line is calculated using, for example, the least square method.

  With reference to FIG. 11 and FIG. 12B, the measurement unit 24 measures the height of the component 30 and the base body 40 along the line 78 using the height measuring instrument 54 (step S32). Thereafter, the process ends and the process proceeds to step S14 in FIG.

  Next, processing of the determination unit 26 will be described. FIG. 13 is a flowchart showing the process of step S14. FIG. 14A is a diagram showing an example of the height measurement result, and FIG. 14B is a diagram showing an example of the height frequency. Referring to FIG. 14A, the horizontal axis indicates the position along the line 78, and the vertical axis indicates the height 86. The height 86 indicates the height measured by the height measuring device 54 in step S32. For the height 86, the height H0 of the upper surface of the base 40 and the height H1 of the upper surface of the terminal 34 are repeated. Since the Type B terminal 34 is floating, the height 86 becomes a height H2 larger than the height H1 of the other terminals at the Type B terminal position.

  Referring to FIG. 13, the determination unit 26 creates a height frequency distribution (step S40). Referring to FIG. 14B, the horizontal axis indicates frequency and the vertical axis indicates height. The frequency 88 becomes a peak 90 at the height H0 of the upper surface of the substrate 40. The frequency 88 becomes a peak 92 at the height H1 of the terminal 34. If there is no Type B terminal, there are two peaks. When there is a type B terminal, a peak 94 with a frequency of 88 appears at the height H2.

  Referring to FIG. 13, the determination unit 26 calculates the number N of peaks with frequency 88 (step S42). Referring to FIG. 14B, the number of peaks is 3. Referring to FIG. 13, the determination unit 26 determines whether the peak number N is smaller than the threshold value TH (step S44). The threshold value TH is 3, for example. In the case of Yes, the determination unit 26 determines to be good (step S46). In the case of No, the determination unit 26 determines that it is defective (step S48). In the example of FIG. 14B, the number of peaks is 3. Therefore, the determination unit 26 determines that it is defective. Then, the process ends.

  According to the first embodiment, as illustrated in FIG. 8B, the image processing unit 22 extracts a plurality of patterns 72 each including the previous number of terminals 61 from the image 70. As illustrated in FIG. 9A, the image processing unit 22 performs pixel expansion processing on the plurality of patterns 72, and sets a connected pattern among the plurality of patterns 72 as a determination pattern 74. The measurement unit 24 measures the height along the line 78 including the terminal 34 included in the determination pattern 74 for each determination pattern 74 as illustrated in FIGS. 12A and 12B. The determination unit 26 determines the quality of joining for each determination pattern based on the measured height.

  By setting the patterns connected by the pixel expansion process as the determination pattern 74, the adjacent patterns 72 can be made into one group. The adjacent patterns 72 are considered to have substantially the same height of the base 40. For each determination pattern 74, the height of the terminal 34 is measured, and the quality of bonding is determined based on the height of the terminal in the determination pattern 74. As a result, the heights of the terminals 34 to which the bases 40 to which the terminals 34 are bonded are substantially the same are compared. Therefore, as shown in FIG. 3, even when the heights of the components 30a and 30b are different from each other, it is possible to appropriately inspect the bonding between the terminal 34 and the base 40. Moreover, it is not necessary to create inspection information like an automatic visual inspection apparatus.

  Each of the plurality of patterns 72 only needs to include the terminal 34, but the plurality of patterns 72 are preferably metal patterns including the electrodes 42 and the terminals 34. Since the metal pattern has the same level of brightness, it can be easily extracted by the binarization process.

  It is considered that the upper surface of the base body 40 to which the terminals 34 on the same side of the component 30 are joined has almost the same height. Therefore, the image processing unit 22 performs pixel expansion processing so that the patterns 72 corresponding to the same side of the component 30 provided with the plurality of terminals 34 among the plurality of patterns 72 are connected. As a result, the heights of the terminals 34 to which the bases 40 to which the terminals 34 are bonded are substantially the same are compared.

  The measurement unit 24 may measure the height of the terminal 34 in the same determination pattern 74. As in the first embodiment, the measurement unit 24 measures the height of the terminal 34 included in the determination pattern along a line passing through the terminal included in the determination pattern 74. Thereby, the height of the terminal 34 in the same determination pattern 74 can be measured. Further, the measurement unit 24 measures the height along the approximate line of the pattern contracted by the pixel contraction process. In this way, the approximate line can be automatically calculated.

  The determination unit 26 may determine whether or not the terminal 34 and the base body 40 are bonded based on the height measured by the measurement unit 24. The determination unit 26 determines the quality of joining based on the number of peaks of the height frequency. Thereby, the quality of joining can be determined easily.

  In the first embodiment, the approximate line is described as an example of the approximate line. However, the approximate line may be a curve.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

In addition, the following additional notes are disclosed regarding the above description.
(Appendix 1) Extracting a plurality of patterns each including a terminal from an image obtained by bonding a plurality of terminals to a substrate, subjecting the plurality of patterns to pixel expansion processing, and determining a connected pattern among the plurality of patterns An image processing unit, a measurement unit for measuring the height of a terminal included in the determination pattern for each determination pattern, and a determination of bonding quality based on the measured height for each determination pattern And a determination unit.
(Supplementary note 2) The inspection apparatus according to supplementary note 1, wherein the image processing unit extracts, as the plurality of patterns, a metal pattern formed on the substrate and including an electrode joined to the terminal and the terminal. .
(Additional remark 3) The said image processing unit performs the said pixel expansion process so that the pattern corresponding to the same edge | side of the components in which the said several terminal was provided among these patterns may be connected. The inspection apparatus according to Supplementary Note 1 or 2,
(Additional remark 4) The said measurement unit measures the height of the terminal contained in the said determination pattern along the line which passes along the terminal included in the said determination pattern, The additional description 1-3 characterized by the above-mentioned. Inspection equipment.
(Supplementary note 5) Any one of Supplementary notes 1 to 4, wherein the image processing unit performs pixel contraction processing on the plurality of patterns, and the measurement unit measures a height along an approximate line of the reduced pattern. The inspection apparatus according to claim 1.
(Additional remark 6) The said determination unit determines the quality of joining based on the peak number of the frequency of the said height, The inspection apparatus as described in any one of Additional remark 1 to 5 characterized by the above-mentioned.
(Supplementary note 7) The inspection apparatus according to supplementary note 5, wherein the approximate line is an approximate straight line.
(Additional remark 8) The said terminal is joined to the said base | substrate with solder, The inspection apparatus as described in any one of additional remark 1 to 7 characterized by the above-mentioned.
(Supplementary Note 9) Extracting a plurality of patterns each including a terminal from an image obtained by joining a plurality of terminals to electrodes, subjecting the plurality of patterns to pixel expansion processing, and determining a connected pattern among the plurality of patterns as a determination pattern And, for each of the determination patterns, measuring the height of the terminal included in the determination pattern, for each of the determination patterns, determining the quality of the joint based on the measured height, The inspection method characterized by including.
(Additional remark 10) Let the computer extract the some pattern which each contains a terminal from the image which joined the some terminal to the electrode, and perform the pixel expansion process of the said some pattern, The pattern connected among the said some patterns Characterized in that, for each of the determination patterns, the height of a terminal included in the determination pattern is measured, and for each of the determination patterns, the quality of bonding is determined based on the measured height. Inspection program.

DESCRIPTION OF SYMBOLS 10 Computer 20 Inspection apparatus 30 Parts 32 Package 34 Terminal 36 Solder 40 Base 42 Electrode 70 Image 72 Pattern 74 Judgment pattern 76 Representative point 78 line

Claims (8)

Image processing in which a plurality of patterns each including a terminal are extracted from an image obtained by bonding a plurality of terminals to a base, the plurality of patterns are subjected to pixel expansion processing, and a concatenated pattern among the plurality of patterns is used as a determination pattern Unit,
For each determination pattern, a measurement unit that measures the height of a terminal included in the determination pattern;
For each of the determination patterns, a determination unit that determines the quality of bonding based on the measured height,
An inspection apparatus comprising:   The inspection apparatus according to claim 1, wherein the image processing unit extracts a metal pattern formed on the base and including an electrode bonded to the terminal and the terminal as the plurality of patterns.   The image processing unit performs the pixel expansion processing so that patterns corresponding to the same side of a part provided with the plurality of terminals are connected among the plurality of patterns. Or the inspection apparatus of 2.   4. The inspection apparatus according to claim 1, wherein the measurement unit measures a height of a terminal included in the determination pattern along a line passing through the terminal included in the determination pattern. 5. . The image processing unit performs pixel contraction processing on the plurality of patterns,
The inspection apparatus according to claim 1, wherein the measurement unit measures a height along an approximate line of a reduced pattern.   The inspection apparatus according to claim 1, wherein the determination unit determines whether or not the bonding is good based on a peak number of the height frequency. Extracting a plurality of patterns each including a terminal from an image obtained by joining a plurality of terminals to electrodes, subjecting the plurality of patterns to pixel expansion processing, and using a connected pattern among the plurality of patterns as a determination pattern; ,
Measuring the height of a terminal included in the determination pattern for each determination pattern;
For each of the determination patterns, determining whether or not the bonding is good based on the measured height;
The inspection method characterized by including. On the computer,
Extracting a plurality of patterns each including a terminal from an image obtained by bonding a plurality of terminals to electrodes, subjecting the plurality of patterns to pixel expansion processing, and connecting a pattern among the plurality of patterns as a determination pattern,
For each of the determination patterns, the height of the terminal included in the determination pattern is measured,
An inspection program for causing each of the determination patterns to determine whether the bonding is good or not based on the measured height.

Images