JP2007248145A - Inspection method and inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the processing time, required in imaging, and to sharply enhance the inspection efficiency. <P>SOLUTION: Either one of three stages of resolving power levels is preset to each of parts corresponding to the size. These parts are successively put in the order starting from the part of high resolving power, and noticing the respective parts successively from the first (No. 3), imaging target regions B1, B2, etc. are set corresponding to the set resolving power levels. However, when other nearby parts can be included by the set regions, they are alloted to the imaging target regions, without having to take into consideration the resolving power levels set. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  According to the present invention, a work including a plurality of parts to be inspected (for example, a component mounting board) having a variation in imaging magnification setting is to be inspected, and the work is imaged while switching the imaging magnification of the imaging means. The present invention relates to a method for performing an inspection of each inspected region using an acquired image, and an apparatus for executing the method.

  In an inspection device that inspects a component mounting board by image processing, when multiple components with different sizes are mounted, or taking into account the fact that the mounting density of components varies depending on the location, imaging is performed while switching the imaging magnification of the camera There is.

  For example, in the following Patent Document 1, an imaging magnification suitable for each component is associated with each component on the substrate in advance, and the components associated with the magnification can be collectively imaged for each imaging magnification. As described above, the setting position of the imaging target area (described as “imaging area” in Patent Document 1) at each magnification is determined.

Japanese Patent No. 2570650

In the above-mentioned Patent Document 1, only the components in which the imaging magnification for each area is set are allocated to the imaging target area for each imaging magnification. Therefore, even if a part for which another imaging magnification is set is included in an imaging target area with a certain imaging magnification, image processing for that part is not performed, and is separately generated by imaging with an imaging magnification corresponding to that part. Need to process the image.
Such a method has an advantage that an image having a resolution suitable for each component can be obtained for each component, but the number of imaging tends to increase. Further, since the mechanism must be moved to switch the imaging target region and the imaging magnification, there is a problem that the processing time required for imaging becomes long and inspection cannot be performed efficiently.

  The present invention has been made paying attention to the above-mentioned problem, and devised the setting of the imaging target region so that the number of imaging for inspection is as small as possible, thereby shortening the processing time required for imaging and thereby improving the inspection efficiency. The purpose is to greatly increase.

  The measurement processing method according to the present invention is based on the premise that the workpiece design drawing information is obtained by imaging a workpiece including a plurality of parts to be inspected with different imaging magnification settings while switching the imaging magnification of the imaging means a plurality of times. And the positional relationship between the workpiece and the imaging means so that each imaging target area set in the preparing step is sequentially imaged after executing the preparation step of setting the imaging target area of each imaging magnification using A plurality of times of imaging is performed by adjusting the imaging magnification, and a predetermined measurement process is executed for each site to be inspected using an image generated by each imaging.

In the above, the setting of the imaging magnification for each site to be inspected changes according to the size and type of the site to be inspected and the relationship with other sites to be inspected.
For example, the smaller the region to be inspected, the larger the image required, so the imaging magnification may be set higher. In addition, when the imaging magnification is set higher than that of a simple shape for a region to be inspected with a complicated shape, or when the portion with a low arrangement density is applied to a portion to be inspected with a high arrangement density of the region under inspection. In some cases, an imaging magnification higher than that of the examination site is set.
The higher the imaging magnification, the higher the resolution of the image obtained by imaging, so that it becomes easier to perform detailed measurement processing or confirm a fine part.
Note that the setting of the magnification for the region to be inspected may be performed by data indicating the magnification itself, but is not limited thereto, and for example, data indicating the resolution of the image to be generated may be used.

"Work design drawing information" is used to indicate the position, size, inclination, etc. of each part to be inspected. For example, CAD data is used.
According to the present invention, in the preparation step, after each of the inspected parts on the workpiece is ordered in the order of the set imaging magnification in the order of high or low, 1 is assigned to each inspected part in the design drawing information along the order. Focusing on the imaging target area of the imaging magnification corresponding to the inspected part, on the condition that the inspected part in focus is not already assigned to another imaging target area. In addition to setting the position including the region to be inspected, all the regions to be inspected that are included in the imaging target region and are not allocated to other imaging target regions are allocated to the set imaging target region.

In the above preparation step, for example, when the parts to be inspected are ordered in descending order of magnification, the imaging target region set first is the region with the smallest area. Thereafter, the set imaging target region becomes larger as the site of interest to be inspected changes and the magnification decreases.
Here, when a region to be inspected other than the region to be inspected is included in the set imaging target region, the magnification corresponding to the region to be inspected is lower than that corresponding to the region to be inspected. Even in such a case, the part is assigned to the same imaging target region as the part to be inspected under consideration. Therefore, regardless of the set magnification, it is possible to assign a site to be inspected in the vicinity of the site to be inspected to the same imaging target region, so that the number of times of imaging can be reduced as compared with the conventional case.

  In addition, according to the above setting process, since the inspected part with the highest magnification can be imaged with a surely set magnification, it is possible to inspect the part requiring inspection using a high resolution image. Accuracy can be ensured. Further, even when a region to be inspected for which a low magnification is set is assigned to an imaging target region having a magnification higher than the set magnification, the entire image of the region to be inspected can be acquired, so that there is no possibility of causing trouble in the inspection.

  In addition, when setting the imaging target area by paying attention to the parts to be examined in ascending order of magnification, the imaging area is set in order from the largest area, contrary to the above, and the number of imaging is further reduced. Can do.

  In a preferred aspect of the above inspection method, in the process of setting the imaging target area in the preparation step, the inspection target part that has been assigned to the set imaging target area does not come out of the imaging target area. Then, the setting position of the imaging target region is adjusted so as to include other parts to be examined that are not assigned. In this way, any imaging target area can be adjusted so that more parts to be inspected can be assigned within a range that does not leave the assigned parts to be inspected. can do. Therefore, it is possible to reduce the number of times of imaging at the time of inspection and improve the processing efficiency.

In another preferred aspect of the inspection method, when a region to be inspected that does not correspond to the imaging magnification of the region is assigned to the region to be imaged corresponding to the image to be processed, the image of the region to be inspected is assigned to the region to be inspected. Is converted into an image having a resolution suitable for the imaging magnification corresponding to the above, and image processing for the inspection is executed on the converted image.
For example, if the region to be inspected corresponding to the magnification n is included in the imaging target region having the magnification 2n, the image of the region to be inspected is compressed to an image having a resolution half that of the original image. Convert. Further, when the region to be inspected corresponding to the magnification 2n is included in the imaging target region having the magnification n, the image of the region to be inspected is expanded to be converted into an image having a resolution twice that of the original image. . In addition, about the to-be-inspected part corresponding to the magnification concerning the said imaging object area | region, the image of the to-be-inspected part should just be processed as it is, without performing said conversion process.

  Generally, inspection parameters such as judgment reference values are often set for each part to be inspected on the premise that an image with a resolution suitable for the magnification set for that part is processed. If an image having a resolution different from the original resolution is generated by being assigned to an imaging target region having an imaging magnification different from the original magnification, the parameters cannot be used as they are. However, in the present invention, if the imaging target region corresponding to the processing target image includes an inspection site corresponding to an imaging magnification different from the imaging magnification applied to the region, the image of the inspection site is displayed. Since the image is converted by being compressed or expanded into an image having a resolution suitable for the original magnification, the inspection can be performed without changing the parameters.

Next, an inspection apparatus for performing the inspection method includes an imaging unit capable of switching an imaging magnification; an area setting unit that sets an imaging target area of each imaging magnification using design drawing information of a workpiece to be inspected; Storage means in which information necessary for imaging each imaging target area set by the area setting means is registered; based on registration information in the storage means, the positional relationship between the workpiece and the imaging means and the imaging magnification are adjusted. Imaging control means for performing the plurality of times of imaging by driving the imaging means; and image processing means for executing image processing for the inspection using the images generated by the plurality of times of imaging in order. It has.
Since the area setting means assigns each inspection site on the workpiece to one of a plurality of imaging target areas by executing the above-described preparation step, the number of imaging at the time of inspection is determined in the same manner as described above. Reduction and processing efficiency can be increased.

  According to the present invention, a region to be inspected in the vicinity can be assigned to one imaging target region regardless of the set imaging magnification, so that the number of times of imaging at the time of inspection can be reduced and efficiency can be reduced. Good inspection can be done.

FIG. 1 shows a configuration example of a substrate inspection apparatus to which the present invention is applied.
The board inspection apparatus according to this embodiment performs an inspection at each component mounting position on a substrate that has undergone a component mounting process in a component mounting board manufacturing line, and includes a controller 1, a camera 2, a substrate stage 3, A lighting device 4, an input unit 5, a monitor 6, and a read / write processing device 7 (CD drive, optical disk drive, etc.) for a storage medium are included.

  The camera 2 is a color camera capable of switching the imaging magnification, and is fixedly arranged above the substrate stage 3 with the imaging surface facing downward. The substrate stage 3 has a table (not shown) for horizontally supporting a substrate to be inspected, and a table for moving the table in the X direction (the substrate length direction) and the Y direction (the substrate width direction). A moving mechanism (not shown) is included. The illumination device 4 is for illuminating a substrate to be inspected.

The controller 1 includes an image input unit 12, a magnification adjustment processing unit 13, an XY stage control unit 14, an illumination control unit 15, a memory 16, an inspection result output unit 17, and the like, in addition to a computer control unit 11.
The image input unit 12 includes an interface circuit for the camera 2 and an A / D conversion circuit. The magnification adjustment processing unit 13 performs switching control of the imaging magnification of the camera 2. The XY stage control unit 14 controls the movement of the substrate stage 3, and the illumination control unit 15 adjusts the turning on / off operation of the lighting device 4.

In the board inspection apparatus according to this embodiment, the board 2 is imaged a plurality of times while switching the imaging magnification of the camera 2 to generate an image necessary for determining the presence / absence of the part, positional deviation, inclination, and the like for each part. . In addition to a program in which a series of processing procedures for inspection is described, the memory 16 stores information (hereinafter referred to as “imaging data”) indicating an imaging target area for hourly imaging, an inspection data file, and the like. .
In the inspection data file, in addition to the inspection area setting data (representing the position and size of the area) for each part, the binarization threshold for detecting the color of the part and the suitability of the detected part are determined. Information (hereinafter referred to as “inspection parameters”) such as determination reference values for storing the information is stored.

  The control unit 11 adjusts the imaging magnification of the camera 2 using the magnification adjustment processing unit 13 based on the imaging data, and controls the movement of the substrate stage 3 using the XY stage control unit 14. Perform imaging with. An image generated by this imaging is input to the control unit 11 via the image input unit 12 and stored in an internal memory (RAM). The control unit 11 sets an inspection region for each part of the image stored in the RAM using the setting data in the inspection data file, and extracts an inspection site for the image in the region. Each process of measurement and determination is sequentially executed.

  When the determination processing for all components on the board is completed, the control unit 11 collects these determination results and determines whether the board is good or bad. Information regarding the final determination result and the defective part when it is determined to be defective is given to the inspection result output unit 17 and then output from the inspection result output unit 17 to an external device (not shown).

Each of the parts to be inspected is associated with one of the following three levels L1, L2, and L3 as the image resolution necessary for inspecting the part. This resolution level is also registered in the inspection data file.
L1 is the highest level, and a resolution of 10 μm is set for each pixel. L2 is the second highest level, and a resolution of 15 μm is set for each pixel. L3 is the lowest level, and a resolution of 20 μm is set for each pixel.

In the memory 16 of this embodiment, library data in which the resolution of an image necessary for the inspection of the component and the inspection parameter corresponding to the resolution are registered for each component type. Prior to the inspection, the CAD data of the substrate to be inspected is read using the read / write processing device 7 and the like, and the CAD data and the library data are linked, so that the resolution level and inspection parameters of each component on the substrate are linked. Set. Furthermore, based on the arrangement state of the components of each imaging magnification, the imaging magnification in the hourly imaging and the position of the imaging target area are determined, and the components to be allocated to each imaging target area are determined.
Hereinafter, a method for setting an imaging target region and a method for assigning parts will be described in detail.

  FIG. 2 shows the configuration of the substrate to be inspected. In this figure, in order to simplify the illustration, each component is represented as a rectangle reflecting its size, and the identification number of the component is described in each rectangle. Hereinafter, this identification number is referred to as “part number”. Further, when referring to individual parts, the part numbers of the parts to be referred to are used, such as “No. 1”.

  In this embodiment, the resolution level is determined according to the size of the component. Specifically, the size of each part is divided into three groups, the level L1 (10 μm / pixel) is assigned to the smallest group, and the level L2 (15 μm / pixel) is assigned to the intermediate size group. The level L3 (20 μ / pixel) is associated with the group having the largest size.

  In the setting process of the imaging target area, after ordering the parts on the board based on the resolution, pay attention to each part one by one from the top part in the order, and the position and correspondence of the part under consideration The imaging target area is set according to the resolution to be performed. Further, if there is a component that can be included in the imaging target region in the vicinity of the component under consideration, the component is assigned to the imaging target region regardless of the resolution corresponding to the component.

  FIG. 3 shows the result of ordering the components based on the resolution for the substrate having the configuration shown in FIG. 2, and the order of the components is indicated by a circled number in the vicinity of each component. In this example, the parts are ordered in descending order of resolution. However, the parts having the lower part numbers are placed in front of parts associated with the same resolution level.

FIG. 4 shows a configuration example of a table (hereinafter referred to as “imaging data table”) in which the imaging data is stored.
In this imaging data table, for each imaging target area, the identification number of the area (hereinafter referred to as “area number”), the corresponding resolution level, the coordinates of the representative point (upper left vertex, center point, etc.) of the area, and the area Stores the part number of the assigned part. Note that the imaging data table shown here is generated by executing the following processing of FIG. 5 for the ordered substrates of FIG.

FIG. 5 shows the flow of processing for setting the imaging target area. In FIG. 5, parts are represented as Ai and Ak, and an imaging target area is represented as Bj. i and k correspond to the arrangement order of the components indicated by the circled numbers in FIG. Among these, i is a counter indicating the component under consideration, and changes in a range from 1 to the maximum value i _max . On the other hand, k varies in a range from i + 1 to _imax for each value of i.

  First, in ST1 (ST stands for “Step (STEP)”), the parts are ordered based on the resolution described above, and then in ST2, initial values “1” are set in i and j, respectively.

  In ST3, the initial value of resolution R is set to L1, which is the maximum level. The resolution R determines the size of the imaging target region Bj (hereinafter sometimes simply referred to as “region Bj”). When R is set to the maximum resolution L1, the region Bj is the smallest as shown in FIGS.

ST4 to 12 are processes for determining the position of the region Bj having a size corresponding to the resolution R. This process is performed using the CAD data.
First, in ST4, the region Bj is temporarily set so that the part Ai is positioned at the center of the region Bj. Subsequently, in ST5, the counter k is set to the initial value i + 1. Thereafter, the loop of ST6 to 12 is repeated until k becomes i _max .

  In ST7, it is checked whether or not the part Ak has already been assigned to any one of the imaging target areas. If the allocation of the part Ak is not completed, the process proceeds to ST8, and it is checked whether the part Ak is included in the area Bj. Here, if the part Ak is included in the area Bj, ST8 becomes “YES”, the process proceeds to ST11, and the part Ak is assigned to the area Bj.

On the other hand, when a part of the part Ak protrudes from the area Bj or the part Ak is completely outside the area Bj, ST8 becomes “NO” and the process proceeds to ST9.
In ST9, it is checked whether or not the region Bj can be adjusted so that the part Ak is included in the region Bj. This adjustment process is performed under the condition that parts already allocated to the area Bj do not protrude from the area Bj.

Here, the determination method of ST9 will be described with reference to FIG.
In this process, the coordinates of all the parts included in the area Bj (only the part Ai in the example of FIG. 6) and the vertices of the part Ak that is the target of determination as to whether or not included in the area Bj are obtained. Then, it is determined whether or not the range in which these coordinates are distributed is smaller than the region Bj. Specifically, in the x-axis direction, it calculates the difference between the most right certain point coordinates x _M and most left a point on the coordinate x _L, the width of the difference (x M _{-x L)} the area Bj Compare with dx. In the y-axis direction, it calculates the difference between the most point lies at the bottom with coordinates y _M of a point on the coordinate y _L, comparing the difference (y M _{-y L)} and height dy of the area Bj . If where _{(x M} -x L) <dx and _{(y M -y L) <dy} , it is possible to include a component Ak in the area Bj. Therefore, the region Bj can be moved from the position indicated by the one-dot chain line in the drawing to the position indicated by the solid line.
Note that FIG. 6 shows an example in which only the component Ai of interest is allocated in the area Bj. Similarly, when other components are allocated, each of the x and y axis directions is also shown. Then, the width of the range in which each vertex is distributed may be obtained and compared with dx and dy.

Returning to FIG. 5, if the determination in ST9 is “YES” for the part Ak, the process proceeds to ST10, the position of the region Bj is adjusted so that the part Ak is included, and then ST11 is executed. When the part Ak is assigned to the region Bj in ST11, the process proceeds to ST12, the value of k is increased by 1, and the process returns to ST6.
When the part Ak has already been assigned to another imaging target area (when ST7 is “YES”), or when it is determined that adjustment of the area Bj is impossible (when ST9 is “NO”). In step ST12, the process of ST11 is not executed, and the value of k is updated.

In this way, the loop of ST6 to ST12 is executed until k exceeds i _max , and the process proceeds to ST13 where the counter i is changed to one larger value. If the updated i is equal to or less than i _max , the process proceeds to ST15, and it is checked whether or not the imaging target area is allocated to the component Ai specified by the updated i.

If the part Ai has been allocated, the process returns from ST15 to ST13, and the value of i is updated again.
On the other hand, when the part Ai is not assigned to any imaging target region, ST15 is “NO”, the process proceeds to ST16, and the counter j is updated to one larger value.
Further, in ST17, it is checked whether or not the part Ai corresponds to the resolution R. If it corresponds, ST17 becomes “YES” and the process proceeds to ST4. As a result, a new area Bj having the same size as the previous area is set for the new target part Ai.

  If the part Ai does not correspond to the resolution R, ST17 is “NO”. In this case, the resolution R is changed to a lower level in ST18 (for example, changed from L1 to L2), and then the process proceeds to ST4. As a result, the new imaging target area Bj becomes a larger area than the previous imaging target area.

  Similarly to the above, ST6 to 12 are executed for the newly set area Bj, so if there is a part that has not been assigned in the vicinity of the part Ai, the part can be included in the area Bj. It becomes possible.

Thereafter, when the same process is executed while changing the target component, if the counter i exceeds i _max , ST14 becomes “YES” and the process ends.

  7 to 16 show the change in the setting state of the imaging target area when the process of FIG. 5 is executed on the substrate shown in FIG. 3 in order. Hereinafter, the setting process of the imaging target area will be described more specifically with reference to these drawings. In the following, step numbers in FIG. 5 are referred to as necessary.

  FIG. 7 shows No. 1 which is set first by the ordering. 3 shows a state in which the imaging target area B1 is set by the process of ST4 for the three components. Thereafter, the processes of ST6 to 12 are performed for the second and subsequent parts. At this stage, ST7 is “NO” for any part, but no. Since it is not located near the part 3, both ST8 and ST9 are “NO”. For this reason, in the imaging target area B1, No. Parts other than 3 are not assigned.

  FIG. 8 shows a state where the imaging target region B2 is set for the second component (No. 10) by the process of ST4. After this, the processing of ST6 to 12 is executed for the third and subsequent parts, but at this time as well, the third, fourth and fifth parts (No. 11, No. 4, No. 7) Since ST7, 8, and 9 are “NO”, allocation to the area B2 is impossible.

  However, since the next sixth part (No. 8) and seventh part (No. 9) are located within the range included in this area B2 by adjusting the area B2, ST9 is “YES”. It becomes. Therefore, the area B2 is adjusted to the position shown in FIG. 8, 9 parts are assigned.

FIG. 10 shows a state where the imaging target region B3 is set for the third component (No. 11) by the process of ST4. In this area B3, it is checked whether or not the fourth and subsequent parts are included. However, since the sixth and seventh parts have already been assigned to the area B2, ST7 becomes “YES”.
For other parts, ST7 is “NO”, but the fourth, fifth, eighth, ninth and eleventh parts (No. 4, No. 7, No. 1, No. 2, No. 6) is No. ST8 and ST9 are “NO” because they are separated from the third part. The 10th and 12th parts (No. 10, No. 12) are No. Although it is near 3, it is too large to be included in the region B3. Therefore, for these parts, ST8 and ST9 are “NO” and are not assigned.

  As a result, the position of the region B3 is determined at the position shown in FIG. Next, the fourth component (No. 4) is the target of attention, but since this component is associated with the resolution level L2, ST17 becomes “NO”, and the resolution R is changed to L2 in ST18. The As a result, when ST4 is executed, as shown in FIG. A region B4 larger than the regions B1 to B3 is set around the four components.

  At this stage, the fifth and subsequent parts are to be processed in ST6 to ST12, but all parts other than the tenth part (No. 5) are “YES” in ST7 or “NO” in ST9. , Is not subject to allocation. However, said No. The part No. 5 is not completely included in the area B4, but is in a position where it can be included in the area by adjusting the area B4. Therefore, ST9 becomes “YES”, and the area B4 is adjusted in ST10. Is called. As a result, the region B4 is adjusted to the position shown in FIG.

  Next, focus on the fifth part (No. 7). Since this component is also associated with the resolution of the level L2, the region B5 having the same size as the region B4 is set at the position shown in FIG.

  At this stage, the sixth and subsequent parts are to be processed in ST6 to ST12. Among them, the eleventh part (No. 6) is in a position that can be included in this area B5 by adjusting the area B5. Therefore, ST9 becomes “YES”. Therefore, the position of the region B5 is adjusted by the processing of ST10 and ST11. Six parts are assigned to the region B5.

In addition, No. The parts 8, 9, and 10 are in the range included in the area B5, but are already assigned to the area B2, so that ST7 becomes “YES” and is not an assignment target. Other parts are also not assigned because ST7 is “YES” or ST8, 9 is “NO”.
Therefore, the position of the region B5 is adjusted as shown in FIG. 7 and no. Six parts are assigned to this area B5.

Next, attention is focused on the sixth part (No. 8), but since this part has already been assigned to the area B2, ST15 is “YES”, and no unique imaging target area is set. The same applies to the seventh part (No. 9).
Next, the eighth part (No. 1) is a target of attention, but since this part is a part of level L3, the size of the imaging target region is changed by the processing of ST17 and ST18. As a result, as shown in FIG. 1 part is set as a reference.

Here, the ninth part (No. 2) is the processing target of ST6 to ST12. No. 2 is No. Since it is located in the vicinity of one component, ST9 becomes “YES” and the process of ST10 is performed. On the other hand, since the tenth and eleventh parts (No. 5, No. 6) have already been assigned to the areas B4 and B5, ST7 becomes “YES” and is excluded from the assignment. The twelfth part (No. 12) is also No. Since they are separated from one part, ST8 and ST9 are “NO” and are not assigned.
Therefore, the area B6 is adjusted as shown in FIG. 1 and no. Two parts are assigned.

After this, since the 10th and 11th parts have already been assigned, ST15 is “YES” for these, and the focus target moves to the last 12th part (No. 12) and ST4 is executed. And region B7 is set.
When the counter k is updated in ST5 after this processing, k> i _{max is established} , and ST6 becomes “YES”. Upon receiving this determination, the process proceeds to ST13, and when the counter i is updated, i> i _max . Therefore, ST14 becomes “YES”, and the process ends.

  In FIG. 16, together with the area B6 after the position adjustment, the last No. An area B7 set for 12 parts is shown. When the state shown in FIG. 16 is reached, the imaging data table shown in FIG. 4 is completed and registered in the memory 15.

  As described above, in this embodiment, focusing on each component in descending order of the set resolution, the imaging target region is allocated, and components that can be included in the imaging target region in the vicinity of the component being focused are included. If there is, the number of imaging target areas can be reduced as compared with the conventional method because the allocation is made to the imaging target areas regardless of the resolution. Therefore, the number of times of imaging at the time of inspection can be reduced.

Next, the flow of processing in the inspection will be described with reference to FIG.
First, in ST21, an initial value “1” is set in a counter n for specifying the imaging data, and in ST22, the nth imaging data is read from the imaging data table.

In ST23, the imaging magnification of the camera 2 is adjusted to a value corresponding to the resolution level in the imaging data, and the coordinates (x _n , y _n ) of the representative point in the imaging data correspond to the center of the field of view of the camera 2. In this manner, the positional relationship between the camera 2 and the substrate is adjusted. When these adjustments are completed, a trigger signal is given to the camera 2 to perform imaging. As a result, for the n-th imaging target region, an image with the resolution set in that region is generated.

In ST24, based on the part number included in the imaging data, the inspection information corresponding to the number is read from the inspection data file in the memory 15. Then, the inspection area is set for the part on the image by using the setting data of the inspection area therein.
Note that the inspection area setting data is set by imaging a non-defective board based on the setting after receiving the imaging target area setting process and receiving an area specifying operation for the generated image. It is.

  In ST25, it is checked whether or not the resolution corresponding to the part for which the inspection area is set is compatible with the image to be processed. If the resolution is not suitable, ST25 is “NO” and the process proceeds to ST26, and compression processing is performed so that the image in the inspection area becomes an image having a resolution corresponding to the part.

  In this compression process, the number of pixels is reduced according to the resolution of the image after compression, with one vertex (for example, the lower left vertex) of the inspection region as the origin, and for each R, G, B for each pixel after conversion. A density interpolation process is performed to determine a density value. In this embodiment, with respect to each pixel after conversion, the coordinates of the corresponding point in the image before conversion are obtained in units of subpixels with respect to the origin, and the density of four pixels in the vicinity of the corresponding point is determined for each pixel. And a weighted average calculation using the distance between the corresponding points as weights. Since this method is a known method called “linear interpolation method”, detailed description is omitted here.

  If an image having a resolution corresponding to the component is obtained by the above compression processing, the process proceeds to ST27. If the resolution set for the component is the same as the resolution of the image, ST25 is “YES”, and the process proceeds to ST27 without performing the process of ST26.

  In ST27, the image of the inspection area is binarized, the area where the color of the part appears is extracted, and the position and area thereof are measured. Further, in ST28, the suitability of the component is determined by comparing the measured value with a determination reference value.

  Hereinafter, when other part numbers are included in the imaging data, the process returns from ST29 to ST24, and ST24 to ST28 are similarly executed for the parts corresponding to the next part number. When the parts corresponding to all the part numbers are processed, the process proceeds from ST29 to ST31 through ST30, the value of n is updated to one larger value, and the image data corresponding to the new n is used to perform the same process. Execute the process.

  When the processing for the registered N pieces of imaging data is completed in this way, ST30 becomes “YES” and the process proceeds to ST32. In ST32, the determination results at every hour are integrated to determine whether the substrate is good, the determination result is output, and the process is terminated. If there is a part determined to be defective, the part number of the part is also output in ST32.

According to the above inspection, for parts set with a resolution lower than the resolution of the generated image, processing is performed after converting the image in the inspection area into an image with a resolution suitable for the part. There is no need to change inspection parameters such as reference values. In particular, when setting inspection parameters using library data as in this embodiment, it is only necessary to extract the corresponding library data without considering the resolution of the imaging target area to which the parts are assigned. It is possible to prevent the processing during work from becoming complicated.
For components that do not match the resolution of the generated image, the value of the inspection parameter may be changed instead of the process of converting the image.

  Further, in the above embodiment, the parts on the board are ordered in the order of high resolution, and the imaging target region is set in order from the top part along the order, so for the parts for which the resolution of the level L1 is set, The image can always be assigned to an imaging target area corresponding to the resolution. Therefore, it is possible to inspect parts that need to be inspected with high resolution without reducing accuracy. Moreover, since the whole image can be acquired also about the components in which the resolution of the level L2 or L3 is set, there is no problem in the inspection. In addition, since an image having a higher resolution than the original image is generated as the entire image, the accuracy of the image after the compression processing can be ensured.

However, depending on the purpose of the inspection, in contrast to the above, the imaging target region may be set by ordering the components in ascending order of resolution.
18 to 24 show the result of setting the imaging target region by ordering the components of the board shown in FIG. 2 in ascending order of resolution, step by step.

  As indicated by the circled numbers in each figure, in this embodiment, in contrast to the example in FIG. They are ordered in order from one part. The procedure for setting the imaging target area is the same as that in FIG. 5 except that the order of ST1 is reversed and the resolution R is set to the lowest level L3 in ST3. Therefore, the detailed description of this embodiment will be omitted with reference to FIGS. 18 to 24 (in these drawings as well, the respective imaging target areas are denoted by B1, B2,... In the order of setting. The state after adjustment of the second region B2 and the initial setting state of the third region B3 are collectively shown in FIG.

  In the inspection using the imaging data set in the embodiments of FIGS. 18 to 24, a part (for example, No. 4) in which an image having a resolution lower than the set resolution level is generated in the inspection area. The resolution is adjusted by expanding the image. In this case, if the pixel complementing process is executed during the expansion process, a reduction in resolution can be suppressed to some extent.

In the above embodiment, the image pickup target areas are set in order from the maximum size, and therefore the total number of the image pickup target areas is smaller than in the previous embodiment. Therefore, since the number of times of imaging at the time of inspection can be reduced, the time required for the inspection can be shortened accordingly.
Therefore, if a highly accurate inspection is not required, the imaging target area may be set by the method of this embodiment.

It is a block diagram of the board | substrate inspection apparatus concerning one Example of this invention. It is explanatory drawing which outlines and shows the structure of the board | substrate to be examined. It is explanatory drawing which shows the result of having ordered each component on the board | substrate of FIG. 2 in order with high resolution. It is explanatory drawing which shows the structural example of an imaging data table. It is a flowchart which shows the flow of a setting process of an imaging target area. It is explanatory drawing which shows the method of determining the possibility of component allocation. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is a flowchart which shows the flow of a test | inspection. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate. It is explanatory drawing which shows transition of the setting process of the imaging target area | region with respect to a board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Controller 2 Camera 3 Board | substrate stage 11 Memory 12 Magnification adjustment process part 14 XY stage control part 16 Memory

Claims (4)

Assuming that a workpiece including a plurality of parts to be inspected with different imaging magnification settings is imaged a plurality of times while switching the imaging magnification of the imaging means, the imaging target area of each imaging magnification is determined using the design drawing information of the workpiece After performing the preparation step for setting the image, multiple times of imaging by adjusting the positional relationship between the workpiece and the imaging means and the imaging magnification so that each imaging target area set in the preparation step is sequentially imaged In a method for inspecting each inspected part using an image generated by each imaging,
In the step of preparing, after ordering each site to be inspected on the workpiece in order from the highest or lowest imaging magnification set, the first site to be inspected in the design drawing information along the order is arranged. Pay attention in order from the examination site, and on the condition that the site to be inspected is not already assigned to another region to be imaged, the imaging target region of the imaging magnification corresponding to the site to be examined is inspected. An inspection method characterized by assigning all the parts to be examined that are included in the imaging target area and are not assigned to other imaging target areas to the set imaging target area, while setting the position including the part. . The inspection method according to claim 1,
In the process of setting the imaging target area in the preparation step, other untested parts to be examined are provided on the condition that the part to be examined that has been assigned to the set imaging target area does not come out of the imaging target area. The inspection method of adjusting the set position of the imaging target region so as to include. The inspection method according to claim 1,
In the inspection, when a region to be inspected that does not correspond to the imaging magnification of the region is assigned to the region to be imaged corresponding to the image to be processed, the image magnification of the region to be inspected corresponding to the region to be inspected An inspection method for converting to an image having a resolution suitable for the above and performing image processing for the inspection on the converted image. A workpiece including a plurality of parts to be inspected with variation in imaging magnification setting is imaged a plurality of times while switching the imaging magnification of an imaging means capable of switching the imaging magnification, and each image is generated using the images generated by each imaging. In the device that inspects the inspected part,
Area setting means for setting an imaging target area for each imaging magnification using the design drawing information of the workpiece; storage means for registering information necessary for imaging each imaging target area set by the area setting means; Based on the registration information of the storage means, the imaging control means for performing the plurality of times of imaging by adjusting the positional relationship between the workpiece and the imaging means and the imaging magnification and driving the imaging means; generated by the plurality of times of imaging Image processing means for executing image processing for the inspection using each of the obtained images in order,
The region setting means arranges each inspected part on the workpiece in order of the set imaging magnification in order of high or low, and then firstly inspects each inspected part in the design drawing information along the order. Pay attention from the region in order, and on the condition that the region to be inspected being focused is not already assigned to another region to be imaged, the region to be inspected with the imaging magnification corresponding to the region to be inspected being focused A measurement processing apparatus that executes a process of assigning all the parts to be examined that are included in the imaging target area and are not assigned to other imaging target areas to the set imaging target area.

Images