JP4573255B2 - Appearance inspection apparatus and appearance inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an appearance inspection technique. In particular, the present invention relates to an appearance inspection apparatus and an appearance inspection method for scanning an upper surface of an object to be inspected and acquiring an image for inspection.
[0002]
[Prior art]
The manufacturing process of the substrate of the electronic device includes a mounting process for mounting the electronic component on the substrate and an inspection process for inspecting the mounting state of the component. The mounting process is progressing in density, and the mounting position of the electronic component is determined on the order of several tens of microns. In addition, the demand for IT-related devices, particularly mobile devices such as mobile phones, is increasing, and the mounting process is increasing year by year. On the other hand, in the inspection process after component mounting, it is extremely difficult to find defects due to the high density of the substrate. In conventional inspection, contact type test methods such as ICT (In-Circuit Tester) using a prober were used. However, the recent high mounting density makes it difficult to handle with a contact type inspection device, and it is non-contact. There is an increasing demand for visual inspection devices using molds, particularly image recognition technology.
[0003]
In such an appearance inspection apparatus, it is necessary to photograph the mounting state of a component with a very high resolution corresponding to high-density mounting and to detect a defect with high accuracy. Therefore, the time required for inspection tends to be longer. Even if the demand for integrated circuits increases and the speed of the mounting process increases, if the inspection process takes a long time, the shipment of products will be delayed, making it impossible to withstand the recent severe manufacturing competition. In addition, once a defect is found in a product that has been shipped, extra work such as collection, repair, and re-shipment occurs, and the costs for that are not covered by the sales profit of the product. Accordingly, there is an urgent need to realize a one-way logistics that can reduce the inspection time and bring the product defects and complaints about the product to zero as much as possible by using a more accurate appearance inspection apparatus.
[0004]
As an example of such an appearance inspection apparatus, Patent Document 1 discloses that a camera is driven in the X and Y directions to spotly image an inspection site on a non-defective substrate surface, which is stored in a memory as a reference model, and inspected. There has been disclosed a circuit board inspection apparatus that performs inspection in comparison with a captured image of a substrate.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-140087 (full text, Fig. 1-10)
[0006]
[Problems to be solved by the invention]
In the apparatus disclosed in Patent Document 1, the camera is moved in the X and Y directions, an image of a specific inspection region is spot-photographed, and compared with the image of the inspection region of the reference model acquired in advance. In such an appearance inspection apparatus that moves the imaging location in the XY directions, even if a 1 million pixel CCD (charge-coupled device) image sensor is used, an image is captured at a pixel pitch of 20 to 30 micrometers. Then, it is only possible to photograph an area of 2 to 3 cm in length and width at a time, and it takes a very long time to inspect the entire substrate. In addition, it is necessary to prepare and store an image of a reference model in advance for each inspection frame, and set inspection reference parameters, which makes setting work before inspection very complicated.
[0007]
In recent years, substrate manufacturing has increased in the form of multi-model, small-volume production. Therefore, it is necessary to determine inspection points according to individual substrates and set appropriate inspection parameters. There may be tens of thousands of inspection points, and the work of setting inspection parameters for each one requires a lot of labor.
[0008]
Also, in the actual board production line, even if the same board is produced, there are always lot-to-lot differences such as subtle differences in the external shape and color of the components mounted in each lot. In the setting of the inspection parameter ignoring, a good product may be determined to be defective. Although it is necessary to adjust the parameter for defect determination every time the lot changes, the work becomes a heavy burden at the manufacturing site, and the work efficiency is lowered.
[0009]
The present invention has been made in view of such circumstances, and an object thereof is to provide a high-speed and high-precision appearance inspection technique suitable for introduction into a substrate production line.
Another object is to provide an appearance inspection technique capable of easily and highly accurately performing a flexible inspection according to an actual production situation that is frequently changed.
[0010]
[Means for Solving the Problems]
One embodiment of the present invention relates to an appearance inspection apparatus. This apparatus has a one-dimensional sensor that detects reflected light from the upper surface of the object to be inspected, and obtains an inspection image over the entire upper surface of the object to be inspected by scanning of the one-dimensional sensor, and the scanning head An image memory that stores an image of the entire upper surface of the object to be inspected acquired as an inspection image, and an analysis unit that determines the quality of the object to be inspected by comparing the inspection image with a reference image. The reference image is an image that is stored in the image memory and covers the entire top surface of a non-defective object. Here, both the inspection image and the reference image are full-size images obtained by imaging the entire upper surface of the inspection object.
[0011]
The scanning head includes a plurality of illumination sources that project light onto the inspection surface of the object to be inspected, and the plurality of illumination sources are configured to be selectively lit and the image memory includes each illumination pattern. A plurality of inspection images may be formed. The plurality of illumination sources may project light from different angles onto the inspection surface of the object to be inspected, and by selectively controlling lighting of these illumination sources, different illumination patterns are formed to form a plurality of inspections. An image can be taken. The scanning head includes an epi-illumination source that projects light onto the inspection surface of the object to be inspected from above and a side illumination source that projects light from an oblique direction onto the inspection surface of the object to be inspected. And the side illumination source can be selectively controlled to be lit, and the image memory may include an inspection image from the epi-illumination source and an inspection image from the side illumination source. .
[0012]
When it is determined by the analysis unit that the object to be inspected is non-defective, the inspection image of the object to be inspected determined to be non-defective when the user gives an instruction is used as the reference image. It may be stored in an image memory. In the image memory, the inspection image of the object to be inspected determined to be a non-defective product by the inspection by the analysis unit may be automatically stored as the reference image. Thereby, even when the reference image is not prepared in advance, the non-defective inspection image can be used as the reference image as it is.
[0013]
In the image memory, a plurality of non-defective images may be stored as reference images. Alternatively, the reference image in the image memory may be sequentially updated with the inspection image of the non-defective product obtained by the immediately previous inspection. As a result, even if the color of each lot is slightly different, for example, the inspection image of the non-defective product that was inspected immediately before can be used as the reference image for the next inspection, so that the difference between lots can be immediately reflected in the inspection. Therefore, it is possible to save the trouble of adjusting the inspection parameters for each lot.
[0014]
The analysis unit includes a determination criterion storage unit that stores a predetermined determination criterion for each inspection frame set on the inspection image, and inspects the inspection image in the inspection frame against the determination criterion. Good. If sufficient inspection is not possible just by inspecting the inspection image against the reference image, or if detailed inspection is required for a specific inspection site, by inspecting against the predetermined criteria for each inspection frame, A finer inspection is possible.
[0015]
Another aspect of the present invention relates to an appearance inspection method. A step of storing an inspection image over the entire inspection surface of the inspection object in an image memory by scanning the upper surface of the inspection object with a one-dimensional line sensor, and collating the inspection image stored in the image memory with a reference image Accordingly, a non-defective inspection image obtained in the inspection process is reused as the reference image.
[0016]
It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a configuration diagram of an appearance inspection apparatus 10 according to the embodiment. In this apparatus, an inspection surface of an object to be inspected is scanned with a line sensor to form an image, and pass / fail of a component mounting state is determined by image recognition. By driving the scanning head perpendicular to the imaging line by the line sensor, an image for each line is obtained sequentially, and an entire image of the inspection surface is acquired by one-dimensional movement of the scanning head. The present applicant has previously proposed an appearance inspection apparatus using such a one-dimensional sensor in Japanese Patent Application Laid-Open No. 8-254500, which may be used in this embodiment.
[0018]
As shown in FIG. 1, the appearance inspection apparatus 10 includes a main unit 12 and a test unit 14. A support base 22 is provided below the test unit 14 to hold the substrate 1 as an example of an object to be inspected. Above the test unit 14, a scanning head 16, a stepping motor 20 that drives the scanning head 16, and a guide 18 such as a linear guide that supports the scanning head 16 are provided.
[0019]
The scanning head 16 has an illumination unit 30, a lens 32, and a line sensor 34. These members are fixed on the frame 36. The illumination unit 30 includes an epi-illumination source, a side illumination source, a half mirror, and the like. The reflected light vertically upward from the substrate 1 is guided to the lens 32 by the half mirror, and after passing through the lens 32, is input to the line sensor 34 which is a one-dimensional CCD sensor. The line sensor 34 images the substrate 1 line by line and outputs the image data 54.
[0020]
The main unit 12 controls the entire apparatus as a whole. The main unit 12 can be realized by a CPU, memory, or other LSI of any computer in terms of hardware, and an appearance inspection loaded into the memory in terms of software. It is realized by a functional program or the like, but here, functional blocks realized by their cooperation are depicted. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.
[0021]
First, the head control unit 40 of the main unit 12 supplies the illumination control clock 50 to the illumination unit 30, and switches on and turns off the epi-illumination and the side illumination for each line. The head control unit 40 further outputs a motor control signal 52 to the motor 20 and a test start signal 56 to the memory control unit 42, respectively. The motor 20 is step-controlled by the motor control signal 52, and the scanning head 16 moves to the end of the substrate 1 at the start of inspection. With this position as the start position, the scanning head 16 advances by one line by the motor control signal 52 every time one line is imaged thereafter. On the other hand, referring to the test start signal 56, the memory control unit 42 controls the writing of the image data 54 to the image memory 44. Thereafter, the image data 54 is recorded in line units. The image data 54 is selectively input for each line by epi-illumination and side-illumination, and when all lines have been imaged, the image memory 44 stores the appearance inspection image by epi-illumination. An image for appearance inspection by side illumination is formed. Hereinafter, these two types of appearance inspection images may be collectively referred to as an inspection image 41. Note that the internal configuration of the image memory 44 and the arrangement of the image data 54 in the image memory 44 have a degree of freedom in design, and various configurations are possible. For example, in the image memory 44, two independent storage areas for individually storing the inspection image by the epi-illumination and the inspection image by the side illumination are provided, and the memory control unit 42 stores each storage area for each line. Alternatively, the image data 54 may be controlled to be stored separately. Alternatively, in the image memory 44, a single storage area for storing the inspection image by the epi-illumination and the inspection image by the side illumination is provided, and the memory control unit 42 stores the image data in the single storage area. It may be controlled so that 54 is alternately stored line by line.
[0022]
The image memory 44 also stores a reference image 43 used for comparison with the inspection image 41. The reference image 43 is obtained by reusing the non-defective inspection image 41 as it is, and as described above, there are an incident illumination and a side illumination. The analysis unit 46 compares the inspection image 41 in the image memory 44 with the reference image 43 to check whether the features on the image match. For example, applying normal image processing techniques such as comparing brightness, saturation, chromaticity, extracting contour lines based on pixel values, and comparing differential values of pixel values Compare image features.
If there is a difference in image characteristics between the inspection image 41 and the reference image 43, there is a possibility that a part is missing, a different part is mounted, or there is a falling part. The analysis unit 46 determines that the substrate 1 is a defective product. Otherwise, the analysis unit 46 determines that the substrate 1 is a non-defective product. When the analysis unit 46 determines that the substrate 1 is non-defective, the non-defective inspection image 41 is automatically replaced with the reference image 43 in accordance with a user instruction or automatically. That is, the reference image 43 already stored in the image memory 44 is overwritten by the inspection image 41 of the substrate 1 currently being inspected.
[0023]
The reference image 43 stored in the image memory 44 is stored in the hard disk 45 as necessary. For example, the necessary reference image 43 can be read from the hard disk 45 into the image memory 44 and used again at the next day's inspection. . Also, the user can manually create the reference image 43 and store it in the hard disk 45, and read it from the hard disk 45 into the image memory 44 as necessary. Further, a plurality of reference images 43 may be stored in the image memory 44 and used depending on the lot of the substrate 1, or a plurality of reference images 43 may be stored in the hard disk 45 to store the substrate 1. Depending on the type and lot, the necessary reference image 43 may be read from the hard disk 45 into the image memory 44 and used.
[0024]
In addition to comparing the inspection image 41 and the reference image 43 in the image memory 44, the analysis unit 46 can perform an inspection based on the determination criterion set for each inspection frame. However, this inspection may be performed as necessary. For the substrate 1 determined to be defective by comparing the inspection image 41 and the reference image 43, the substrate 1 is immediately replaced without performing inspection for each inspection frame. The inspection may be terminated by treating it as a defective product. If detailed inspection for each inspection frame is not necessary, the inspection of the substrate 1 may be completed only by comparing the inspection image 41 and the reference image 43.
[0025]
When performing the inspection for each inspection frame, the analysis unit 46 reads the inspection image 41 from the image memory 44 and determines pass / fail for each inspection item in light of the determination criterion recorded in the determination criterion storage unit 48 in advance. Items to be inspected include part misalignment due to epi-illumination test, determination of missing parts, solder leakage, etc., and presence / absence of solder bridges, incorrect mounting parts, polarity inversion, etc. For example, the determination of soldering due to the epi-illumination test can be accepted if a dark portion is uniformly formed around the electrode of the part, and can be rejected if a dark circle is formed away from the electrode. In the latter case, there is a high possibility that the solder does not rest on the electrode and remains on the land of the substrate 1 without melting in a low mountain shape. In any case, judgment criteria or a reference image regarding pass / fail is recorded in advance in the judgment criteria storage unit 48 for component mounting of the board 1 to be inspected, and these judgment criteria or reference images are applied to the synthesized image. A pass / fail decision is made.
[0026]
FIG. 2 is a perspective view of the test unit 14, and FIG. 3 is a schematic view of the test unit 14 as viewed from an imaging line direction 110 of the line sensor 34 (hereinafter simply referred to as an imaging direction). The illumination unit 30 has an epi-illumination source 100 and a side illumination source 102 that surround the half mirror 108. A lenticular sheet 106 is inserted between the epi-illumination source 100 and the half mirror 108, and the epi-illumination light passes through the lenticular sheet 106 and the half mirror 108 and is incident on the inspection surface of the substrate 1 with an incident angle of substantially zero. An acrylic sheet 104 is provided below the side illumination source 102. In this embodiment, the epi-illumination source 100 is given a width so that an epi-illumination component is present so that the incident angle becomes zero even when the substrate 1 is warped.
[0027]
As shown in FIG. 3, the epi-illumination source 100 is divided into two sub-boards 100 a and 100 b from the center, and each has an LED (light emitting diode) group 120 in the scanning direction 110. These sub-boards 100a and 100b are connected so as to face each other in a delicate manner, and each LED group 120 is arranged to efficiently project incident light onto the line 112 under inspection. On the other hand, the two side illumination sources 102 have the LED group 120 and, like the epi-illumination source 100, are inclined so as to efficiently project side light to the line 112. The reflected light from the line 112 is reflected by the half mirror 108 and directed to the lens 32. If this is shown in FIG. 2, the incident light L1 from a certain point P in the incident illumination source 100 is reflected near the point Q on the substrate 1, and the reflected light L2 is reflected again by the half mirror 108, and the reflected light L3. Enters the lens 32. It should be noted that the two groups of LED groups 120 close to the center of the epi-illumination source 100 and the other LED groups 120 have separate power sources (not shown) so that they can be controlled independently.
[0028]
The acrylic sheet 104 diffuses side light from the side illumination source 102. Since the side illumination source 102 is an aggregate of LEDs that are point light sources, if there is no diffusing action, there is a concern that spot-like light is reflected in image data and adversely affects inspection accuracy. On the other hand, the lenticular sheet 106 acts to narrow incident light to a component perpendicular to the substrate 1 in the scanning direction 110. The diffusing action related to the incident light is realized by the lenticular sheet 106.
[0029]
When the image data for one line is captured in the state of FIG. 2 or FIG. 3, the scanning head 16 is sent out for one line in the driving direction 114 by the guide 18. Thereafter, similar processing is repeated to obtain image data over the entire surface of the substrate 1.
[0030]
The configuration of the appearance inspection apparatus 10 has been described above. Next, an appearance inspection procedure by the appearance inspection apparatus 10 having the above configuration will be described.
[0031]
FIG. 4 is a flowchart showing an appearance inspection procedure according to the present embodiment. First, an initial reference image 43 used for the appearance inspection of the substrate 1 is set in the image memory 44. As the initial reference image 43, for example, a good product image that has been used in the inspection up to the previous day and stored in the hard disk 45 may be read and used. When a completely new substrate 1 is inspected, the reference image 43 may not exist. In such a case, the reference image 43 may be manually created and set in the image memory 44 by photographing the appearance of the substrate 1 once known to be non-defective.
[0032]
Next, the board | substrate 1 is installed in the support stand 22 (S12). The test unit 14 scans the upper surface of the substrate 1 to acquire an image (S14). At this time, an image from the epi-illumination source 100 and an image from the side illumination source 102 are taken and stored as an inspection image 41 in the image memory 44. Subsequently, the analysis unit 46 compares the inspection image 41 with the reference image 43 in the image memory 44 (S16). If there is a difference in image characteristics (Y in S18), the substrate 1 is determined to be defective (S20), the inspection of the substrate 1 is completed, and the process returns to step S12 to move to the next inspection of the substrate 1. .
[0033]
If there is no difference in image characteristics between the inspection image 41 and the reference image 43 (N in S18), the analysis unit 46 reads out the inspection frame data set in advance in the determination criterion storage unit 48, for each inspection frame. In addition, the parts are inspected for each inspection item in view of the feature amount of the inspection image 41 in accordance with the criterion (S22). As a result, component position deviation, polarity reversal, solder slip, solder bridge, and the like are inspected. Also in the inspection for each inspection item, a method may be used in which the reference image 43 in the image memory 44 is used to compare the feature amounts of the inspection image 41 and the reference image 43 on an inspection frame basis. Alternatively, a reference image prepared separately for each inspection frame may be read from the determination reference storage unit 48 and used for determination.
[0034]
When there is an unacceptable part inspection for each inspection frame by the analysis unit 46 (N in S24), the board 1 is determined to be defective and the defective part is presented to the user (S20). Exit. When the component inspection has passed for all the inspection frames (Y in S24), the analysis unit 46 determines that the board 1 is a non-defective product (S26). The analysis unit 46 determines whether or not to adopt the inspection image 41 of the substrate 1 determined to be non-defective as the reference image 43 (S28). This determination may be performed by an instruction from the user, and the inspection image 41 of the substrate 1 determined to be non-defective may be automatically adopted as the reference image 43. When the inspection image 41 of the non-defective substrate 1 is adopted as the reference image 43 (Y in S28), the reference image 43 in the image memory 44 is rewritten and updated with the inspection image 41 (S30). When the inspection image 41 of the non-defective substrate 1 is not adopted as the reference image 43 (N in S28), the same reference image 43 is used in the next inspection of the substrate 1 without rewriting the reference image 43 in the image memory 44. The After these processes for the inspection of the substrate 1, the process returns to step S12 again, the next substrate 1 is installed, and the inspection is repeated.
[0035]
As described above, according to the appearance inspection apparatus of the present embodiment, the upper surface of the substrate is scanned with a line scanner to obtain a single image, and the image is compared with a reference image prepared in advance. Therefore, it is possible to inspect defective products efficiently. In the conventional appearance inspection method, it is necessary to set an inspection frame, and it is necessary to register inspection data of about tens of thousands of points in advance, but in this embodiment, parts are missing due to comparison with the reference image. It is possible to easily identify defects such as falling parts and the like, and no inspection frame setting is required.
[0036]
In addition, in the part inspection for each inspection frame, since an area not designated in the inspection frame is not inspected, an unexpected defect cannot be found, but in this embodiment, by comparison with a reference image For example, it is possible to deal with a case where a foreign object is dropped in an area other than the inspection frame or a new type of problem encountered for the first time. Furthermore, it is possible to use both inspection by comparison with the reference image and detailed inspection for each inspection frame. In that case, the number of points and inspection items to be specified as inspection frames can be greatly reduced. It leads to efficiency.
[0037]
In addition, according to the appearance inspection apparatus of the present embodiment, inspection can be performed simply by adopting a non-defective image as a reference image. Therefore, when generating inspection data, advanced skills for setting determination logic, parameters, and the like are not required. Also, since inspection data generation does not take time, it is very suitable for high-mix low-volume production.
[0038]
In addition, by reusing a non-defective image after the inspection as a reference image, it is not necessary to create and register a non-defective or defective image in advance, thus eliminating the setting work before the inspection and improving work efficiency. be able to. Furthermore, even if there are subtle differences between lots, such as the color and shape of parts differing from lot to lot, even on the same board, the inspection data is matched to the lot by sequentially updating the reference image with a non-defective image. This eliminates the need to re-set, and allows inspection to be continued by absorbing lot differences.
[0039]
The present invention has been described based on some embodiments. It is understood by those skilled in the art that these embodiments are exemplifications, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. By the way.
[0040]
As such a modification, in the above description, both the image by the epi-illumination and the image by the side illumination are used as the inspection image 41, and the image by the epi-illumination and the side illumination is stored as the reference image 43, respectively. However, the inspection may be performed by capturing three or more types of inspection images using more illuminations. Due to differences in the angle and intensity of the illumination light with respect to the inspected object, differences in brightness, saturation, chromaticity, etc. occur in the image of the inspected object, and the characteristics on the image differ greatly. It is effective to use and inspect. Conversely, depending on the inspection content, the inspection may be performed using only one of the image by epi-illumination and the image by side illumination.
[0041]
In the above description, the inspection of the substrate 1 after soldering of the components has been described as an example. However, the inspection image 41 and the reference image 43 are compared with respect to the inspection of the substrate 1 in the cream solder application state before the components are bonded. The appearance inspection by doing is possible. In particular, when inspecting the application state of cream solder, it is often possible to easily determine whether or not it is defective by comparing features on the image.
[0042]
【The invention's effect】
According to the present invention, it is possible to efficiently inspect a substrate to be inspected by appropriately using an image of a non-defective substrate.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an appearance inspection apparatus according to an embodiment.
FIG. 2 is a detailed perspective view of a test unit according to the embodiment.
FIG. 3 is a side view of a scanning head including an illumination unit.
FIG. 4 is a flowchart showing a procedure of an appearance inspection method according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Board | substrate 10 Appearance inspection apparatus 12 Main unit 14 Test unit 16 Scan head 30 Illumination unit 32 Lens 34 line sensor 40 Head control unit 42 Memory control unit 41 Inspection image 43 Reference image 44 Image memory, 45 hard disk, 46 analysis unit, 48 criteria storage unit.

Claims (8)

A scanning head having a one-dimensional sensor for detecting reflected light from the upper surface of the substrate on which the component is mounted, and acquiring a full-size inspection image over the entire upper surface of the substrate by scanning of the one-dimensional sensor;
An image memory for storing a full-size image of the entire top surface of the substrate acquired by the scanning head as an inspection image;
On the inspection image, a determination criterion storage unit that stores a predetermined determination criterion for each inspection frame set in advance for the component of the board;
The full-size inspection image including the area not specified in the inspection frame is a full-size image stored in the image memory and covering the entire upper surface of the non-defective substrate, and is not specified in the inspection frame. An analysis having means for determining the quality of the substrate by collating with a reference image including a region, and means for inspecting the inspection image in the inspection frame with respect to the determination reference for each part of the inspection frame Including units,
The analysis unit compares the inspection image with the reference image to determine pass / fail of the substrate, and when it is determined that the substrate is defective, the analysis unit does not perform component inspection within the inspection frame. A visual inspection device. A scanning head having a one-dimensional sensor for detecting reflected light from the upper surface of the substrate on which the component is mounted, and acquiring a full-size inspection image over the entire upper surface of the substrate by scanning of the one-dimensional sensor;
An image memory for storing a full-size image of the entire top surface of the substrate acquired by the scanning head as an inspection image;
On the inspection image, a determination criterion storage unit that stores a predetermined determination criterion for each inspection frame set in advance for the component of the board;
The full-size inspection image including the area not specified in the inspection frame is a full-size image stored in the image memory and covering the entire upper surface of the non-defective substrate, and is not specified in the inspection frame. An analysis having means for determining the quality of the substrate by collating with a reference image including a region, and means for inspecting the inspection image in the inspection frame with respect to the determination reference for each part of the inspection frame Including units,
The appearance inspection apparatus characterized in that the means for determining the quality of the board determines whether a component is missing, a different component is mounted, or a falling component is present.   The scanning head includes a plurality of illumination sources that project light onto the inspection surface of the substrate, and the plurality of illumination sources are configured to be selectively controllable. The image memory includes a plurality of illumination sources for each illumination pattern. The appearance inspection apparatus according to claim 1, wherein the inspection image is formed.   When the analysis unit determines that the substrate is non-defective, the inspection image of the substrate determined to be non-defective when the user gives an instruction is stored in the image memory as the reference image. The appearance inspection apparatus according to claim 1, wherein the appearance inspection apparatus is provided.   4. The image memory automatically stores the inspection image of the substrate determined to be non-defective by the inspection by the analysis unit as the reference image. Appearance inspection apparatus as described.   6. The appearance inspection apparatus according to claim 5, wherein the reference image in the image memory is sequentially updated by the inspection image of the non-defective product obtained by the immediately preceding inspection. A step of acquiring a full-size inspection image over the entire inspection surface of the substrate by scanning the upper surface of the substrate on which the component is mounted with a one-dimensional line sensor, and storing it in an image memory
A full-size inspection image that includes an area that is stored in the image memory and that is not designated in the inspection frame set in advance for the parts of the substrate on the inspection image is displayed over the entire upper surface of a non-defective substrate. A step of determining pass / fail of the substrate by collating with a reference image including a region not designated in the inspection frame, and
When it is determined that the substrate is defective in the step of determining whether the substrate is good or bad, the inspection image is performed in accordance with the determination criteria set for each inspection frame in the inspection frame. And a step of performing component inspection for each inspection frame when it is determined that the substrate is not defective in the step of determining whether or not the substrate is good without performing inspection.   The appearance inspection method according to claim 7, wherein a non-defective full-size inspection image obtained in the inspection process is reused as the reference image.

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