JP2001264265A - Automatic appearance inspecting device for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect for an existence of a defect of the like in a BGA.CSP printed wiring board, particularly in a gold-plated part, with very high accuracy including delicate difference in color tone. SOLUTION: This automatic appearance inspecting device inspecting the shape of gold-plating on the printed wiring board has CCD cameras CB and CS obtaining images related to an inspection objective portion formed on the printed wiring board, inspection stages TB and TS mounting the board, XY stages SS and SB positioning the cameras above the inspection objective portion on the board, conveying units UB and US provided with adsorbing tools conveying the board for mounting it on the inspection stage device and conveying the board from the inspection stage device after finishing the inspection of the board, and an inspection process control part arithmetically processing image data obtained from the cameras on the basis of color information for extracting an image pattern related to the gold-plating of the inspection objective portion, detecting a detect of the extracted pattern, and storing the detection result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic appearance inspection apparatus for an electrode portion formed on a printed wiring board, and more particularly to an automatic inspection apparatus for automatically inspecting a gold plated portion on an electrode formed on a printed wiring board for defects. The present invention relates to an automatic appearance inspection device.

[0002]

2. Description of the Related Art With the recent miniaturization and high integration of information communication devices such as mobile phones and personal computers, and the advent of new media such as memory cards for mobile terminals, the mounting area for internal mounting components has become very narrow. The range is limited. Under such circumstances, the semiconductor package has been conventionally a lead frame package type (QFP type), but a ball grip package (BGA) has been adopted. Furthermore, recently, when the ball pitch is O.D.
With the transition to a chip size package (CSP) that is a fine BGA having a size of 8 mm or less, the need for so-called light-weight, ultra-small packages has rapidly risen.

The development of printed wiring boards used for these BGAs and CSPs has been remarkable, and the production volume has rapidly increased due to the rapid spread of information terminal equipment and the like. In addition to the rapid increase in production volume, the quality requirements for PCBs at the time of acceptance at each assembly maker are becoming increasingly strict, and each manufacturer of printed wiring boards will maintain and operate a certain level of quality control. Is becoming very costly.

[0004] As one of the quality improvements inside such a new type of semiconductor package, when wire-bonding or bump connection from a semiconductor chip is performed, it is necessary to form a connection on a micro copper pattern as a connection destination in order to make these connections easier. Gold plated. Here, whether or not the applied gold plating is accurately and reliably formed on the extremely small copper pattern may be close to the final step of semiconductor package manufacturing, and particularly affects quality control.

Therefore, the shape of the gold plating applied to the copper pattern of the printed wiring board is inspected by a black and white image inspecting machine. Through this inspection, an abnormal state of the gold plating is detected and quality control is performed.

[0006]

FIG. 1A to FIG. 1H show various abnormal states which occur in the shape of gold plating applied on a copper pattern of a printed wiring board. Here, A represents the copper pattern of the electrode on the printed wiring board, and B represents the shape of the gold plating applied on the copper pattern of the electrode.

FIG. 1A shows an example in which the shape B is not applied to a normal position on the pattern A and is shifted from each other.
(B) is an example in which the shape B is applied to a normal position on the pattern A, but the gold plating projects outside the pattern as a defective portion _Bd . (C) is an example in which the state of (b) is further enlarged and combined with the gold plating on the adjacent pattern A.

[0008] (d) is the shape B was subjected to a normal position on the pattern A, gold is not applied in the middle part as a defective portion B _d, the shape of the gold plating, part B _1, B ₂
This is an example where it is divided into two. (E)
Although this example is similar to the example of FIG. 9A, the shape B is not applied to a normal position on the pattern A, and as a result, an adjacent gold-plated part is approached.

[0009] (f) is, the shape B is performed in a normal position above the pattern A, an example that is not gold is applied in the peripheral portion of the pattern A as a defective portion B _d. (G)
The figure shows an example in which the shape B is applied to a normal position on the pattern A, but the gold plating of the shape B has a flaw or the like. (H) shows that the shape B was applied to a normal position on the pattern A, but foreign matter such as a resist
This is an example in which discoloration exists.

As described above, when the gold plating provided on the copper pattern relating to the electrodes of the printed wiring board has discoloration, spots, scratches, no gold plating, pattern defect, or foreign matter adhesion, bonding connection from the semiconductor chip is performed. When doing
The possibility of connection failure is high. In order to inspect and find these abnormal defects, a binarized black-and-white image inspection machine has conventionally been introduced. However, even if this inspection machine is actually introduced, (d), (f), and
In the method based on binarization of a black and white image as shown in (g) and (h), it is very difficult to identify defects such as discoloration, spots, and pattern defects in a gold-plated pattern portion having extremely similar luminance to a copper pattern. Have difficulty.

For this reason, these abnormal defects are often overlooked, and the yield is reduced. On the other hand, the appearance inspection machine itself is very expensive, and in many cases, ultimately it is necessary to rely on visual inspection. Then, only the visual inspection has a problem in terms of cost such as labor cost and inspection quality. Further, protective paper is inserted between the substrates to prevent sulfidation on the surface of the printed wiring board. For example, when transported to the next step, these substrates are stored in a magazine together with protective paper. In this state, it is carried into the inspection process. Then, the protective paper must be removed from the substrate before the inspection, and when the inspected substrate is stored in the magazine, the protective paper must be placed again between the substrates. These operations are performed manually, which is troublesome for the inspector.

[0012] Further, as described above, in the case of a black-and-white image obtained by binarization, there is a case where it is difficult to discriminate the image. In the case of this re-examination, the operation is troublesome as in the case of the inspection. Then, it takes time to identify an abnormal defect portion on the substrate at the time of the re-inspection. As described above, there are various problems at the inspection site of the printed wiring board.

Therefore, the present invention improves the inspection quality of a gold-plated portion defect on a printed wiring board, automates the transfer of the printed wiring board and protective paper, and improves the inspection efficiency in conjunction with the re-inspection process. Aim.

[0014]

Therefore, in order to solve the above problems, an automatic appearance inspection apparatus for inspecting the shape of gold plating on a printed wiring board uses an image related to a portion to be inspected formed on the printed wiring board. A CCD color camera that obtains an image, an inspection table device on which the substrate is mounted, an XY drive device that moves the camera and positions the inspection object above a portion to be inspected on the substrate, and an inspection table that transports the substrate and Placed on the apparatus, after the inspection of the substrate, after the substrate, a transport device having a suction device for transporting the substrate from the inspection table device,
Further, by performing an arithmetic process on the image data obtained from the camera based on the color information, an image pattern relating to gold plating of the inspection target portion is extracted, a defect of the extracted pattern is detected, and a detection result is stored. A processing control unit.

The transport device removes the protective paper from the substrate magazine, and then transports the substrate while sucking and holding the substrate. After the inspection of the substrate, stores the substrate in the substrate magazine, and removes the protective paper from the protective paper magazine. And the protective paper is placed on the substrate. Further, the automatic appearance inspection apparatus includes a re-examination table apparatus arranged apart from the inspection table apparatus, and a visual re-examination apparatus arranged in the re-examination table apparatus and re-inspecting the failed board. Have.

The reinspection table apparatus is moved and adjusted in accordance with the position information stored in the inspection result so that the reinspection target portion on the substrate enters the inspection range of the visual reinspection apparatus. A spotlight can be illuminated from the visual reexamination device on the portion to be reexamined. A first CCD color camera for inspecting a front side of the substrate and a first CCD color camera;
An inspection table device, a second CCD color camera and a second inspection table device for inspecting the back side of the substrate, and a reversing device for reversing and transporting the substrate from the first inspection table device to the second inspection table device. A first transport device that removes the protective paper on the substrate stored in the substrate magazine and transports the substrate to the first inspection platform device; and a substrate that has been inspected from the second inspection platform device. And a second transport device that transports and stores the protective paper in the magazine, takes out the protective paper from the protective paper magazine, and places the protective paper on the stored substrate.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.
FIG. 2 shows an automatic appearance inspection apparatus for inspecting an electrode portion formed on a printed wiring board (hereinafter, referred to as a board). Here, the outline of the configuration related to the automatic inspection process of the automatic appearance inspection apparatus is shown in a bird's-eye view.

The automatic inspection step of the automatic appearance inspection apparatus is performed in the first
It comprises an inspection stage T _S , a second inspection stage T _B , a first transport unit U _S , a second transport unit U _B , a first CCD color camera C _S , a second CCD color camera C _B , and a substrate supply magazine M. The inspection can be performed on both the front side and the back side of the substrate. However, in FIG. 2, the support members of each part of the configuration,
The drive device and the like are omitted, and the relative positional relationship is exaggerated.

The first inspection stage T _S and the second inspection stage T _B have inspection tables 1 and 2 respectively, and a fixture 3 for positioning and fixing the conveyed substrate is provided on those inspection tables. , 4 are provided. The inspection tables 1 and 2 are fixed. First conveying unit U _S and the second
Conveyance unit U _B has arms 5,7 movable in the X direction, respectively, in their arms 5,7, adsorbing the substrate or protective paper, the holder 6 and 8 can hold is provided . The holders 6 and 8 are configured to move up and down in the Z direction, and are provided in a required number so as to be able to hold a substrate or protective paper.

[0020] The 1CCD color camera C _S and the 2CC
D color camera C _B is the 1XY stage respectively S _S
And by the 2XY stage S _B, it can be moved in the XY direction on the substrate, and is supported so as to be a distance adjustment between the substrate in the Z direction. For various magazines,
First, in the front side inspection process, the board supply magazine M and the protection paper discharge magazine M _P1 are arranged on the upstream side of the first inspection stage T _S , and in the back side inspection process, the OK substrate magazine M _O and the protection paper supply magazine M _P2 and NG board magazine M _N is disposed on the downstream side of the second inspection stage T _B.

Then, between the first inspection stage T _S and the second inspection stage T _B , the substrate fixed on the front side is inverted from the first inspection stage T _S to the back side, and the second inspection stage T _S is inverted. A reversing device R for transporting on T _B is provided. FIG. 2 shows a case in which the reversing device R is provided with a chuck 9 for reversing 180 degrees and transports the substrate in the X direction while reversing the substrate, but is not limited to this mode.
For example, a first inspection stage T _S and a second inspection stage T _B
When the arm reaches the both sides by rotating by 180 degrees, the substrate can be turned upside down and transported similarly to the reversing device R even if an arm having a substrate chuck at the tip is used.

In the automatic appearance inspection apparatus configured as described above, first, the substrate to be inspected is a substrate supply magazine M
Is placed on the upstream side of the first inspection stage T _{S while} being stored together with the protective paper. First conveying unit U _S is a protective sheet is put drives the arm 5 on the substrate of the substrate feed in the magazine M adsorbed and held, transported to the protective sheet discharge magazine M _P1, houses.

Next, the substrate in the substrate supply magazine M is sucked and held and transported onto the inspection table 1 of the first inspection stage T _S. When the substrate is placed on the inspection table 1, the substrate is positioned and fixed at a predetermined position. And the first CCD
The color camera CS is moved and adjusted in the _X and Y directions,
Images are sequentially acquired for a plurality of inspection target areas on the substrate.

[0024] the front side of the inspection of the substrate at the first inspection stage T _S is completed, the inversion apparatus R while reversing the substrate is conveyed onto the examination table 2 of the second inspection stage T _B. Here, similarly, it is positioned and fixed on the inspection table 2. Next, on the back side of the substrate, as in the front side, the second CCD
Color camera C _B is gradually being moved and adjusted in the XY direction acquired sequentially image the inspection target region of the back.

Second inspection stage T_BInspection of the back side of the board with
Is completed, the second transport unit U _BDrives the arm 7
The board on the inspection table 2 that has passed the inspection
Has OK board magazine M_OConveyed to and rejected
NG board magazine M_NTransport to
Furthermore, the pass / fail is selected and the board is
After being transported and stored, the suction device 8 of the arm 7
Protective paper supply magazine M _P2Remove the protective paper stored in
And put the protective paper on the board stored in each magazine.
Pay.

The automatic board inspection process is completed as described above. Next, the structure of the re-inspection process for re-inspection of the board stored in the NG board magazine _MN will be described with reference to FIG. I do. The reinspection process of the automatic appearance inspection apparatus includes a reinspection stage T _R , an optical inspection apparatus O, and an NG board magazine _MN . Here, similarly to FIG. 2, the supporting device or the driving device of each component is omitted.

[0027] re-examination stage T _R, the optical inspection apparatus O,
For example, the movement can be adjusted in the X and Y directions so as to move relatively to the microscope. In the optical inspection device O, the inspector can confirm the position of the defect portion to be re-inspected on the substrate,
A cross mark is placed at the center of the field of view, or a defective portion on the substrate is illuminated with a spotlight using, for example, a red LED. Alternatively, the light may be illuminated in a ring shape only to indicate the location of the part. When illuminating with this LED, re-inspection is possible also by visual inspection from the side without passing through the optical inspection device O.

According to the re-inspection process configured as described above,
Auto inspection process is NG board magazine M _N you exit brought, the inspector, the substrate is taken out while removing the protective paper from the NG board magazine M _N, bring on the inspection table of the re-examination stage T _R. On the inspection table, the substrate is positioned and fixed at a predetermined location. Reinspection stage T _R on the basis of the acquired position information of the defect portion in the automatic inspection step, the substrate is moved in the XY direction, the defect portion of the re-inspected is set to be in a position directly below the optical inspection device O . When there are a plurality of defective portions to be re-inspected, the defect portions are sequentially moved and adjusted to a position directly below the optical inspection apparatus O while receiving an instruction input from the inspector.

After the re-inspection of the front side and the back side of the board is completed, the inspector puts the board in the OK board magazine M _O if the board has passed the re-inspection, Are stored in the NG substrate magazine _MN . When the substrate is stored, a protective paper must be interposed. Therefore, a protective paper supply magazine _MP2 is prepared, the protective paper is taken out of the magazine, and placed on the substrate every time the substrate is stored.

In FIG. 3, the optical inspection apparatus O is employed as the inspection means for re-inspection, but the CCD shown in FIG.
A color camera may be used. In this case, the visual inspection is performed by the monitor device. Then, as in the case of FIG. 2, instead of moving the retest stage T _R in the XY directions, it is also possible to move toward the CCD color camera. Further, for example, a mark surrounding the defective portion is displayed on the screen of the monitor device so that the position of the defective portion to be re-inspected can be known. Further, the color image acquired by the CCD color camera can be re-examined by changing the attribute conditions.

As described above, the automatic inspection step and the re-inspection step of the automatic appearance inspection apparatus according to the embodiment of the present invention are configured as shown in FIGS. 2 and 3. FIG. An example of a magazine layout relationship is shown. 4, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals. FIG. 4A shows the arrangement of each inspection stage and each magazine divided into an automatic inspection process and a re-inspection process.
They are arranged to flow from top to bottom on the paper.

FIG. 4B corresponds to this automatic inspection process.
As shown in, the first conveying unit U _S and the second conveying unit U _B, and the reversing device R is arranged. This arrangement is similar to the configuration of FIG. However, in the automatic inspection process, instead of inspecting both sides of the substrate, for example,
If only the front side of the substrate is inspected first, and then the back side is inspected, if a batch process is performed, it is sufficient if any one of the substrate surface inspection stage T _S or the substrate back surface inspection stage T _B is used, Along with this, CCD color camera C
_S or CCD color camera C _B also requires one inspection station. Further, the reversing device R is not required.

FIG. 3 shows a case where the inspector transfers the substrate and the protective paper in the re-inspection step, but this operation can be automated. As shown in FIG.
For example, it can be a second conveying unit U retest conveying unit U _R a configuration of _B used in the substrate backside inspection shown in FIG. Further, in the automatic appearance inspection apparatus shown in FIGS. 2 and 3, the NG board magazine _MN is transferred to the reinspection step, and the board to be reinspected is taken out of the transferred NG board magazine _MN . . Here, in order to shift the board rejected in the automatic inspection process from the automatic inspection process to the re-inspection process, the NG substrates must be stored in the NG substrate magazine _MN each time, and a protective paper must be interposed. No. Therefore, if the re-inspection step is performed at a position apart from the automatic inspection step, it is unavoidable, but the number of operations for transporting the NG substrate increases and it takes time.

As shown in FIG. 4C, the second transfer unit U _{B is used} to reduce the transfer operation of the NG substrate.
To the re-inspection process. Then, conveying the NG substrates became failed the automatic inspection process, instead of storing the NG board magazine M _N placed in the automatic inspection process, directly on the inspection table retesting stage T _R of the re-inspection process I do. However, took time to reinspection, when still in the NG substrate retest on stage T _R, since confusing and next NG substrate is conveyed, in this case, automatic inspection the following NG substrate step Of the NG board magazine _MN .

The configuration of the automatic appearance inspection apparatus has been described so far with reference to FIGS. 2 to 4. Next, the inspection processing control unit of the automatic appearance inspection apparatus will be described with reference to FIG. The inspection processing control unit 20 includes a microcomputer 21. The microcomputer 21 issues an instruction to each unit to operate and adjust each unit. The color selector 12, the camera XY controller 14, the substrate transport controller 15, the input device 16, the storage device 17, and the monitor device 18 are connected to the inspection processing control section 20.

The color selector 12 includes the CCD camera 1
3 is connected, and an image captured by the CCD camera 13 is supplied. The CCD camera 13 includes the CCD color cameras C _S and C _B shown in FIG. 2 and, when a CCD color camera is used in the reinspection step, the color cameras. The color selector 12 is provided for each CCD.
For a color image obtained from a color camera, color information can be selected, and image data in which lightness, saturation, and chromaticity color information have been selected can be output, and selected by an instruction from the computer 21.

The camera XY controller 14 controls the XY stages S _S and S _{B in accordance} with an instruction from the computer 21 to move and adjust the inspection position of the CCD color cameras C _S and C _B with respect to the substrate. In some cases, it may also include CCD color camera C _S, the position adjustment in the Z direction of C _B, or magnification adjustment of the camera. Substrate transfer controller 15
Controls substrate transport unit U _S, a U _B by an instruction from the computer 21, the substrate and the protective sheet from each magazine removed, transported or housed, further or placed on each stage, or move or . Further, the controller 15 controls the driving of the reversing device R.

The input device 16 is a controller having a keyboard, input buttons, and the like.
The necessary setting conditions are stored in the storage unit 26. Also, an instruction to the next position of the re-inspection target in the re-inspection process, or NG
This can be done by inputting information and the like. If only the instruction is given, a foot switch can be used. The storage device 17 stores inspection information relating to the inspection board. This is, for example, a floppy disk, a magnetic tape, or the like, and may flow to the downstream process together with the inspected substrate magazine. These may be stored in the storage unit 26 if they are not required for the downstream process.

The monitor device 18 displays an image indicating CCD color camera C _S in the automatic inspection process, the inspection status obtained from the C _B. The monitor device in the automatic inspection process does not necessarily need to be installed. However, CCD is used in the re-inspection process.
When a color camera is used, a visual inspection is performed on a screen displayed on the monitor device. Next, a process of determining an abnormal defect in the inspection process control unit 20 with respect to the shape of the gold plating formed on the substrate will be described.

The inspection processing control unit 20 includes a binarization processing unit 2
2, composed of an image memory 23, an arithmetic processing unit 24, an address arithmetic unit 25, and a storage unit 26, which are controlled by the microcomputer 21. When the CCD camera 13 is located at the inspection target site on the substrate, the CCD camera 1
From 3, a color image of the gold-plated shape of the site is acquired. Then, the color information is selected by the color selector 12 in accordance with an instruction from the computer 21 and the color information is filtered in accordance with a specific condition to create image data. Based on this image data, a binarization processing unit 2
In step 2, an image pattern is created and stored in an image memory, and the image pattern is displayed on the monitor device 18.

The arithmetic processing unit 24 performs a labeling process based on the image pattern data stored in the image memory 23 to extract a pattern. Therefore, shape measurement is performed on the extracted pattern. The processing program for the shape measurement is stored in the storage unit 26. For example, it is determined whether the extracted pattern is a single connection or a multiple connection. If it is a single connection, the vertical and horizontal sizes and the minimum width of the pattern are measured, and the center of gravity and the contour area are calculated. In the storage unit 26, non-defective products are registered in advance as to whether or not an abnormal defect exists as reference information, and a threshold value is set in advance. Here, by comparing the calculation result with the reference information, the shapes as shown in FIGS. 1A to 1F can be determined.

In the case of the multiple connection, in addition to the same processing as the single connection, the calculation of the hole area and the hole center of gravity is performed, and the calculation results are compared with the reference information.
An abnormality as shown in (g) and (h) can be determined. For example, as shown in FIG. 1 (h), when there is a foreign matter such as a resist or a stain on the gold plating, the foreign matter or the foreign matter is transparent to light from the conventional black and white binary image. In this case, since the outer shape of the pattern looks normal, it cannot be determined that there is a foreign substance or adhesion. Also,
As shown in FIG. 1 (h), because the position of the gold shape B for copper pattern A is normal, even if there is defective portion B _d, the color information of the copper that is exposed to the defective portion B _d, black and white image This defect can be overlooked because it cannot be determined from this.

Further, the color itself of each gold-plated pattern portion on both the bonding pad surface and the ball pad surface of the BGA / CSP gold-plated printed wiring board is automatically assigned to three attributes (brightness, saturation, and hue) for each pattern. Conversion can further improve accuracy. According to the inspection processing control unit 20 of this embodiment, a color image obtained from the CCD camera 13 can be processed with color information to accurately create an image pattern of a gold-plated shape. Abnormal defects can be easily detected.

Therefore, the computer 21 stores the position information on the substrate corresponding to each inspection target portion and the inspection result information of the portion, for example, NG information, abnormal defect type, and the like in the storage device 17. In the re-inspection step, the computer 21 instructs the position of the defective portion on the NG substrate to the substrate transport controller 15 based on the inspection result information stored in the storage device 17, and the defective portion is It is controlled to be directly below O. At the same time, if a monitor is provided, the position is displayed and the defect type of the defective portion is displayed, so that the inspector can easily perform the re-inspection.

The configuration of the automatic appearance inspection apparatus for substrates has been described above. Next, the operation of the automatic appearance inspection apparatus will be described with reference to the flowcharts shown in FIGS. First, the substrate supply magazine M, which is stored in a state where the substrates are stacked with protective paper interposed therebetween, is carried into a predetermined position of the automatic appearance inspection apparatus (S1). As shown in FIGS. 2 and 4A, the protection paper discharge magazine M _P1 is previously arranged in an empty state.

[0046] Therefore, the first conveying unit U _S is driven, in sucker 6 provided in the arm 5, while adsorbing and holding the protective paper at the top is stored in the substrate supply magazine M, the protective sheet discharge magazine Transfer to M _P1 (S2). Next, the first transport unit U _S is driven, the substrate in the uppermost housed in the board supply magazine M is adsorbed and held by the sucker 6 (S3).

At this time, if the substrate is still on the inspection table 1 of the first inspection stage T _S , the substrate cannot be transported onto the inspection table 1. It is determined whether or not (S4). Here, if there is a substrate on the inspection table 1 (Y), it stands by in the substrate supply magazine M. If there is no substrate on the inspection table 1 (N), the sucked and held substrate is transported to the inspection table 1 and placed thereon.

When the substrate is placed on the inspection table 1 at the first inspection stage T _S , the substrate is positioned and fixed by the fixture 3 (S5). When the substrate is fixed on the inspection table 1, the 1CCD color camera C _S starts operation, while stepping up the printed wiring pattern on the substrate, gradually acquires a color image. The shape of the gold plating is inspected based on the acquired image. NG which is an abnormal defect
The inspection results of the parts and the like are stored in the storage device 17 or the storage unit 26 (S6). Step S6 will be described in detail with reference to FIG.

Next, it is determined whether the inspection of the entire surface of the substrate has been completed (S7). If not yet completed (N), the process returns to step S6, the first 1CCD color camera C _S by the step-up to get the next image, continues checking. Here, the case where the entire surface of the substrate is inspected one by one has been described, but the inspection target may be partially set in advance.

In step S7, the inspection of the substrate is completed.
(Y), the second inspection stage T _BOn the inspection table 2
After confirming that there is no plate, the reversing device R is activated and the
The substrate on the inspection table 1 is sandwiched and held by the hook 9. And j
The substrate is turned over by turning the jack 9 and the second inspection stage T
_BIs transported onto the inspection table 2. Turn the substrate upside down on the inspection table 2
(S8).

When the substrate is placed on the inspection table 2, the substrate is positioned and fixed as in step S5. When the substrate is fixed on the inspection table 2, the back side of the substrate is inspected in the same procedure as in step S6, and the inspection result is stored (S9). It is determined whether or not the entire rear surface of the substrate has been inspected (S10). This step S10
Is the same as in the case of the inspection on the front side.

When the inspection of the entire rear side of the substrate is completed (Y), it is determined whether or not there is an NG portion which is an abnormal defect on the front side and the rear side of the substrate (S11). Since the inspection results of the front and back sides of the board are stored in the storage device 17 or the storage unit 26, it is determined whether the board as a whole passes or rejects based on the inspection results stored here. There must be.

When the entire substrate is viewed, if there is even one NG portion, the substrate can be an NG substrate. Alternatively, depending on the type of the defective portion, the substrate can be accepted as an OK substrate. Further, in consideration of the yield of the entire substrate, NG
Even if there is a portion, it can be used as an OK substrate. These criteria are set in the storage unit 26 in advance.

[0054] Here, upon completion of the back side inspection, the second conveying unit U _B runs, the substrate is on the examination table 2 adsorbed and held by the suction device 8 transports. At this time, step S1
1, in the case where the substrate is determined to be OK substrate accommodated in the (N), OK substrate magazine M _O (S12).
Further, the second conveying unit U _B is protective paper supply magazine M
By adsorbing and holding the protective paper from the _P2, now, to accommodate the protective paper to OK on a plate which was housed in the OK board magazine M _O.

In step S11, the substrate is an NG substrate.
If determined (Y), re-inspection in the re-inspection process
Stage T_RTo determine if the NG board is under inspection.
It is turned off (S13). This step S13 corresponds to FIG.
As shown in (c), the second transport unit U_BExtend
This is necessary when automating the re-inspection process continuously. Figure
3 and FIG. 4B, the second transport unit U_B
Is not necessary, the determination in step S13 is necessary.
NG board placed in the automatic inspection process
Plate Magazine M_NTo be stored. Then, insert the protective paper into the protective paper
Supply Magazine M _P2And place it on an NG substrate.

Meanwhile, as shown in FIG. 4 (c), if it is extended a second conveying unit U _B is in the inspector re inspection stage T _R, there is NG substrate on examination table At this time (Y), since the substrate cannot be placed on the inspection table, the NG substrate is stored in the NG substrate magazine _MN arranged in the automatic inspection process (S15). Here, when there is no NG board on the inspection table of the re-examination stage T _R (N),
Conveying the NG substrate inspection table of re-inspection stage T _R to be positioned and fixed NG board on the inspection table (S1
6).

NG board is re-test stage T_ROn the inspection table
Is fixed to the retest stage T _RIs driven. This
Based on the NG position information of the inspection result of the NG board,
Position so that the upper NG part is directly below the optical inspection device O
Adjusted. When the position is adjusted, the NG portion
Is illuminated with red LED. Inspectors use this lighting
Visual inspection of the pattern of the part
Inspection is performed (S17). The monitor 18 has an inspection
The inspector can refer to this information because the result information can be displayed.
Considering this, an abnormal defect in the shape of the NG portion is determined.

If the result of the determination indicates that the NG determination in the automatic inspection process can be determined to be erroneous, this is
, The NG information is changed to OK information and stored again. Then, if it is possible to the NG substrate and OK substrate (N), housed in OK substrate magazine M _O in retesting process, take out the protective paper from the protective paper supply magazine M _P, OK on the substrate Is placed (S19). When the NG substrate can be determined to be an NG substrate also from the result of the reinspection (Y), the NG substrate is subjected to the N
Accommodated in G substrate magazine M _N, removed protective paper from the protective paper supply magazine M _P, placed NG substrate (S20).

Here, as a result of the re-inspection, for example, the rate of change from an NG board to an OK board, or the rate of change from an NG section to an OK section, is used to determine a criterion for an abnormal defect in the automatic inspection process. You can reset it.
As described above, the transport of the substrate and the protective paper has been mainly described with reference to FIGS. 6 and 7. Next, referring to the flowchart of FIG. 8, step S6 of FIG. 6 and step S9 of FIG. The details of the operation of the gold plating shape inspection will be described.

When the substrate is placed on the inspection table 1 of the first inspection stage T _S and fixed (S 101), the camera XY controller 14 starts to operate, firstly adjusts on the XY axes, and adjusts the CCD camera. the C _S moves to the reference position to obtain an image on the substrate. Then, it is moved to a position where an image of the inspection target portion is acquired (S102). Here, the CCD camera C _S, obtains a color image of the inspection target portion (S
103), and sends the image data to the color selector 12.

The color selector 12 performs image data selection processing based on the set color information (S10).
4). This image data is sent to the inspection processing control unit 20 shown in FIG. The image data is binarized and stored in the image memory 23. At this time, the image memory 23
The image data can be read out from and displayed on the monitor device 18 (S105).

Further, based on the image data stored in the image memory 23, the arithmetic processing unit 24 extracts an image pattern, and specifies a shape of one gold plating in a portion to be inspected on the substrate (S106). Thus, the non-defective shape information of the gold plating which should be in the inspection target portion registered in advance is read from the storage unit 26. The shape pattern extracted in step S106 is compared with the conforming shape pattern (S107). Based on a preset reference level, it is determined whether the extracted gold-plated shape of the portion to be inspected is acceptable or unacceptable. If unacceptable, it is determined as an NG pattern.

Next, when the pattern extraction processing of the inspection target portion is completed, and when it is necessary to perform the pattern extraction processing based on different color information (S108), step S108 is performed.
Returning to step 104, the attribute is selected again to perform the pattern extraction processing. When the attribute does not need to be changed (N), if there is no defect in the extracted gold-plated shape (S109), it is necessary to judge a defect in another gold-plated shape in the inspection target portion, and thus step S10.
6, the same pattern extraction is performed again.

On the other hand, the detection result for the gold plating shape which is determined to have an NG pattern in step S107 because there is a defect in the extracted gold plating shape is stored in the storage device 17 (S110). In this way, the pattern of the all-gold-plated shape in one image obtained from the inspection target portion is extracted, and defects are inspected (S111).

[0065] Then, when the inspection target portion of the total gold shape pattern processing is completed for (Y), for inspecting with other inspection target portion of the substrate (N), the process returns to step S102, XY a CCD camera C _S The position is adjusted in the direction, and a color image of another inspection target portion is obtained. The subsequent processing procedure is the same as described above.
It is repeated each time a color image of another inspection target portion is obtained (S112).

When the inspection of the inspection target portion on the entire surface of the substrate is completed (Y), the substrate placed on the inspection table of the inspection stage is transported to the next step (S).
113). Although the case where the front side of the substrate is inspected in the automatic inspection process has been described above, the case where the back side of the substrate is inspected is the same as the processing flow shown in FIG.

As described above, according to this embodiment, in the BGA / CSP printed wiring board appearance inspection apparatus, the presence or absence of a defect or the like of the BGA / CSP printed wiring board, particularly, the gold-plated portion is delicately determined. Very high-precision inspection including the difference of various shades can be performed.
The transport of the substrate and its protective paper can be automated.

[0068]

Therefore, according to the present invention, it is possible to achieve the effects of eliminating variations in inspection accuracy, reducing the number of on-site inspection personnel due to labor saving, and suppressing the production and inspection costs in the production of printed wiring boards. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a gold plating defect pattern on a printed wiring board.

FIG. 2 is a diagram showing a schematic configuration in an automatic inspection process of the automatic appearance inspection apparatus for a substrate.

FIG. 3 is a diagram showing a schematic configuration in a re-inspection process of the inspection device.

FIG. 4 is a diagram showing an example of an arrangement of inspection stages and magazines in the inspection apparatus.

FIG. 5 is a diagram showing a configuration of an inspection processing control unit in the inspection device.

FIG. 6 is a flowchart showing a procedure of transferring a substrate in the inspection apparatus.

FIG. 7 is a flowchart showing a substrate transfer procedure following FIG. 6;

FIG. 8 is a diagram showing a flow of a gold plating inspection process on a substrate.

[Explanation of symbols]

1,2 ... examination table 3,4 ... fixture 5,7 ... arms 6,8 ... sucker 9 ... chuck 12 ... color selector _{13, C B, C S ...} CCD camera 14 ... camera XY controller 15 ... substrate transport controller DESCRIPTION OF SYMBOLS 16 ... Input device 17 ... Storage device 18 ... Monitor device 20 ... Inspection process control part M, _MN , _MO ... Substrate magazine _MP , _MP1 , _MP2 ... Protective paper magazine O ... Optical inspection device R ... Reversing device S _{S, S B} ... XY stage _{T B, T S, T R} ... inspection stage U _B, U _S ... transport unit

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukio Osada 8-22-20 Tsuji, Urawa-shi, Saitama F-term (reference) 2G051 AA65 AB07 CA04 DA07 DA08 DA13 EA17 ED05 ED08

Claims (7)

[Claims] A CCD color camera for acquiring an image of a portion to be inspected formed on a printed wiring board; an inspection table device on which the substrate is placed; and an inspection target on the substrate by moving the camera. An XY driving device for positioning the upper part, a transport device for transporting the substrate from the inspection table device after transporting the substrate, placing the substrate on the inspection table device, and completing the inspection of the substrate; An inspection process for extracting an image pattern relating to gold plating of the inspection target portion, detecting a defect in the extracted pattern, and storing a detection result by performing an arithmetic process on the image data obtained from the camera based on the color information; An automatic appearance inspection device having a control unit. 2. The transfer device according to claim 1, wherein the transfer device removes the protective paper from the substrate magazine, transports the substrate while sucking and holding the substrate, and stores the substrate in the substrate magazine after the inspection of the substrate. 2. The automatic appearance inspection apparatus according to claim 1, wherein the protection paper is taken out and the protection paper is placed on the substrate. 3. A re-examination table apparatus arranged apart from the inspection table apparatus, and a visual re-examination apparatus arranged on the re-examination table apparatus and re-inspecting the failed board. 2. The automatic appearance inspection device according to 1. 4. The re-inspection table apparatus moves and adjusts a re-inspection target portion on the substrate into an inspection range of the visual re-inspection apparatus according to position information stored in the inspection result. The automatic appearance inspection device according to 1. 5. The re-examination table device, based on the position information, moves and adjusts a re-inspection target portion on the substrate to be located immediately below the visual re-examination device. 5. The automatic appearance inspection apparatus according to claim 4, wherein a spotlight is illuminated on the inspection target portion. 6. A first CCD color camera and a first inspection table device for inspecting the front side of the substrate, a second CCD color camera and a second inspection table device for inspecting the back side of the substrate,
2. A reversing device for reversing and transporting the substrate from the first inspection table device to the second inspection table device.
The automatic appearance inspection device according to 1. 7. A first transport device for removing a protective paper from a substrate stored in a substrate magazine and transporting the substrate to the first inspection table device, and a substrate that has been inspected from the second inspection table device. 7. The automatic appearance inspection apparatus according to claim 6, further comprising: a second transport device that is transported and stored in a substrate magazine, takes out the protective paper from the protective paper magazine, and places the protective paper on the stored substrate.