JP2007017311A - Appearance inspection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an appearance inspection method, in which a threshold value of threshold data for determination of the first inspection device is changed linking with recognition of a visual inspection device to inspect rapidly and certainly an appearance of a printed board with accurate failure detection. <P>SOLUTION: The appearance inspection method has a first inspection device 4 for inspecting an appearance state of an inspected object and determining a failure state, a first computer 21 for processing data indicating the appearance state obtained by inspecting the inspected object with the first inspection device 4, and a visual inspection device 31 for visually inspecting the inspected object after the inspection of the first inspection device 4. The inspected object of which appearance state is determined to be failure by the first inspection device 4 is visually inspected by the visual inspection device 31, and determination result data of no-failure/failure of the appearance state is transmitted to the first computer 21. Based on the determination result data, the first computer 21 varies the threshold of teaching data indicating the normal state used for determining the appearance failure state of the first inspection device 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is used for an appearance inspection system used for inspection (appearance inspection) of defects in mounting of electronic components such as resistors, capacitors, and ICs on a printed circuit board.

  FIG. 6 shows a conventional method for inspecting a printed circuit board 1 on which electronic components 2 such as resistors, capacitors, and ICs are mounted and for managing a defective board. In FIG. 6, cream solder is printed on the mounting surface side of the printed circuit board 1 by the printing machine 14. The printed circuit board 1 on which the cream solder is printed is carried out of the printing machine 14 by the conveyor 3 and carried into the mounting machine 13, and the electronic components 2 such as resistors, capacitors, and ICs are mounted on the mounting surface side of the printed circuit board 1 (printing the solder paste). The electronic component 2 is mounted on the surface. The printed circuit board 1 on which the electronic component 2 is mounted is carried into the reflow furnace 12 by the conveyor 3 and soldered.

  The printed circuit board 1 that has come out of the reflow furnace 12 and has been soldered is carried into the first inspection device 4 to inspect the appearance state (soldering state) of the printed circuit board 1. The first inspection device 4 can be a method of inspecting the mounting surface of the printed circuit board 1 by imaging with a camera, or a method of inspecting by irradiating a semiconductor laser. Any number can be used.

  The printed circuit board 1 that has been inspected by the first inspection device 4 is carried by the conveyor 3 and carried to the sorting conveyor 5, and is sorted into the non-defective product rack 7 or the defective product rack 8 depending on whether the inspection result is OK or NG. . The defective rack 8 includes, for example, six magazine racks A to F that can actually store about 20 printed circuit boards 1. The defective printed circuit board 1 is carried into an empty magazine rack 10 when it is carried into the defective product rack 8, and when one magazine rack 10, for example, A is full, the defective printed circuit board 1 is loaded into the next magazine rack B. The A detailed description of the mechanism of the defective product rack 8 and the magazine rack 10 is omitted here.

  Data on which magazine rack 10 in which defective rack 8 the defective printed circuit board 1 is housed (in what number) is stored in the first computer 21, and data on the defective part of the printed circuit board 1 is also stored. It is stored in the first computer 21.

  The magazine racks 10 of the defective product rack 8 can be removed and carried one by one. When all the magazine racks 10 are filled with defective printed circuit boards 1, they are exchanged with another empty magazine rack 10. be able to.

  The first computer 21 can perform data processing such as rearranging the inspection results of the printed circuit board 1 by the first inspection apparatus for each defective item. For example, when it is desired to confirm a printed circuit board that is defective in mounting a specific electronic component 2 on the printed circuit board 1, when a corresponding defective item is selected on the first computer 21, a display device 22 attached to the first computer 21 is attached. Shows which position (how many steps) of which magazine rack 10 the corresponding printed circuit board 1 is in. Therefore, if the printed circuit board 1 at the corresponding position of the corresponding magazine rack 10 is taken out, the printed circuit board 1 Can be confirmed.

When the specific electronic component 2 is defective in the first inspection device 4 and continues to be good in the visual inspection, the numerical value of the inspection determination of the first inspection device 4 is not appropriate. In this case, it is necessary to stop the first inspection device 4 and change the range of numerical data for determining whether the first inspection device 4 is good or bad.
Japanese Patent Laid-Open No. 7-170092

  The first inspection device automatically inspects the appearance of the printed circuit board, and determines whether it is good or bad based on numerical data. Although this numerical data is performed for each soldering part of each electronic component on the printed circuit board, the range of data indicating that the inspection result is good is generally set initially narrow in order to avoid overlooking defective products. For this reason, there is a tendency for an overdetermination to occur, which is judged as bad even for a printed circuit board that is normally good when visually inspected. In this over-determination, when the defective printed circuit board is visually confirmed and judged to be good, the numerical data (threshold value) for judgment of the first inspection apparatus is manually corrected. However, in this method, it is necessary to manually change the numerical data (threshold value) of the judgment of the first inspection apparatus, and it takes time and cannot perform efficient printed circuit board inspection.

  On the other hand, the first inspection device and the visual inspection device are combined, the first inspection device, the visual inspection device, and the first computer are connected by a communication line, and the first inspection device is defective in the visual inspection. Therefore, when it is determined to be good by confirmation with the visual inspection device, the numerical data (threshold value) of the determination of the first inspection device is automatically changed, so that the defect in the first inspection device is eliminated. A reliable printed circuit board appearance inspection method is provided.

  In order to solve the conventional problems, an appearance inspection system according to the present invention controls a first inspection device that inspects an appearance state of an object to be inspected to determine a defective state, and controls the first inspection device. A first computer that converts inspection data of an appearance state inspecting an object to be inspected by the first inspection apparatus into predetermined numerical data, and visual inspection that visually inspects the inspection object after the inspection by the first inspection apparatus. An inspection device, and numerical data indicating an appearance state by the first inspection device is visually checked by the visual inspection device for an object to be inspected determined to be defective based on teaching data for teaching a normal range of the numerical data. The inspection result is transmitted to the first computer as a result of the visual inspection of the good and bad appearance, and the first computer determines whether the first inspection apparatus is correct based on the determination result data. To change the threshold value of the teaching data indicating a range.

  According to the appearance inspection system of the present invention, when the appearance state of the printed circuit board is defective in the first inspection apparatus and is determined to be good by the confirmation with the visual inspection apparatus, the numerical data of the determination of the first inspection apparatus By automatically changing the (threshold value), a quick and reliable appearance inspection of the printed circuit board is provided.

Embodiments of a visual inspection support system according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an appearance inspection system 100 and its periphery used in an embodiment of the present invention, FIG. 2 shows a printed circuit board 1, and FIG. 3 shows teaching data and numerical data for data processing. An example is given. A barcode 38 is attached to the printed circuit board 1, and individual management of the printed circuit board 1 can be performed by reading the unique barcode 38 with a barcode reader (not shown). Here, the barcode 38 and a barcode reader (not shown) are used, but the present invention can also be realized by using an IC tag or other identification code without using a barcode. It is.

  In FIG. 1, when cream solder is printed on the surface side (mounting surface side) on which the electronic component 2 of the printed circuit board 1 is mounted in the printing machine 14, it is carried to the mounting machine 13 by the conveyor 3, and electronic devices such as resistors, capacitors, and ICs. The component 2 is mounted on the mounting surface side of the printed circuit board 1. The printed circuit board 1 on which the electronic component 2 has been mounted is carried to the reflow furnace 12 by the conveyor 3 and soldered. The printed circuit board 1 carried out by the conveyor 3 from the reflow furnace 12 is carried into the first inspection device 4 by the conveyor 3.

  The first inspection apparatus includes various methods in addition to a method for inspecting the appearance of the printed circuit board 1 by, for example, irradiating a laser on the mounting surface side of the printed circuit board 1 and measuring reflected light and diffused light. The first inspection apparatus 4 of any method may be used. In any method, the first inspection apparatus 4 automatically inspects the printed circuit board 1 and takes the measured data (diffuse light and reflected light are measured in the case of a laser system) into the first computer 21. , Converted into numerical data 51. In the present embodiment, the first computer 21 is separate from the first inspection device 4, but the first computer 21 may be inserted into the first inspection device 4. In this case, the contents of the first computer 21 can be displayed in two ways: a method of displaying on the display device (monitor) (not shown) of the first inspection device 4 and a method of displaying on the first display device 22. is there.

  The numerical data 51 referred to here is three data of height data, luminance data, and epi-illumination data, and is converted into this data over the entire surface to be inspected of the printed circuit board 1. Here, the height data is data indicating the height of the printed circuit board 1, and the portion where the electronic component 2 is mounted or the portion where the solder is present is a high numerical value. Luminance data is the numerical value of the illuminance level of the reflected laser light. If the surface of the printed circuit board 1 is solder, the amount of reflection increases, so the luminance data increases, and the surface is black. If it is a component, the amount of reflection is small, so the numerical value of the luminance data is small. The epi-illumination data is a numerical value representing the reflected light vertically reflected from the surface to be inspected of the printed circuit board 1. Even when the solder is the same, when the solder is inclined, the reflected light reflected vertically is horizontally It becomes smaller than the case where it becomes, and the numerical value of epi-illumination data becomes small. These numerical data 51 are expressed by numerical values of 0 to 200, where 0 is small and 200 is large. For example, regarding the height data in the numerical data 51, the electronic component 2, no solder, etc. on the surface to be inspected of the printed circuit board 1, that is, the value of the surface of the printed circuit board 1 is 0. If the electronic component is mounted, the height data value is a high value in accordance with the vertical height of the electronic component.

  Numerical data 51 obtained by converting data measured by the first inspection device 4 into a predetermined format is teaching data that is data indicating the correct soldering state of the printed circuit board 1 stored in the first computer 21 in advance. 52 is compared. The value of the teaching data 52 is specified within a predetermined value range. For example, in the case of a soldered portion of the lead of the electronic component 2 of the printed circuit board 1, teaching data 52 indicating the correct soldering state for this lead portion is set as numerical values for each of height data, luminance data, and incident data. ing. An example of the data is shown in FIG. Here, the teaching data 52 of the point A is set to a value as shown, and the value of the numerical data 51 of the point A is shown, and the numerical data 51 is the value of the teaching data 52. Since it falls within the range, it is determined that the soldering state at point A is correct. On the other hand, at point B, since the value of the height data out of the numerical data 51 is outside the range of the teaching data 52, it is determined that the soldering state is poor at point B.

  The teaching data 52 is arbitrarily set by the operator on the printed circuit board 1. For example, if only one point is set, numerical data is acquired over the entire surface to be inspected of the printed circuit board 1, but only one point is set for the teaching data. Determine good or bad. In other words, even if there is a soldering failure at another point where the teaching data 52 is not set, it is determined as good. For this reason, the more the set points of the teaching data 52, the more accurate the soldering inspection of the printed circuit board 1 is performed.

  In this way, the teaching data 52 and the numerical data 51 are compared with respect to all the points where the teaching data 52 is set, so that the quality is judged as good or bad. If it is determined that even one location is defective, the printed circuit board 1 is determined to be in a poor soldering state, and the position information of the set point of the teaching data 52 and the value of the numerical data at that point are visually checked. Data is transmitted to the second computer 23 that controls the inspection apparatus 4. Here, the visual inspection device 4 is controlled by the second computer 23, but both the first inspection device 4 and the visual inspection device 4 are used by the first computer 21 without using the second computer 23. Control may be performed.

  The printed circuit board 1 carried out from the first inspection device 4 by the conveyor 3 is carried into the visual inspection device 31 by the conveyor 3. The visual inspection device 31 is a device that directly picks up an image of a portion determined to be defective by the first inspection device 4 with a camera and visually confirms the corresponding portion with the human eye using the second display device 24. Since it is not directly related to the present invention, a detailed description is omitted here.

  Although it is determined that the first inspection apparatus 4 is defective, there are many substrates that are determined to be good by visual confirmation with the human eye in the visual inspection apparatus 31. The reason is that the teaching data in the first inspection apparatus 4 is set based on past experience, etc., but the range of teaching data that is initially determined to be good is set in a narrow range in order to eliminate oversight of defects. For this reason, it is unavoidable that there are many overdetermined failures in the first inspection device 4 even if the visual inspection by the visual inspection device 31 is determined to be good.

  FIG. 4 is a graph showing data obtained by inspecting the soldering state of the electronic component 2 on the printed circuit board 1 with the first inspection device 4 and converting the data into numerical data 51. Although the numerical data 51 includes three data, only one data will be described here for the sake of simplicity. In FIG. 4, the horizontal axis represents the numerical data 51, the vertical axis represents the number of cases (number of printed circuit boards), and 100 to 140 is the range of the teaching data 52. That is, if the numerical data is in the range of 100 to 140, the first inspection apparatus 4 determines that the inspection of the soldering state of the electronic component 2 is good, and if it is outside this numerical value, determines that the electronic component 2 is defective. I mean.

  As described above, it is inevitable that the first inspection device 4 is over-determined. However, if the over-determination increases, the visual inspection device 31 needs to visually check the corresponding part, and inspection tact (inspection time). There is a problem that increases. On the other hand, if five of the numerical data 51 to 100 in FIG. 4 are all good by visual confirmation with the visual inspection device 4, the range in which the teaching data 52 of the first inspection device 4 is judged as good is determined. By changing the enlargement direction from 100 to 140 to 80 to 140, the visual inspection device 31 reduces the number of times that the printed circuit board 1 is checked for defects.

  The teaching data is changed in the following procedure. For the printed circuit board 1 in the range of 80 to 100 in the graph of FIG. 4 (the range next to the teaching data 52), the visual inspection device 31 shows the soldering state of the corresponding electronic component 2 on the corresponding printed circuit board 1 as the second. If the operator checks the display device 24 and determines that it is acceptable, the operator operates the second computer 23 that controls the visual inspection device 31. When such an operation is repeated, there are cases where it is judged that N of N sheets (N is equal to or less than a natural number) have good confirmation results with the visual inspection apparatus 31 having numerical data in the range of 80 to 100. As described above, in the numerical data 51 range (80 to 100 in this case) adjacent to the teaching data 52, the determination by the first inspection device 4 is poor and the determination by the visual inspection device 31 is determined to be good. In this case, it is considered that the determination is excessive, and the range of the teaching data 52 of the first inspection device 4 is changed from 100 to 140 to 80 to 140.

  Regarding the condition for changing the teaching data 52, the number of the printed circuit boards 1 in which the determination by the first inspection device 4 is poor and the confirmation by the visual inspection device 31 is good is N in the range of the numerical data 51 adjacent to the teaching data 52. If there are N of the sheets, the teaching data 52 is expanded to the range of the corresponding numerical data 51, but the operator or the administrator can arbitrarily set N. For example, if the value of N is N = 5, the range of the teaching data 52 is expanded if five consecutive printed circuit boards that are judged as defective by the first inspection device 4 and judged good by the visual inspection device 31 are continued. Proceed to the procedure described below.

  When the condition for widening the range of the teaching data 52 is satisfied, the display device 24 of the visual inspection device 31 displays whether or not the teaching data 52 may be changed. When “Yes” is selected, the teaching data 52 is changed. I do. When “No” is selected, teaching data is not changed.

  At this time, the second computer 23 sends a data transmission for changing the range in which the teaching data 52 is determined to be good to the first computer 21 and further to the first inspection device 4, and the first inspection device 4. The range in which the teaching data 52 is determined to be good is changed. When the teaching data 52 is changed to 80 to 140, the first inspection device 4 determines that the numerical data 51 is, for example, 90, which is good, and is carried by the conveyor 3 without being checked by the visual inspection device 31, and distributed. The product is distributed to the non-defective product rack 7 by the conveyor 5 and is carried into the non-defective product rack 7.

  In the example of the teaching data 52 described above, the numerical data 51 is divided into 20 steps. However, if this step is further reduced, for example, 5, the setting of the teaching data 52 can be changed with higher accuracy.

  In the case of FIG. 4 (the initial teaching data 52 is 100 to 140), the area of the numerical data 51 in which the setting of the teaching data 52 can be changed is only the area of the numerical data 51 on both sides of the teaching data 52. In this case, there are only 80 to 100 and 140 to 160 regions. For example, even if the inspection by the visual inspection apparatus 31 is good in the area of the numerical data 51 of 60 to 80, the area of 80 to 100 is the area of the teaching data 52 even if the number of teaching data 52 is changed. Unless it is an area, it cannot be teaching data. That is, the range of the teaching data value is always a continuous value range. If the area of 80 to 100 enters the area of the teaching data 52, the area of numerical data 60 to 80 becomes the teaching data 52 if the conditions for expansion of the teaching data 52 are satisfied. That is, the teaching data 52 is divided, and the teaching data 52 of the data classification judged to be good only in a form including the adjacent classification of the teaching data is expanded.

  The printed circuit board 1 whose appearance state (soldering state) is determined to be defective in both the first inspection device 4 and the visual inspection device 31 is carried into the repair rack 8 by the sorting conveyor 5.

  As another embodiment, an appearance inspection system 101 that does not use the visual inspection apparatus 31 as shown in FIG. 5 will be described. Here, only differences from the first embodiment will be described.

  Until the surface of the printed circuit board 1 is automatically inspected by the first inspection device 4, it is the same as that of the first embodiment, and inspection data in the first inspection device 4 is transmitted to the first computer 21. The printed circuit board 1 determined to be good by the first inspection device 4 is carried into the non-defective product rack 7 by the sorting conveyor 5. For the printed circuit board 1 determined to be defective by the first inspection device 4, numerical data 51 of the defective portion is stored in the first computer, and the printed circuit board 1 is carried into the repair rack 8 by the sorting conveyor 5.

The repair rack 8 can be removed and transported to a repair process at a location different from the appearance inspection system 101. In the repair process, a third computer 27 connected to the first computer and A third display device 28 is provided, and the printed circuit board 1 is taken out from the repair rack 8 to check a defective portion and repaired. When confirming the defective portion, the third display device 28 confirms the defective portion, and the operator visually confirms the final good or defective. In the case of good, when information indicating good is inputted to the third computer 27, it is transmitted to the first computer 21 and stored. Similar to the determination of good in the visual inspection device 31 in the first embodiment, the teaching data 52 may be changed to the third display device 28 when the good in the repair process satisfies the criterion for changing the teaching data 52. When the display of heel is displayed and “Yes” is selected, the range of the teaching data 52 is changed. The change of the range of the teaching data 52 is determined to be good only in the form in which the teaching data 52 is divided into the data sections that teach the non-defective range and the adjacent sections of the teaching data 52 are included, as in the first embodiment. The teaching data 52 of the data classification is enlarged.
As described above, according to the appearance inspection system of the present invention, it is possible to optimize the teaching data, which is the data for determining the quality of the first inspection apparatus, at an early stage, and to quickly perform the appearance inspection of the printed circuit board. Is to provide.

  The present invention can be used for inspection of a mounted printed circuit board in a mounting process for mounting electronic components such as capacitors, resistors, and ICs on the printed circuit board.

1 is a schematic configuration diagram of an appearance inspection system in Embodiment 1 of the present invention. The figure which shows the printed circuit board of the to-be-inspected object in the external appearance inspection system of this invention The figure which shows an example of the teaching-data and numerical data which are used for the external appearance inspection system of this invention The figure for demonstrating the relationship between the teaching data used for the external appearance inspection system of this invention, and numerical data Schematic configuration diagram of another visual inspection system used in Embodiment 1 of the present invention Schematic configuration diagram of a conventional visual inspection system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Electronic component 3 Conveyor 4 1st inspection apparatus 5 Sorting conveyor 7 Good quality rack 8 Repair rack 10 Magazine rack 12 Reflow furnace 13 Mounting machine 14 Printing machine 21 1st computer 22 1st display apparatus 23 1st display apparatus 23 2 computer 24 second display device 27 third computer 28 third display device 31 visual inspection device 38 barcode 51 numerical data 52 teaching data 100 visual inspection system 101 visual inspection system (method without using visual inspection device)

Claims (6)

A first inspection device for inspecting the appearance of an object to be inspected to determine a defective state;
A first computer that controls the first inspection device and converts inspection data of an appearance state obtained by inspecting an inspected object from the first inspection device into predetermined numerical data;
A visual inspection device that visually inspects an object to be inspected after the inspection by the first inspection device;
The numerical data indicating the appearance state by the first inspection apparatus is visually inspected by the visual inspection apparatus for the object to be inspected determined based on the teaching data for teaching the normal range of the numerical data. Send judgment result data of good and bad visual inspection to the first computer,
An appearance inspection system in which a threshold value of teaching data indicating a normal range of the first inspection apparatus is changed by the first computer based on the determination result data. The visual inspection device is controlled by a second computer that receives position information and numerical data of set points of teaching data determined to be defective by the first inspection device transmitted from the first computer. 2. The appearance inspection system according to claim 1, wherein the defective portion is visually inspected to determine whether the object to be inspected is good or bad, and the threshold value of the teaching data of the first inspection device is changed based on the determination result. . In the visual inspection, when the numerical data obtained by inspecting the appearance state with the first inspection device is divided into a predetermined numerical width and evaluated based on teaching data indicating a normal range, the predetermined numerical data width 2. The appearance inspection system according to claim 1, wherein when it is determined that a predetermined number of objects to be inspected are continuously good, the teaching data range is expanded by a numerical data width adjacent to the teaching data range. A first inspection device for inspecting the appearance of an object to be inspected to determine a defective state;
A first computer that controls the first inspection device and converts inspection data of an appearance state obtained by inspecting an inspected object from the first inspection device into predetermined numerical data;
A sorting conveyor that sorts the inspected object determined by the first inspection apparatus into a non-defective product and a defective product;
A repair rack for carrying in an object to be inspected that has been determined to be defective by the distribution conveyor;
A third computer that receives numerical data indicating an appearance state of the first computer of an object to be inspected and stored in the repair rack;
With
The third computer visually inspects the defective object to be inspected based on numerical data indicating the appearance state, determines the appearance state, and passes the pass / fail judgment result data from the third computer to the first computer. An appearance inspection system that transmits and changes a threshold value of teaching data indicating a normal state for the first computer to determine an appearance defect state of the first inspection apparatus based on the determination result data. In the visual inspection, when the numerical data obtained by inspecting the appearance state with the first inspection device is divided into a predetermined numerical width and evaluated based on teaching data indicating a normal range, the predetermined numerical data width 5. The appearance inspection system according to claim 4, wherein when it is determined that a predetermined number of objects to be inspected are continuously good, the teaching data range is expanded by a numerical data width adjacent to the teaching data range. The appearance inspection system according to claim 1, wherein the inspection data includes at least height data, luminance data, and incident light data.

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