JPH02226008A - Method and apparatus for inspecting electronic part mounting state - Google Patents

Abstract

PURPOSE:To detect a lead state without being affected by the distortion of a substrate itself and an adjacent lead row by projecting slit light on the lead row almost vertically and detecting the profile of the slit light in an oblique direction crossing the lead row at a right angle. CONSTITUTION:Slit light is projected on the lead row arranged on a substrate 9 from a slit projector 2 in the direction vertical to the surface of the substrate 9 and the state of the lead row is imaged by two TV cameras I, II in the direction of an angle theta of 45 - 60 deg. to the surface of the substrate so as to hold the slit light between said cameras. At this time, when the slit light is projected on the leading ends of leads, the leading ends of the leads shine like (a) to be detected. When the slit light is projected on the sides reverse to the TV cameras so as to hold the leads between the cameras, the cutting of the slit light due to the leads is detected like (b). When there is no leads, the profile of the slit light becomes linear. These data obtained by the two TV cameras are combined to judge the presence of the leads.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to electronic component mounting and mounting, which is performed as part of a final appearance inspection to determine the state of the leads after various electronic components are mounted on a board via through-holes. This invention relates to a condition inspection method and apparatus.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. 58-131797, conventional lead detection is performed by irradiating only the lead tip with parallel light of a certain width and extracting the reflected light from the lead tip. The lead tip is now detected.

[Problem to be solved by the invention]

However, the conventional technology relates to lead detection before the electronic component is mounted on the board, and does not particularly consider lead detection on the back surface of the board after the electronic component is mounted on the board. Detection of leads after mounting on a board is performed as part of a visual inspection of the mounted board to check whether the electronic components are lifted up from the surface of the board and whether the leads are inserted into the specified through-hole positions. Inspection is necessary to detect poor attachment of leads to through-holes and incorrect mounting positions. Up to now, the visual inspection of mounted boards has been carried out exclusively by visual inspection, but this visual inspection is also becoming increasingly automated, and lead detection is no exception.

By the way, if lead detection is performed by applying the conventional technology, various problems will occur. Problems such as vertical movement of the lead due to distortion of the board itself, bending of the lead due to clinching, optical path obstruction due to leads of adjacent electronic components, etc. occur, such as the inability to properly irradiate parallel light to the lead tip to be detected. It has become a thing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for inspecting the mounting and mounting condition of electronic components that can satisfactorily inspect the lead condition of electronic components mounted and mounted on a board. In addition, other objects of the present invention include speeding up the mounting direction and inspection of electronic components, an optimal slit light profile extraction direction and extraction method, active detection of through-holes themselves, and classification and classification of lead states using slit light profiles. The purpose of the present invention is to provide a method for inspecting the mounting and mounting state of electronic components in which a method for determining a more desirable lead state is taken into consideration.

A further object of the present invention is to provide an electronic component mounting condition inspection device that can satisfactorily inspect the lead condition of electronic components mounted and mounted on a board, and furthermore, to provide an electronic component mounting condition inspection device capable of properly inspecting the lead condition of electronic components mounted on a board.
An object of the present invention is to provide an electronic component mounting and mounting state inspection device that takes into consideration simultaneous extraction from different directions.

[Means to solve the problem]

The above purpose is basically to irradiate the slit light onto the lead row to be inspected from almost directly above or below, while extracting the slit light profile from diagonally above or diagonally below, perpendicular to the direction of the lead row. is achieved. Another purpose is to irradiate the slit light in the same direction as the lead row direction, and if the next inspection target exists in a parallel state nearby, the deflection-controlled slit light can be irradiated to the next inspection target. By doing so, the slit is placed at an angle of 45° to 6° with respect to the substrate surface, with the surface that almost contains the slit light in between.
By extracting the slit light profile from two diagonally upward or downward directions having an angle of 0'', the slit light profile is extracted as the difference between the slit light irradiation state and the slit light non-irradiation state to the lead row. By detecting the light detection position from the substrate surface as a through hole, the slit light profile portion corresponding to each lead position can be classified as one of the states of lead tip detection, lead shadow detection, and lead not detected. When the slit light profile is obtained from two directions, the state of each lead position is determined as a combination of two states, thereby achieving each state.

Furthermore, another object of the present invention is to provide slit light irradiation means, X, Y
The structure includes a direction substrate position setting means, a slit light deflection means, a lead row imaging means, and a lead state recognition/judgment means, and furthermore, the two lead row imaging means can be positioned in a predetermined state corresponding to the lead row direction. Each of these can be achieved by setting them.

[Operation] In short, in order to inspect the lead array condition without being affected by distortion of the board itself or adjacent lead arrays, the lead array is irradiated with slit light from almost directly above or directly below, and the slit light irradiation state is It is only necessary to detect the lead row located in the diagonal direction. Since the profile of the slit light is extracted in a predetermined manner according to the lead state, the lead state can be known from the profile state corresponding to the lead position. Generally, the direction of the lead array of electronic components is either the X direction or the Y direction depending on the mounting direction, and since this direction is known in advance, it is sufficient to irradiate the lead array with slit light in the direction corresponding to that direction. be. In the lead row to be inspected, the board itself is
The slit light is irradiated while the board is positioned in a predetermined direction, but if there is a parallel lead array nearby to be inspected, the slit light is irradiated without the need to newly position the board itself. By deflecting itself and irradiating the next inspection target with slit light, the lead array can be inspected more quickly. just,
Considering that the lead condition is generally not uniform and the leads are bent, it is not appropriate to extract the slit light profile from only one diagonal direction, and it is possible to extract it from other diagonal directions simultaneously. It is appropriate. Slit light profile extraction is performed by extracting the positions of high-level pixels from a two-dimensional image of a lead row taken from an oblique direction. By calculating the difference between images, the profile of the slit light can be extracted as a more visible profile.

Now, in order to actively detect a through hole in which no leads are inserted, it is necessary to detect the fact that light from the front side of the board that is not irradiated with slit light is detected on the back side of the board through the through hole. It is possible. Additionally, the state of the broach depending on the lead position is generally detected as lead tip detected, lead shadow detected, or lead not detected, but the presence of a lead can now be detected by detecting the lead tip or lead shadow. There is. However, even if a lead is not detected from an oblique direction, a lead shadow may be detected from another diagonal direction, so it is more common to extract slit light profiles from two diagonal directions at the same time. It is effective in dealing with such cases.

The electronic component mounting and mounting state inspection apparatus according to the present invention is also configured to include a slit light irradiation means, an XY direction board position setting means, a slit light deflection means, an imaging means, and a recognition/judgment means. If two are prepared corresponding to the irradiation direction or the lead row direction, and these four are set in predetermined diagonal positions, the lead condition can be inspected more generally.

〔Example〕

The present invention will be explained below with reference to FIGS. 1 to 8.

First, to explain the mounted board appearance inspection apparatus according to the present invention, FIG. 2 shows the appearance configuration of one example. In addition to visual inspections such as recognizing characters, symbols, and polarity marks when they are displayed, and comparing them with pre-prepared data and detecting the presence or absence of polarity marks, we also perform inspections on the various electronic component numbers. In addition to detecting the lead condition on the back side of the board, it is also detected whether the lead is mounted correctly.

As shown in Fig. 2, this device moves a board 9 on which various electronic components are mounted in an upside-down state in the X and Y directions, and sets a lead row as a recognition target at a predetermined position. A child table, a slit projector 2 for creating slit light used to detect the lead row state, a galvanometer mirror 3 for finely adjusting the slit light irradiation position on the substrate 9, and a galvanometer mirror 3 for capturing a recognition target image. 4
1 TV left camera, a recognition device 5 for processing images from the TV left camera, a monitor 6 for displaying the close-up image or the processed image, and a monitor 6 for inputting various data to control the operation of these devices. It is equipped with a keyboard 10, a CRT 7 for displaying these various data, a printer 8 for outputting test results, a setting panel 11 for inputting interrupts, and the like.

Incidentally, in this example, since the board 9 is inspected by turning it over, the optical system (2, 3° 4), which requires a large space, is placed at the top of the device. The device itself has also been miniaturized. Note that the optical system (1
2 and 13) are for visual inspection, but the ring-shaped light source 12 is effective for actively detecting the through-hole itself, as will be described later.

FIG. 3 shows the optical system (2, 3, 4) in detail. Since electronic components on the board 9 are generally mounted in two directions, such as the X direction or the Y direction, one slit projector 2 for producing slit light is prepared for each of the X and Y directions. , the slit light from these is transmitted through the triangular prism 15 and the Kieub beam splitter 1.
6 etc., the same position on the substrate 9 is irradiated. Further, a galvano scanner 14 to which a galvano mirror 3 is attached is provided for each slit light, and the slit light can be freely transmitted in the X and Y directions to the substrate 9.
Moreover, it is possible to perform polarized irradiation at high speed. In addition, the TV left camera for capturing images to be recognized is installed two in the direction orthogonal to each slit light to ensure stable recognition, and at an angle of 45 to 60 degrees (with clinched leads) relative to the board surface. The position is set at an angle that is the optimum lead detection angle under consideration.

FIG. 4 also shows the configuration of the recognition device and its surroundings. In this case, the image output board 19 performs quantization of the human-powered image from the TV left camera, stores it in the image memo IJ 23, outputs and displays various images on the monitor 6, and the DSP board 18 performs high-speed calculation processing. , a disk controller 26 that controls the hard disk 24 and the Frembie disk 25, a χYZ controller 27 that controls the XY child table and its Z axis, and a galvano mirror that controls the galvano scanner 14.
Controller 20, DI1028 that performs interrupt input from setting panel 11, and CP that controls all of these
It is composed of U17.

Image data (slit light irradiation state image and slit light non-irradiation state image) from the TV camera 4 is stored in the image memory 23 in the image turnout board 19 according to a command issued from the CPU 17 according to a program written and stored in advance.
It is stored in , and is allowed to be processed by the CPLJ17. Further, these images are transferred from the image memory 23 to the DSP board 18 according to instructions from the CPU 17.
The DMA is transferred to the image memory 21 in the DSP board 1.
This figure shows the principle of read state detection when the DSP inspects the line state using the commands stored in the command word memory 22 in 8. Slit light is irradiated from a slit projector 2 to the lead rows lined up on the board 9 in a direction perpendicular to the board surface, and two TV cameras I and II are used to project 45 to 45 m across the board surface with the slit light in between. If the lead row state is imaged from an angle θ of 60 degrees, the slit light profile can be roughly classified into three types depending on the lead state.

For example, assuming that the image is captured from the TV camera I side, if the slit light is irradiated to the lead tip, the 6th
As shown in Figure (a), the tip of the lead is illuminated and the profile of the slit light is discontinuous only at the lead portion, indicating that the lead is protruding from the substrate. In addition, as shown in Figure 6 (■), if the slit light is irradiated on the side opposite to the TV camera I with the lead in between, the profile of the slit light will be on the back side of the lead and However, in this case, the lead is still the basis lol.
It is known that it protrudes from above 9.

Furthermore, if the leads do not protrude above the substrate 9, the profile of the slit light will be 1 as shown in FIG. 6(C).
It is extracted as a continuous linear shape of a book.

FIG. 1 shows the overall flow of the mounting/attachment state determination process based on the lead state detection as described above. In this case, first, an image of the lead array to be inspected in a state where the slit light is irradiated is manually input, and then an image with the slit light not irradiated is input.

A through hole is detected from the image input without slit light irradiation, but the through hole itself is detected when light from the ring-shaped light source 12 is detected from the front side of the board at a certain lead position. The presence of this is detected.

After the presence or absence of a through hole is detected, the difference between the already input slit light irradiation state image and slit light non-irradiation state image is calculated, and the slit light profile is calculated from the resulting difference image. It has become something that From the profile of the slit light, the presence or absence of leads is detected depending on the lead position, and by comparing these detection results with pre-registered data, it is determined whether the mounting and mounting state of the electronic component is normal. This is what is meant to be done.

The mounting state of the electronic components is determined in the above manner, but considering that the leads are bent at -g, the two TV cameras I and I can be connected with the slit light in between.
By recognizing the same lead position portion using I and making a determination by combining these two recognition results, it is possible to more stably and accurately detect the presence or absence of a lead.

Figure 7 shows two TV cameras 1. This figure shows the logic for determining the presence or absence of a lead based on the results obtained from II. When the lead tip is illuminated with slit light as shown in Figure 6(a), the lead tip can be detected by both TV cameras 1 and 2, but the lead is clinched and bent. In this case, the lead tip cannot be detected because the slit light is not irradiated onto the lead tip. However, the TV right camera on one side cannot detect the lead, but the other TV camera detects the lead as a lead shadow, so 2
Based on the results from the TV camera, it can be determined that there is a lead. In addition, when the front side of the board is not illuminated by the ring-shaped light source 12, the through holes are connected to the TV camera 1. Both are detected as lead shadows by II.

FIG. 8 shows the flow of the mounting/attachment state determination process when two TV cameras are used.

In this case, a difference image is calculated from the slit light irradiation state image and the slit light non-irradiation state image input from each TV camera, and each of these difference images is calculated in a direction perpendicular to the slit light. The profile of the slit light is extracted by scanning while taking a weighted average. Based on the profile of the extracted slit light, the lead state corresponding to the lead position is estimated to be one of the following states.

Condition 1 The optical profile is interrupted.

(Through hole, shadow of lead) State 2 The profile of the Nislit light exists as discontinuous.

(Tip of lead) Condition 3: There is a slight peak in the Nisrit light profile.

(solder buildup on the board) State 4: The profile of the slit light is a straight line.

(Board surface) From the two profiles, the lead states corresponding to the same lead position are estimated and classified as described above, but from the combination of the two lead states corresponding to the same lead position, the The lead status is determined comprehensively. The determination result for each lead position is compared with pre-registered standard mounting and mounting data for that electronic component, thereby comprehensively determining the mounting and mounting state of the electronic component.

Finally, the table-type data registered in advance in the system will be explained. Data in the system is broadly classified into sequence data and type data. Of these, sequence data consists of design data for the arrangement of components on a board, and is generally created using a CAD device. On the other hand, type data is individual data for each type of part necessary for recognition, and is taught for each object. These two types of data are independent of each other, and their settings, modifications, deletions, etc. can be performed independently using the keyboard and CRT in the device. The appearance of the mounted board is inspected while referring to the type data according to the order of the sequence data, and at this time, the mounting state of the electronic components is also inspected.

〔Effect of the invention〕

As explained above, according to claim 1, the lead condition of electronic components mounted on a board can be satisfactorily inspected without being affected by distortion of the board itself or adjacent lead rows. According to the present invention, the lead condition can be inspected according to the mounting direction of the electronic component, and in the case of the third aspect, the lead condition can be inspected at a higher speed.

In the case according to claim 4, the slit light profile is also extracted from the optimum direction, and in the case according to claim 5, the slit light profile is extracted as a more pronounced one. Further, according to claim 6, the through hole itself can be actively detected, and according to claim 7, the lead state can also be classified and determined from the slit light profile, and according to claim 8, the slit light profile from two directions can be detected. Accordingly, a more desirable lead state can be determined.

Furthermore, according to claim 9, it is possible to obtain an apparatus in which simultaneous extraction of the slit light profile from two directions is taken into consideration when the lead state of the electronic component mounted on the board is caused by distortion of the board itself. FIG.
3 is a diagram showing the external configuration of an example of a mounted board appearance inspection device according to the present invention, FIG. 3 is a diagram showing the optical system as the main part in detail, and FIG. FIG. 7 is a diagram for explaining the principle, and FIG. 7 is a diagram showing a more desirable lead presence/absence determination logic, and FIG. 8 is a diagram showing a flow of the mounting/attachment state determination process according to the determination logic.

1...XY child table 2...Slit projector, 3...Galvano mirror 54...TV camera, 5...
... Recognition device, 9... Board.

Agent Patent Attorney Masami Akimoto outfit figure (a) No. figure Kusuputof’Tl siegebu (b) (C) Condolence figure

Claims (10)

[Claims] 1. An electronic component for inspecting the state of lead rows corresponding to each of the electronic components protruding from the back surface of the substrate, by making the substrate on which various electronic components are mounted and mounted through through holes movable in the X and Y directions within a horizontal plane. A method for inspecting the mounting and mounting state, in which a slit light profile is applied from diagonally above or diagonally below perpendicular to the direction of the leads, with respect to a state in which slit light is irradiated from almost directly above or directly below onto a lead array to be inspected. An electronic component mounting condition inspection method in which the condition of each lead constituting a lead row is inspected based on extraction. 2. Irradiation of the slit light onto the lead row is carried out by
, and the Y direction. 3. When the lead arrays to be inspected are in the same direction and are parallel to each other in the vicinity, the slit light is irradiated onto the next inspection target by parallel movement due to deflection without moving the board itself. Items 1 and 2
A method for inspecting the mounting condition of any electronic component mounted. 4. The slit light profile is a lead row state taken from two diagonally upward or diagonally downward directions, each at an angle of 45° to 60° with respect to the substrate surface, with a vertical plane that almost contains the slit light in between. Claim 1 extracted from
2. The electronic component mounting mounting state inspection method according to any one of 2 and 3. 5. 5. The method for inspecting the mounting and mounting state of electronic components according to claim 1, wherein the extraction of the slit light profile is performed based on the difference between the slit light irradiation state and the slit light non-irradiation state on the lead array. 6. Claim 1: When light from the front side of the substrate is detected through a through hole included in the lead array in a state where the slit light is not irradiated to the lead array, the hole position is determined to be in a lead-uninserted state. , 2, 3, 4, or 5. 7. From the extracted slit light profile, the state of each lead position is determined by the lead tip detection,
6. The electronic component mounting and mounting state inspection method according to claim 1, wherein the state is classified and determined as one of lead shadow detection and lead non-detection. 8. 8. The electronic component mounting and mounting state inspection method according to claim 7, wherein the state of each lead position is determined as a combination of states corresponding to the lead position of slit light profiles extracted from each of two diagonally upward directions or diagonally downward directions. 9. An electronic component for inspecting the state of lead rows corresponding to each of the electronic components protruding from the back surface of the substrate, by making the substrate on which various electronic components are mounted and mounted through through holes movable in the X and Y directions within a horizontal plane. The mounting installation state inspection device includes a slit light irradiation means that selectively irradiates slit light in either the X or Y direction from almost directly above or directly below, and a predetermined array of leads to be inspected at the slit light irradiation position. a slit light deflection means for deflecting the slit light from the slit light irradiation means within a certain range by changing the amount of deflection; and a lead array in the slit light irradiation state. An imaging means for two-dimensionally capturing an image from an obliquely upward direction or an obliquely downward direction orthogonal to the direction of the lead array, and a slit light profile extracted from the two-dimensional image from the imaging means, are used to determine the lead array from the lead position. An electronic component mounting and mounting state inspection device including at least recognition/judgment means for recognizing and determining a compatible state. 10. Two imaging means prepared for the X and Y directions of the lead row are arranged diagonally upward or diagonally at an angle of 45° to 60° with respect to the substrate surface, with a vertical plane containing the slit light in between. 10. The electronic component mounting and mounting state inspection device according to claim 9, wherein the electronic component mounting and mounting state inspection device is positioned downward.