JP2684656B2 - Electronic component appearance inspection method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for inspecting the appearance of an electronic component, which inspects the electronic component mounted on a substrate for misalignment, missing parts, and the like. (Prior Art) After mounting an electronic component on a substrate, a visual inspection of the electronic component is performed. Typical inspection items for visual inspection are displacement inspections that check whether electronic components are mounted at prescribed coordinate positions without displacement, and that defective components are inspected whether electronic components are present at prescribed coordinate positions. and so on. In general, the types and number of electronic components mounted on a board are quite large, and therefore it is desirable to perform visual inspection automatically using an optical device such as a camera, but at present, automatic visual inspection technology has been established. Since it is not available, it is the actual situation that the visual inspection is performed by the operator's eyes. (Problems to be Solved by the Invention) However, there are problems that the visual inspection by the operator does not improve the work efficiency, and the quality judgment is likely to vary due to the individual error of the operator. Therefore, an object of the present invention is to provide a visual inspection method for an electronic component, which is capable of accurately inspecting a displacement of the electronic component and a missing item by using a camera. (Means for Solving the Problem) To this end, the present invention includes a plurality of corner portions that are characteristic portions of a planar shape of the electronic component when the electronic component mounted on the substrate is observed by an upper camera. If you set multiple areas and all of these multiple areas include the image of the corner, which is a characteristic part, it is determined that the mounting state is good,
If at least one of the plurality of areas does not include a corner, which is a characteristic portion, the mounting state is determined to be defective. Further, the electronic component is a two-electrode rectangular electronic component, the characteristic portion is four corners of the two-electrode rectangular electronic component, and the area including each of these four corners is set. (Operation) According to the above configuration, by inspecting the images of the corners, which are the characteristic portions in the plurality of areas obtained by the camera, it is possible to accurately and automatically inspect the positional deviation of the electronic component and the missing item. Example Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an appearance inspection apparatus for electronic parts according to an embodiment of the present invention, and FIG. 2 is a perspective view of a recognition unit. 1 is a main frame, 2 is a base plate, 3 is a pre-conveyor which carries in the substrate 4 in the direction of arrow H, 5 is a rear conveyor which carries out the substrate 4 in the direction of arrow M, 6 is a substrate holder for positioning the substrate 4, and 7 is defective A defective substrate stocker having a magazine 8 for accommodating the substrates 4a, and a recognition unit 9 provided above the substrate holder 6. The board holder 6 has two guide rails 10 and a motor.
A movable base 12 is provided which moves in the direction of arrow A by means of 11 and a ball screw 11a. 2 on the movable base 12
A book guide 13 is provided, and the movable conveyor 14 is driven by a drive motor 15. In addition, the movable base 12 is provided with a fixed side conveyor 14a, and the movable side conveyor 14 is configured to move with the fixed side conveyor 14a as a reference. Moreover, the handle 16 and the screw 17 are provided to adjust the distance between the movable side conveyor 14 and the fixed side conveyor 14a according to the width of the substrate 4, and the lock handle 18 is provided.
The movable conveyor 14 is thereby locked. The fixed side conveyor 14a has an arrow B by a cylinder 19
A substrate stopper 20 that operates in the direction and a sensor 21 that detects the presence or absence of the substrate 4 are provided. Movable conveyor 14
Is provided with a clamper 23 that clamps the substrate 4 in the direction of arrow C by a cylinder 22. Therefore, when the substrate 4 is clamped and fixed by the clamper 23 and the driving motor 11 is driven, the movable base 12 horizontally moves along the guide rail 10 in the arrow A direction, and the substrate 4 also horizontally moves in the same direction. That is, the motor 11 and the movable base 12 are the substrate 4
Is a moving means for moving in a horizontal direction with respect to the recognition unit 9. The rear conveyor 5 is provided with a fixed side conveyor 25 supported by a bracket 24 and a movable side conveyor 28 supported by a guide 26 and a bracket 27 and slidably provided. The movable conveyor 28 can be moved in the arrow D direction by a handle 29, a screw 30, and a lock handle 31. Furthermore, the movable side conveyor 28 is
It is driven by a motor 32, a pulley 33, and a shaft 34. The defective substrate stocker 7 is provided with two bearings 35 and two shafts 36 fixed to the base plate 2. Further, the drive device 37 and the rack 37a allow the lifter base 38 provided on the upper part of the drive device 37 to move in a pitch direction in the arrow E direction. The recognition unit 9 is provided with two posts 39 fixed on the base plate 2, and a block 40 is provided on the posts 39. The block 40 is provided with two guides 41 in the same direction as the substrate 4 is conveyed, and is provided with another block 42 that slides along the guides 41.
The block 42 is moved in the arrow F direction by a motor 43 and a ball screw 44. On the block 42, the light source 45, the fiber 45a, and the slit unit 4 that blocks light
5b is provided. Further, the block 42 is provided with a drive device 47 having a motor 46 for horizontally rotating the recognition unit 9 in the direction of arrow G, and a bearing 49 for allowing the main body frame 48 of the recognition unit 9 to rotate is provided below the drive device 47. It is provided. By driving the motor 46 to horizontally rotate the recognition unit 9 in the direction of the arrow G, it is possible to change the image capturing direction of the electronic component according to the direction of the electronic component mounted on the substrate 4. The body frame 48 has a camera for recognizing the position of the substrate 4.
50 and a lighting lamp 51 are provided. A camera 53 (hereinafter referred to as a top camera) arranged on the body frame 48 so that the optical axis is perpendicular to the upper surface of the substrate 4.
And a ring-shaped illumination lamp 54 for irradiating the substrate 4 with light from above, and a plurality of cameras 55, 55a, 55 arranged so that the optical axis is oblique to the upper surface of the substrate 4.
b, 55c (hereinafter referred to as side cameras), and a plurality of illumination lamps 56, 56a, 56b, 56c connected to the fiber 45a and irradiating the substrate 4 with light obliquely from above. A marker 57 for marking a defective electronic component or defective portion is provided according to the appearance inspection result of the mounted state or the soldered state of the electronic component 52 mounted on the board 4. When the driving motor 43 is driven, the block 42 guides
Move horizontally along arrow 41 in the direction of arrow F. The recognition unit 9 and the marker 57 are assembled integrally with the block 42, and therefore move horizontally in the direction of arrow F together with the block 42. That is, the guide 41, the block 42, and the motor 43 are moving means for moving the recognition unit 9 and the marker 57 in the horizontal direction (F direction) with respect to the substrate 4. Here, the arrow A direction and the arrow F direction are directions orthogonal to each other, and
By driving the motor 11 and the motor 43, the board 4 moves to the recognition unit 9
It is possible to move horizontally relative to the marker 57 in the directions A and F. The operation of the appearance inspection apparatus for electronic parts configured as described above will be described. In FIG. 1, first, the substrate 4 is placed on the front conveyor 3. Then, the substrate 4 is transported by the front conveyor 3 in the direction of arrow H, and the stopper 20 positions the substrate in the substrate transport direction. Substrate detection sensor 21 then substrate 4
, The clamper 23 moves in the C direction by the cylinder 22, and the substrate 4 is clamped and positioned.
Then, the state of the positioned substrate 4 is recognized by the camera 50 and the illumination lamp 51, and the controller calculates the inclination and the positional deviation of the substrate 4. Then, the motor 11 and the motor 43 are driven based on the correction value calculated from the inclination and the positional deviation of the substrate 4 and the master pattern data stored on the substrate 4 in advance, and the substrate 4 is moved relative to the recognition unit 9. Predetermined electronic components mounted on the board 4 by horizontally moving in the A direction and F direction
The 52 is positioned at the appearance inspection position by the recognition unit 9, and the appearance inspection described later is performed on the electronic component 52. Next, the control device will be described. FIG. 3 is a functional block diagram relating to the inspection. 53,55,55a, 55b, 55c are substrate 4
This is a television camera that captures the image of the electronic component 52 above.
TV camera 53 is the top camera and TV camera 5
5,55a, 55b, 55c are side cameras. 58 to 62 are camera control units that convert the image levels captured from the TV cameras 55, 55a, 55b, and 55c into standardized composite video signals, and 63 is a video switching unit,
Only one of the images captured from each television camera can be selected by the camera switching selection signal. 64 is a video circuit for generating an external synchronizing signal. With this external synchronization signal, all the television cameras can take in completely synchronized images. 65 is a video bus,
66 is a status and control bus. 67 is 512 × 5
This is a frame memory consisting of 12 x 8 bits, and is a place to store the original images captured by each TV camera. 68 and 69 are working memories (512 × 512 × 8 bits) for storing image information that has undergone image conversion after being subjected to necessary processing, and one working memory 68 stores image information classified by brightness, The other working memory 69 stores filtered video information. Reference numeral 70 denotes a control unit including a CPU that controls operations related to inspection. Reference numeral 71 is a memory including a read-only memory and a random access memory, and 72 is an I / O control unit. Next, the operation of the control unit 70 will be described. FIG. 4 shows the control unit 70.
6 is a flowchart showing the operation of the first embodiment. In step 1,
First, an image of the electronic component 52 mounted on the board 4 is captured from the top camera 53. In step 2, an inspection parameter is searched by data such as coordinates, brightness, direction, type of the electronic component 52 mounted on the board 4. Step 3
Then, the frame memory 67 transfers to the working memory 68 an image in which only the necessary brightness is extracted. In step 4, the limbal-emphasized or smoothed image or the like is transferred from the frame memory 67 to the working memory 69. In step 5, the brightness of the electrode part of the electronic component 52 mounted on the board 4 and the position displacement dimension at a predetermined place are determined. In step 6, the camera is switched or not switched. If the cameras are not switched, the inspection ends. In addition, when switching cameras, in step 7, the top camera 53 to the side cameras 55, 55a, 55b, 55c
, And newly captures the image of the electronic component 52. The appearance inspection apparatus for electronic parts is configured as described above. Next, the appearance inspection method for electronic parts will be described. First, a method for inspecting a positional shift of electronic components and a missing item by the top camera 53 will be described. FIG. 5 is a plan view of the two-electrode prismatic electronic component 73 observed by the top camera 53. The two-electrode rectangular electronic component has electrodes on both sides. As shown in the figure, four areas 74, 74a, 74b, 74c, which respectively include four corners, which are flat-shaped features, are set based on the master pattern data stored in advance, and each area 74-
The image data of 74c is taken into the top camera 53. If the corner area image is included in all of the four areas 74 to 74c, the mounting state is determined to be good. Also four areas 74
~ 74c, if at least one of the areas does not include the image of the corner, it is determined that there is misalignment, and if there is no image of the corner in all four areas 74-74c, it is out of stock. To determine. FIG. 6 is a plan view of a mini-transistor leg electronic component 75 having three electrodes as an electronic component. The method of determining the quality of the mounted state of the mini-transistor electronic component with foot 75 is the same as in the case of the two-electrode rectangular electronic component 73, and includes three feet (electrodes) based on the master pattern data stored in advance. Set three areas 76-76b. If the images of the legs (electrodes) of the mini-transistor leg electronic component 75 are included in all the areas 76 to 76b, the mounting state is determined to be good. Also three areas 76-76
If the foot (electrode) image is not included in any one of the areas b, it is determined that there is misalignment, and if all three areas 76 to 76b are not included in the foot image, it is out of stock. To determine. As described above, according to this method, the two-electrode rectangular electronic component 73
Angle and electronic parts with mini transistor foot 75 feet (electrode)
By setting an area that contains a plurality of planar features of an electronic component such as, and inspecting whether the image of the feature is included in the area, the electronic component is misaligned or missing. You can easily and surely judge such as. Next, a method for determining the quality of the soldered state will be described. FIG. 7 is a plan view of the electronic component 52 observed by the top camera 53. As shown in the figure, scanning lines 77, 77a, 77 are provided between the electrodes based on the master pattern data stored in advance.
Set b and 77c. And the solder 78 on the scan lines 77-77c
The presence or absence of solder is inspected, and if solder 78 is present, it is determined to be a solder bridge, and the soldering state is determined to be defective. In the case of the two-electrode prismatic electronic component 73 shown in FIG. 8, scanning lines 79, 79a, 79b are set between them. Then, the presence or absence of the solder 78 on the scanning lines 79 to 79b is confirmed, and if there is the solder 78, it is determined to be a solder bridge, and the soldering state is determined to be defective. As described above, according to this method, the presence or absence of a solder bridge that causes a short circuit can be easily inspected. Next, referring to FIGS. 9 to 12, side cameras 55 to 55c
The external appearance inspection method will be described. FIG. 9 shows a case where the electronic component 52 is not floated or displaced with respect to the substrate 4, and two images 80 and 81 of the electronic component 52 captured by the two side cameras are reference images. Now, as shown in FIG. 10, when there is no displacement of the electronic component 52 with respect to the substrate 4 but there is a float of Δh, the position of the image 82 of the electronic component 52 captured by one side camera is displaced in the direction of arrow I. Then, the position of the image 83 captured by the other side camera is displaced in the arrow J direction. Therefore, by comparing the positions of the images 82 and 83 with the positions of the reference images 80 and 81 and obtaining the displacements thereof, it is possible to easily determine that the electronic component 52 is floating. Further, as shown in FIG. 11, when the electronic component 52 does not float with respect to the substrate 4 but the position shifts by Δx, the position of the image 84 of the electronic component 52 captured by one side camera is displaced in the arrow K direction. The electronic component 52 captured by the other side camera.
The position of the image 85 is displaced in the arrow L direction. Therefore, it can be easily determined from this displacement that there is a displacement. Next, as shown in FIG. 12, when both the Δh float and the Δx position shift of the electronic component 52 with respect to the substrate 4 occur, the images 86 and 87 of the electronic component 52 captured by the side camera show the Δx position shift and the Δx position shift. The displacement of Δh causes displacement as illustrated. In this case, the deviation amount of Δx is obtained from the image of the electronic component 52 captured from the top camera 53, and the floating amount of Δh is obtained from the image of the electronic component 52 captured from the top camera 53.
It can be obtained from the image of the electronic component 52 captured from the side camera based on the shift amount of x. The visual inspection of electronic parts is performed as described above.
For defective electronic parts, the motor 11 and motor 4 shown in FIG.
By driving 3 to move the marker 57 horizontally relative to the substrate 4, a defective electronic component or defective portion is marked. Then, the non-defective board 4 is carried out in the direction of the arrow M, but the defective board 4a is moved by the board holder 6 in the arrow A direction.
And is stored in the magazine 8 of the defective substrate stocker 7. (Effect of the Invention) As described above, according to the present invention, a simple method of observing an electronic component with an upper camera and inspecting an image of a corner portion that is a characteristic portion in a plurality of areas is mounted on a substrate. It is possible to automatically and accurately perform a visual inspection such as a positional deviation of the electronic component or a missing item.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an appearance inspection apparatus for electronic parts according to an embodiment of the present invention, and FIG. 2 is a recognition unit of the appearance inspection apparatus for electronic parts according to an embodiment of the present invention. FIG. 3 is a perspective view, FIG. 3 is a functional block diagram of the control unit of the appearance inspection apparatus for electronic parts according to the embodiment of the present invention, and FIG. 4 is an operation of the control unit of the appearance inspection apparatus for electronic parts according to the embodiment of the present invention. 5, FIG. 6, FIG. 7, FIG. 8 and FIG. 8 are plan views of electronic parts showing the inspection method of the appearance inspection apparatus for electronic parts in one embodiment of the present invention, FIG. 9, FIG. Figure, Figure 11, Figure 12
FIG. 1 is an explanatory diagram of a visual inspection method using a side camera of an electronic component visual inspection apparatus according to an embodiment of the present invention. 4 ... Board 6 ... Board holder 9 ... Recognition unit 11 ... Motor (moving means) 12 ... Movable base (moving means) 13 ... Guide (moving means) 41 ... Guide (moving means) 42. Block (moving means) 43 …… Motor (moving means) 53 …… Top camera 54 …… Lighting lamp 55 …… Side camera 55a …… Side camera 55b …… Side camera 55c …… Side camera 56 …… Lighting lamp 56a… … Lighting lamp 56b …… Lighting lamp 56c …… Lighting lamp 52 …… Electronic parts 73 …… Electronic parts 74 …… Area 74a …… Area 74b …… Area 74c …… Area 75 …… Electronic parts 76 …… Area 76a… Area 76b Area 77 scan line 77a Scan line 77b Scan line 77c Scan line 78 Scan line 78 Solder 79 Scan line 79a Scan line 79b Scan line

Claims (1)

(57) [Claims] Observing the electronic components mounted on the board with the camera above, set multiple areas including the corners, which are the features of the planar shape of this electronic component, and characterize all of these multiple areas. If the image of the corner portion that is a part is included, the mounting state is determined to be good, and if the corner portion that is the characteristic portion is not included in at least one of the plurality of areas, the mounting state is determined to be defective. A method for inspecting the appearance of electronic parts, characterized by: 2. The electronic component is a two-electrode rectangular electronic component, the characteristic portion is four corners of the two-electrode rectangular electronic component, and the area including each of these four corners is set. The method for inspecting the appearance of an electronic component according to claim 1.