JP2000214098A - Method and apparatus for visual inspection to substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set an optimum pickup condition for visual inspection to substrates by dividing into matrix the whole of a substrate by a pickup section as a range which can be picked up by an image pickup means, and sequentially correcting coordinates of the pickup sections. SOLUTION: Visual inspection to substrates in a printed wiring board- mounting line or the like is first executed by dividing in matrix the whole of the printed wiring board by a pickup section of a camera or the like. Then the pickup section is divided to, for instance, A-D areas. Coordinates of the pickup section for each area are sequentially corrected. For instance, if an electronic part 2a as an inspection point is partly included in the area A, the entirety is accommodated in the pickup section and the inspection point is positioned to the center, or the like process is carried out. A new pickup section is added when an electronic part which is not included in any pickup section appears during the correction. The pickup section to which no electronic part is allotted is deleted. After the above process is repeated, a pickup order for the pickup sections is optimized by a predetermined method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for inspecting the appearance of a substrate.

[0002]

2. Description of the Related Art In a mounting line in which electronic components are mounted on a printed wiring board and circuit connection is performed by soldering or the like, the printed state of cream solder (for example, excessive soldering, insufficient soldering, clogging of a screen, etc.), and electronic component Mounting state (for example, unsoldered,
A board appearance inspection device for inspecting an excessive amount of solder, an insufficient amount of solder, a missing item, a deviation, a bridge, etc.) is arranged. This board appearance inspection apparatus irradiates light from above and laterally with a light to an inspection place on a printed wiring board, takes a picture with a camera, and compares these two images to judge the quality of the above state. It has become.

[0003]

In the above-described conventional board appearance inspection apparatus, when each electronic component is photographed by the camera, it is necessary for the operator to manually move the camera to determine the photographing place. That is, before inputting the inspection data of the printed wiring board, the operator manually performs a camera split for photographing, that is, a process of setting while checking the inspection location on the printed wiring board with the camera (hereinafter, referred to as allocation). I had to. Further, this allocation has to be set so that the servo operation is minimized.

The present invention has been made in view of the above circumstances, and has as its object to provide a method and an apparatus for inspecting the appearance of a board, which can automatically set the optimal photographing conditions for the appearance of the board.

[0005]

According to the present invention, there is provided a method of inspecting the appearance of a substrate by photographing the appearance of the substrate with an image pickup means. The matrix is divided in a matrix, and each of the photographing sections is divided into a plurality of areas. For each of the photographing sections, the coordinates of the photographing section for each of the areas are sequentially corrected, and the coordinates of the photographing section for each of the areas are corrected. During the correction process, if an inspection location that is not included in any of the imaging sections appears, a new imaging section containing the inspection location is added, and the center coordinates of each imaging section are sequentially corrected, During the process of correcting the center coordinates of each imaging section, when an inspection location included in another imaging section appears, the inspection location is changed to the other imaging section, and the imaging section is changed. If test points are not in, remove the imaging section, it is achieved by optimizing the imaging order of the respective imaging sections.

According to the above configuration, the position of the imaging section can be automatically corrected or a new imaging section can be added or changed so that the inspection section is located at the center of the imaging section. Inspection accuracy can be improved by improving imaging quality. Furthermore, since the imaging section having no inspection location can be deleted, the number of imaging sections can be optimized and the inspection time can be reduced.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is a schematic perspective view showing an embodiment of a board appearance inspection apparatus according to the present invention. This board appearance inspection device 1
The printed wiring board (substrate)
Conveyor 102 for conveying the
Table (mounting means) 103 on which the printed wiring board conveyed by the apparatus is mounted, and this inspection table 103
A moving mechanism (moving means) 104 for moving the moving object is provided.

The conveyor 102 is composed of two rails or the like which are arranged so as to cross the main body 101 to form a mounting line, and support and transfer both ends of the printed wiring board. Although not shown, the inspection table 103 is configured to sandwich and fix the mounted printed wiring board by a clamp mechanism operated by an air cylinder. The moving mechanism 104 is composed of, for example, a ball screw / nut, a motor, and the like, and moves the inspection table 103 in the X direction by rotating / linearly driving them.

An inspection table 10 is provided above the main body 101.
A camera (imaging means) 106 for photographing and displaying the external appearance of the printed wiring board on the monitor 3; a monitor 107;
A moving mechanism (moving means) 108 for moving the unit and an operation unit 109 for operating each unit are provided, and a control unit 110 connected to the operation unit 109 is provided inside the main body 101.

The camera 106 includes, for example, a CCD (solid-state image sensor) and the like, and shoots the upper surface of the printed wiring board 1. The moving mechanism 108 includes, for example, a ball screw / nut, a motor, and the like, and is configured to move the camera 106 in the Y direction by rotating / linearly driving them. The operation unit 109 is composed of, for example, a touch panel and a monitor, and is used to input operation programs and data for controlling the board appearance inspection apparatus 100.
It is displayed. The control unit 110 includes, for example, a CPU, a memory, and the like.
9 to control the board appearance inspection apparatus 100 by executing an operation program and the like input from the CPU 9.

In such a configuration, an example of the operation will be described with reference to the flowchart of FIG. 2 and a specific example of a substrate on which electronic components are mounted as shown in FIGS. The printed wiring board 1 on which the electronic components 2 shown in FIG.
No. 02 is carried in from the substrate entrance, is positioned at the inspection position, is clamped and fixed on the inspection table 103, and the following allocation and the like are started.

First, the entire printed wiring board 1 is
The image is divided into a matrix shown by a dotted line in FIG. Here, in order to identify each photographing section on the printed wiring board 1, the printed wiring board 1
In the longitudinal direction and the lateral direction, symbols a to g and p to s are assigned, respectively, and for example, an imaging section located at a lower left corner in the drawing is represented by ap (step S1). Then, each photographing section is divided into a plurality of areas, for example, four areas A to D as shown in FIG. 2A (step S2).

Next, the coordinates of the photographing section for each of the areas A to D are determined in the order of the area A in order from the photographing section near the servo origin.
The correction is made in the order of D. For example, as shown in FIG.
When the area A includes a part of the electronic component 2a that is the inspection location, the coordinates of the imaging section are changed so that the entire electronic component 2a fits in the corresponding imaging section. However, when a plurality of electronic components 2a and 2b are arranged across the area A as in this example, the electronic component 2a is preferentially photographed at a position closer to the servo origin above or below the Y axis. Correct the parcel coordinates. It is assumed that the electronic component 2a once allocated to the imaging section does not go out of the imaging section during the correction process.

When the above-described correction of the coordinates of the shooting section with respect to the area A is performed on the printed wiring board 1, as shown in FIG.
Of the imaging sections of the printed wiring board 1, the imaging section indicated by the solid line does not move, and the imaging section indicated by the dashed line moves. Then, with the movement of the photographing section, the black-painted electronic component 2 protrudes from the photographing section (step S3).

Subsequently, when the coordinates of the photographing section with respect to the area B are corrected on the printed wiring board 1, as shown in FIG. 5, of the photographing sections of the printed wiring board 1, the photographing section indicated by a solid line is moved. , The shooting section bq indicated by a dashed line,
dq, cr, dr, as, and ds move. Then, with the movement of the shooting section, FIG.
Although the parts 21 to 27 of the black-painted electronic component 2 shown in (1) will fit in the above-mentioned photographing section, a new black-painted electronic component 28 will protrude from the photographing section dr (step S4). .

Next, when an electronic component 2 not included in any of the imaging sections appears during the process of correcting the coordinates of the imaging section for each of the areas A and B, the electronic component 2 is centered. Add a new shooting section. Since no electronic component 2 not included in any of the photographing sections has appeared on the printed wiring board 1 at this stage, no new photographing section is added (step S5).

Subsequently, when the coordinates of the photographing section with respect to the area C are corrected on the printed wiring board 1, as shown in FIG. 6, of the photographing sections of the printed wiring board 1, the photographing section indicated by a solid line is moved. Instead, only the imaging section br indicated by the dashed line moves. Then, one of the black electronic components 2 shown in FIG.
Is contained in the photographing section, and the parts 30, 31, and 32 of the black-painted electronic component 2 shown in FIG. 5 still protrude from the photographing section (step S6).

Further, during the process of correcting the coordinates of the photographing section with respect to the area C, electronic parts (hatched electronic parts) 33 to 36 which are not included in any of the photographing sections appear. , 35 ′ and 36 ′, new imaging sections b′-q ′, d′-r ′,
g′−q ′ is added (step S7).

Subsequently, the coordinates of the photographing section with respect to the area D are corrected on the printed wiring board 1. At this time, as shown in FIG. 7, each photographing section of the printed wiring board 1 does not move at all (step S8). ). Then, a new imaging section b ″ indicated by a broken line centering on the electronic components (hatched electronic components) 30, 31, and 32 not included in any of the imaging sections.
−q ″ and d ″ −q ″ are added (step S
9). As described above, the shooting section indicated by the solid line in FIG. 8 is set, and each electronic component 2 is registered as data belonging to the shooting section including the shooting section.

At the stage when the above-described coordinate correction of the photographing section is completed, for example, as shown in FIG. 2C, the electronic components 2c and 2d in the photographing section are positioned at the center of the photographing section. The center coordinates of the imaging section are corrected. The reason for performing the correction of the center coordinates is that the edge of the image of the camera 106 is distorted, so that the electronic components 2c and 2d
This is because there is a risk that a misrecognition test may be performed if is located.

If, during the process of correcting the center coordinates of each photographing section, an electronic component 2 that is 100% included in another photographing section appears, the electronic component 2 is stored in the data belonging to the other photographing section. (Step S10). Further, when a shooting section to which no electronic component 2 is assigned appears, the shooting section is deleted (step S11). Steps S10 and S11 above
Is repeated until the center coordinates need not be corrected. However, in order to prevent an infinite loop, for example, a maximum of 10 repetitions is limited.

When the correction of the center coordinates of the photographing section, the change of the photographing section and the deletion of the photographing section are repeated four times on the printed wiring board 1, for example, each photographing section becomes as follows. That is, in the first time, as shown in FIG. 9, each imaging section moves, and the imaging sections er, e-
s is deleted. In the second time, as shown in FIG.
The photographing section indicated by the dashed line is moved, and the electronic components (hatched electronic parts) 37 and 38 are the photographing sections bp shown in FIG.
From the data belonging to gr, the photographing section a- shown in FIG.
The data is changed to data belonging to p and g-s. In the third time, as shown in FIG. 11, the imaging sections ap, bp, and g
−s moves, and the imaging section cp is deleted. In the fourth time, the imaging section g-s moves as shown in FIG.

Next, immediately before the examination, the photographing order of each photographing section is optimized such that the photographing sections are arranged upward or downward in an order as shown in FIG. . Here, as shown in, for example, FIG. 2E, the search range of the imaging section to be set in the next order to the imaging section z is an imaging section related to a hatched portion. That is, the imaging section z1 whose X axis is closer to the imaging section z is set to the next order, and the imaging section z2 whose X axis is closer to the next imaging section z1 is set to the next order. If there are no more imaging sections close to the X-axis direction, the next imaging section serving as a reference for the Y-axis is searched upward or downward, and the imaging section z3 is set in the next order (step S12).

Then, after the inspection in each imaging section is completed, the printed wiring board 1 is carried out to the next process from the board outlet 102c of the conveyor 102. According to the above-described board appearance inspection, since the optimal layout work, particularly the optimization of the photographing section and the photographing order is automatically performed without human intervention, the operator concentrates on the work of creating the inspection data of the printed wiring board. And the time required to generate inspection data can be reduced. Further, the inspection tact can be shortened.

[0026]

As described above, according to the present invention,
Optimal photographing conditions for the appearance of the substrate can be automatically set, and the inspection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a board appearance inspection apparatus of the present invention.

FIG. 2 is a flowchart showing an operation example of the board appearance inspection apparatus of FIG. 1;

FIG. 3 is a first plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 4 is a second plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 5 is a third plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 6 is a fourth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 7 is a fifth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 8 is a sixth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 9 is a seventh plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 10 is an eighth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 11 is a ninth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

FIG. 12 is a tenth plan view showing a specific example of a substrate for describing an embodiment of the substrate appearance inspection method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Printed wiring board, 2 ... Electronic component, 100
..Substrate appearance inspection apparatus, 101, main body, 102 ..
・ Conveyor, 103 ・ ・ ・ Inspection table, 104 ・ ・ ・
Moving mechanism, 106: camera, 107: monitor,
108: moving mechanism, 109: operation unit, 1
10 Control unit

Claims (10)

[Claims] 1. A method of inspecting the appearance of a substrate by photographing the appearance of the substrate by an image pickup means, wherein the whole substrate is divided into a matrix by photographing sections which are photographable areas of the image pickup means, and each of the photographing sections is divided into a plurality of areas. In each of the photographing sections, the coordinates of the photographing section for each of the areas are sequentially corrected, and during the process of correcting the coordinates of the photographing section for each of the areas, the coordinates are included in any of the photographing sections. If there is no inspection location, a new imaging section for accommodating the inspection location is added, the center coordinates of each imaging section are sequentially corrected, and during the processing of correcting the center coordinates of each imaging section, other processing sections are added. If an inspection location included in the above imaging section appears,
A board, wherein the inspection location is changed to the other imaging section, and if there is no inspection location in the imaging section, the imaging section is deleted, and the imaging order of each imaging section is optimized. Appearance inspection method. 2. The method according to claim 1, wherein the correction of the coordinates of the imaging section with respect to each of the areas is performed such that the entire inspection location falls within the imaging section for an inspection location that is partially included in the area. The board appearance inspection method according to 1. 3. The board appearance inspection method according to claim 1, wherein the correction of the center coordinates of each imaging section is performed such that an inspection location in the imaging section is located at the center of the imaging section. 4. A method of inspecting the appearance of a substrate by photographing the appearance of the substrate with an image pickup means, wherein the whole substrate is divided into a matrix in a photographing section which is a photographable range of the image pickup means, and each photographing section is divided into a plurality of areas. Respectively, for each of the shooting sections, sequentially correcting the coordinates of the shooting section with respect to each of the areas, sequentially correcting the center coordinates of each of the shooting sections, and optimizing the shooting order of each of the shooting sections. Characteristic board appearance inspection method. 5. When an inspection location not included in any of the imaging sections appears during the process of correcting the coordinates of the imaging section for each of the areas, a new imaging section containing the inspection location is set. The board appearance inspection method according to claim 4, further comprising: 6. When an inspection location included in another imaging section appears during the processing of correcting the center coordinates of each imaging section, the inspection location is changed to the other imaging section. 5. The method for inspecting the appearance of a substrate according to item 4. 7. The board appearance inspection method according to claim 4, wherein when there is no inspection place in the imaging section, the imaging section is deleted. 8. An apparatus for inspecting the appearance of a substrate, comprising: mounting means for mounting the substrate; imaging means for photographing the appearance of the substrate on the mounting means; Moving means for relatively moving the means, and control means for controlling each of the means and inspecting the appearance of the substrate, wherein the control means is an imaging section in which the entire substrate is a photographable range of the imaging means. In each of the photographing sections, the photographing section is divided into a plurality of areas, and for each photographing section, the coordinates of the photographing section with respect to each area are sequentially corrected, and the coordinates of the photographing section with respect to each area are calculated. During the correction process, if an inspection location that is not included in any of the imaging sections appears, a new imaging section containing the inspection location is added, and the center coordinates of each imaging section are sequentially corrected, Said During the process of correcting the center coordinates of the imaging section, when an inspection location included in another imaging section appears, the inspection location is changed to the other imaging section, and the inspection location is included in the imaging section. When there is no board, the board section inspection apparatus deletes the shooting section and optimizes the shooting order of each of the shooting sections. 9. The correction of the coordinates of the imaging section with respect to each of the areas is performed such that the entire inspection area is included in the imaging section for an inspection area partially included in the area. The board appearance inspection device according to 1. 10. The board appearance inspection apparatus according to claim 8, wherein the correction of the center coordinates of each imaging section is performed such that an inspection location in the imaging section is located at the center of the imaging section.