JP2002111300A - Apparatus and method for inspecting mounting board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an inspecting accuracy and to improve operability. SOLUTION: A method for inspecting a mounting component comprises, when setting the method, the steps of automatically selecting a method for inspecting having a high application frequency from a plurality of inspecting methods stored in a library 19 for a set mounting component by a controller 18, and manually selecting a suitable one from the plurality of the methods stored in the library 19 by an operator when the inspecting method is not suitable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for inspecting a mounted board for inspecting the mounted state of components such as chips and ICs mounted on the board.

[0002]

2. Description of the Related Art There has been proposed a mounting board inspection apparatus for automatically determining whether a mounted state of a component is good after soldering an electronic component to a printed circuit board. This mounting board inspection device shines light on the mounted components and solder on the board from above, shoots the mounted components and solder with a camera, and detects the position, amount of light, reflection angle, etc. of the reflected light. Then, the quality of the mounted state is determined by estimating the shapes of the mounted components and the solder.

In this case, as an inspection method for one mounted component and its solder, a number of inspection methods can be considered depending on the type of the mounted component and the mounting position. Therefore, if the inspection method for the mounted component is set each time, the workability is not good, so that a plurality of inspection methods are stored in advance according to the type of the mounted component, and an inspection method to be applied is selected from among these. Such a configuration is described in, for example, Japanese Patent Publication No. 7-122901.

[0004]

The above-described inspection method using the conventional mounting board inspection apparatus includes measuring areas such as a range for performing a solder inspection and a range for performing a presence / absence inspection, such as dimensions of components, the number of locations to be inspected, Adjust solder pad dimensions,
Select lighting conditions and cameras to make it easy to distinguish between good and bad, and binarize the measurement area to select an algorithm, such as whether to find an area of a certain brightness or average brightness in the measurement area. A dependent determination threshold value or the like is determined.

However, in an actual board, if a tall mounting component is mounted around the inspection component, the standard inspection method selected to reduce the amount of light makes it possible to perform an appropriate inspection. It may not be possible. Recently,
The components are the same, but the solder pad size has become smaller, so the normal solder shape has changed from the conventional one, and the standard method did not match the pads or the average brightness was calculated instead of obtaining a certain brightness It is necessary to categorize the cases in detail such that the quality can be determined more stably. Similarly, since the material of the solder has recently been changed, the rear of the solder becomes bright, and the stability inspection may not be performed by the previously prepared standard method.

However, in the initial stage of generating test data,
First, it is common to assign a standard method and start the test run stage, and then notice that the same component, but a different method can be used for more stable inspection. Also, in recent board designs, users who know the trend of increasing the number of small pads and increasing the number of brightly shining solder materials, have taken into account this at the initial stage of inspection data generation, and have registered many The trouble of searching for a technique corresponding to a pad with a small pad from the inspection techniques has occurred. For this reason, there has been a problem that it takes a lot of time to generate inspection data.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a mounting board inspection apparatus and method which improve inspection accuracy and workability.

[0008]

According to a first aspect of the present invention, there is provided a mounted board inspecting apparatus for photographing a component mounted on a board, and a plurality of inspections for the mounted component. Inspection method storage means for storing a method, application frequency storage means for storing the application frequency of the inspection method for the mounted component, and storage in the application frequency storage means from a plurality of inspection methods stored in the inspection method storage means Inspection method selecting means for selecting an inspection method in accordance with the frequency of application of the selected inspection method, and determining a mounting state of the mounted component photographed by the component photographing means using the inspection method selected by the inspection method selecting means. Component determination means.

Further, in the mounting board inspection apparatus according to the present invention, the inspection method selection means can change the inspection method based on the determination result of the component determination means.

According to a third aspect of the present invention, the inspection method selection means includes display means for listing inspection methods for each type of the mounted component, and the display means is provided for listing. It is characterized in that a comment can be displayed for each of the inspection methods.

Further, in the mounting board inspection apparatus according to the present invention, the inspection method selecting means can narrow down the inspection method by inputting a keyword.

According to a fifth aspect of the present invention, there is provided a method for inspecting a mounted board, comprising selecting a frequently applied inspection method from among a plurality of inspection methods for a component mounted on a substrate, and selecting the selected inspection method. Is used to determine the mounting state of the mounted component, if it is difficult to determine the mounted component by the inspection method,
The inspection method is changed based on the determination result of the mounted component to determine a mounting state of the mounted component.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic configuration of a mounting board inspection apparatus according to a first embodiment of the present invention, FIG. 2 is a flowchart of a teaching operation by the mounting board inspection apparatus of the embodiment, FIG.
FIG. 4 shows a flowchart of the inspection method correction processing, and FIG. 4 shows an outline of a display screen of the inspection method selection processing.

In the mounting board inspection apparatus of this embodiment,
As shown in FIG. 1, a support table 12 is provided on a base 11 by a moving mechanism 13 so as to be orthogonal to each other in a horizontal direction.
It is movable in the direction and the Y direction and is supported so as to be pivotable, and can be driven and controlled by the NC control unit 14. The substrate A on which various electronic components are mounted can be positioned on the support table 12. In this case, the moving mechanism and the turning mechanism may be provided on the head side separately from the substrate positioning mechanism.

Above the support table 12, a CCD camera 1 as a component photographing means for photographing the mounting board A
5 is provided facing downward in the vertical direction, and an LED lighting 16 is provided. In this case, a fluorescent lamp or the like may be used instead of the LED lighting 16, and a method of scanning a one-dimensional line sensor may be used as the upper photographing means, which is not specified in these devices. . Then, the CCD camera 15 is connected to a control unit (CPU) 18 via an image processing unit 17, and the LED illumination 1
6 is connected to the control unit 18. In this case, the LED lighting 16 is of two types, top lighting and horizontal lighting, and the CCD camera 15 captures two images when each lighting is turned on.
The image processing unit 17 captures two images when the respective lights are turned on, and the image processing unit 17 captures the two images and outputs the captured images to the control unit 18. Note that, here, two images are captured as the LED illumination 16 as the upper illumination and the lateral illumination, but one image or multiple images may be captured as the single illumination or the multi-stage illumination. .

In this case, with respect to the light from the upper illumination, the mounting substrate A strongly reflects on a relatively flat portion and enters the CCD camera 15, and reflects weakly on the inclined surface so as to reflect the CCD camera 15.
to go into. On the other hand, with respect to the light from the lateral illumination, the CCD camera 15
And enters the CCD camera 15 after being weakly reflected on the flat surface. That is, the flat portion shines brightly in the upper illumination, and the inclined portion shines brightly in the horizontal illumination.

Therefore, the CCD receiving the reflected light of the upper illumination
The image of the camera 15 has such a feature that if there is solder, the inclined portion of the solder becomes dark, and if there is no solder, the surface of the substrate A becomes a flat portion and becomes bright. Control unit 18
Selects a defect by comparing the brightness of this image with a preset threshold value. On the other hand, in the image of the CCD camera 15 that has received the reflected light of the horizontal illumination, the surface of the substrate portion of the mounting substrate A is dark because the surface of the substrate portion is flat, and is bright because the solder is the inclined portion. Since the image has the characteristic of becoming dark, an image in which the outline of the mounted component can be easily extracted is obtained. The control unit 18 extracts a mounted component from the image,
By comparing with a preset threshold value, the presence or absence of a mounted component and a shift failure are selected.

Further, as described above, the control unit 18 measures and determines the type and presence / absence of components on the mounting board A, displacement of the mounting position, floating of the leads, and the state of the solder in accordance with the inspection data. For example, when the material of the solder is changed from a material having a good affinity to a material having a bad affinity, in the image returned to the CCD camera 15 after the upper illumination has been randomly reflected, the darkness which means the degree of sticking of the solder is obtained. The area of the region is expected to decrease. As a result, in order to perform stable detection, the threshold value for determining the area must be set lower than before. In addition, when the design criteria for the pad dimensions are changed, the degree of solder sticking is different from before, so that the measurement area needs to be changed.

To this end, a library 19 is connected to the control unit 18 as an inspection method storage unit and an application frequency storage unit. In the library 19, inspection methods for various types of components are registered. In one product type, there are stored a plurality of inspection methods suitable for each situation such as the case of solder having good affinity or not, the case where the pad is small or large, the case where it is shaded by an adjacent component, and the like. The application frequency of each inspection technique is stored. Then, the control unit 18 selects an inspection method from among the plurality of inspection methods stored in the library 19 according to the application frequency (inspection method selection unit), and uses the selected inspection method to determine the mounting state of the mounted component. (Component determination means). If only recent solder materials with poor affinity are used, and inspection data for several types of boards has already been created, the frequency of application of methods that have poor affinity is high. Should be. When creating inspection data for a new board, if you select the most frequently applied inspection method from among multiple inspection methods registered for a certain part type, you must select the method again at the test run stage. The probability of disappearance decreases.

In this case, an operation unit (keyboard) 20 and a display unit (monitor) 21 are connected to the control unit 18, and information stored in the library 19 by the operation of the operation unit 20 by an operator is transmitted to the display unit 21. Can be displayed. That is, as shown in FIG. 4, at the top of the screen of the display unit 21, there is a component type selection unit 21a for selecting a large classification (IC, chip, etc.) of the mounted component. A plurality of inspection methods can be listed in the registration list 21b for each classification (part name),
Comments and application frequencies can be displayed for each of the listed inspection methods. This comment is described as “dark”, “bright”, “standard” or the like to indicate the application target of the inspection method when creating and registering the inspection method, and can be changed. The application frequency is the number of times the inspection method is applied, and is counted and increased each time the inspection method is applied. Therefore, the larger the number is, the higher the application frequency is. In addition, in order to clarify the recent application status, a method of counting with a higher weight the more recently registered one may be considered.

At the bottom of the screen of the display unit 21, there is a search condition (keyword) input unit 21c. When "Automatic" is selected, an inspection method with a high application frequency is automatically selected. The inspection method can be manually selected by the operator regardless of the frequency. Further, when search conditions (for example, dark / bright / large pad / medium pad / small pad / small solder) are input to the input unit 21c, the registration list 21 is entered.
It is possible to narrow down a plurality of inspection methods listed in b. At the bottom of the screen of the display unit 21, there is an assignment button 21d, and the selected inspection method can be determined. Further, it is possible to change the inspection method once determined on the display unit based on the determination result of the mounted component.

In the case of inspecting a mounting board using the mounting board inspection apparatus configured as described above, an inspection program is created in advance based on the design data of the mounting board and the reference mounting board, and the inspection work is performed by the inspection program. Do.

In the work of creating the inspection program,
As shown in FIG. 2, in step S1, the operator operates the operation unit 20 while viewing the display unit 21, selects a type of component to be mounted on the board A, and registers a plurality of inspection methods for each type of mounted component. It is listed in the list 21b. In step S2, first, the search condition input unit 21c is set to "automatic" on the screen of the display unit 21, and an inspection method with a high application frequency is automatically selected. Then, in step S3, when the selection of the inspection method is completed by clicking the allocation button 21d, in step S4, the XY coordinates are designated to set the inspection area of the mounted component.

Subsequently, in step S5, it is checked whether there is a next mounted component to be inspected. If not, the process is terminated. If there is, the process proceeds to step S6 to determine whether the component is the same.
If the components are the same, the process proceeds to step S4 to specify the XY coordinates and set the inspection area of the mounted component. If they are not the same part, the process proceeds to step S1 and the processes up to step S4 are repeated. In this way, once an inspection program is created by assigning an inspection method to all components to be inspected on the mounting board, a test operation of the inspection operation is performed, and a correction operation of a portion where the inspection method does not conform to the mounted component is performed. .

In the process of correcting the inspection program, as shown in FIG. 3, a test operation of the inspection operation for the reference mounting board is executed in step S11 based on the inspection program. When this test run is completed in step S12, it is checked in step S13 whether or not there is a part judged to be NG among many inspected mounted parts. If there is no NG detection, the inspection program is good. At step S14.

On the other hand, if there is an NG detection in the mounted component at step S13, at step S15 the display unit 21 is detected.
Displays the NG parts list. Then, step S16
, The image of the first NG detection from the NG detection list is displayed on the display unit 21, and the operator checks the image in step S17. Here, the cause of the NG detection error is presumed from the image of the CCD camera 15 photographing the component that is erroneously detected as NG, and a dark environment due to insufficient light due to the presence of a tall component around the inspection component. If it is inferred that there is a search condition, in a step S18, "dark" is inputted as a search condition into the input section 21c (see FIG. 4) of the display section 21 and a step S1 is performed.
At 9, a plurality of inspection methods for the corresponding mounted component are narrowed down by the search condition “dark” and listed in the registration list 21b. Then, in step S20, a corresponding inspection method is selected.

After the change of the inspection method for the NG detection is completed in this way, in step S21, the test operation of the inspection work is executed only for the NG detection. And
If it is not NG detection in step S22, but is good, the next NG detection is confirmed in step S23. If there is NG detection, the process returns to step S16 to repeat the shift processing. If not, the process is terminated and saved in step S14. On the other hand, step S
If it is determined in step 22 that the mounted component whose inspection method has been changed is not an NG component and is not good, the process proceeds to step S24, and it is determined whether “dark” is to be changed as a search condition of the inspection method, and if not changed, Returning to step S20, another inspection method is selected in step S20, and steps S21 and S21 are selected.
At 2, the test run and the judgment of the inspection result are performed.

When the search condition of the inspection method is changed from "dark" to another in step S24, the process shifts to step S25, and "pad small" is input to the input unit 21c of the display unit 21 as the search condition. In step S26, a plurality of inspection methods for the corresponding mounted component are narrowed down by the search condition "pad small" and listed in the registration list 21b. Then, as described above, step S2
In steps 7 to 30, processing such as selection of an inspection method, test operation, determination, and the like are repeated. Although “dark” and “pad small” have been described as search conditions for the inspection method, a new inspection method may be created if there is no appropriate inspection method.

When the correction processing of the inspection program is completed, the inspection program is given a name and stored. At this time, the control unit 18 stores a number of inspection methods set in the inspection program in the library 19. The frequency of application is counted for each inspection method used.

Then, the mounting state of each electronic component mounted on the board can be properly inspected on the manufacturing line of the mounting board by the inspection program created as described above.

As described above, in the mounting board inspection apparatus and the inspection method according to the present embodiment, when setting the inspection method of the mounted component, the control unit 18 controls the plurality of stored components stored in the library 19 for the set mounted component. Automatically selects an inspection method having a high application frequency from the inspection methods described above, and when the inspection method is not appropriate, the operator manually selects an appropriate inspection method from a plurality of inspection methods stored in the library 19. Like that.

Therefore, the optimum inspection method suitable for the mounted component can be easily allocated in a short time, and the inspection accuracy can be improved and the workability can be improved.

FIG. 5 shows a schematic configuration of a mounting board inspection apparatus according to a second embodiment of the present invention. Note that members having the same functions as those described in the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

In the mounting board inspection apparatus of this embodiment,
As shown in FIG. 5, three CCD cameras 21, 32, and 33 as part photographing means are disposed above the support table 12, and three laser light sources 34, 35, and 36 are provided.
Are arranged. These laser light sources 34, 35, 36
Can irradiate sheet-like laser beams L ₁ , L ₂ , L ₃ from the substrate A and project the laser beams onto components and solder on the substrate A, and the CCD cameras 21, 32, 33 emit laser beams L ₁ , L ₂ , L _{3 respectively.} , And the image processing unit 37 captures the captured image, extracts the shape line, and sends it to the control unit 18.

Based on one shape line, the control unit 18 determines the type of the component on the mounting board A, the presence or absence of the component on the mounting board A, based on the solder joint height from the board, the solder joint angle, the lead height, the solder joint area, and the like. In addition, it is possible to extract and determine (inspection) the displacement of the mounting position, the floating of the lead, the state of the solder, and the like.

The other components such as the library 19, the operation unit 20, and the display unit 21 are almost the same as those of the above-described embodiment, and the inspection method is also almost the same.
Detailed description is omitted.

As described above, in the mounting board inspection apparatus of the present embodiment, the component photographing means for photographing the components mounted on the board may be a two-dimensional CCD camera 15 image.
The images of the CCD cameras 21, 32, and 33 may be used.
Other methods may be used.

In the above-described embodiment, the inspection program is created on the basis of the design data of the mounting board and the reference mounting board. However, the inspection program is created on the basis of the mounting board on which NG parts may be present. N by inspection method
The G component and the mounted NG component may be distinguished.

[0040]

As described above in detail in the embodiment, according to the mounting board inspection apparatus of the present invention, the inspection method storage means for storing a plurality of inspection methods for the mounted component and the inspection method of the mounted component Application frequency storage means for storing the application frequency of the plurality of inspection methods, the inspection method selection means selects an inspection method from a plurality of inspection methods according to the application frequency, and the component determination means uses the selected inspection method for the component. Since the mounting state of the mounted component photographed by the photographing means is determined, the inspection accuracy can be improved and the workability can be improved by easily selecting an appropriate inspection method in a short time.

According to the mounting board inspection apparatus of the second aspect, the inspection method selection means can change the inspection method based on the determination result of the component determination means, so that the inspection method selected in accordance with the application frequency. If is not appropriate, the inspection accuracy can be improved by changing the inspection method to another inspection method and assigning an optimal inspection method suitable for the mounted component.

According to the third aspect of the present invention, the inspection method selection means includes display means for listing inspection methods for each type of mounted component, and the display means includes each of the listed inspection methods. Can be displayed for comments, so when manually setting the inspection method for mounted parts,
The operator can make settings while looking at the list screen and the comments, and can easily assign an optimum inspection method.

According to the fourth aspect of the present invention, the inspection method selection means can narrow down the inspection method by inputting a keyword. Therefore, when manually setting the inspection method of the mounted component, the operator can select the inspection method from the list. Can be narrowed down by keywords, and an optimum inspection method can be easily assigned.

According to the mounting board inspection method of the present invention, an inspection method having a high application frequency is selected from a plurality of inspection methods for the components mounted on the substrate, and the selected inspection is performed. The mounting state of the mounted component is determined by using the method, and when it is difficult to determine the mounted component by the inspection method, the inspection method is changed based on the determination result of the mounted component to determine the mounted state of the mounted component. As a result, by assigning an optimal inspection method suitable for a mounted component, inspection accuracy can be improved and workability can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a mounting board inspection device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a teaching operation performed by the mounting board inspection apparatus according to the embodiment;

FIG. 3 is a flowchart of an inspection method correction process.

FIG. 4 is a schematic diagram of a display screen of an inspection method selection process.

FIG. 5 is a schematic configuration diagram of a mounting board inspection device according to a second embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 12 support table 13 moving mechanism 14 NC control unit 15 CCD camera (component photographing unit) 16 LED illumination 17 image processing unit 18 control unit (inspection method selection unit, component judgment unit) 19 library (inspection method storage unit, application frequency storage unit) ) 20 operation unit 21 display unit 31, 32, 33 CCD camera (component photographing means) 34, 35, 36 laser light source 37 image processing unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA61 CC28 FF04 GG03 GG07 GG14 HH13 HH14 JJ25 JJ26 MM22 PP12 UU00 2G051 AA65 AB14 AC21 BA01 CA04 CA07 DA07 EA14 EB09 FA01 5B057 AA03 BA02 CA08 CA12 DB01 DC04

Claims (5)

[Claims] 1. A component photographing unit for photographing a component mounted on a board, an inspection method storage unit for storing a plurality of inspection methods for the mounted component, and an application frequency for storing an application frequency of the inspection method for the mounted component. Storage means; inspection method selection means for selecting an inspection method from a plurality of inspection methods stored in the inspection method storage means according to the application frequency of the inspection method stored in the application frequency storage means; A mounting board inspection apparatus, comprising: a component determination unit configured to determine a mounting state of the mounted component captured by the component imaging unit using the inspection method selected by the selection unit. 2. The mounting board inspection apparatus according to claim 1, wherein the inspection method selection unit is capable of changing an inspection method based on a determination result of the component determination unit. 3. The mounting board inspection apparatus according to claim 1, wherein the inspection method selection unit includes a display unit that lists an inspection method for each type of the mounted component, and the display unit lists the inspection method. A mounting board inspection apparatus characterized in that a comment can be displayed for each inspection technique. 4. The mounting substrate inspection apparatus according to claim 1, wherein the inspection method selection unit can narrow down the inspection method by inputting a keyword. 5. An inspection method having a high application frequency is selected from a plurality of inspection methods for a component mounted on a board, and a mounting state of the mounted component is determined using the selected inspection method. A method of inspecting a mounted board, wherein when it is difficult to determine a mounted component by the inspection method, the inspection method is changed based on a result of the determination of the mounted component to determine a mounting state of the mounted component. .