JP2009115479A - Inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize automatic inspection under a uniform condition of the whole inspection window, in an inspection device using a one-dimensional image sensor camera. <P>SOLUTION: A substrate is imaged by the one-dimensional image sensor camera, and a component domain is set following the mounting position, the size and the mounting direction of a component on the substrate, and an enlargement rate when enlarging automatically the component domain in the periphery and forming an inspection window is taught. Then, a pixel value in the inspection window of a reference substrate whole surface image and a corresponding pixel value in the inspection window of a specimen substrate whole surface image are subjected to a differential image processing with a uniform pixel density relative to the whole inspection window, and the quality is determined by a uniform acceptance determination standard, to thereby enable automatic inspection of the mounting substrate wherein excessive detection is minimized by simple teaching. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inspection apparatus that performs an appearance inspection by imaging a component mounting board with a one-dimensional image sensor camera in an electronics factory or the like.

  Inspection apparatuses for inspecting the mounting quality of a component mounting board are roughly classified into those using a two-dimensional area image sensor camera and those using a one-dimensional image sensor camera. The latter is superior in terms of speeding up to capture images like a scanner, but in order to inspect the type of mounted components and soldering quality, image inspection is limited to the component mounting area only. In order to do this, it is common to set an inspection window, and in this respect, it is similar to an inspection machine using an area image sensor camera. Inspection data creation for attaching inspection algorithms for each window setting or for each type of part or solder joint is not only labor-intensive, but also depends on the skill of the operator. There were problems such as performance not being realized easily.

On the other hand, the applicant has already disclosed a technique for omitting the setting of an inspection window in an inspection machine using a one-dimensional image sensor camera (see Patent Documents 1 to 5). This is to compare the entire image of the reference substrate and the entire image of the inspection substrate by difference image processing, and is intended to greatly reduce the time and skill required for the teaching.
JP 2004-296564 A JP 2005-265493 A JP 2006-242873 A JP2007-101415A JP2007-147320

However, when the image of the entire surface of the board is subjected to differential image processing under uniform image processing conditions, printing on the board and other minute fluctuations that are not related to the component mounting quality are all detected, and so-called overdetection often occurs. For this reason, it is necessary to set an inspection window as described above even in an inspection machine using a one-dimensional image sensor camera.
However, in the inspection machine using a one-dimensional image sensor camera, the simplification of the operation is still strongly demanded and left as a problem.

  The problem to be solved is that in an inspection apparatus using a one-dimensional image sensor camera, if an advantage of differential image processing on the entire surface of the substrate that does not require teaching of an inspection window is to be utilized, over-detection occurs at a location unrelated to quality. This is what happened.

The present invention relates to a mounting position, size, and mounting of components on a substrate in an inspection apparatus that acquires a substrate image by moving the substrate relative to a one-dimensional image sensor camera in a direction orthogonal to the pixel arrangement of the image sensor. Set the part area according to the direction, teach the enlargement ratio when creating the inspection window by automatically enlarging the part area around, set the pixel density and pass / fail judgment criteria applied to the differential image processing, and the reference board whole image Difference image processing between the pixel value in the inspection window and the corresponding pixel value in the inspection window of the entire image of the specimen substrate, and the mounting quality and soldering quality of the component are judged with uniform pixel density and pass / fail criteria for all inspection windows The main feature is to do.
The present invention also provides a threshold value of a difference pixel value as a pass / fail criterion in an inspection apparatus that acquires a substrate image by moving the substrate relative to a one-dimensional image sensor camera in a direction orthogonal to the pixel arrangement of the image sensor. The main feature is that an allowable range of an abnormal image is set in a peripheral region surrounded by the inspection window and the component region.

  The inspection apparatus of the present invention teaches an enlargement ratio when an inspection window is created by automatically enlarging a component area around a one-dimensional image sensor camera to acquire a substrate image, and inspects a reference substrate whole surface image. The difference between the pixel value in the window and the pixel value in the inspection window corresponding to the entire image of the specimen substrate is subjected to differential image processing with a uniform pixel density for all the inspection windows, and the quality is determined based on the uniform quality criterion. There is an advantage that the component mounting quality can be inspected by minimizing the above teaching to only the component area teaching.

  The purpose of realizing an inspection device using a one-dimensional image sensor camera with simple inspection data teaching and less over-detection is to teach the enlargement ratio when creating an inspection window by automatically enlarging the part area around Difference image processing is performed on the pixel values in the inspection window of the entire substrate image and the corresponding pixel values in the inspection window of the entire surface image of the specimen substrate at a uniform pixel density for all inspection windows, and the quality is determined based on the uniform quality criterion. Realized by doing.

  FIG. 1 is an overall configuration diagram of an embodiment of the inspection apparatus according to the present invention. A one-dimensional image sensor camera 4 is disposed above the substrate 1.

  The one-dimensional image sensor camera 4 is connected to a control device 5. The control device 5 includes a one-dimensional sensor imaging unit 6, an image storage unit 7, an image processing arithmetic unit 8, an integrated system control unit 9 for controlling the entire system, and teaching. A unit 10 and a pass / fail judgment unit 11 are provided, and each of the units 6 to 11 exchanges data through the bus 16.

  Further, the control device 5 includes an input unit 12 for inputting teaching data and the like, an output unit 13 for printing inspection results and the like, a communication unit 14 for transmitting and receiving data to and from an external device, and images and inspection results. A display unit 15 for displaying the above is connected.

  Next, the teaching steps of this embodiment inspection apparatus will be described with reference to the flowchart of FIG. First, the reference substrate 1 (FIG. 1) is loaded on the table 3 (ST1), the ID data of the substrate is taught (ST2), and then the reference substrate is moved on the table 3 and scanned with the one-dimensional image sensor camera 4 (FIG. 1). ST3). The acquired entire image of the reference board is stored in the image storage unit 7 (ST4) and displayed on the display unit 15 (ST5) (not shown).

Next, a component area is set on the displayed reference board image (ST6). The part area may be set by surrounding the part image manually while viewing the display image, or board design data (CAD data) or mounter data may be used. When all the component areas are set correctly, the process proceeds to teaching of the inspection window (ST7). The inspection window is created by automatically enlarging each part area in accordance with the designated enlargement ratio (see FIG. 3). In this automatic enlargement, the inspection window setting program provided in the image processing arithmetic unit 8 calculates the position of the center of gravity of each part area, enlarges it at a fixed rate according to the long side and the short side of the part area, and sets it as an inspection window. . The enlargement ratio can be input in advance. The reason for setting the enlarged region is to detect a component mounting error or a solder bridge as an abnormal image in the peripheral region surrounded by the inspection window and the component region.

  Next, a test substrate is loaded on the table 3 (ST8), scan imaging is performed (ST9), and the image processing arithmetic unit 8 performs difference image processing between the obtained test substrate image and the reference substrate image (ST10). This difference image processing is tried with a default pixel density and pass / fail judgment criteria. This difference result is displayed on the display unit 15 (ST11), and if there is a misjudgment such as missing a defect or overlooking a non-defective product, by adjusting the pixel density or pass / fail judgment criteria used for default difference image processing, Image processing conditions optimum for this substrate are set (ST12).

Next, the automatic inspection operation in this embodiment will be described with reference to the flowchart of FIG.
First, in FIG. 1, the sample substrate 1 is loaded on the table 3 (ST21), and when the ID data of the sample substrate is input or read (ST22), the sample substrate 1 is moved one-dimensionally in response to a command from the control device 5. The one-dimensional image sensor camera 4 scans and images the entire surface of the sample substrate 1 under the control of the dimension sensor imaging unit 6 (ST23). At this time, after the image storage unit 7 stores the entire image of the sample substrate, the process may proceed to the subsequent processes.

  Therefore, the image processing arithmetic unit 8 performs differential image processing for each pixel in the inspection window of the reference substrate image and the sample substrate image (ST24), and if there is an inspection window in which a defective image has occurred, the window frame is indicated and displayed. The presence is indicated, inspection result data is reported together with the address of the inspection window (ST25), and the sample substrate is removed from the stage 3 (ST26).

  In this embodiment, it is possible to set the pixel density of the differential image processing, the threshold value of the differential pixel value, or the allowable range of the abnormal image in the component peripheral area surrounded by the inspection window and the component region. As a result, all inspection windows can be automatically inspected under uniform conditions.

  The board is imaged with a one-dimensional image sensor camera, the part area is set according to the mounting position, size, and mounting direction of the part on the board, and the enlargement ratio when the inspection window is created by automatically enlarging the part area around is taught. Then, differential image processing is performed on the pixel values in the inspection window of the reference substrate whole surface image and the corresponding pixel values in the inspection window of the whole surface image of the specimen substrate with a uniform pixel density for all inspection windows, and the quality is determined according to the uniform quality criterion. And can be applied to an inspection apparatus that reports an inspection result for each inspection window.

It is explanatory drawing which showed the whole structure of the test | inspection apparatus. It is the flowchart which showed the operation | movement of the teaching and automatic test | inspection in a test | inspection apparatus. It is a figure explaining the setting of the components area | region and inspection window in an inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Components 4 One-dimensional image sensor camera 5 Control apparatus

Claims (2)

Imaging means for acquiring a substrate image by relatively moving the substrate in a direction orthogonal to the pixel arrangement of the image sensor with respect to the one-dimensional image sensor camera;
Area setting means for setting a component area according to the mounting position and size of the component on the board and the mounting direction;
Teaching means for automatically enlarging a part area around and creating an inspection window, and setting a pixel density and pass / fail judgment criteria applied to differential image processing;
An image processing means for performing differential image processing on the pixel value in the inspection window of the reference substrate entire surface image and the corresponding pixel value in the inspection window of the specimen substrate entire image;
An inspection apparatus comprising determination means for determining a component mounting quality and a soldering quality based on a uniform pixel density and pass / fail criteria for all inspection windows.   2. The inspection apparatus according to claim 1, wherein the quality determination criterion set by the teaching unit is a threshold value of a difference pixel value or an allowable range of an abnormal image in a component peripheral area surrounded by an inspection window and a component region.

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