Device and method for automatic optical detection

Abstract

The invention discloses a device and a method for automatic optical detection, wherein the device comprises an image acquiring unit and an image processing unit; the image acquiring unit is used for performing stepping two-dimensional scanning movement relative to a detected circuit board, and photographing the detected circuit board once after stepping every time, wherein the sum of images acquired by the photographing every time covers the complete surface of the detected circuit board; and the image processing unit is used for seamlessly splicing the images acquired by the photographing every time into a complete image of the detected circuit board, and performing image difference analysis between the complete image acquired by the splicing and the design standards of the detected circuit board, so as to detect the apparent defects of the detected circuit board. Via the device and the method disclosed by the invention, the complete image of the detected circuit board can be acquired, so that an omni-directional accurate detection can be performed on the detected circuit board.

Description

Technical field [0001] The invention relates to an automatic optical inspection device (AOI, Automated Optical Inspector), in particular to an automatic optical inspection device and an automatic optical inspection method realized by the automatic optical inspection device. Background technique [0002] PCB (Printed Circuit Board, printed circuit board) has a wide range of applications, and can be seen everywhere in the interior of electronic products such as mobile phones, telephones, televisions, computers, automobiles, copiers, printers, and air conditioners. In the PCBA (Printed Circuit Board Assembly, printed circuit board assembly) production process, because the components on the PCB have been showing a trend of continuous miniaturization and density, it is no longer possible to rely on traditional manual visual inspection methods to lay out the PCB Precise components perform fast, reliable and stable appearance defect inspection, and can not save accurate inspection recor...

AI Technical Summary

Problems solved by technology

In the PCBA (Printed Circuit Board Assembly, printed circuit board assembly) production process, since the components on the PCB have been showing a trend of continuous miniaturization and densification, it is impossible to rely on the traditional manual visual inspection method to check the layout on the PCB. Precision components perform fast, reliable and stable appearance defect detection, and accurate detection records cannot be kept. Among them, common defects include: missing parts, offsets, wrong parts, reverse poles, short circuits, lack of tin, and excess tin , False soldering, standing on the side, erecting a monument, reverse sticking, damage, multiple pieces, tin beads, gold finger scratches, dents, printed circuit board scratches, poor incoming materials, etc.

[0008] First, because only the area with components on the inspected PCB is photographed, it is impossible to detect the appearance defects in the area without components on the inspected PCB, such as multiple pieces, tin, etc. that may exist in these areas. Beads, gold finger scratches, dents, printed circuit board scratches, poor incoming materials, etc., which lead to the appearance of blind spots in the detection

[0009] Second, since only the area with components on the inspected PCB is photographed, it is impossible to obtain a complete image of the inspected PCB, so that the real-time output and storage of the inspected PCB's complete image cannot be realized, which will further lead to inability to Establish a corresponding traceable and complete image file for each inspected PCB, which brings great restrictions and inconvenience to production quality control

For such barcodes whose length is longer than a single FOV size, the current AOI device is helpless at all, and cannot directly read the barcode information through the barcode reading software equipped on the computer used for image processing, which will cause subsequent production quality traceability. to very large limits

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