Paper
21 March 1989 Automated Optical Pattern Inspection For High-Density Printed Wiring Boards
Moritoshi Ando, Hiroshi Oka, Satoshi Iwata, Takefumi Inagaki
Author Affiliations +
Proceedings Volume 1004, Automated Inspection and High-Speed Vision Architectures II; (1989) https://doi.org/10.1117/12.948982
Event: 1988 Cambridge Symposium on Advances in Intelligent Robotics Systems, 1988, Boston, MA, United States
Abstract
A new technique for automated optical inspection of printed wiring boards (PWBs) has been developed. It uses black line sensing and a radial matching algorithm. The sensing method uses black line illumination and a CCD line sensor. The PWB is brightly illuminated except for the area under observation. Because the PWB substrate is translucent, copper patterns are sensed as shadows and their color and roughness do not affect the sensing. The inspection algorithm describes the copper pattern with binary codes. The pattern width is measured radially in four directions from the pattern centers. A combination of length and direction is encoded in a 12-bit binary code. Codes are assembled and make up a dictionary. The method can be used to inspect many kinds of patterns by changing the contents of the dictionary. An inspection system using this technique has a 5-μm resolution and can inspect a 490 x 540 mm area in 5 minutes.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Moritoshi Ando, Hiroshi Oka, Satoshi Iwata, and Takefumi Inagaki "Automated Optical Pattern Inspection For High-Density Printed Wiring Boards", Proc. SPIE 1004, Automated Inspection and High-Speed Vision Architectures II, (21 March 1989); https://doi.org/10.1117/12.948982
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KEYWORDS
Inspection

Sensors

Associative arrays

Bridges

Copper

Sensing systems

Defect detection

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