Research Output

Excluding inclusions [PCB inspection]

  The authors look at the causes of a persistent annoyance for manufacturers of printed circuit boards, and suggest some steps that would help to speed inspection and reduce both genuine faults and false rejects from the visual inspection system. This article goes into one detail of the problem: the inclusions in laminates that can cause false rejection in PCB manufacture. Laminate inclusions are now becoming prevalent because of the higher resolution needed to inspect reduced track and gap widths. Tests on rejected PCBs show that contamination inside laminates accounts for a large percentage of rejects. There are four main types of inclusions: tadpoles, burnt resin, metal and others. The most efficient way of spotting them is using visual methods

  • Type:


  • Date:

    31 August 1999

  • Publication Status:


  • DOI:


  • ISSN:


  • Library of Congress:

    QA75 Electronic computers. Computer science

  • Dewey Decimal Classification:

    621.38 Electronics & Communications engineering


Scott, A. V., & Buchanan, W. J. (1999). Excluding inclusions [PCB inspection]. Manufacturing Engineer, 78(4), 154-156.



energy disperse x-ray analysis, printed circuit boards, visual inspection system, PCB manufacture, false rejection, laminate inclusions, contamination, tadpoles, burnt resin, metal, scanning electron microscope

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