Browse Prior Art Database

Location of Covered Vias in Circuit Boards

IP.com Disclosure Number: IPCOM000041080D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-02

Publishing Venue

IBM

Related People

Authors:
Interrante, M Williams, D Ziemins, A [+details]

Abstract

Polarized light is used to illuminate E.C. pads 10 with via holes 12 beneath them. A camera is polarized for maximum contrast detection. When this image is converted to black and white, the edges of the pad and the via "glow", whereas the rest of the pad is dark. (Image Omitted)