1 August 1990 Profile measurement for printed wiring boards
Author Affiliations +
Proceedings Volume 1265, Industrial Inspection II; (1990) https://doi.org/10.1117/12.20240
Event: The International Congress on Optical Science and Engineering, 1990, The Hague, Netherlands
We developed pattern inspection techniques for simultaneously measuring both the width and the thickness of conductive patterns printed on ceramic green sheets. The measuring optics use a He-Ne laser scanner. Thickness is measured by beam splitting, and width, by light diffusion. The beam-splitting optics measure the height by determining the ratio of reflected to transmitted light intensity. By optimizing the arrangement of the optics, we attain a resolution of 5 im and a height measurement range of [70 pm. Pattern width measurement is based on the fact that a beam of light diffuses when it strikes the substrate, but does not diffuse when it strikes the conductive pattern. A spatial ifiter in the focal plane raises the S/N ratio to four regardless of the state of the conductor surface. We used these techniques to inspect the conductive patterns on green sheets. Our system inspects conductor patterns 3-dimensionally at 12 Mplxels per second with a 5 i.m resolution.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Moritoshi Ando, Moritoshi Ando, Hiroshi Oka, Hiroshi Oka, } "Profile measurement for printed wiring boards", Proc. SPIE 1265, Industrial Inspection II, (1 August 1990); doi: 10.1117/12.20240; https://doi.org/10.1117/12.20240

Back to Top