Product Particulate Contamination Inspection System
Original Publication Date: 1985-May-01
Included in the Prior Art Database: 2005-Feb-18
This apparatus permits surface contamination to be detected which cannot be seen under normal lighting conditions by either the unaided eye or by a microscope. In particular, the problems addressed are detecting small particulate matter within dense semiconductor patterns and on multilayer ceramic (MLC) greensheet, where the surface background scatters the light. The main feature which permits detection of particles under these conditions is the design of a lower tier 10 (Fig. 1) of lights 12. The lower tier 10 of lights 12 is arranged in a square, as shown in Fig. 2. The lens end lamps are fixed to a housing 14 at a 0Œ incidence angle. This provides a significant improvement over the prior art [*].