Patent ID: 6246788
Filing Date: 2001-06-12
Classification: G01N,G06T,H01L

Abstract:
A system for inspecting a production printed circuit board (PCB) having a top surface and at least one component mounted thereon, said system comprising:a PCB support for supporting the production PCB;a first device that emits light at an angle relative to the top surface of the production PCB such that the component casts a first shadow upon the production PCB;a second device that emits light at an angle relative to the top surface of the production PCB, wherein the second device emits light of a different wavelength and in a different direction than the first device such that the component casts a second shadow upon the production PCB;an image capturing device mounted above the PCB support for simultaneously and separately capturing the first and second shadow images produced by the light-emitting devices; anda computer that executes a defect-detection analysis using the captured shadow images.