Test Head With Integrated Positioning Sensors
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
A test head is proposed for testing multilayer conductor networks of a ceramic substrate which dispenses with mapping the substrate contact pads on a separate mapper. For that purpose, a thin (N 80 m diameter) glass fiber (Fig. 1) is provided at least on two suitable elements (fiducials, stress relief vias, EC-pads) such that its alignment matches that of the test head buckling beams. Reflecting illuminated marks 3 are positioned on the surface of ceramic substrate 2. The reflected light, collected by glass fiber 1, is fed to a photodetector. Maximum light intensity (Fig. 2) indicates, as a function of the relative movement of ceramic substrate 2 and the test head, that they are properly aligned to each other and that testing may begin.