Print alignment method for multiple print thick film circuits

Abstract

An improved method of making a multiple print thick film circuit wherein the alignment between successive conductor print steps is both optically inspectable and electrically testable. The first of two or more successive conductor print layers includes a pair of adjacent alignment features with a non-conductive gap therebetween, and the successive conductor print layer includes a pair of identical alignment features which are printed directly on top of the alignment feature pair of the first print layer. When the successive print layer is properly aligned with the first print layer, the non-conductive gap between the alignment features of the first print layer will be preserved, and test probes brought into contact with the features or associated probe pads will reveal a high or open-circuit impedance therebetween. If the successive print layer is mis-aligned relative to the first print layer, one or more of its alignment feature segments or surfaces will bridge the non-conductive gap between the alignment features of the first print layer, and test probes brought into contact with the features or associated probe pads will reveal a low or short-circuit impedance therebetween. Additionally or alternatively, the gap between adjacent alignment features may be optically inspected.