Abstract: Disclosed is a method of fabricating a multichip interposer comprising an insulating support with thin film fine line metallization on one side thereof. A layer of masking material is adhered to in other side and selective areas of the masking material are removed in a desired pattern to expose areas of the support. The exposed areas of the support are then etched until the metallization is reached to form via holes which are subsequently filled with interconnecting metallurgy. Contact pads are then formed around each filled via hole.

Abstract: A bar formed of a material having a known coefficient of expansion has probe holders arranged thereon with each of the probe holders being at a selected distance from each of the adjacent probe holders. The distance between adjacent probe holders is selected in accordance with the design distance between adjacent chip sites on a substrate so that the probes in each probe holder will contact the pads of a particular chip site. During processing, the overall dimensions of the substrate can shrink more or less than the design shrinkage so as to shrink the distances between the adjacent chip sites from the design distances. The support bar is heated to a selected temperature at which the probe holders are spaced the design distances. If the substrate has shrunk less than the design shrinkage, then additional heating of the support bar from its selected temperature expands the support bar.