Abstract: Methods for forming multilayer circuit structures are disclosed. In some embodiments, conductive layers, dielectric layers and conductive posts can be formed on both sides of a circuitized core structure. The conductive posts are disposed in the dielectric layers and can be stacked to form a generally vertical conduction pathway which passes at least partially through a multilayer circuit structure. The formed multilayer circuit structures can occupy less space than corresponding multilayer circuit structures with stacked via structures.

Abstract: A method of fabricating a multi-layer interconnected substrate structure. The inventive method includes forming a multi-layer structure from multiple, pre-fabricated power and/or signal substrates which are laminated together. A drill is then used to form a via through the surface of a ring-type pad down to a desired depth in the multi-layer structure. The via hole is cleaned and then filled with a conductive material. The via so formed between two or more substrates is self-aligned by using the ring pad(s). This contributes to an increased signal routing density compared to conventional methods.

Abstract: Multilayer circuit lamination methods and circuit layer structures are disclosed which enable one to manufacture high-density multichip module boards and the like at lower cost, with higher yield, with higher signal densities, and with fewer processing steps.

Abstract: An interposer structure permits a differential transverse displacement of contact pads on opposite sides of the interposer to reduce thermal stresses when the interposer is bonded to contact pads of a chip and a substrate with different thermal coefficients of expansion. The effective elasticity of the interposer between top and bottom contact pads of the interposer is facilitated by perforations which define flap-like regions. A flexible trace couples top contact pads to bottom contact pads through a via while permitting substantial transverse relative displacement of the top and bottom contact pads in flap-like regions.