High-performance, high-density connectors utilizing multiple layer metal/polymer construction

The use of a multiple-layer controlled impedance flexible tape as an interconnect between high-density substrates or hybrids has been previously investigated by the authors. Their design features 200 connections per inch and can be fabricated in sections that are 2 inches or longer in a 70-mm tape format. The authors reported here that single-point thermosonic bonding can be successfully used to permanently attach the connector tape to the substrate. The stresses and deformations that are relevant to the bonding process and to the demountable (pressure) connection that can also be used with this type of connector technology are evaluated. The raised profile contacts of the demountable connection can possess very odd electrical characteristics and even with operation of the interface materials (copper and gold) at stresses below the elastic limit. The previous prediction that the high-frequency performance of this connector technology is exceptionally useful for transmission of fast risetime signals (ca 100 picoseconds) with negligible crosstalk is experimentally verified.<>