THIN-FILM TRANSFER PROCESS FOR LOW-COST MCM-D FABRICATION

This paper describes a unique, highly flexible cost competitive method to fabricate microelectronic packages that require thin film intercon nections. The method involves fabricating thin film metal/polymer stru ctures multi-up on a reusable temporary glass carrier; the thin film s tack is transferred later onto product substrates of choice. The final product substrate can be silicon, co-fired alumina or glass-ceramic, aluminum nitride, diamond, or a printed wiring board. Optionally, one can also use the released thin film decal as a flexible high wireabili ty interconnect by itself, as an interposer, or in applications like w afer level testing for known good die (KGD). The thin film wiring stru cture can be fabricated multi-up on a standardized form factor carrier (independent of the characteristics of the final product substrate) i n a thin film interconnect foundry, thus significantly reducing cost b oth from the economies of scale and full utilization of the thin film factory for a variety of customer needs.