Reworkable Epoxy Bonding for Superconductor Multi-chip Modules

HYPRES, in collaboration with University of Arkansas (UA), proposes to develop a method for manufacturing superconductor multi-chip modules (MCMs) using nano-engineered cryogenic adhesives. A superconductor MCM comprises a carrier and several flipped chips. Before final assembly on the carrier, these chips need to be screened by temporarily attaching each one to another carrier with active test circuitry. Therefore, a detachable die attachment process is needed for selecting a set of known good die. In Phase I, a set of active carriers will be fabricated and qualified by testing along with a set of chips for mounting on them. The best composition of the adhesive will be obtained by conducting a series of experiments on adhesion strength, thermal and electrical conductivity, and removal without damage to the carrier and the chip. This will provide a platform for developing a two-chip MCM, with chips such as analog-to-digital converters flipped on top of a carrier with digital circuitry, during the Phase I option period in preparation for more complex MCMs.