Flip chip assembly for cryogenics and flexible substrates

Many elementary-particle and nuclear physics experiments are performed at cryogenic temperatures. As channels counts and sensor densities increase there is a growing need for flip-chip bonding as a method for forming interconnections. Given the disparate materials that are often involved, differential contraction of the bonded material stack as the system cools is a major concern. Flexible substrates are widely used in the construction of photon science and particle physics detectors. The ability to flip-chip bond flexible substrates to rigid parts or other flexible substrates can be enabling and is not a standard process. This is particularly true for science experiments, which often operate in extreme temperature or radiation environments.