ABSTRACT
The field of electronics packaging ranges from the packaging of a single semiconductor die to the electrical, thermal, mechanical, and physical implementation of an electronic system. The package provides mechanical and chemical protection for the die, a means of electrically interconnecting to the die at the next level of system integration and a path for internally generated heat removal. To decrease system size and weight, multiple semiconductor die can be packaged in a multichip module. The primary challenges to low-temperature electronics packaging are changes in material properties as a function of temperature and stresses induced by the differences in coefficients of thermal expansion of the materials. Assemblies with conventional plastic packages, PCBs, and solder joints have been used to test and demonstrate electronics operating at low temperatures. Low-temperature electronics packaging is a specialized field with limited data on suitable materials, packaging approaches, and reliability.
