Thermomechanical Strength of Element Connections in Microelectronic Modules

The design and technology of solder and adhesive bonds, as well as the elastic strength and plastic properties of the materials of a Si crystal, solder, and glue joint, are the most significant factors characterizing the reliability and durability of a microelectronic module. The structure proposed in this paper is designed to reduce its weight and size characteristics, improve reliability, and ensure efficient heat dissipation. When simulating the stress-strain state of microconnections in the microelectronic module, it is discovered that, when using a stannum-bismuth (SnBi) solder, the stresses in the assembly materials are distributed more uniformly and their values are significantly lower than those when using SnPb and SnZn solders: in silicon by 5–30% and in a copper conductor by 20–90%. It is determined that, under operating conditions and tests at elevated temperatures, the stresses in the SnBi solder are lower by factor of 1.5 and 2.2 than those in the SnPb and SnZn solders, respectively. It is shown that the cold-cure epoxy glue used has good adhesion to various structural materials and is durable with the corresponding technological process being characterized by low labor intensity. The rational thickness of the glue joint (50–200 μm) and copper conductor (20 μm) is determined. Some recommendations for the design of microconnections in microelectronic modules are made.