Design of Mechanical Properties of Transient Liquid Phase Bonds with Tertiary Metal Particles

In this article, an approach is explained to controlling the Young's modulus of bonding layers formed using a Transient Liquid Phase (TLP) process. The three focus points of this research include: 1) development of a new bond microstructure for thermal stress mitigation, i.e. Young's modulus reduction, 2) a novel approach to the preparation of bulk specimens for mechanical property tests, and 3) mechanical property evaluation via tensile tests with bulk specimens. The bulk specimens of the bonding structure are fabricated using spark plasma sintering. Tensile tests are then performed with these samples to compare mechanical properties. The test results indicate that the Young's modulus of a TLP bonding structure is lowered through the addition of tertiary aluminum particles relative to a conventional nickel-tin binary material system. Moreover, a TLP bond layer Young's modulus that is 63% lower than conventional tin-based solders is realized. A framework for material microstructure computational analysis is proposed as a next step for experimental results validation based on high resolution 3-D imaging and model reconstruction.