Local shear stress-strain response of Sn-3.5Ag/Cu solder joint with high fraction of intermetallic compounds: Experimental analysis

Abstract

Current trend in miniaturization of microelectronic devices is the motivating factor for size reduction of joints and interconnects. The electronic industry is expecting to reduce the scale of interconnects in the next generations microelectronic devices. Mechanical behavior of these joints will significantly be different from traditional solder joints due to the effects such as geometrical and microstructural constraints, anisotropy caused by the reduction in a number of grains, and the presence of brittle intermetallics (IMCs). Mechanical experiments at this scale are very challenging. This study was focused on investigating the effect of different volume fraction of IMCs on the shear behavior of micro-scale solder joints with a 50µm stand-off height. A single lap-shear specimen was designed to conduct the study. Two Copper (Cu) substrates were soldered together with Sn-3.5Ag solder foil and a thickness of 50µm was achieved. The soldering temperature of 260°C and soldering time of 10, 30 and 60 minutes were utilized to achieve approximately 40%, 60% and 80% IMCs of total joint thickness. The experiments were conducted using a micro-tensile tester which is integrated with an optical microscope for monitoring and observing deformation in the testing materials. To investigate the local shear strain behavior, an optical technique along with a developed image processing computer program was used. The single lap-shear tests were conducted with the shear strain rate of 0.015s -1 and 0.15s -1 to observe

Influence of Interfacial Intermetallic Growth on the Mechanical Properties of Sn-37Pb Solder Joints under Extreme Temperature Thermal Shock

“…Table 1 lists the values of the time exponent n and the correlation factor R 2 for the interfacial IMCs. The n value is considered to be a pointer to the growth mechanism of interfacial IMCs [18,19]. If the n value is closer to 0.33, the IMC growth is dominated by grain-boundary diffusion.…”

“…If the n value is closer to 0.33, the IMC growth is dominated by grain-boundary diffusion. If the n value is on the order of 0.5, the IMC growth is dominated by bulk diffusion [18,19]. The values of the time exponent n implied that the growth of the interfacial IMCs at the lead side was dominated by bulk diffusion, and the growth of the interfacial IMCs at the Ni-P layer side was dominated by grain-boundary diffusion under extreme temperature thermal shock.…”

Kesan Pigmen Pewarna terhadap Pertumbuhan Sebatian antara Logam Sambungan Pateri Sn-3.0Ag-0.5Cu

“…Lapisan ini terbentuk semasa tindak-balas pembasahan sewaktu proses pematerian dan tumbuh membesar dalam keadaan pepejal disebabkan oleh tindakan teraktif terma melalui proses resapan. Dalam kajian lepas, isu tentang pertumbuhan IMC merupakan isu yang sering menjadi perhatian (Choudhury & Ladani 2016). Lapisan IMC pada antaramuka pateri-substrat merupakan indikasi kebolehbasahan serta ikatan metalurgi bagi sambungan pateri yang baik.…”

Simulation Analysis and Experimental Study on Strength Optimization of a Plug‐In Oil Hose Joint

“…eir research shows that the ultimate shear strength and strain to failure are largely dependent on the volume fraction of IMCs. In addition, the far-field or nominal shear strain is completely different than the local shear strain behavior at the solder joint region [19].…”