Effect of Processing Variables on the Mechanical Reliability of Free Solder Joints
Authors: Mohammed Genanu, Babak Arfaei, James Wilcox , Eric Perfecto, Eric J.Cotts Company: Physics and Materials Science Binghamton University, Universal Instruments Corporation, Global Foundries Date Published: 9/17/2017
Abstract: Strong correlations exist between processing parameters of Sn-Ag-Cu solder joints and both microstructure and reliability performance. The present study examines the effect of solder joint geometry, in particular length scale, on Pb free solder joint microstructure and reliability. The advent of 2.5/3D packaging technologies in microelectronics has further decreased joint diameters below one hundred microns. This study investigates the effects of solder joint size on Ag3Sn precipitate morphology. The size and number density of Ag3Sn precipitates were quantified for Cu pillar solder caps and Cu pillar solder joints with different metallizations, at diameters from 30 to 100 micron. The shear strengths of solder caps as-reflowed on Cu pillars were measured.
Cu pillars, Lead-Free Solder Alloys, 2.5D Packaging, Precipitate Strengthening, Microstructure.