Thermodynamics, Diffusion and Activation Energy Of Sn-Cu Solder On Copper Substrates

Abstract This paper presents the study of thermodynamics, diffusion and the activation energy of Sn-Cu solder on copper substrate. The present research presents composition of 99.3Sn-0.7Cu (SC) solder wire with model: SC G227 (provided by Rosin Core Solder Flux for Electronic Co., Ltd.), United State selected as a solder wire for the experimental procedures. Copper plate was used and modified for various surface roughness(400, 600, 800, 1000, 1200, and 2000 m). Solder joints of samples were tested at extreme temperature of 150 °C at intervals of reaction times (100, 200, 300, 400, 500, 600, 700, 800, 900, and 1000h). Effect of surface roughness on thermodynamics potentials in IMCs formation were analysed, how the diffusion process influences the IMCs formation and growth were also studied. The study focused on the kinetic equations that follows the diffusion-controlled method under liquid and solid-state conditions using first principle of thermodynamics. Activation energy and diffusion coefficients were determined using a modified Arrhenius growth equation with surface roughness fits. Findings reveal that (1000h) reaction time has the highest activation energy Q (871.43KJ/mol) with diffusion coefficient Do (3.58m2/s), and (800h) reaction time produced the lowest activation energy Q (64.29KJ/mol) with diffusion coefficient Do (1.97m2/s). Metallurgical engineering, and electronics industry are the beneficiaries of this research.