CORRELATION BETWEEN GAMMA RADIATION DOSE ON HARDNESS, THICKNESS OF INTERMETALLIC COMPOUND AND CONTACT ANGLE

Abstract

In this study, the effect of low dose gamma radiation on the hardness and the microstructural properties of SAC305 solder was characterized. The solder paste was applied to the printed circuit board via stencil printing and reflow soldering, and then subjected to low doses of gamma radiation (5, 10, 15, 20 and 25 Gy). After the exposure, the samples undergo metallographic procedure prior to the indentation test. The hardness, intermetallic compound (IMC) thickness, and contact angle after irradiation were observed via nanoindentation and optical microscope. It was found that, the percentage of hardness increased by 43.05% up to 15 Gy exposure and gradually decreased to 11.54% for 25 Gy due to disturbance in the atomic arrangements of materials in the solder. Gamma radiation altered the microstructure of SAC305 solder resulting a change in IMC thickness as the radiation increases. The contact angle measured for SAC305 solder were in the range of acceptable wetting (24-35˚), ensuring its solderability.