Title :
Mechanical properties and joint reliability improvement of Sn-Bi alloy
Author :
Wang, Jianhui ; Wen, Long ; Zhou, Jianwei ; Chung, Myungkee
Author_Institution :
Samsung Semicond. (China) R&D Inst., Suzhou, China
Abstract :
Sn-58Bi is a eutectic alloy that melts at 139°C, it is lead-free and strong, but brittle. Also, its fatigue resistance is questionable [1]. The aim of this research is to study the properties of Sn-58Bi low melting temperature solder ball and the method to improve its reliability. 78 ball grid array (BGA) with ball size 0.45mm and 0.8 mm pitch was selected as the target device. Joint protect flux (JPF) was used to enhance the component side joint reliability. The result shows that JPF can solve the ball off problem and improve the ball shear, thermal cycling, drop life time and bending performance of Sn-Bi solder. Simulation work was succeeding to confirm the experiment results. The drop result is good if the Sn-Bi solder ball using Sn-Ag-Cu (SAC) paste, but the result is bad if the SAC solder ball using SnBi paste.
Keywords :
ball grid arrays; bending; eutectic alloys; fatigue; melting; reliability; solders; BGA; JPF; ball grid array; ball shear; bending performance; drop life time; eutectic alloy; fatigue resistance; joint protect flux; joint reliability improvement; mechanical properties; melting temperature; solder ball; temperature 139 degC; thermal cycling; Bismuth; Electronics packaging; Joints; Reliability; Stress; Temperature;
Conference_Titel :
Electronics Packaging Technology Conference (EPTC), 2011 IEEE 13th
Conference_Location :
Singapore
Print_ISBN :
978-1-4577-1983-7
Electronic_ISBN :
978-1-4577-1981-3
DOI :
10.1109/EPTC.2011.6184470
