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

fYear

2011

fDate

7-9 Dec. 2011

Firstpage

492

Lastpage

496

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;

fLanguage

English

Publisher

ieee

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

Type

conf

DOI

10.1109/EPTC.2011.6184470

Filename

6184470