Title :
Bonding interface materials evolution of intermediate In/Ag layers for low temperature fluxless solder based MEMS wafer level packaging
Author :
Lee, Chengkuo ; Yu, Daquan ; Yu, Aibin ; Yan, Liling ; Wang, Haitao ; Lau, John H.
Author_Institution :
Dept. of Electr. & Comput. Eng., Nat. Univ. of Singapore, Singapore
Abstract :
In this paper, we proposed new intermediate bonding layers (IBLs) of Ag-rich composition in In-Ag solder systems in contrast to previous studies mainly based on eutectic composition. The intermetallic compounds (IMCs) at the bonding interface were investigated with respect to the bonding condition, post-bonding room temperature storage and post-bonding heat treatment. The IMCs of Ag2In and Ag9In4 with high temperature resist to post-bonding process are derived under process condition of wafer bonding at 180degC, 40 mins and subsequent 120degC~130degC annealing for 24 hours. Based on our results, we can design proper packaging process flow so as to get reliable wafer level packaged MEMS devices.
Keywords :
annealing; circuit reliability; heat treatment; indium alloys; micromechanical devices; silver alloys; solders; wafer bonding; wafer level packaging; Ag2In; Ag9In4; MEMS wafer level packaging; annealing; bonding interface materials; eutectic composition; fluxless solder; intermediate bonding layers; intermetallic compounds; post-bonding heat treatment; post-bonding room temperature storage; temperature 180 degC; temperature 293 K to 298 K; time 24 h; time 40 min; wafer bonding; Annealing; Heat treatment; Intermetallic; Micromechanical devices; Packaging; Process design; Resists; Temperature; Wafer bonding; Wafer scale integration;
Conference_Titel :
Electronic Materials and Packaging, 2008. EMAP 2008. International Conference on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-3620-0
Electronic_ISBN :
978-1-4244-3621-7
DOI :
10.1109/EMAP.2008.4784267
