pp. 199-213
S&M643 Research Paper Published: 2006 Fabrication and Characterization of a Low-Temperature Hermetic MEMS Package Bonded by a Closed-Loop AuSn Solder Line [PDF] Seong-A Kim, Young Ho Seo, Young-Ho Cho, Geunho Kim and Jong-Uk Bu (Received May 13, 2005; Accepted May 30, 2006) Keywords: hermetic MEMS packaging, low-temperature bonding, solder-line bonding, pressurized hermeticity test
In this paper, we present a hermetic MEMS package bonded by a closed-loop 80Au20Sn solder line. We designed three different test specimens including a substrate-heated specimen without an interconnection line (SHX), a substrate-heated specimen with an interconnection line (SHI), and a locally heated specimen with an interconnection line (LHI). A pressurized helium leak test was carried out to evaluate the hermetic seal along a critical pressure test to measure bonding strength. In the bonding process, the substrate heating methods (SHX, SHI) require 400℃ and 40 min, while the local heating method (LHI) requires a heater power of 6.76 W for 4 min. In the hermeticity test, SHX, SHI, and LHI show leak rates of 8.4±6.7×10–10 mbar-l/s, 13.5±9.8×10–10 mbar-l/s, and 18.8±9.9×10–10 mbar-l/s, respectively, for the same internal volume of 6.89±0.2×10–6 l. In the critical pressure test, no fracture was found in the bonded specimens at an applied pressure of 1±0.1 MPa. From these results, we determine an approximate bonding strength of the test specimen as 3.53±0.07 MPa. We have experimentally verified that LHI shows the potential of hermetic MEMS packaging with an interconnection line and a bonding process for mass production that requires little time.
Corresponding author: Young-Ho ChoCite this article Seong-A Kim, Young Ho Seo, Young-Ho Cho, Geunho Kim and Jong-Uk Bu, Fabrication and Characterization of a Low-Temperature Hermetic MEMS Package Bonded by a Closed-Loop AuSn Solder Line, Sens. Mater., Vol. 18, No. 4, 2006, p. 199-213. |