TY - GEN
T1 - Improved low temperature gold-gold bonding using nanoporous powder bump using vacuum ultraviolet irradiation pre-treatment
AU - Kaneda, Tatsushi
AU - Mizuno, Jun
AU - Okada, Akiko
AU - Matsunaga, Kaori
AU - Shoji, Shuichi
AU - Saito, Mikiko
AU - Nishikawa, Hiroshi
N1 - Publisher Copyright:
© 2015 The Japan Institute of Electronics Packaging.
PY - 2015/5/20
Y1 - 2015/5/20
N2 - This paper describes a novel low temperature Au-Au bonding method using nanoporous Au-Ag powder and vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3) pre-treatment. The nanoporous powder, which was fabricated by dealloying Ag-Au alloy sheet, was used to form the bump structure on the Au substrate by simple filing process, while an Au-coated Si substrate was used as the chip. The VUV/O3 treated bumps and chip was bonded under a bonding pressure of 20 MPa at 200 °C for 20 min in a vacuum atmosphere of 1 kPa. A ligament size of the nanoporous structure on powder surface was found to be grown dramatically during bonding process. The tensile strength reached 10.1 MPa which is 2.3 times higher than that without VUV/O3 treatment. This suggests that organic contaminants on the each ligament surface were effectively removed by VUV/O3 treatment, and consequently, the diffusion of gold atoms in the nanoporous powder was significantly promoted to change into bulk structure. The proposed method will be highly a promising method for 3D-LSI and MEMS packaging.
AB - This paper describes a novel low temperature Au-Au bonding method using nanoporous Au-Ag powder and vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3) pre-treatment. The nanoporous powder, which was fabricated by dealloying Ag-Au alloy sheet, was used to form the bump structure on the Au substrate by simple filing process, while an Au-coated Si substrate was used as the chip. The VUV/O3 treated bumps and chip was bonded under a bonding pressure of 20 MPa at 200 °C for 20 min in a vacuum atmosphere of 1 kPa. A ligament size of the nanoporous structure on powder surface was found to be grown dramatically during bonding process. The tensile strength reached 10.1 MPa which is 2.3 times higher than that without VUV/O3 treatment. This suggests that organic contaminants on the each ligament surface were effectively removed by VUV/O3 treatment, and consequently, the diffusion of gold atoms in the nanoporous powder was significantly promoted to change into bulk structure. The proposed method will be highly a promising method for 3D-LSI and MEMS packaging.
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U2 - 10.1109/ICEP-IAAC.2015.7111061
DO - 10.1109/ICEP-IAAC.2015.7111061
M3 - Conference contribution
AN - SCOPUS:84936096740
T3 - ICEP-IAAC 2015 - 2015 International Conference on Electronic Packaging and iMAPS All Asia Conference
SP - 473
EP - 477
BT - ICEP-IAAC 2015 - 2015 International Conference on Electronic Packaging and iMAPS All Asia Conference
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2015 International Conference on Electronic Packaging and iMAPS All Asia Conference, ICEP-IAAC 2015
Y2 - 14 April 2015 through 17 April 2015
ER -