A low-temperature sintered conductive silver paste containing Bi2O3-B2O3-ZnO glass frit was used for sintering thick silver film on the surface of aluminum alloy to realize aluminum alloy soft soldering. First, Bi2O3-B2O3-ZnO glass with glass transition temperature (Tg) of 360 ℃ was synthesized by using a melt-quenching method. Then, it was mixed with submicron silver powder to prepare lead-free low-temperature sintered silver paste, which was coated on the surface of 6061 aluminum alloy and sintered at temperatures of 440, 470, 500 and 530 ℃, respectively. The effects of sintering temperature on the resistivity and the solderability of silver thick film, and the bonding strength of the silver thick film on the substrate were studied. The results show that a thick silver film with glass and silver powder content ratio of 1∶9 (wt.%) sintered at 530 ℃ for 10 min has a low resistivity of 2.2 μΩ·cm and a high shear strength of 56.0 MPa at room temperature. Increasing the sintering temperature can effectively promote the flow, wetting and spreading of the glass, the growth of necking between Ag particles, and the growth of Ag particles, thereby improving the solderability of silver thick film significantly. In addition, the nano-scale elemental bismuth produced by the oxidation-reduction reaction of Al, Mg and Bi2O3 was detected at the interface of silver thick film and aluminum substrate. It shows that an excellent metallurgical bond was formed between the silver thick film and the aluminum substrate.
SUN Guoji
,
SUN Qin
,
YANG Wanchun
,
XU Hongbo
,
LI Mingyu
. Sintering performance analysis of conductive silver paste on aluminum alloy surface[J]. Transactions of The China Welding Institution, 2021
, 42(1)
: 38
-43,64
.
DOI: 10.12073/j.hjxb.20201005002
[1] 王超. 电子封装铝用软钎焊无铅焊锡丝配套助焊剂的研究与应用[D]. 广州: 华南理工大学, 2012.
Wang Chao. Research and development of a soldering flux for lead-free solder wires in Al soldering process of electronic packaging[D]. Guangzhou: South China University of Technology, 2012.
[2] 薛松柏, 董健, 吕晓春, 等. LYl2铝合金中温钎焊技术[J]. 焊接学报, 2003, 24(3): 21-22, 51
Xue Songbai, Dong Jian, Lü Xiaochun, et al. Brazing technology of LY12 Al-alloy at middle temperature[J]. Transactions of the China Welding Institution, 2003, 24(3): 21-22, 51
[3] Hilz E, Dudziak S, Schmid-Fetzer R. Formation and properties of intermetallic compounds in an Al-Cu roll-bonded connection[C] // The 27th International Conference on Electrical Contacts. Dresden: VDE, 2014.
[4] Sun Q, Yang W C, Liu Y H, et al. Microstructure and mechanical properties of tempered glass joint bonded with Bi-B-Zn low melting glass[J]. Journal of Materials Processing Technology, 2019, 271: 404-412.
[5] Che Q D, Yang H X, Lu L, et al. A new environmental friendly silver front contact paste for crystalline silicon solar cells[J]. Journal of Alloys & Compounds, 2013, 549(5): 221-225.
[6] Yang W C, Sun Q, Lei Q, et al. Formation of a highly conductive thick film by low-temperature sintering of silver paste containing a Bi2O3-B2O3-ZnO glass frit[J]. Journal of Materials Processing Technology, 2018, 267: 61-67.
[7] 陶业卿. 保护气氛回流SAC305无铅焊点的可焊性与温度循环可靠性研究[D]. 上海: 上海交通大学, 2017.
Tao Yeqing. Research on solderability and temperature cycling reliability of SAC305 lead-free solder joints fabricated in protective reflow atmospheres[D]. Shanghai: Shanghai Jiao Tong University, 2017.
[8] 余向磊. 太阳能电池正银浆料烧结过程与导电机理研究[D]. 昆明: 昆明理工大学, 2017.
Yu Xianglei. Research on sintering process and conductive mechanism of positive silver paste for solar cell[D]. Kunming: Kunming University of Science and Technology, 2017.
[9] Yao S S, Xing J J, Zhang J F, et al. Microscopic investigation on sintering mechanism of electronic silver paste and its effect on electrical conductivity of sintered electrodes[J]. Journal of Materials Science: Materials in Electronics, 2018, 29(21): 18540-18546.
[10] Liu Y, Liu L, Xu R S, et al. Microstructure, hardness, and shear behavior of Sn3.0Ag0.5Cu–Sn58Bi composite solder joint[J]. Materials Research Express, 2019, 6(11): 116328.
[11] Cox J D, Wagman D D, Medvedev V A. CODATA key values for thermodynamics[M]. New York: Hemisphere Publishing Corp, 1989.
