(大連理工大學(xué) 材料科學(xué)與工程學(xué)院，大連 116085)
摘 要: 通過在釬料中添加Fe粉顆粒，研究其對Sn-3Ag-0.5Cu復(fù)合無鉛釬料的黏度、熔點(diǎn)、釬焊接頭界面微觀組織、與Cu基板之間的潤濕性及焊點(diǎn)力學(xué)性能的影響。結(jié)果表明：微米級Fe粉的添加增加了復(fù)合釬料焊膏單位體積內(nèi)焊粉的接觸面積，使得焊膏內(nèi)摩擦力增大，導(dǎo)致復(fù)合釬料焊膏的黏度增加；微米級Fe粉的添加對Sn-3Ag-0.5Cu釬料的熔化特性沒有顯著影響；釬焊時，由于重力偏聚及界面吸附作用，F(xiàn)e粉顆粒集中沉積于Sn-3Ag-0.5Cu-Fe/Cu釬焊接頭界面處靠近釬料一側(cè)，由于增大液態(tài)釬料黏度而導(dǎo)致釬料與Cu板間的潤濕性降低；與Sn-3Ag-0.5Cu/Cu相比，Sn-3Ag-0.5Cu- Fe/Cu界面處釬料一側(cè)粗大的β-Sn枝晶區(qū)消失，取而代之的是細(xì)小的等軸晶。Sn-3Ag-0.5Cu-1%Fe/Cu的剪切強(qiáng)度為46 MPa，比Sn-3Ag-0.5Cu/Cu剪切強(qiáng)度提高39%；靠近界面金屬間化合物處釬料基體的顯微硬度提高約25%。
關(guān)鍵字: 復(fù)合無鉛釬料；Sn-3Ag-0.5Cu；黏度；潤濕性；剪切強(qiáng)度
Sn-3Ag-0.5Cu lead-free solder
（Dalian University of Technology, School of Materials Science and Engineering, Dalian 116085, China）
Abstract:The effects of Fe particles on the viscosity, melting point, microstructure, wettability and mechanical properties of Sn-3Ag-0.5Cu solder paste were investigated. The results show that the addition of Fe particles with micro size increases the contact area between the solder balls and friction force of solder pastes, which is due to the increasing viscosity of solder paste. The density of Fe is higher than that of the Sn-3Ag-0.5Cu, and Fe particles are adsorbed to the interface to increase the viscosity of liquid solder, so, the wettability of solder alloys are degraded. Compared with the Sn-3Ag-0.5Cu/Cu, the fine equiax crystal in Sn-3Ag-0.5Cu-Fe/Cu is found instead of the bulky β-Sn arborescent crystal. The shear strength of the Sn-3Ag-0.5Cu-1%Fe/Cu is 46 MPa, which is 39% higher than that of the Sn-3Ag-0.5Cu/Cu. The microhardness of the matrix increases approximately 25% as a result of incorporation of Fe particles.
Key words: composite lead-free solder; Sn-3Ag-0.5Cu; viscosity; wettability; shear strength
