(中南大學 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 通過加速溫度時效方法針對電子器件可靠性評估中等溫時效對In-3Ag焊料顯微觀組織和剪切性能的影響進行研究。采用掃描電鏡(SEM)、能量色散儀(EDS)和X射線衍射(XRD)分別對焊點基體及其與銅基板界面金屬間化合物層的組織結構進行觀察和分析，采用力學試驗機測試焊點的剪切強度，并通過SEM觀察分析其斷裂特征。結果表明：隨著等溫時效時間延長，基體中二次相AgIn2顯著長大，由顆粒狀轉(zhuǎn)變?yōu)榇髩K狀；界面IMC層(成分為(Ag,Cu)In2)的厚度逐漸增加，其生長由組元擴散速率控制；焊點剪切強度呈下降趨勢，由焊后的5.94 MPa降至時效1000 h后的2.35 MPa；在100 ℃分別時效100、250、500和750 h后，焊點剪切失效均呈焊料內(nèi)部韌性斷裂模式，時效1000 h后，斷裂模式轉(zhuǎn)變?yōu)轫g脆混合斷裂。
關鍵字: In-3Ag焊料；金屬間化合物；等溫時效；剪切性能；釬焊
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The effects of isothermal aging on the microstructure and shear property of In-3Ag solder were investigated by accelerated temperature aging. Scanning electricity microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD) were used to observe and analyze the intermetallic compound (IMC) layer microstructure and the composition of solder joint. The mechanical testing machine was used to test the shear strength of solder joint, and the shear fractography was measured by SEM. The results show that, with the isothermal aging time increases, the quadratic phase AgIn2 in solder matrix grows prominently, and the shape changes from grain to blocky ship. The thickness of (Ag,Cu)In2 layer increases gradually, which is controlled by component diffusion rate. The shear strength of solder joints decreases with isothermal aging time increases, and it decreases from 5.94 MPa after soldering to 2.35 MPa after 1000 h aging. The fracture type is ductile fracture in solder matrix after being aged at 100 ℃ for 100, 250, 500 and 750 h, respectively. After being aged for 1000 h, the fracture type belongs to the toughness-brittleness fracture mode.
Key words: In-3Ag solder; intermetallic compound; isothermal aging; shear property; soldering
