(1. 上海大學(xué) 材料科學(xué)與工程學(xué)院, 上海 200072；2. 上海大學(xué) 中瑞聯(lián)合微系統(tǒng)集成技術(shù)中心新型顯示技術(shù)與應(yīng)用集成教育部重點(diǎn)實(shí)驗(yàn)室, 上海 200072；3. SMIT Center, Chalmers University of Technology, 412-96 Göteborg, Sweden)
摘 要: 研究了Cu/Sn-3.0Ag-0.5Cu/Cu焊點(diǎn)在(150±1)℃時(shí)效溫度下，0~1 000 h不同時(shí)間時(shí)效后焊點(diǎn)的拉伸斷裂性能以及界面金屬間化合物(IMC)的組織形態(tài)和成分。結(jié)果表明：隨著時(shí)效時(shí)間的延長，焊點(diǎn)拉伸強(qiáng)度降低，拉伸斷裂主要發(fā)生于Solder/IMC界面或/和IMC/IMC界面，而且斷口形貌逐漸由韌窩狀斷口為主向解理型脆性斷口轉(zhuǎn)變。SEM研究發(fā)現(xiàn)，時(shí)效過程中界面IMC不斷長大、增厚并呈針狀或塊狀從Cu/Solder界面向焊點(diǎn)心部生長，時(shí)效1 000 h的焊點(diǎn)中IMC分層明顯。半焊點(diǎn)結(jié)構(gòu)為Cu/Cu3Sn/Cu6Sn5/Solder，同時(shí)，在靠近銅基體的IMC中有Kirkendall空洞存在。
關(guān)鍵字: 金屬間化合物；Cu/Sn-3.0Ag-0.5Cu/Cu焊點(diǎn)；拉伸斷裂；多層結(jié)構(gòu)；柯肯達(dá)爾洞
（1. School of Materials Science and Engineering, Shanghai University,Shanghai 200072, China;2. Key Laboratory of New Displays and System Integration,Ministry of Education, Sino-Swedish Microsystem Integration Technology(SMIT) Centre, Shanghai University, Shanghai 200072, China; 3. SMIT Center, Chalmers University of Technology, 412-96 Göteborg, Sweden）
Abstract:The tensile fracture behavior and the intermetallic compound’s(IMC’s) morphology and composition at the interface of Cu/Sn-3.0Ag-0.5Cu/Cu solder joint specimens after aging at (150±1)℃ for 0−1 000 h were studied. The results show that, with the increasing aging time, the tensile fracture strength of the solder joints decreases and the crack initiates mostly at the interfaces between the solder and IMC layer or/and IMC and IMC layer. The morphology of fracture surface changes from dimple-like to cleavage-like surfaces. SEM analysis indicates that the needle-like or block-like interfacial IMC forms at the interface of Cu/solder and grows into the solder matrix. After being aged for 1 000 h, the obvious IMC multilayer structure is observed, which is defined as Cu/Cu3Sn/Cu6Sn5/solder structure for the half-joints. Moreover, the Kirkendall voids can be observed in the multilayer structure close to the copper substrate. These voids are possibly one of the factors of the tensile fracture mechanism.
Key words: intermetallic compound (IMC); Cu/Sn-3.0Ag-0.5Cu/Cu joint; tensile fracture; multilayer structure; Kirkendall void
