SnAg及SnAgCu无铅焊料接头中金属间化合物在时效中的演变  

Evolution of intermetallic compounds in SnAg and SnAgCu lead-free solder joints during aging

作　　者：李晓延[1] 杨晓华[2] 吴本生[2] 严永长[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100022 [2]福州大学测试中心,福建福州350002

出　　处：《中南大学学报（自然科学版）》2007年第1期30-35,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50475043);国家教育部博士点基金资助项目(20040005012);北京市自然科学基金资助项目(2052006)

摘　　要：对SnAg共晶合金及SnAgCu共晶合金无铅焊料与Cu或Ni／Cu或Au／Ni／Cu衬底经钎焊方法焊接后,在焊接界面和焊料内部形成的金属间化合物(IMC)的类型、形貌和分布形式,以及焊接接头在随后时效过程中IMC的类型、成分和形貌的演变规律进行综述。分析结果表明,在钎焊过程中,IMC的类型与焊料成分有关,与衬底金属在焊料合金中的溶解度及扩散速度有关;IMC的形貌与加热温度、冷却速度及焊接界面的温度梯度有关;IMC的分布与焊料成分及接头中金属元素的扩散能力有关;焊料接头的断裂机理与接头合金成分、时效温度、时效时间、载荷方式有关;在时效过程中,焊料共晶组织粗化,焊料强度下降,断裂会在焊料内部发生;当IMC厚度增大到临界尺寸时,应力集中严重,多层IMC形成,空穴形成及长大,在IMC界面层断裂;若两者强度接近,则断裂部分发生在焊料,部分发生在界面IMC处。The types, morphology and distribution of intermetallic compounds （IMCs）, and the evolution of the types and composition and morphology of IMC in the joints during the subsequent aging process were presented. The analysis results show that the types of IMCs mainly depend on solder composition and the solubility and diffusion rate of metal substrate in solder alloy; the morphology of IMC is closely related with the soldering peak temperature, cooling rate and the thermal gradient of the interface of joints; the distribution of IMC is related with solder composition and the diffusivity of metal elements in the joints. The analysis results also show that the fracture mechanism of the joints is mainly controlled by the solder composition, the peak temperature and duration of aging as well as the applied loads. The eutectic structures of the solder are coarsened during the aging process and the strength of the solder decreases, thus the fracture occurrs inside the solder. If the thickness of IMC increases to critical size, the stress concentration wil be serious. Some time multilayer IMCs will be formed and cavity will be formed and grow, and the fracture will occur in the interracial layer of IMCs. If the strengths of the solder and IMC are close during aging, the fracture will occur both inside the joints and in the interfacial layer of IMCs.

关 键 词：无铅焊料 金属间化合物 时效 

分 类 号：TN604[电子电信—电路与系统]