基于Au/Ni-W多层薄膜修饰铜基微纳分级结构固相瞬态焊接方法  

Solid-phase Transient Soldering Method Based on Au/Ni-W Composite Thin-film-modified Copper-based Micro-nano Hierarchical Structures

作　　者：肖金 田学锋 冯晓杰[1] 刘志明 徐创 XIAO Jin;TIAN Xuefeng;FENG Xiaojie;LIU Zhiming;XU Chuang(School of Advanced Manufacturing,Guangdong Songshan Polytechnic,Guangdong Shaoguan 512100,China)

机构地区：[1]广东松山职业技术学院先进制造学院,广东韶关512100

出　　处：《表面技术》2024年第12期260-267,共8页Surface Technology

基　　金：韶关市科技计划项目(210806154531768);先进制造学院教师教学创新团队专项经费(SG1004)。

摘　　要：目的以特殊形貌的铜基微纳结构为基板,在其上依次镀覆Ni-W合金层和Au纳米层,在超声能量和室温条件下,实现瞬时与锡基焊料的焊接,解决无铅焊料由于高熔点对薄芯片和热敏器件造成的热冲击和热损伤问题,保证器件安全性和性能可靠性。方法采用电化学方法沉积出特殊形貌铜基微纳分级结构,在其上化学镀覆层厚为180 nm的Ni-W合金层和50 nm的Au层。将获得的Au/Ni-W多层薄膜修饰的铜基结构与商用焊料(SAC305)在焊接压力98 N(20 MPa)、焊接时间3 s、超声振动3 s条件下实现固相瞬态焊接。将不同表面修饰层的铜基微纳分级结构与焊球进行破坏剪切测试。将焊接后的样品在180℃下分别进行10、30、60 min的时效处理。结果铜基微米级突起结构高度为2~4μm,底端尺寸为800~1200 nm,具有优良的凸起结构密度和长径比。Au/Ni-W修饰后的铜基微纳分级结构与SAC305焊球所形成的焊接界面嵌入效果好,没有任何孔洞存在,焊接界面平均剪切强度为43.06 MPa。结论铜基微纳分级结构插入焊球内部形成镶嵌,产生机械互锁,而Au/Ni-W合金修饰层能有效提高铜基微纳分级结构表面硬度,与锡焊料形成较大的硬度差,在插入式焊接中减少了孔洞的形成,焊接效果优良。Ni-W合金层的存在延缓了Cu-Sn之间的互扩散,阻挡了Cu-Sn金属间化合物的生长,减少了因界面失效而产生的可靠性问题。A copper-based micro-nanostructure with special morphology is used as the substrate to coat Ni-W alloy layer and Au nanolayer sequentially.Instantaneous soldering with tin-based solder is realized under ultrasonic energy and room temperature conditions,solving the thermal shock and thermal damage caused by the high melting point of lead-free solder on thin chips and thermal devices.This method ensures device safety and performance reliability.Electrochemical deposition of copper-based micro-nano-graded structures with special morphology was carried out.An amorphous Ni-W alloy layer with a thickness of 180 nm was deposited on the Cu-based micro-nano-graded structures by adjusting the atomic ratio of the plating solution.Since the Ni-W layer was easily oxidized,an Au layer with a thickness of 50 nm was electrodeposited on it to prevent oxidation.The obtained Au/Ni-W composite film-modified Cu-based micro-nano-graded structures were solid-phase transiently soldered with a commercial solder(SAC305)under a soldering pressure of 98 N(20 MPa),a soldering time of 3 s,and an ultrasonic vibration of 3 s.The copper-based micro-nano-graded structures with different surface modification layers were subject to destructive shear testing with solder balls.The soldered samples were aged at 180℃for 10,30,and 60 min,respectively.Scanning electron microscopy and X-ray fluorescence thickness gauge were used to study the microstructure,thickness of intermetallic compound composition,and properties at the soldered interface.The copper-based micron-scale protrusion structure had a height of 2-4μm and a base size of 800-1200 nm,which had a sharp tip,excellent protruding structure density and aspect ratio.The solder interface formed by the Au/Ni-W modified Cu-based micro-nano-graded structure and the SAC305 solder ball was well embedded without any hole.The average shear strength of the soldered interface was 43.06 MPa.The fracture surface of Au/Ni-W modified Cu-based micro-nano-graded structure basically occurred inside the solder bal

关 键 词：微纳分级结构 薄膜 焊接 扩散 

分 类 号：TB34[一般工业技术—材料科学与工程]