微连接和纳连接的研究新进展

Recent progress in microjoining and nanojoining

微连接和纳连接是微/纳级机械、电子和医疗等器件或系统结构制造的关键技术,综述其最新研究进展.针对电子封装,阐述无铅钎料的研制现状和铜引线键合新技术.针对医疗器件和铋系超导带材,分别介绍细丝、薄片连接的典型方法如微电阻焊、微激光焊和钎焊以及一步法扩散焊.对于碳纳米管,介绍电子束辐照连接、双壁碳纳米管薄膜卷覆法连接及钎焊.对于纳米金属颗粒,介绍飞秒激光辐照实现连接.最后,重点阐述了微-纳米Ag,Ag-Cu,Cu以及Ag2O颗粒膏低温烧结连接及其在电子封装中的可能应用.

Micro-joining and nano-joining have been identified as the key technologies in the construct fabrication such as micro-and nano-mechanical,electronic and medical devices and systems,and their recent progresses are briefly reviewed in this article.For electronic packaging applications,the developed lead-free solders and the two-step loading procedure accompanied with a superimposed ultrasound for copper-wire-bonding were expounded.Typical joining methods including resistance micro-welding,laser micro-welding and brazing for similar and dissimilar wires or pieces used for medical devices were discussed,as well as one-step diffusion bonding with pressing at high temperature for Bi-Sr-Ca-Cu-O superconductive leads.Joining technologies were also introduced,including electron beam irradiating welding,strand wrapping bonding with Double-walled Carbon Nanotube Strands(DWNT) film and brazing,the welding technologies of metal nanoparticles realized through laser irradiation,and the novel process of low-temperature sintering bonding by using Ag,Cu,Ag-Cu and Ag2O micro/nano-particle pastes for electronic packaging applications.Based on the existing and new processes,the challenges and outlooks in micro-and nano-joining were pointed out.