锡镀层表面晶须问题的研究现状与进展

Review of Whisker Growth on Tin Coating

随着电子封装无铅化的趋势,选择无铅锡基镀层已成为必然。但是,纯锡及锡基合金镀层具有自发生长锡晶须的倾向,因此研究并阐明锡晶须的生长机理,并采取有效的预防措施,成为目前人们关注的焦点。回顾了锡晶须研究的历史和现状,综述了关于锡晶须的形貌特征、影响锡晶须生长的各种因素及目前对锡晶须生长机理的认识等问题,介绍并分析了几种工业界预防锡晶须生长的主要措施,包括合金化、去应力退火、电镀隔离层、热风整平或热熔。讨论并提出了一些需要研究的课题。

With lead-free trend in electronic package, it is necessary to choose lead-free tin-base electrodeposits for electronics industry. However, pure tin and tin alloy coatings have the propensity to grow tin whiskers spontaneously. As a result, whiskers have been as an industry concerns about both the growth mechanism and the mitigation strategies. The history and recent development of the tin whisker research are reviewed. The summary of the growth morphologies, the effect factors on tin whisker growth as well as the growth mechanism of the tin whiskers on tin coating are presented. The different technologies to prevent from the whisker growth on tin coating, including alloying, annealing, barrier-layer, fusing and reflowing process are also introduced. The interesting research issues in this area are discussed and suggested.