化学镍金基板焊点的失效分析

Failure Analysis on 2^(nd) Bonding on PCB

硅麦克风在消费类电子产品中成功应用,近年来得到了迅猛发展。硅麦克风的封装工艺由于MEMS的特殊结构和封装材料的特殊性,与常见IC封装有许多不同点。其中引线键合工序由于所使用的PCB基板材料特殊的加工工艺,使得引线在PCB基板上的焊点失效成为研究硅麦克风封装成品率和可靠性的一个重要课题。文章重点探讨了硅麦克风封装过程中引线键合工序焊点失效问题,通过不同金线键合方式和金线键合参数的分析,确立了适合于硅麦克风封装的金线键合工艺。

Sisonic Microphone is more and more popular in consumable electronic market. There are two types of design of Sisonic microphone now, one is that MEMS and IC are integrated in one die; the other one is that there are two dies, MEMS and IC, in one package. The first design is still in research phase and only produced in lab. Second design is much mature and already realizes mass production. Assembly process of Sisonic microphone is much different from that of common IC package due to MEMS structure and other special material. Especially in wire bonding process, The PCB used in Sisonic microphone isn＇t the common electrical plating PCB but chemical plating board. Wire is easily lift or broken at second bond point on PCB surface due to PCB material characteristic. The study of the failure analysis on second bond point on PCB side is very critical to improve the assembly yield and reliability of Sisonic microphone assembly process. Wire bond temperature, wire bonding parameter, as well as wire bonding tooling were studied in this article by DOE experiment and theoretical calculation. This article＇s purpose is to finalize the proper wire bonding process parameter setting and tooling selection for Silicon Microphone by the failure analysis on 2nd bond on PCB surface.