摘要
沉锡因其优良的可靠性被广泛应用于PCB表面处理工艺申,但同时也存在一些不足和缺陷,比如锡面发黑是很常见的一个技术难题。文章结合沉锡板生产实例,利用扫描电镜、能谱分析,以及现场模拟实验等分析手段对导致沉锡板锡面发黑的原因进行了系统研究和分析,结果显示该板在后浸锡后第一道水洗浸泡时间超过15分钟,在弱酸性的条件下会造成锡面粗糙,进而在视觉光线的影响下显现出锡面发黑的现象。
Immersion tin is widely used in PCB surface treatment for its good reliability, but simultaneously it has some insufficiencies and shortcomings. Surface blackening, for example, is a common technical problem. Combining production practice, this article studied and analyzed the surface blackening problem of immersion tin PCB methods of SEM, EDX, simulation experiment, etc. The results showed that these PCBs were soaked more than 15min in the first wash after the post-immersion, the tin surfaces were etched again under weak-acid condition, which caused roughness of tin surfaces and thus led to the surface blackening problem under the influence of visual light.
出处
《印制电路信息》
2017年第A01期181-187,共7页
Printed Circuit Information
关键词
线路板
表面处理
沉锡
焊盘
锡面发黑
PCB
Surface Treatment
Immersion Tin
PAD
Tin Surface Blackening