有关金属表面处理和保护的四个问题，各位给给意见吧，谢谢

1.ituation:After 260 degree Celsius reflow three times,each time 10 second,pure tin electrolytic surface will have discoloration.why? do you have any suggestion to prevent this occurring?

2.　Situation:After reflow process , tin/lead surface will easily occur dewetting. What is the root cause of it?why?How do you start to investigate it? Do you have any suggesting to minimize this?

3.　How can you reduce whiskers appearing on the pure tin　electrolytic surface? what is the reason appearing whiskers?
Please state.

4.　During CVS analysis,the analysis results often show unstable and fluctuation.What is the problem here?　How can we solve this problem.Please state suggestion.

中英文答复均可．谢谢．