锡铜镍无铅热风整平产品回流焊后焊盘变色的研究与解决

无铅锡铜镍热风整平工艺产品在下游客户端做回流焊接工艺时，经过1—2次高温回流焊接后，仍然会有少量的焊盘未被焊接而裸露，这时未被焊接的焊盘表面变色发黄了。文章将围绕如何改善此类未焊接的焊盘发黄的问题进行一系列的试验和测试，最终得出最有效的处理方式。既降低了加工成本，又有效地解决了回流焊后焊盘发黄的问题，满足了客户的要求，杜绝了客户反馈的发生，保住了订单。

SCN-HASL-free reflow pad change color research and solve

Lead free tin copper nickel hot air leveling product reflow soldering process in the lower reaches of the client, after 1-2 times of high temperature reflow soldering, there will still be a small amount of not welding pads and bare, surface discoloration pad yellow when is not welded. In this paper, a series of tests and test focused on how to improve the welding pad yellow without question, the most effective way to reach processing. Not only the processing cost is reduced, but also effectively solves the problem of yellow pad after reflow, meet customer requirements.