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一、样品描述 所送来的样品为型号M84C2X1的PCBA。该板的R15和R16的两个贴片电阻的焊点处被腐蚀和有一条导带被污染变色,客户希望分析其原因。二、分析过程1.外观检查 通过目测和显微镜可以观察到贴片焊点处已被严重腐蚀。焊点已经失去光泽,贴片上的靠近焊料处的标识也被腐蚀,在焊盘上长出了蓝色的铜盐晶体(见照片1)。板上被污染的导带颜色变深、变灰,失去了原有的光泽(见照片2)。
First, the description of the sample sent to the model M84C2X1 PCBA. The board’s R15 and R16 two chip resistors are corroded at the solder joints and a conductive tape is contaminated and discolored, and customers want to analyze the cause. Second, the analysis process 1. Visual inspection Visual inspection and microscopy can be observed at the patch solder joints have been severely corroded. The solder joints have been tarnished, the marks on the patches near the solder are also eroded, and blue copper crystals grow on the pads (see photo 1). The contaminated tape on the board becomes darker, grayer and loses its original luster (see photo 2).