引发电控模块短路之PCB孔口发黑原因研究
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摘要
PCB在使用过程中在经常会出现短路故障,对相关故障电子模块进行分析时发现模块PCB较多孔口存在发黑物质,严重者出现黑色物质连孔,通过测试确认黑色物质具有导电功能。本文通过理论分析及模拟实验论证,确认了黑色物质是引发电子模块故障的根源,同时明确了其产生机理,并提出了针对性的预防措施。
PCB short-circuit fault often occurred during use. It was found there was black substance around many holes of PCB when we analyzed the fault module. In some severe cases, connected holes occurred. The module ran normally again by removing the black substance. The black substance with conductivity was confirmed by test. In the paper, we confirmed that the black substance was the root cause of the electronic module failures through theoretical analysis and simulation experiments demonstrated. The generation mechanism was clarified and targeted preventive measures were proposed also.
PCB short-circuit fault often occurred during use. It was found there was black substance around many holes of PCB when we analyzed the fault module. In some severe cases, connected holes occurred. The module ran normally again by removing the black substance. The black substance with conductivity was confirmed by test. In the paper, we confirmed that the black substance was the root cause of the electronic module failures through theoretical analysis and simulation experiments demonstrated. The generation mechanism was clarified and targeted preventive measures were proposed also.
引文
[1]Dr.Chris Hunt,Sulphur Corrosion on Solder Joints,Printed Circuit Design&Fab,30 May 2014.
[2]Jing Li Fang,Daniel K.Chan.(2007),The advantages of mildly alkaline immersion silver as a f inal f inish for solderability,Circuit World,Vol.33 Iss:2,pp43-51.
[3]Changqing Liu,David A.Hutt.(2003),Surface coatings for fluxless soldering of copper,Circuit World,Vol.29 Iss:1,pp19-23.
[4]Lenora Toscano.A Brief Summary of Creep Corrosion,Printed Circuit Design&Fab,07 October 2010.
[5]Paul T.Vianco.(1999),An overview of surface finishes and their role in printed circuit board solderability and solder joint performance,Circuit World,Vol.25 Iss:1,pp6-24.
[6]C.C.Lee*,H.Y.Chuang,C.K.Chung,and C.Robert K ao.Oxidation behavior of ENIG and ENEPIG surface f inish,Department of Materials Science and Engineering,National Taiwan University,Taipei 106,Taiwan,ROC.
[7]Paul Mazurkiewicz,ph.D,Accelerated Corrosion of printed circuit bodrds due to high levers of reduced sulfur gasses in industrial environments,November-12-16,2006,renaissance Austin hotel,Austin,texas,USA.
[2]Jing Li Fang,Daniel K.Chan.(2007),The advantages of mildly alkaline immersion silver as a f inal f inish for solderability,Circuit World,Vol.33 Iss:2,pp43-51.
[3]Changqing Liu,David A.Hutt.(2003),Surface coatings for fluxless soldering of copper,Circuit World,Vol.29 Iss:1,pp19-23.
[4]Lenora Toscano.A Brief Summary of Creep Corrosion,Printed Circuit Design&Fab,07 October 2010.
[5]Paul T.Vianco.(1999),An overview of surface finishes and their role in printed circuit board solderability and solder joint performance,Circuit World,Vol.25 Iss:1,pp6-24.
[6]C.C.Lee*,H.Y.Chuang,C.K.Chung,and C.Robert K ao.Oxidation behavior of ENIG and ENEPIG surface f inish,Department of Materials Science and Engineering,National Taiwan University,Taipei 106,Taiwan,ROC.
[7]Paul Mazurkiewicz,ph.D,Accelerated Corrosion of printed circuit bodrds due to high levers of reduced sulfur gasses in industrial environments,November-12-16,2006,renaissance Austin hotel,Austin,texas,USA.