Analysis of laser typing spots at gold-plated kovar alloy cavity

摘要：

　　Based on the phenomenon that a large number of spots appear in the type area on the surface of the gold-plated kovar alloy cavity,combined with scanning electron microscope(SEM)and energy disperse spectroscopy(EDS)analysis method,this paper analyzed the causes of spots and promoted effective encapsulation of electronic components.The result shows that uneven laser typing edge affect the smoothness of gold plating,increasing the coating porosity and specific surface area,which provides high probability for water and Cl-attachment,even reach to kovar alloy layer through pore.Whats more,the strong penetrating power of Cl-through the atoms gap contributes to react with metal layer and form chloride.The reaction products,such as NiCl2、 FeCl2 、 FeCl3 become electrolyte layer of the electrochemical corrosion.Anode is iron and nickel corrosion,while cathode is oxygen corrosion.As the reaction,the chemical environment tends to alkaline.Fe2+and Fe3+easy to combine with Ohto produce Fe(OH)2 and Fe(OH)3,and the further evolution products,oxide Fe2O3,characterized by a large number of spots in macroscopic.Internal stress of the electrochemical corrosion gradually turns gold layer gap to crack,exposing internal kovar alloy layer.The formation of the electrochemical corrosion aggravates coating damage.

关键词： gold-plated Cl- electrochemical corrosion

作者: Yuwei Zheng Shengxiang Bao Zhenzhen Rao Chengshi Zhang Yao Yan

作者单位: State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China,Chengdu,China

会议类型: 国际会议

会议名称: The 15th International Conference on Electronic Packaging Technology (ICEPT 2014) ) (第十五届电子封装技术国际会议)

会议地点: 成都

会议语种:英文

页码: 992-995

在线出版日期: 2014-08-12（万方平台首次上网日期，不代表论文的发表时间）