| 摘要: |
| 分别用Sn37Pb钎料和Sn3Ag0.5Cu钎料组装高密度LED灯板,试验观察了焊后和老化后焊点的显微组织,测试了焊点的抗剪强度.结果表明,Sn3Ag0.5Cu焊点的金属间化合物层明显大于Sn37Pb焊点,但都在合格范围内,不会造成脆断,且其β-Sn初晶晶粒被网状共晶物包覆的特殊结构使其抗剪强度明显大于Sn37Pb焊点;老化后,两组焊点的抗剪强度均有所减小.虽然无铅焊膏代替Sn37Pb焊膏是电子工业界的发展的必然趋势,但是利用无铅焊膏组装小尺寸、高密度LED组件需要更精确的回流工艺. |
| 关键词: LED组装 共晶钎料 显微组织 抗剪强度 |
| DOI： |
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| 基金项目:国家自然科学基金面上项目(51071006);北京市教育委员会科技发展计划资助项目(KZ200910005004) |
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| Analysis for microstructure and mechanical property of Sn3Ag-0.5Cu solder joints in high density LED packages |
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WANG Xinxin1, LIU Jianping1, GUO Fu1, LIU Li2, LEI Yuanhong2
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1.College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China;2.R & D Center, Beijing Leyard Electronic Science Technology Co., Ltd, Beijing 100091, China
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| Abstract: |
| The microstructure of Sn37Pb and Sn3Ag0.5Cu solder joints under as-reflowed and isothermal aged conditions were observed respectively.The shear strength of samples were also measured.The results suggested that despite the IMC layer of the Sn37Pb solder joints was thicker than the Sn3Ag0.5Cu solder joints, both of them were within the acceptable range.The Sn3Ag0.5Cu solder joints shows a bigger shear strength due to its special structure of β-Sn primary crystal coated by reticular eutectic.Besides, the shear strength of the two solder joints decreased after aging.Although lead-free solder is the inevitable trend to the development of electronic packaging industry instead of Sn37Pb solder, precision reflowing process still plays an important role to improve the quality of the solder joints. |
| Key words: LED package eutectic solder alloys microstructure shear strength |
