作者：朱桂兵^1,2, 汪春昌², 刘智泉³

作者单位：1. 南京信息职业技术学院, 江苏 南京 210046;
2. 安徽大学, 安徽 合肥 213001;
3. 香港科技大学机械工程系, 香港

关键词：微尺度焊点;热力耦合;芯片尺寸封装;失效机制

摘要：

该文设计热循环和跌落耦合冲击试验，选用Sn_96.5Ag_3.0Cu_0.5（SAC305）和Sn₆₃Pb₃₇（Sn-37Pb）两种焊料制成焊球，以芯片尺寸封装（CSP）芯片为研究基底，焊盘分别进行Ni/Au化学电镀和有机保焊膜涂覆两种工艺处理，研究该环境对CSP微尺度焊点疲劳寿命的影响。结果表明：CSP微尺度焊点的失效模式是先快后慢，初期失效的变化率最高，产品具有固有的耐耦合冲击能力，无铅焊点更适用于低周热循环和低能级跌落耦合冲击环境，有铅焊点的抗跌落冲击能力较强，Ni/Au处理的焊盘配合无铅焊球制成的CSP器件具有更高的耐高周耦合冲击可靠性，焊点的失效机制是由离散的空洞逐渐向界面裂纹转变。

Analysis on fatigue life of interconnection micro-scale solder joint under thermal-drop coupling cycling loads
ZHU Guibing^1,2, WANG Chunchang², LIU Zhiquan³
1. Nanjing Vocational College of Information Technology, Nanjing 210046, China;
2. Anhui University, Hefei 213001, China;
3. The Hong Kong University of Science and Technology, HongKong, China
Abstract: The coupling impact testing between thermal cycling with dropping were designed, and the two kind of selected solder material Sn_96.5Ag_3.0Cu_0.5(SAC305) and Sn₆₃-Pb₃₇(Sn-37Pb) were used to make solder ball for chip size package(CSP) chips that was used as the research substrate. The two kind processes of electroless nickel immersion gold(ENIG) and organic solderability preservative(OSP) were used to deal with the pads, the effect of the environment on the fatigue life of micro-scale solder joint was studied. The results indicated that the failure mode of micro-scale solder joint of CSP is fast first and then slow, and the speed of failue rate is the most highest in the the condition of relatively lower cycles coupling impacting, and an inherent ability of anti-coupling impacting exists in the electronic product, and the lead-free solder joint is more suitable for the coupling impacting environment between the low cycle thermal cycling and low energy level dropping, and the ability of anti-dropping impacting is relatively high for the lead solder joint. The relatively higher reliability of high cycle anti-coupling impacting can exist in the CSP micro-scale solder joint made by ENIG pads and lead-free solder balls than it, and the failure mechanism of solder joint is a transition from discrete void to interface crack.
Keywords: micro-scale solder joint;thermal-drop coupling;chip size package (CSP);failure mechanism
2019, 45(8):33-37,43  收稿日期: 2019-02-01;收到修改稿日期: 2019-03-10
基金项目: 南京信息职业技术学院重点科研基金项目（YK20160203）；国家自然科学基金资助项目（51502001,51572001）；江苏省“青蓝工程”项目资助（JSQL2017-06）

作者简介: 朱桂兵(1979-),男,江苏南通市人,高级工程师,副教授,博士,主要从事微电子封装可靠性、介电功能材料研究
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