Sn-Ag-Cu-xBN复合钎料润湿性及IMC界面生长行为研究  

Wettability and interface IMC growth behavior of Sn-Ag-Cu-xBN composite lead-free solder

作　　者：李航 屈敏 唐昊 刘园 崔岩 LI Hang;QU Min;TANG Hao;LIU Yuan;CUI Yan(School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学机械与材料工程学院,北京100144

出　　处：《电子元件与材料》2024年第12期1539-1544,共6页Electronic Components And Materials

基　　金：国家自然科学基金(51604012);北方工业大学毓秀创新项目资助(2024NCUTYXCX105)。

摘　　要：针对Sn-3.0Ag-0.5Cu无铅钎料润湿性差和IMC层生长等问题,采用纳米BN为增强颗粒,研究了不同含量的BN对无铅钎料Sn-3.0Ag-0.5Cu的润湿性、熔点以及界面金属间化合物(IMC)生长特性的影响。采用机械混合法制备不同质量分数(0~0.025%)的BN纳米颗粒增强Sn-3.0Ag-0.5Cu复合无铅钎料,经回流焊制备焊点并对其进行170℃等温时效处理,采用SEM和EDS进行微观组织表征。结果表明:BN纳米颗粒可以显著改善复合钎料的润湿性,BN含量为0.01%时润湿角降低到最小,为22.5°,降幅达25.5%,但BN纳米颗粒对Sn-3.0Ag-0.5Cu无铅钎料熔化特性的影响可忽略。此外,添加BN纳米颗粒可显著降低界面IMC层厚度,通过对界面生长动力学研究,计算得到复合钎料的扩散系数,BN含量为0.01%时复合钎料的扩散系数最小,为1.90×10^(-16) m^(2)/s。表明BN纳米颗粒可以显著抑制IMC层的生长。综合分析得出BN纳米颗粒在质量分数0~0.025%范围内的最佳添加含量为0.01%。In order to improve the wettability and intermetallic compound(IMC)layer growth in Sn-Ag-Cu lead-free solder,nano-sized boron nitride(BN)particles was applied to reinforce Sn-Ag-Cu lead-free solder.The effects of different BN contents on the wettability,melting behavior,and IMC growth characteristics of Sn-3.0Ag-0.5Cu solder were investigated.The composite solders with varying BN mass fractions(0-0.025%)were prepared using a mechanical mixing method.The solder joints were fabricated through reflowing and then subjected to isothermal aging at 170℃for various aging time.The microstructures were characterized using scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS).The results show that the wettability of the composite solder was significantly improved by BN nanoparticles.When the BN content was 0.01%,the wettability angle decreased to the minimum of 22.5°,representing a 25.5%reduction.However,the effect of BN on the melting characteristics of Sn-3.0Ag-0.5Cu solder was negligible.Additionally,the thickness of the IMC layer was significantly reduced.Through the analysis of the growth kinetics of the IMC layer,the diffusion coefficient of the composite solder was calculated.The results indicated that the diffusion coefficient reached the minimum of 1.90×10^(-16) m^(2)/s when the BN content was 0.01%,indicating that the growth of the IMC layer was effectively inhibited.Based on the comprehensive analysis,the optimal BN content in the range of 0-0.025%was found to be 0.01%.

关 键 词：BN纳米颗粒 SN-AG-CU无铅钎料 润湿性 金属间化合物(IMC) 

分 类 号：TG425.1[金属学及工艺—焊接]