Ag_(3)Sn纳米颗粒对焊料金属间化合物形貌和厚度的影响

Effect of Ag_(3)Sn Nanoparticles on the Morphology and Thickness of Solder Intermetallic Compounds

选用氧化还原法制备Ag_(3)Sn纳米颗粒,以不同质量比(0、0.1%、0.15%、0.2%)添加到SAC305焊料中来探讨Ag_(3)Sn纳米颗粒对焊料显微组织、润湿性和可靠性的影响。采用X-射线衍射仪和扫描电子显微镜对制备的Ag_(3)Sn纳米颗粒进行物相分析和形貌观察,采用金相显微镜观察焊点的显微组织。将焊点在150℃高温时效不同时间后(0、50、100、150、200 h),采用金相显微镜对焊点界面进行观察,并采用Image J软件计算界面金属间化合物(IMC)层的厚度,得到生长系数。结果表明,向SAC305焊料中添加适量的Ag_(3)Sn纳米颗粒可以提高焊料的润湿性;Ag_(3)Sn纳米颗粒可以有效细化SAC305焊料的微观组织并抑制IMC层生长;随着时效时间的延长,Cu6Sn5金属间化合物层由扇贝状向平面状转变,同时出现Cu3Sn金属间化合物层。向SAC305焊料中添加0.15 wt.%的Ag_(3)Sn纳米颗粒可获得最佳综合性能,润湿性最好(铺展面积为167.447 mm2),生长系数最小(0.04),组织细化也较为明显。

In this study,Ag_(3)Sn nanoparticles were synthesized using the redox method and incorporated into SAC305 solder at varying mass ratios(0,0.1%,0.15%,0.2%)to investigate their impact on the microstructure,wettability,and reliability of the solder.The physical phase and morphology of the Ag_(3)Sn nanoparticles were characterized by X-ray diffractometer and scanning electron microscope,while the microstructure of the solder joints was observed using a metallographic microscope.Subsequently,the solder joints were aged at 150℃for different durations(0,50,100,150,200 h),and the interfacial intermetallic compound(IMC)layer thickness was measured using Image J software to calculate the growth coefficient.Results indicate that the addition of an appropriate amount of Ag_(3)Sn nanoparticles to SAC305 solder enhances wettability,refines the microstructure,and inhibits IMC layer growth.As aging progresses,the Cu 6Sn 5 intermetallic compound layer transitions from scalloped to planar,accompanied by the appearance of the Cu 3Sn intermetallic compound layer.The optimal performance was observed with the addition of 0.15 wt.%Ag_(3)Sn nanoparticles to SAC305 solder,resulting in improved wettability(spreading area of 167.447 mm 2),minimal growth coefficient(0.04),and enhanced microstructural refinement.