BGA焊点SAC305/ENEPIG/Cu界面反应演化及力学性能的尺寸效应  

Size effects on reaction and evolution of intermetallic compound and mechanical properties of Sn3.0Ag0.5Cu/ENEPIG/Cu solder joints in ball grid array(BGA)packages

作　　者：王海燕 石永华[2] 崔国涛 龚长青 刘志勇 WANG Hai-yan;SHI Yong-hua;CUI Guo-tao;GONG Chang-qing;LIU Zhi-yong(School of Mechanical&Automotive Engineering,Heze University,Heze 274015,China;School of Mechanical&Automotive Engineering,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]菏泽学院机电工程学院,山东菏泽274015 [2]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《材料热处理学报》2023年第8期211-218,共8页Transactions of Materials and Heat Treatment

基　　金：山东省自然科学基金(ZR2021ME060)。

摘　　要：将直径为300、500和760μm的SAC305(Sn3.0Ag0.5Cu)焊球在ENEPIG/Cu焊盘上进行3次回流焊形成SAC305/ENEPIG/Cu焊点,并在185℃对焊点进行了时效(0~1000 h)处理,研究了焊球直径对回流及时效后微焊点界面金属间化合物(IMC)反应和演变的影响,分析了不同焊球直径的焊点在不同剪切速率下(0.2和20 mm/s)的剪切强度与断裂模式。结果表明:随焊球直径减小和时效时间延长,焊点界面金属间化合物(IMC)由单相(Cu,Ni)_(6)Sn_(5)向(Ni,Cu)_(3)Sn_(4)和(Cu,Ni)_(6)Sn_(5)两相演化,IMC生长速率随焊点尺寸的增大而减小,表现出明显尺寸效应;焊点剪切强度随剪切速率减小和时效时间增加而降低,且大尺寸焊点剪切强度的下降程度明显弱于小尺寸焊点,在高速(20 mm/s)剪切条件下,所有尺寸焊点时效300 h后断面均呈韧性断裂。Sn3.0Ag0.5Cu solder balls with different diameters(300,500 and 760μm)were soldered onto electroless nickel electroless palladium immersion gold(ENEPIG)/Cu by three reflows to form SAC305/ENEPIG/Cu solder joints,and then the solder joints were aged at 185℃for 0-1000 h.The effect of solder ball diameter on reaction and evolution of interfacial intermetallic compound of the solder joints after reflow and aging was investigated.The shear strength and fracture modes of the solder joints with different solder ball diameters at different shear speeds(0.2 mm/s and 20 mm/s)were analyzed.The results show that with the diameter of the solder ball decreases and the aging time increases,the intermetallic compound(IMC)at the solder joints interface changes from single-phase(Cu,Ni)_(6)Sn_(5) to double-phase(Cu,Ni)_(3)Sn_(4) and(Cu,Ni)_(6)Sn_(5).The growth rate of IMC decreases with the increase of solder joint size,showing obvious size effect.The shear strength of the solder joints decreases with the decrease of shear speed and the increase of aging time,and the decrease of shear strength of large size solder joints is significantly smaller than that of small size solder joints.Under the high-speed(20 mm/s)shear condition,the fracture surface of all size solder joints presents ductile fracture after aging for 300 h.

关 键 词：微焊点 金属间化合物 剪切强度 尺寸效应 

分 类 号：TG457[金属学及工艺—焊接]