Sn基无铅钎料晶须生长行为的研究

Growth Behavior of Whiskers in Sn-Based Lead-Free Solders

摘要:

研究了有机-无机笼形硅氧烷齐聚物（POSS）对Sn基无铅钎料晶须生长行为的影响。分别采用纯Sn和Sn3.0Ag0.5Cu（SAC305）作为基体，加入3%（质量分数）的POSS硅三醇制备复合钎料。样品在–45~85 ℃的高低温循环条件下进行晶须生长加速实验，并观察样品表面及界面显微组织的演变。结果表明，POSS可在加速条件下稳定钎料基体，同时通过提高钎料的强度和硬度，来缓解钎料在热循环应力作用下产生的塑性形变，进而有效抑制2种钎料的晶须生长。

Abstract:

The effects of organic-inorganic cage-type polyhedral oligomeric silsesquioxane (POSS) on the whisker formation behavior of Sn-based lead-free solders were investigated. Pure Sn and Sn3.0Ag0.5Cu (SAC305) solders were used as solder matrix, and the composite solder was fabricated with 3 wt% POSS trisilanol addition. The samples were tested under thermal cycling to accelerate whisker growth, and the temperature range varied between –40 °C and 85 °C. The surficial evolution and interfacial microstructure were observed. The results indicate that POSS would stabilize solder matrix under thermal cycling condition. Meanwhile, the strength and microhardness of solders are improved by POSS significantly, which consequently reduce the deformations in the solders caused by deformations, and inhibit whisker formation eventually.