Ce的添加及等温时效对Sn-Ag-Cu钎料及钎焊界面生长行为的影响

Effect of Ce Addition and Isothermal Aging on the Growth Behavior of Sn-Ag-Cu Solder and Brazing Interface

研究微量稀土元素Ce在钎焊和等温时效后对Sn-Ag-Cu无铅钎料与铜基板的钎焊界面金属间化合物(IMC)及钎料组织的形成与生长行为的影响。结果表明,微量Ce的添加对钎料微观组织有一定的细化作用,并且对其形貌也有一定的影响。钎焊后钎焊界面区形成连续的笋状Cu_6Sn_5金属间化合物(IMC),在160℃等温时效条件下,随着时效时间的延长,粗糙的Cu_6Sn_5由笋状转变成尺寸较大的扇贝状,再转变成较为平缓的层状。在此过程中,Cu_6Sn_5和铜基板之间逐渐会有Cu3Sn金属间化合物析出,且界面金属间化合物总厚度也是随着时效时间延长而增加。在相同时效条件下,添加0.5%Ce的钎焊界面区IMC层比未添加Ce的IMC层更为平缓和细薄,在钎焊接头Cu_6Sn_5层处可能会有CeSn_3相生成且添加稀土元素Ce对钎焊界面Cu、Sn原子之间的反应扩散均有一定的影响。

This paper presents the effects of brazing and isothermal aging on the formation and growth behavior of intermetallic compound （IMC） and brazing filler metal of Sn - Ag - Cu lead - free solder and copper substrate. The results show that the addition of Ce has a certain effect on the microstructure of brazing filler metal and has some influence on its morphology. The continuous Cu6Sn intermetallic compound （IMC） is formed in the interfacial area after brazing. Under the condition of 160℃ isothermal aging, the rough Cu6Sn5 changs from bamboo shoot to larger scallop, and then into a more gprocess,CeSn intermetallic compounds will gradually precipitate between Cu6Sn and copper substrates,and the totalthickness of intermetallic compounds increases with the aging time. Under the same aging conarea IMC layer with 0.5% Ce addition is more gentle and thinner than the Ce - free IMC layer. CeSn phase may be formed at the Cu6Sn layer of the brazed joint, and the Ce element addition has a certain impact for the reaction and diffusion of Cu,Sn atoms in Welding interface.