- 學位論文
非反應添加合金元素對液態錫系銲料與銀基材界面反應之影響
The effect of non-reactive alloying elements on the growth kinetics of the intermetallic compound between liquid Sn-based solders and Ag substrate
摘要
本實驗研究在反應溫度260-290℃下，非反應性添加合金元素對液態錫系銲料與銀基材界面反應的影響。實驗結果顯示，非反應性元素 Sb、Pb、Bi不與銀基材產生界面反應，但液態錫系銲料與銀基材的界面反應會生成一介金屬化合物Ag3Sn。基於錫擴散控制反應機制，導出拋物線反應動力學方程式，比較四種不同銲料的動力學數據而量化錫濃度及非反應性元素的影響。Sn、Sn-Sb、Sn-Pb 及Sn-Bi等四種銲料的視活化能分別為54.8、40.7、28.8、24.9 KJ mol-1。視活化能包含Sn本質擴散係數的活化能及界面平衡常數活化能，前述四種銲料具有相同的反應機構-錫擴散通過介金屬化合物為反應速率決定步驟，故本質擴散係數的活化能相同。由於非反應性元素會影響界面平衡常數活化能，因而造成從實驗得到的視活化能不相同。此外，除了錫濃度會影響錫系銲料與Ag基材反應所生成的Ag3Sn相的成長速率，不同的添加合金元素亦會影響界面平衡常數的前指數常數，其會影響Ag3Sn表面的錫濃度。
並列摘要
This study investigated the effect of the non-reactive alloying elements on the growth kinetics of the intermetallic compound (IMC) formed between liquid Sn-based solders and Ag substrate between the temperature of 260-290℃. Experimental results showed that Sb, Pb, and Bi, the non-reactive alloys elements, did not react with Ag substrate. Only one IMC, Ag3Sn, was formed at the interface of the interfacial reaction between liquid Sn and Ag substrate. Base on the diffusion controlled reaction mechanism, a parabolic kinetic equation in which both Sn concentration and alloying element effects were quantified, was derived and verified by comparing the kinetic data obtained by using four different solders with Sn concentrations and alloying elements. The apparent activation energies for pure Sn , Sn-Sb, Sn-Pb, and Sn-Bi solders reacting with Ag, are 54.8, 40.7, 28.8, 24.9 KJ mol-1, respectively. Since the diffusion of Sn atoms through IMC is the rate controlling step, the activation energies of the intrinsic diffusion coefficients for these four Sn-based solders are the same. The variation between the above-mentioned four apparent activation energies, comprised of activation energy of the equilibrium constants and that of the intrinsic diffusion coefficients, showed that the activation energies of the equilibrium constants for four solders are varying with different alloying elements. Other than the effect of Sn concentration on the growth rate of Ag3Sn, the non-reactive alloying element also exerted on the pre-exponential factor of the equilibrium constant which multiplied by the bulk concentration of Sn in solder gives the surface concentration of Sn in Ag3Sn.