由於歐盟制定規範限制了電子電器產品中鉛的含量，且傳統電子構裝銲接中所使用的銲料主要為錫鉛合金，因此開始了無鉛銲料的研發。Fe-42wt% Ni (Alloy 42)，因其具有優異機械性質與矽基材相近之熱膨脹係數，在工業上通常被使用做為導線架材料。目前文獻上有關無鉛銲料與Alloy 42的界面反應相關研究甚少。本研究將針對純Sn、Sn-3.5Ag-0.5Cu (SAC)及Sn-9.0Zn (SZ)三種合金與Fe-42wt% Ni基材反應在240、255與270℃下，反應1、2、3、4、5、15與50小時後之液/固界面反應，觀察其界面生成形態、介金屬生成相 (IMC)、探討反應機制、IMC成長速率常數與反應活化能。
實驗結果顯示，純Sn銲料與Alloy 42於界面產生二種不同形態之介金屬相，皆為FeSn2相；其中近基材FeSn2相為連續層；靠近銲料則為不連續的FeSn2相，其形態為針狀及塊狀。SAC銲料與Alloy 42反應界面產生一連續(Fe,Ni)Sn2相。SZ與Alloy 42反應界面生成(Ni,Fe)5Zn21。三個系統之介金屬相厚度隨著反應時間增加與溫度增加而呈現兩段式增厚現象。反應1到5小時呈一線性情形其增厚速率較快且反應遵守拋物線定律；反應5到50小時其反應轉變為熟化現象，呈現另一線性情形且增厚速率明顯減緩，兩線性之厚度與時間的平方根皆成正比，為熱活化現象。

Sn-Pb solders are forbidden in using in electronic products owing to an environmental issue, Pb-free solders have attracted much attention to replace the conventional Sn-Pb solders. The most popular kind of lead-free solders are Sn, Sn-3.0Ag-0.5Cu, Sn-0.7Cu, Sn-58Bi and Sn-9Zn (in wt %). The Fe-42wt%Ni alloy is usually called a 42 invar alloy (Alloy 42). It has been used as an excellent electrode substrate or leads because its coefficient of thermal expansion is much closer to Si devices than those of Cu or Ni. However, the interfacial reaction between solders and Alloy 42 has rarely been studied.
This study is to investigate the interfacial reaction between pure Sn, Sn-3.0 wt% Ag-0.5 wt% Cu,Sn-9.0 wt％Zn and alloy42 at 240, 255 and 270 oC for various reaction times. The surface morphology and IMC formation are examined as well.
The experimental results indicated that two internetallic compounds (IMCs) with different surface morphologies were observed in the Sn/Alloy42 couple. However, both they were the FeSn2 phases. In the SAC/Alloy 42 couples, only the (Fe,Ni)Sn2 phase was formed at the interface. Three layers structure of IMCs were observed in the SZ/Alloy 42 couples and they were the (Ni,Fe)5Zn21 phases. Two stages of IMC thickness change were found in three couples. The IMC thickness in these couples increased as increasing reaction times and temperatures, and it was proportional to the square root of reaction time. The interfacial reaction mechanism of them was diffusion controlled.

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