自1960年以來，電子工業開始快速地成長，IC的製造技術變得愈來愈複雜，晶片與電子元件間接合封裝的技術在環保的考量下也面臨了很大的挑戰。傳統的銲錫合金主要為含鉛的錫-鉛二元合金，其具有良好的機械性質和抗腐蝕等優點，能增進銲錫的強度及可靠度。自從歐盟開始實施WEEE與RoHS指令後，由於鉛也是對人體及環境有害的物質之一，而開始被限制或禁止使用，因此開發無鉛銲錫來替代傳統的錫-鉛合金是刻不容緩的。
本研究分別採用了化學還原法(Chemical reduction method)及高溫/低溫化學還原法(High/Low temperature chemical reduction method)來進行Sn-3.5Ag、Sn-3.5Ag-0.5Zn無鉛銲錫合金的製備。在常壓下，使用硫酸錫、硝酸銀及硝酸鋅等鹽類為前驅物，NaBH4當作還原劑，並在反應過程中添加PVP作為保護劑，於反應完成後得到Sn-3.5Ag、Sn-3.5Ag-0.5Zn的奈米合金粉末。結果顯示，高溫化學還原法(50℃)能得到更分散且粒徑分佈在10-20nm間的奈米合金粉末。
樣品藉由XRD進行結構鑑定，並在掃描式電子顯微鏡(SEM)及穿透式電子顯微鏡(TEM)下進行表面形貌觀測及Ag3Sn繞射圖譜分析，並使用能量分散光譜儀(EDS)進行元素的定性及半定量分析，以此證明成功製備出錫-銀-鋅奈米合金，並推論其反應機制。此外，將反應過程中所產生的氣體收集後，進行GC的分析，證明在反應的過程中有氫氣的生成，對於化學還原反應式的推測提供了間接的佐證。

The electronics industry has grown rapidly since 1960s. The corresponding process technology for integrated circuits (IC) has also become more complicated. The challenge faced is the technology of IC devices packaging, with regards to the electrical connectivity and environmental protection. Traditionally, the lead-containing alloy, e.g. tin-lead is used as the solder joint extensively in the assembly of microelectronic packages. The special properties of lead-contained solders, e.g. rheology, mechanical, anti-corrosive etc. help to improve the strength and hence the reliability of the solder joints. However, lead and lead-containing compounds are harmful to the environment due to their toxicity. The Waste Electrical and Electronic Equipment (WEEE) and Restriction of Hazardous Substances (RoHS) banned the lead-containing solders in July 2006 in EU countries. Environmental Protection Agency of the US has cited lead as one of the top 17 harmful chemicals. Therefore, alternatives to replace the lead-containing alloy are urgently needed.
In this study, Sn-3.5Ag and Sn-3.5Ag-0.5Zn alloy nanoparticles were synthesized by chemical reduction method and high temperature chemical reduction method. In the chemical reduction method, the precipitation was carried out by using NaBH4 as a reducing agent and poly-m-vinyl-2-pyrrolidone (PVP) as a stabilizer. Results from the high temperature chemical reduction method revealed that the isolated particles were spherical in shape and the particle size varied from 10 to 20 nm. The nanoparticles obtained were evenly dispersed and less aggregated for the stirring time of 12 hrs and temperature of 50℃.
The microstructure of the nanoparticles were determined by using techniques such as X-ray diffraction, transmission electron microscopy (TEM) and scanning electron microscopy (SEM), etc. X-ray diffraction patterns revealed that Ag3Sn was formed due to the successful alloying process. The composition of the alloy was also measured by an energy dispersive spectroscopy (EDS), both qualitatively and quantitatively. The nano-scaled Sn–3.5Ag solder was prepared successfully by these methods. By analyzing the composition of the gas that was collected during chemical reactions, hydrogen was found from GC analysis result. Combine with the FTIR result, reaction mechanism was proposed and indirectly validated.

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