近年來，電子構裝中
打線接合技術為應用範圍最廣且技術成熟的連接電路方
式，傳統上金和鋁經常作為打線製程中材料之使用，製程上會選用純金拉成 15-50  m的細線來做為打線使用 而鋁則是作為在矽基板上的襯墊所用，但近年來
金價不斷的飆漲，為了降低工廠成本，研究學者已投入多項研究選用不同材料之
線材來取代純金打線的趨勢。銀因為其具有優越的物理性質且價格遠低於金的價
格，目前廣泛的被選作替 代 材料使用。本實驗以 Arc melting方法製作出不同濃
度的金銀合金，與鋁基材做擴散接合，形成 Au-xAg/Al層狀結構擴散 反應 偶 (x=25, 50, 75 wt.%)，在 450 C下進行固 /固擴散處理，以了解在高溫熱處理下不同反應
時間下 反應偶 界面反應之介金屬相 (intermetallic compound, IMC)的演變過程， 希
望用以評估金銀合金取代純金系統的可行性。 而為了更加確定 Au-Ag/Al的反應
機制，本實驗亦 建立 450 C的三元合金相平衡圖 輔以反應路徑 ，來驗證所生成的
相。
在
Au-xAg/Al層狀結構 反應偶 的結果中，當金銀合金中 銀 濃度為 25 wt.%時
在界面會生成 AuAl2、 Au2Al和 Au4Al相，當銀濃度提升至 30、 40、 50和 75 wt.%時，在界面則會生成 Ag2Al、 AuAl2和 Au4Al相 。 介金屬相隨著時間的增加而增
厚，但生成的介金屬相種類不會隨時間而改變，即沒有相變化的出現 。隨著銀濃
度的提升， 中間層的 Ag2Al、 AuAl2相 逐漸以 Ag2Al相變為主要相； 且 各濃度之
間介金屬相的厚度 藉由觀察發現有 逐漸增厚 的現象 ，意味著銀 濃度提升會促進介
金屬相的生成。另外，由結果得知銀的濃度增加時有抑制 Au2Al相生成的效果，
當合金中銀的含量達到 30 wt.%時， 將 不會有 Au2Al相 生成。
在
Ag-Al-Au等溫 三元相平衡之實驗結果中，存在 7個單相區、 13個兩相區
以及 6個三相區，並且沒有三元的介金屬相生成。 Au4Al相幾乎橫越了整個相圖，
因為金和銀的性質相似皆為 FCC的結構， Au4Al相 對銀有極大的溶解度，由結
II
果得知銀很容易與金置換形成金
果得知銀很容易與金置換形成金-鋁的介金屬相，在鋁的介金屬相，在EDS結果中觀察到銀在結果中觀察到銀在Au4Al中含量可高達中含量可高達60 at.%。。

Wire bonding technology in electronic assembly is the most widely used and mature connection circuit in recent years. Traditionally, it is used as a pure gold wire for wire bonding. In the process, a thin gold wire of 15-50 m is used for the wire bonding, and aluminum is used as a bond pad on the substrate. Recent studies have found that the intermetallic compounds formed by the gold-aluminum interface are hard and brittle, and it is easy to form Kirkendall voids in the interface. A more important reason, the price of gold has continued to soar in recent years. In order to reduce costs, scholars have invested in several studies to select different materials wires to replace pure gold. Silver is widely used as a substitute material because of its excellent physical properties such as excellent thermal conductivity, electrical conductivity, and good ductility, and also its price is far below the price of gold.
In this experiment, different concentrations of gold and silver alloys were prepared by arc melting method, and diffusion bonding was performed with aluminum substrates to form Au-xAg/Al layered structure diffusion couples. Solid/solid diffusion treatment at 450°C to understand the interfacial reaction between diffusion couples under high-temperature heat treatment. In order to further determine the reaction mechanism of Ag, Al, and Au, this experiment will also establish a ternary alloy phase equilibrium diagram at 450°C to verify the generated IMC phase. It is hoped to evaluate the feasibility of replacing gold and silver alloys with pure gold systems. In order to determine the reaction mechanism of Ag, Al, and Au, this experiment will also establish a ternary alloy phase equilibrium diagram at 450°C to verify the generated IMC phase.
In the results of the Au-xAg/Al layered structure diffusion couples, when the concentration of silver in the gold-silver alloy is 25 wt.%. AuAl2, Au2Al, and Au4Al phases are formed at the interface. When the concentration of silver is increased to 30,
IV
40, 50 and 75 wt.%. Ag2Al, AuAl2, and Au4Al phases are formed at the interface. The intermetallic phase thickens over time, but the type of intermetallic phase formed does not change over time no phase change occurs. As the concentration of silver increases, the thickness of the intermetallic phase at each concentration gradually increases, which means that the increase in silver concentration promotes the formation of the intermetallic phase. Further, it was found that the effect of suppressing the formation of the Au2Al phase was observed when the concentration of silver was increased. When the content of silver in the alloy reached 30 wt.%, no Au2Al phase was formed.
In the experimental results of the ternary phase equilibrium of Ag-Al-Au, there are 7 single-phase regions, 13 two-phase regions, and 6 three-phase regions, and no ternary metal phase is formed, and the Au4Al phase is almost traversed. In addition, because the properties of gold and silver are similar, they are all FCC structures. It is known that silver is easily replaced with gold to form a gold-aluminum intermetallic phase. Taking Au4Al as an example, it is observed in the EDS results that the content of silver in Au4Al can be as high as 60 at.%, but it is still Au4Al structure by XRD alignment.

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