隨著厚膜導電膏的發展，目前市面上大多使用銀、銅等作為導電粉末，但銀的成本過高，而銅則必須在還原氣氛下燒結，而鋁作為導電性佳的材料之一，但因為鋁即使在真空的環境下也會生成保護性氧化層，這會抑制鋁顆粒之間的接觸導致在厚膜應用上受到限制。本研究利用化學置換反應的方式製備銅包鋁及銀包鋁粉末，以鋁粉作為核心，銅金屬及銀金屬作為包覆鋁粉的殼層，以此核殼結構發揮出鋁粉成本低廉及銅金屬與銀金屬導電性、導熱性的優勢。
本研究分為三個部分，第一部分為粉末的製備，以鋁粉作為核心，測試不同的置換方式、溶劑及反應時間，最後分別以溶解於去離子水的硫酸銅及溶解於乙二醇的硝酸銀作為置換反應的溶劑，成功製備出包覆率高且殼層厚度均勻的銅包鋁粉末及銀包鋁粉末。
第二部分為粉末研究，在製備完銅包鋁及銀包鋁粉末後，以壓模機壓製成錠，在將其放入不同燒結溫度進行燒結，量測其物性及電特性，之後將3wt%、6wt%、9wt%的玻璃粉添加進粉末中，以乾式球磨的方式混和均勻，壓製成錠後再以相同溫度進行燒結，利用玻璃粉液相燒結及降低粉末燒結溫度的特性，使粉末能更緊密排列，電阻率降低，進行熱分析、X-Ray 繞射分析、並以掃描式電子顯微鏡觀察其微結構，最後再以四點探針量測電阻。其中銅包鋁粉末在添加3wt%的玻璃粉下，以550℃進行燒結時能有最低的電阻率，其電阻率為3.593*10-6Ω-m。而銀包鋁粉末最佳的電阻率是在燒結溫度為550℃時，添加3wt%的玻璃粉時出現，其值為1.012*10-7Ω-m。
第三部分為電阻膏的研究，選擇前面粉末研究中電阻率較低的銀包鋁粉末，加入Binder、Solvent及玻璃粉後攪拌均勻，以網版印刷的方式印刷在氧化鋁基板上，在以不同的燒結溫度進行燒結，使用掃描式電子顯微鏡觀察微結構及以四點探針量測其阻值，發現在添加3wt%的玻璃粉時，溫度在600℃的下進行燒結有最佳的緻密性及較低的孔隙率，電阻率為3.329*10-7Ω-m。電阻值較其他鋁膏降低許多，使鋁膏的特性更接近銀膏，期望能成為取代銀粉的粉末。

With the development of thick film conductive paste, most of the current market uses silver, copper, etc. as conductive powders, but the cost of silver is too high, and copper must be sintered in a reducing atmosphere, and aluminum is one of the materials with good conductivity. However, aluminum generates a protective oxide layer even in a vacuum environment. This inhibits the contact between aluminum particles and limits its application in thick film. In this study, the copper-coated aluminum and silver-coated aluminum powders with aluminum powder as the core were prepared by chemical substitution reaction. Copper metal and silver metal are used as the shell layer for coating aluminum powder, and the core-shell structure takes advantage of the low cost of aluminum powder and the electrical and thermal conductivity of copper metal and silver metal.
This study is divided into three parts. First is the preparation of powder, with aluminum powder as the core, testing different replacement methods, solvents and reaction times, and finally using copper sulfate dissolved in deionized water and dissolved in ethylene glycol. Silver nitrate was used as the solvent for the displacement reaction to successfully prepare copper-coated aluminum powder and silver-coated aluminum powder with high coverage and uniform shell thickness. The second part is powder research. After the copper-coated aluminum and silver-coated aluminum powders are prepared, they are pressed into bulks with a compression molding machine. After they are placed in different sintering temperatures, their physical and electrical properties are measured, and then 3wt%, 6wt%, 9wt% of glass frit is added to the powder, mixed uniformly by dry ball milling, and then sintered at the same temperature after pressing into a bulk. The liquid phase sintering of the glass frit and the characteristics of reducing the sintering temperature of the powder are used to make the powder. It can be arranged more closely, the resistivity is reduced, thermal analysis, X-Ray diffraction analysis, and the microstructure of the scanning electron microscope are observed. Finally the resistance is measured with a four-point probe. Among them, the copper-coated aluminum powder can have the lowest resistivity when sintered at 550℃ with the addition of 3wt% glass frit, and its resistivity is 3.593*10-6 Ω-m. The best resistivity of silver-coated aluminum powder is when the sintering temperature is 550℃, when 3wt% glass frit is added, its value is 1.012*10-7 Ω-m. The third part is the research of resistance paste. The silver-coated aluminum powder with low resistivity in the previous powder research is selected. Binder, solvent and glass frit are added and stirred evenly, and printed on the alumina substrate by screen printing. After sintering at different sintering temperatures, use a scanning electron microscope to observe the microstructure and measure its resistance with a four-point probe. It is found that when 3wt% glass frit is added, the sintering temperature at 600℃ has the best compactness having low porosity and the resistivity is 3.329*10-7 Ω-m. The resistance value is much lower than other aluminum pastes, making the characteristics of aluminum paste closer to silver paste, and it is expected that it can replace silver powder.

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