本研究目的將銀廢料經過濕式冶金法回收、洗浸出金屬並加以純化，將是重要的資源再利用。提取銀微粒並合成金屬前驅物，再經由化學還原法，合成金屬銀粒。尋找導電銀膠最佳的配方比，並加以應用。
銀膠廢料是厚膜技術製程常見工業廢棄品，利用THF將銀回收後，用硝酸轉化成硝酸銀。研究適當的反應時間及還原劑，將硝酸銀沉澱成銀粉末，控制銀粒平均粒徑為700~800 nm，目的為增加粒子間接觸及導通的機率，降低薄膜片電阻值。利用不同分散劑與增稠劑，在最佳配方比中，可以維持至少兩個小時以上的懸浮狀態，利於膠體使用性。
嘗試銀膠最佳配方比，應用在軟性基材如：影印紙，可由沾水筆沾取銀膠書寫，在紙張書寫滑順，濕潤性佳，可以快速乾燥並形成導電通路，薄膜片電阻可得到低於10 ·sq-1的良好表現；應用在剛性基材如：陶瓷，因為銀膠與陶瓷表面性質的差異，容易無法良好接著，本研究在銀膠中摻入氧化物，降低銀膠在高溫燒結後，表面破裂、剝離陶瓷的可能性，經過燒結後的片電阻，低至0.0241 ·sq-1，本次研究中的銀膠配方比，不論在常溫或在高溫燒結的部分皆獲得披覆良好的低電阻導電層。

The purpose of this research is to recover the silver paste waste with hydrometallurgical methods, and then use the retrieved silver to prepare a remade silver conducting paste and find the right recipe with low sheet resistances.
The silver paste waste is not uncommon in the processes related to thick film technology. Our study tries to recover the noble metal of silver. The study involves retrieval of silver particles with tetrahydrofuran, dissolution of impure silver with nitric acid, conversion of silver nitrate into silver particles of high purity, and then preparation of a conducting silver paste with low sheet resistance. The emphasis is placed on reduction time and the reducing agent for silver particle conversion, then the recipe for preparing the conductive silver paste, and the sheet resistances on different substrates.
Our results indicate that the reaction time and the reducing agent effect the average particle size of silver particles, and proper measures control the particle size. The silver particles of 700 - 800 nm in size is optimal for sheet resistance since this particle size grants the opportunity for particle contact and reduce the contact resistance between particles.
With a proper recipe, the silver paste of recovered silver can be applied to a soft substrate, such as photocopying paper. When the paste is written by dip pen can perform smoothly on the paper with good wettability. The results show that can quickly dry and form conductive path with low resistance. In addition, the state of silver paste can be settled after two hours and allowing a new steady state, which is good for paste use.
It can also apply to rigid oxide substrates such as ceramics, but the difference in thermal expansion between silver paste and ceramics may cause the silver film to peel off. Therefore, zinc oxide is added to the silver paste in order to help the silver film to grip on its foothold when heated up to 800 degree. In addition to adhesive strength improvement, the sheet resistance after calcination is as low as 0.0241 ·sq-1. The reported two recipes in this study show good performance whether the conducting paste is either applied to low temperatures or high temperature applications.

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