電漿增進PDMS與導電膠體附著性之研究

Abstract

本研究使用大氣電漿改質疏水性聚二甲基矽氧烷（PDMS）表面製備印刷軟性導電薄膜。近年來，軟性電子元件受到廣大的矚目，其中又以聚二甲基矽氧烷（PDMS）最受矚目，但疏水性的表面限制其應用性，因此本文利用大氣電漿處理氧化PDMS表面，製造一層親水性二氧化矽表面層，改善其疏水性質，並用XPS及AFM證實其二氧化矽層存在的特性。此外，本文中改變大氣電漿操作參數，如氣體種類、電漿功率及掃描次數，以獲得親水時效性最長的二氧化矽層的表面。再將商用導電銀膠利用網版印刷方式印刷於大氣電漿處理過的PDMS表面上，以製造可拉伸式且高黏著性導電薄膜。由於導電銀膠中的環氧樹脂和二氧化矽表面層之間的強結合力的結果，在PDMS上印刷圖案經過多種的附著力試驗均完好無損，表現出了良好的附著力，彎曲，扭轉，和拉伸條件印刷導電薄膜顯示出良好的導電性能，展現強大的機械穩定性。最後，我們印刷導電薄膜應用至壓力感測器，展現出良好的靈敏度和快速響應時間。本研究提出的大氣電漿改質PDMS表面具有簡單與方便之特性，可應用於多種塗佈或印刷製程前處理，來增加印刷膠體與疏水性基材的黏著性。

In this study, an effective plasma treatment method was developed to modify polydimethylsiloxane (PDMS) surface to enhance the adhesion of printed conductive thin films. After the plasma treatment, a silica-like surface layer, which was confirmed with XPS results, was formed on the PDMS surface and resulted in a drastic decrease in water contact angle. The silica layer disappeared after a few hours and the treated PDMS surface recovered it hydrophobicity. Effects of gas and plasma powers on the transient contact angle decreases were carefully examined to extend the life time of the surface silica layers. Conductive ink with epoxy resin was screen-printed on the plasma-treated PDMS surface. The printed patterns showed good adhesion, as a result of the strong binding between epoxy resin and the silica surface layer, and can sustain well in tape and sonication tests. Bending and stretching tests were also performed to test the stability of the printed tracks. Finally, printed pressure sensors with good sensitivity and fast response times were fabricated to demonstrate the capability of applying this method for the realization of printed electric devices.