大伸展式微熱致動器在微定位裝置上的研究

Abstract

本研究使用了金屬面型微加工技術來製造一大伸展式微熱致動器（LSMD）以及利用 LSMD 及此製程來設計一定位機構，此製程使用了微影、犧牲層、以及電鍍技術來製造所設計之元件。為了增加 LSMD 之出力及位移以及定位器的定位可靠度，在此增加結構之厚度至 20 微米。 為克服增加厚度所遭遇之製造上的困難，在此需要改進過去的製程之參數，如微影製程與電鍍製程之參數；並且更換黏著層（由鉻換成鈦）與種子層（由鎳換成銅）之材料，可以提高元件存活之良率，由 80% 以下增至超過 95%。 經由測量與模擬結果之皆可發現 LSMD 之受力-位移行為顯現非線性的特性，且在固定操作電壓下其出力隨著位移的增加而減少。但卡榫致動器由於卡榫部分的結構過長，受到表面黏著現象的影響，LSMD 之出力無法克服其附著力來完成開合動作。種子層銅與結構鎳之間的材料附著性不足，受力在超過 50 g 即剝落。

A metal-base surface micromaching technology is developed to realize a long-stretch micro drives (LSMD) and a micro positioner device is designed and fabricated here. This process includes lithography , sacrificial layer and electroplating technique. The thickness of structures is increased to 20 um which is possible to induce larger output force and displacement of LSMD. Because the increasing of the thickness of structures may cause many problems in fabrication, thus we improve some processes of fabrication such as lithography and electroplating. Here, the behavior of LSMD is simulated and tested. The stiffness of LSMD approach to a nonlinear behavior and the output force is decreasing with the increasing of displacement under the controlled voltage. The bayonet of the actuators of positioner has long structure that induces the bayonet stick with the wafer surface. And the adhesion force between seed layer Cu and structure Ni is too weak to reach up to 50 g.