聲能噴墨技術為一種取代過去噴墨技術之高速、低成本的新穎噴墨機制。利用聲能聚焦於墨水表面克服墨水表面張力，推動液面達到噴墨效果，不同於熱氣泡式以及壓電式噴墨法，聲波聚焦噴墨法不需噴嘴即可達到噴墨之效果，可改善噴墨阻塞、墨滴方向性與衛星點等問題。本研究主要分為聚焦透鏡與壓電換能器兩部份，聚焦透鏡部份依據超音波噴墨相關理論設計 100 MHz 及 200 MHz 之微尺寸聚焦透鏡，規劃微機電製程，使用三層光罩蝕刻步驟，並加厚光阻來改善光阻的塗佈不均勻，成功製作出四階層結構。在換能器方面，我們製作結構為 Pt/Ti/SiO2/Si 之溅鍍基板，使用射頻磁控式濺鍍法來沉積氧化鋅薄膜。當濺鍍時間大於四小時氧化鋅壓電膜品質很難掌控，我們嘗試改變不同溅鍍參數與基板，發現當基板經過熱處理 600 ℃ 加熱一小時，其氧化鋅壓電膜品質會更好，其(002)之C軸方向性會更加的明顯。 Acoustic printing technology is an alternative to the standard inkjet printing processes to achieve high quality printing at a relatively high speed and low cost. When acoustic waves are well focused on the top surface of a liquid, the focused acoustic beam is capable of ejecting the liquid droplets from the surface of the liquid, without any nozzle. This method improve some drawbacks arising from thermal-bubble and piezoelectric actuating printing, such as blocked printing head, droplet-directionality and satellite problems. This study contains an investigation of acoustic Fresnel lens and ZnO piezoelectric transducer in order to construct a complete acoustic inkjet model and to validate the performance for further improvement. The four phase level Fresnel focusing lens with operating frequency at 100 MHz and 200 MHz has been manufactured on a silicon wafer by a successive process in micro electro-mechanical systems (MEMS) technology. We restructure the parameter for photoresist coating due to the high aspect ratio of our lens construction and use three masks process for silicon etching. The ZnO piezoelectric transducer has been successfully deposited by RF sputtering system on a Pt/Ti/SiO2/Si substrate. The result of measurements shows that the high c-axis orientation properties of ZnO films are improved after being deposited on a Pt layer annealed at 600 ℃ for one hour.
