| Abstract: | 本篇論文欲發展出一套能使用於現今工具機高速主軸上，希望能夠做到電路設計簡單化、高靈敏、低成本的”雙端固定石英音叉加速規”。由於應用上是以工具機的條件作為考量，除?可靠?及能在??環境下運作之外，亦須針對應用在某些特殊規格上將性能優化。因此在高溫環境下仍要保持一定穩定度感測會非常重要。有鑑於此，根據石英切角材料資訊：Z-cut石英振盪器在20℃-40℃溫?區間的自然頻?約只有小於10ppm 的變化?具有極高溫?穩定性，而此種材料設定上與我們所需要加速規條件符合。並且選用石英的好處是石英音叉樑感受到軸向應?而使振動頻?產生漂移(drift)，由此頻?漂移?可預測加速?值 (假如加速?與頻?漂移?的線性比?關係已建?起?)。假如工作頻?是 32 kHz，它的解析?可達0.01 Hz；相較於CMOS-MEMS因為殘留應力關係以及容易受溫度影響問題，使用石英會較為理想。 在雙端固定石英音叉(Double-Ended quartz Tuning Fork)製程上，我們會提出多種可行製程方式搭配新電極設計，將會從晶圓規格、微影(Lithography)參數、蝕刻(Etch)配方、電極設計與製程，搭配半導體製程實現我們加速規元件來因應台灣目前工具機上對於感測器日益壯大的需求，目前依照工具機高頻率段上的需要，我們的元件共振頻率能夠成功被激發於22 kHz至23 kHz的區間上，且未封裝情況下具有不錯重覆性。於現今國內廠商無自主開發加速規來看，這將會是解決於工具機上加速規高昂的成本問題，對於來達到提升未來機械4.0(生產力4.0)概念上，並且在製程方面上窒礙難行之處以及找出解決方案同時，實現這系統下作為應用資料蒐集的感測器。
This study aims to develop a simple and highly sensitive “double-ended quartz tuning fork accelerometer” with simple circuit design, which can be applied to machine tool high-speed spindles. The application considerations are based on the conditions of machine tools. Thus, the accelerometer must be durable and able to work in an adverse environment. Moreover, its functions must be optimized for applications with certain requirements. Thus, a very important feature is that the sensitivity of the accelerometer must remain stable in a high temperature environment. The characteristics of the quartz material meet the conditions required for the accelerometer. The variation in natural frequency of the z-cut quartz crystal oscillator under the temperature of 20℃ ~ 40℃ is less than10ppm and thus the stability under different temperatures is very high. Thus, quartz is chosen as the material for this study. And another advantage of using quartz is that applying axial stress to the quartz tuning fork beam can result in vibration frequency drift, which can be used to predict acceleration (under the premise that there is already a linear relationship between acceleration and frequency drift constructed). If the operating frequency is 32 kHz, the resolution can reach 0.01 Hz. In comparison, CMOS-MEMS is not as ideal as quartz here for its residual stress and the characteristic of being easily influenced by temperature. Regarding the manufacturing process of the double-ended quartz tuning fork, this study proposes several feasible methods combined with new electrode designs. In order to meet the increasing demands for sensors for machine tools in Taiwan, our accelerometer component is developed with considerations of wafer specifications, lithography parameters, etch formulas, electrode designs, and manufacturing processes for semiconductors. Currently, based on the high-frequency band requirements of machine tools, our component’s resonant frequency can be successfully excited within the interval between 22 kHz and 23 kHz. And in the case without packaging, the repetitiveness is fairly good. Nowadays, there is no company in Taiwan developing accelerometers on its own. Therefore, this study can provide a solution to the issue of high costs of machine tool accelerometers. It also helps to achieve Mechanics 4.0 (Industry 4.0) concept in the future as well as to resolve the difficulties in the aspect of the manufacturing process, so that in this system, the sensors can be applied to collect data. |
