微型化高G值加速度開關之設計與研製

Design and Fabrication of Micro High-G Acceleration Switch

陳俊安(Chun-An Chen)

指導教授 ： 翁宗賢

國立臺灣大學/工學院/應用力學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.03221

摘要

加速度開關是具有特定用途的感測元件，是加速度計的一種型式，當加速度到達定限值(threshold)，開關即開啟，進入鎖定狀態，接觸元件輸出訊號，以觸發後續致動程序。近年來隨著科技的進步，微奈米機電製程技術日益成熟，除了降低微感測器與微致動器的成本與體積，也大幅提高可靠度及加速度的量測範圍。微奈米機電系統的產品應用越來越多元，除了以往的汽車產業、航太與國防工業之外，現今還大量應用於家庭照護、智慧型手機與遊樂器材等，帶來廣大商機。
本文所設計的加速度開關應用於高G值的衝擊環境，為降低研究成本，節省試製及量產前的經費與研發時間，利用CAD輔助設計軟體建立模型，匯入CAE輔助分析軟體進行動態模擬，施加美軍MIL-STD 883E規範之衝擊負載，計算並分析加速度開關在此衝擊歷程下，是否可以達到預期的開關作動，並檢視應力分佈，確保組件不產生應力集中或破壞現象。
經過CAE模擬，本文所設計之加速度開關可在450G及1100G的加速度環境下正常運作，當加速度到達定限值，卡榫機構成功鎖定，接觸元件作動情形符合預先設計。作動過程中的最大應力分別為128MPa與152MPa，僅為材料破壞應力的42%與50.7%，可確保結構不被破壞。模擬完成後，根據各項設計與模擬結果，在SOI晶圓上，以微奈米機電製程技術進行試製，成功製作出所設計的微型加速度開關，最後經切割與封裝，組裝在離心機台上做加速度測試，實驗結果證實製造出的晶片符合預期目標，當加速度達到定限值後，卡榫機構即能鎖定，輸出穩定的訊號。鎖定後的加速度開關能以1V的直流電快速解除鎖定狀態，使加速度開關可重複使用。

關鍵字

加速度開關 ； 高G值衝擊 ； 衝擊模擬 ； 微機電系統

並列摘要

Nowadays the acceleration switch, a special type of accelerometer, has become one of peculiar sensing devices. As the acceleration reaches a threshold, the switch turns into locked state, and the contact components export a signal which can trigger the subsequent action. In recent years, rapid progressive technologies enable micro-nano electro-mechanical systems (MEMS) to develop more sophisticated functionality. Modern MEMS not only reduce the cost and scale, but also improve the reliability and the measuring range of accelerations. The products penetrate into many major businesses, such as home care systems, smart phones, amusement equipment, in addition to the traditional automotive industry, aerospace and defense industries.
In this thesis, we aimed to design acceleration switches which are applicable to the impact of high-G environment. In order to reduce research cost and time, we utilized computer assisted design (CAD) software to create models, then imported to computer assisted engineering (CAE) software for dynamic simulation. From the analysis results, we validated that the G-switches can function well to fulfill the impact specifications of MIL-STD 883E conditions. As the accelerations reach their respective thresholds, the latch mechanism was successfully locked up, the contact elements delivered the touched signal, and materials of the switches did not damaged. Based on the simulation results, we employed MEMS processing technology to fabricate our designs of acceleration switches on SOI wafers. Upon cutting and simple packaging, the switches were examined on a centrifugal machine which was adjusted to specific acceleration levels. The tests proved that all acceleration switches were satisfactorily manufactured and functioned properly to meet the severe impact conditions. The latched mechanism could be quickly released by applying 1V DC power to the releasing device. This thermally releasing device allows the acceleration switch to reuse again.

並列關鍵字

acceleration switch ； high G impact ； impact simulation

參考文獻

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