环境振动试验用印刷电路板之振动分析.doc

環境振動試驗用印刷電路板之振動分析 Vibration Analysis of Printed Circuit Boards for Environmental Vibration Testing 研究生：李英志 Li, Ying-Chih 指導教授：王栢村 Wang, Bor-Tsuen 林鴻裕 Lin, Hong-Yuh 【摘要】 本文旨在對環境振動試驗用印刷電路進行振動特性分析及振動響應預測。本論文結合有限元素分析與實驗模態分析對印刷電路板進行模型驗證。由有限元素分析可得印刷電路板之理論自然頻率、模態振型及頻率響應函數；由實驗模態分析可以求得實際結構之自然頻率、阻尼比、模態振型及頻率響應函數，藉由理論與實驗之振動模態特性參數比對，利用最佳化運算可獲得合理的有限元素模型，而得到足以代表實際結構之等效分析模型。再由實際隨機激振實驗確認實驗治具的訊號傳輸能力。最後利用發展之理論模型進行在標準振動試驗規範下的簡諧響應分析與頻譜響應分析，透過此兩種理論分析對印刷電路板執行響應預測與破壞分析，與實驗分析值比對確認響應預測的正確性，並探討獲得印刷電路板在標準隨機激振試驗中最大破壞區塊。本文建立之分析及實驗技術，以及破壞分析之結果，將可提供針對印刷電路板細部零組件受隨機激振時的破壞分析參考，並可協助建立相關產品在振動可靠度分析的標準分析流程。 關鍵字：印刷電路板、有限元素分析、實驗模態分析、模型驗證、簡諧響應分析、頻譜響應分析、響應預測 【Abstract】 This work aims to perform the dynamic analysis and vibration response prediction of the printed circuit boards PCB for environmental vibration testing. This work first, adopts finite element analysis FEA and experimental modal analysis EMA to perform model verification for the PCB. Both FEA and EMA are performed, respectively, to determine the modal properties of the PCB. Theoretical natural frequencies, mode shapes and frequency response function FRF can be computed by FEA. Experimental natural frequencies, damping ratios, mode shapes and frequency response functions of the PCB can also be obtained by EMA. Via the optimization procedure to verify modal properties obtained from FEA with those from EMA, the equivalent finite element model for the PCB can be validated. Then the fixture is affirmed as good ability to transmit signal by random vibration experiment. Finally, the theoretical model is used to execute harmonic response analysis and spectrum response analysis. The vibration response prediction and maximum damage area of PCB can be obtained and evaluated. The results of this study can not only provide the useful information for sub-component of PCB damage analysis in random vibration testing but also assist to build the standard analysis procedures regarding the vibration testing of PCB. Keywords：PCB, FEA, EMA, model veri