單一封裝印刷電路板之振動測試與驗證分析

Vibration Testing and Verification Analysis for One Package Printed Circuit Board

陶致均(Chin-Chung Tao)

指導教授 ： 王栢村

國立屏東科技大學/工學院/機械工程系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00176

摘要

本文針對環境振動測試所設計之單一封裝體印刷電路板(Printed Circuit Board, PCB)進行振動測試分析與驗證。首先，各別建立封裝體、電路板及單一封裝體印刷電路板(含錫球)之有限元素模型，接著以實驗模態分析配合有限元素分析分別進行封裝體、電路板及單一封裝體印刷電路板於自由邊界狀態下之模型驗證，由模型驗證所取得之模態參數及頻率響應函數可驗證等效有限元素模型是否對應於實際結構。再將單一封裝體印刷電路板驗證完成之等效有限元素模型延伸至鎖固邊界進行模型驗證，並探討有限元素分析中模擬螺絲鎖固之方法與參數之差異。由鎖固邊界驗證完成之等效模型可延伸應用於PCB響應預測，依照JEDEC所制定之JESD22-B103B試驗規範中之E level進行隨機激振實驗並配合頻譜分析可擷取系統在隨機振動下之加速度、應變及應力功率頻譜密度函數，由實驗及理論之驗證，可獲得理論分析的精確度，並推估系統於隨機振動下可能之破壞位置。經由上述理論分析之驗證，可延伸推導至封裝體、電路板及錫球之細部模型，假設隨機振動為常態分佈之情況下，可求得週期應力變化之應力振幅及平均應力，並可預測PCB及其細部模型之疲勞破壞。本研究發展之模型可協助瞭解單一封裝印刷電路板於振動測試時之動態參數及於隨機振動下之動態響應，並對整體印刷電路板之分析模式進行確認，期許未來應用於不同環境狀態時，對封裝體、電路板及錫球之材料轉變亦能快速進行印刷電路板零組件振動特性之分析。

關鍵字

封裝體 ； 印刷電路板 ； 有限元素分析 ； 實驗模態分析 ； 模型驗證 ； 隨機振動 ； 響應預測

並列摘要

This work presents the theoretical analysis and experimental verification for printed circuit board (PCB) in environmental vibration testing. First, the reproducibility study is carried out for the same PCB in both free and fixed boundaries via different experimental modal testing. The equivalent finite element (FE) model of PCB base on the experimental modal parameters can be validated, and the optimum material properties of PCB as well as the fixed boundary spring constants can be specified by statistical quanties. The validated FE model can then be applied to perform spectrum response analysis according to Joint Electronic Device Engineering Council (JEDEC) random vibration test specification. Both acceleration and strain spectra for PCB real tests are also recorded and used to predict their root mean square (RMS) values in comparison with those from FE analysis. Results show reasonable agreement between the prediction and experiments. Additionally, stress spectra response of PCB are further studied by using the same equivalent optimized FE model to quantify the PCB stress level. A macroscopic method to evaluate possible fatigue failure of PCB is presented. This work establishes the analytical and experimental techniques for PCB failure analysis in combining both FEA and EMA. The response prediction technique can be useful for the design of PCB, in particular for joint failure analysis.

並列關鍵字

PCB ； FEA ； EMA ； model verification ； harmonic response analysis ； spectrum response analysis ； response prediction

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