溫濕狀態下電子封裝體之疲勞壽命與可靠度分析

Fatigue Life and Reliability Analysis of Electronic Packages under High Temperature and Moisture Conditions

許志敏(Chih-Min Hsu)

指導教授 ： 吳文方

國立臺灣大學/工學院/機械工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.10211

摘要

有別於以往電子封裝相關研究常僅評估封裝體受到如振動、熱循環、掉落衝擊、溫度、濕氣環境等單一應力狀態下的壽命，本研究兼考慮溫度與濕氣，探討電子封裝體於濕氣環境下的熱疲勞壽命，並將其與不考慮濕氣的熱疲勞壽命比較，藉以瞭解濕氣對封裝體熱疲勞壽命的影響。本研究以有限元素模擬為主要分析工具，而為使分析結果較趨近現實，本研究依據蒙地卡羅概念，以隨機取樣方式，將來自同一母體但相異個體的封裝體尺寸及材料參數代入有限元素進行分析，獲得另一組分析結果的樣本，最後再以量化可靠度方式處理並探討分析模擬結果。本研究發現，濕氣對於所分析探討某一特定電子封裝體的熱疲勞破壞機制雖無太大改變，但確也會使封裝體平均失效時間由無濕氣影響的1,540循環降至考慮濕氣影響的1,200循環，也使得電子封裝體可靠度下降。

關鍵字

電子封裝 ； 疲勞壽命 ； 濕氣擴散 ； 可靠度

並列摘要

Many previous researches on electronic packages focused on assessment of package lives under a single state of stress such as vibration, thermal cycling, drop impact, temperature and humidity. The present study considers both effects of thermal cycling and moisture on the fatigue life of electronic packages. The influence of moisture on thermal fatigue life of a package is for the analysis. A Monte Carlo simulation algorithm is also employed to make the result of finite element simulation closer to reality. A sample of variables consisting of different package sizes and material parameters from their populations are generated and incorporated into the finite element analysis. The result of a numerical example indicates the thermal-fatigue failure mechanism of the electronic packages is not affected very much by the moisture. However, the mean time to failure of the package does decrease from 1,540 cycles to 1,200 cycles when moisture is taken into consideration. The reliability of package decreases as well.

並列關鍵字

Electronic Packages ； Fatigue Life ； Moisture Diffusion ； Reliability

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