- 學位論文
球閘陣列構裝體之振動分析與可靠度評估
Vibration Induced Fatigue Reliability Analysis of BGA Packages
摘要
本論文使用有限元素軟體進行球閘陣列構裝體(Ball Grid Array Package, BGA Package)模型之調和外力(Harmonic Excited)振動分析，並以量化可靠度探討參數變異對其錫球(Solder Ball)疲勞壽命之影響。而由於環保意識高漲，世界各國皆以電子產品無鉛化作為目標，為符合環保構裝(Green Package)的理念與趨勢，Sn-Ag-Cu合金為最廣泛使用來取代舊有含鉛(Pb)錫球的材料，故本文前半段為討論尺寸參數變異對含鉛及Sn-Ag-Cu無鉛錫球疲勞壽命之影響；後半段則僅以Sn-Ag-Cu無鉛錫球為對象，探討尺寸與材料參數變異對其疲勞壽命之影響，再針對其疲勞壽命預估模型做一分析。本研究前半段結果顯示，於相同振動環境下，無鉛錫球之疲勞壽命較舊有含鉛錫球要高，但尺寸參數造成疲勞壽命的離散性(Dispersion)卻較大；本論文後半段以有限元素分析與疲勞壽命預估模型交互驗證得知，無鉛錫球疲勞壽命於尺寸與材料參數交互作用(Interaction)下，所造成疲勞壽命的離散性大於上述兩者的單獨影響。
並列摘要
It has been pointed out that vibration induced fatigue of solder balls is one of the major failure mechanisms of ball grid array (BGA) packages. Therefore, in the present paper, the life and reliability of a BGA package is studied in consideration of fatigue of its solder balls. Special attention is paid to the following issues. First, quantitative reliability in addition to qualitative reliability is studied. Secondly, to be compliant with the green packages requirement, fatigue life and reliability of solder balls made of Sn-Ag-Cu alloy (Pb-free) are compared with that made of Sn-Pb alloy. Thirdly, the influence of uncertainty/variation of solder ball geometry and/or material property on fatigue life and reliability estimation of the BGA is studied. The result shows that, under the same vibration condition, the BGA made of Pb-free solder balls has longer but more dispersive fatigue life than the one made of Pb solder balls. With regard to the uncertainty/variation of solder ball geometry and material property, it is found that interaction of both (geometry and material property) uncertainties results in more dispersive fatigue life than the case that only one uncertainty is considered.