電路板熱傳播漸近等效電路的發展與其在SPICE上程式庫的建立

Abstract

隨著積體電路製作及包裝技術的迅速發展,高功率積體電路元件與多晶 片模組亦日漸普及.因而,印刷電路板與積體電路元件的溫度模擬在電路設 計上也就愈顯重要.本論文使用有限差分法近似熱傳播偏微方程式,並將其 等效地類比為電路形式,而建構電路板與積體電路元件熱傳播的電路模型. 在第一代電路板熱模型方面,我們已將難處理的銅模繞線列入考慮;而在積 體電路元件熱模型上,我們則發展穩態的漸近簡化模型將原先建立的多層 立體電路模型簡化成單層平面的等效電路模型,以節省大量模擬時間與記 憶體空間.而在第二代電路板熱模型中,我們對第一代電路板熱模型的節點 位置作了修正,使模型中的節點更能適切的表示出電路板的溫度分佈,而且 我們更發展了暫態的積體電路元件漸近簡化模型,我們並以此漸近簡化模 型在SPICE上建立元件程式庫.同時我們也發展出任意可變式環境溫度及晶 片消耗功率的簡化熱模型,使得我們的簡化模型更富彈性,最後我們將網目 精製的方法應用在電路板的溫度模擬上,不但使得在模擬過程中對模擬時 間與記憶體空間的需求量大大的減少,更有效的提昇了電路板熱模擬的效 率. As the manufacture and packaging technology of integrated circuits has been rapidly developed so far, power IC's and multichip become more demanded. Heattransfer simulation of PCB's and IC packages are very important for designingthe circuits with high reliability and accuracy. In this thesis, the partialdifferential equations for computing heat transfer in PCB's and IC packagesare approximated by using the finite difference method. We have proposed efficient equivalent circuit models to simulate the heat transfer mechanismof PCB's and IC's. We have also include the complicate wiring models of PCB'sin our first version of PCB's model. The tranditional equivalent circuit modelfor the heat transfer of an IC is a three-dimension one. The objects of the modeling mothed proposed by us is to simplify the three-dimemsion model intotwo-dimension one. Thus, we proposed an asymptotic method to produce the twodimensional transient-state model of the heat trasfer in an IC. In addition, more works have been done here,such as, (1) the method to separate the equivalent circuits produced by the ambient temperature and the electricalpower consumed by IC, and (2) the improvement of the mesh-refinement model ofthe PCB in previous version. The simulation results have already shown thatour models can highly improve the effciency of the simulation time and memorysize.