高效率印刷電路SPICE熱模型之建立

Abstract

隨著積體電路技術的日漸複雜，多晶片模組與高功率積體電路愈來愈普 遍，印刷電路與積體電路的溫度模擬也愈顯重要。本論文使用有限差分法 (finite difference method) 近似熱的偏微分方程式。考慮了傳導 (conduction)、對流 (convection) 及輻射 (radiation)。並將之以電路 型式等效，建立電路板與積體電路熱傳播的電路模型。在建立電路板熱模 型方面，我們特別考慮了難以處理卻不能忽視的銅膜繞線問題，以等效熱 阻的計算與網目精製 (mesh refinement)來加以處理；積體電路構裝方面 ，則採用簡化模型的方法改善原本因為模型過大所導致模擬時間過長，及 模擬時佔用記憶體空間過大的問題。我們將原先所建立的多層模型有效的 簡化為單層模型，節省大量模擬時間與記憶體空間，而其精確度與原模型 比較則在可接受範圍內。 As the technology of the circuit modules with high density packaging has been rapidly developed so far, multichip modules and power IC's becomes more demanded. Thermal simulation of PCB's and IC packages are very important for designing the circuits with high reliability and accuracy. In this thesis,the finite difference method are employed to solve the partial differential equations for computing heat transfer in PCB's and IC's packages. We have proposed efficient equivalent circuit models to simulate the heat transfer mechanism of PCB's and IC's. We have used the simplified equivalent resistance circuits and circuit refinement techniques to generate the complicate wiring models of PCB's. In the modeling of IC's, we also propose a special method to transfer the traditional three dimension equivalent circuits of IC's into two-dimensional-equivalent- circuits. With the usage of this method, the simulation computation time and computer memory size can be reduced greatly. All our simulation results have shown that our modeling methods can have both high accuracy and high efficiency simultaneously.