高頻覆晶構裝之熱傳遞及可靠度分析

Abstract

由於構裝體的設計參數將會影響可靠度，同時也將影響其溫度場，因此本文分別利用有限元素與有限體積之數值模擬方法，在熱循環作用以及在構裝體運作後所產生的溫度下，並藉由改變結構設計的五個參數：凸塊高度、凸塊半徑、線路厚度，基板厚度和晶片厚度，來探討構裝體的應變行為。 研究結果顯示，除了改變凸塊高度以外，其餘參數的改變如果是伴隨著體積的增加，此將有益於散熱效果。在有無填膠比較方面，基本上，填膠可以減少塑性應變以及降低其溫度。在應變方面，較高的凸塊高度，較小的凸塊半徑，較厚的線路、基板和晶片厚度將對未填膠構裝體有較小的應變值；另外較矮的凸塊高度，較大的凸塊半徑，較薄的線路，較厚的基板和晶片厚度將對填膠構裝體有較小的應變值。整體而言，在填膠構裝體的凸塊高度、凸塊半徑、線路厚度、基板厚度和晶片厚度分別為50、35、2、275和110微米情況下，會有最小的應變值。

The design parameters of package structure greatly influence the reliability and also affect its temperature. In this study, we apply finite element and finite volume methods to investigate the strain with thermal cycling test and the operation of package by changing the design of five parameters which included bump height, bump radius, wire thickness, substrate thickness and chip thickness. The result shows that except changing the bump height, change in other parameters will benefit on the thermal dissipation by increasing package's volume. As for with and without underfill, we find that the package with underfill can reduce plastic strain and temperature. If the height of bump is higher, the radius of bump is smaller, and the thickness of wire , substrate and chip is thicker, the strain of package without underfill is smaller. If the height of bump is shorter, the radius of bump is bigger, the thickness of wire is thinner, and the thickness of substrate and chip is thicker, the strain of package with underfill is smaller. Overall, the package has the minimal strain on the bump height, bump radius, wire thickness, substrate thickness and chip thickness are 50, 35, 2, 275 and 110 microns.