早期單一晶片的封裝方式的產品記憶容量已無法滿足消費者的需求，為滿足近年來日益蓬勃發展的個人化行動電子產品對於快閃記憶體(NAND Flash)記憶容量的需求。因此，加大記憶容量的疊晶封裝製程便成為現今甚至未來快閃記憶體封裝的趨勢。
而疊晶的方式又因為使用黏膠的材料不同及快閃記憶體本身的設計而有許多不同的疊晶型態，而每一種不同的疊晶型態因其所使用的材料及結構不同也有不同的成本架構、製程流程及產品結構形式。

本文採用Ansys有限元素分析軟體，以模擬不同材料及不同疊晶結構下，封裝產品在完成封膠製程後產品的翹曲狀況，及將產品昇溫到迴銲作業260℃時產品翹曲現象。再者，分析研究各種疊晶方式在成本、製程條件、製程優缺點及結構尺寸等各方面的狀況，以得到一低成本、易製造及高品質的疊晶封裝體。而目前國內對於疊晶的研究甚多，但大多是局限在封裝體本身的結構應力問題，而對快閃記憶體的疊晶結構之多元研究著墨甚少，故本文將透過對成本、製程、結構及翹曲等分析研究，以提供產品設計工程師在收到客戶快閃記憶體時，能有系統及快速選出適合的疊晶結構及材料，而進行產品設計，進而縮短產品設計開發時間。

Previous products with single chip package couldn’t satisfy with consumers’ needs. In accordance with the flourish development of personalized NAND Flash memory high density mobile electronic products, the stacked-die process to promote memory density has become the trend of NAND Flash memory package nowadays and in the future.

Given stacked-die epoxy material and NAND Flash memory design variances, there are many different stacked-die types. Meanwhile, each different stacked-die type has different cost structure, process and product type based on different materials and structures.

This study applies Ansys’s finite element analysis software to simulate different material and stacked-die structure. The simulation finds out assembly product warpage status after molding process and product reflowing to 260℃. Furthermore, the cost, process condition, working process and structure size etc. of each stacked-die type are analyzed. Hopefully, a stacked-die package with low cost, easy manufacture process and high quality can be obtained. Currently many stacked-die researches confined in package structure stress issue have being conducted in Taiwan. However, a whole set focused on NAND Flash memory stacked-die structure multidirectional research is few. Therefore, this study aims at analyzing the cost, process, structure and warpage to provide engineers with valuable information so that they can systemically and rapidly choose applicable stacked-die structure and material as well as carry out product design to shorten the product design time to meet customers’ requirement for NAND Flash memory product.

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