球柵陣列封裝半導體手動解封膠之標準化流程建立

本文主要針對半導體BGA 封裝產品的分析方法進行標準化研究，本次研究的分析方式稱為 - 解封膠 (De-cap)，解封膠一般利用酸蝕的化學方式，對封裝的膠體進行侵蝕，使其呈裸露出晶片(Die)的內部樣貌，以利不良品內部觀察以及資料蒐集，但分析手法本身存在不穩定性，可能在正常產品中亦出現晶片破裂(Die crack)，影響分析結果的判斷。本文即為了降低此狀況的發生，採用田口實驗方法，將4 種可能影響分析穩定性的因素，透過田口實驗方式加以排列成16 種實驗組別，以實際進行分析的方式確認個組別的結果。樣品部分統一使用同一批生產之BGA (Ball Grid Array)樣品，並透過斷短路測試程式(open /short)，篩選出電性正常之好品；以及透過翹曲量測(Warpage) 排除可能造成實驗果偏差之壞品後進行實驗，實踐結果得到共有三組條件會出現晶片破損現象，將實驗結果推測並歸納，得到必須避開殘留硝酸與丙酮發生化學反應機會之結論，以及其他穩定性較佳的實驗條件，最後以warpage 超過規格，容易發生晶片破損的樣品進行驗證，確認所建立的標準化分析流程，確實能降低分析所造成晶片破裂(Die crack)的現象出現。

關鍵字

解封膠；封裝；標準化；流程；手動

並列摘要

This research utilities a standard analysis process, called De-cap, under specific conditions. This analysis flow used acid to dissolve assembly product surface and investigated the clearly die with naked eyes or microscope. But due to the analysis process still via chemical approach and also need heated, sometimes these dies will crack even for good samples. Therefore, it is not sure that the defect modes are from assembly or not. In this work, four probably factors, temperature, acid conc., solvent of flush, cooling, are employed as control parameters to de-cap the dies and verify the results of the analysis process. As the combination of parameters are 64 experiments, the Taguchi experiment method is utilized to reduce to 16 experiment groups from original 64 groups . From the experiment results, three of 16 groups need to be removed due to they may cause cracks in samples. In addition, these three groups also provide some important facts that the reaction of acetone with nitric acid may yield during oxidation-reduction reaction, and the die crack may occur due to thermal stress increase suddenly. Base on the experimental results, it reveals that the temperature, especially increase suddenly, is the most important factor among four proposed factors. Meanwhile, the proposes analysis process is practicable in de-cap procedure excluding the aforementioned chemical effects, and it can be adopted ordinary analysis de-cap procedure.