隨著電子產業的蓬勃發展，對3C產品的需求不斷攀升。目前，半導體元件已普遍朝向短小、輕薄的趨勢發展，而在這樣的趨勢下，覆晶封裝技術(Flip-Chip Packaging)成為主流，此種封裝型態將晶片連接到銲錫凸塊(Solder Bump)，並將晶片翻轉過來使凸塊與基板連接，縮短了信號傳輸的距離，增加了晶圓I/O密度和散熱性能及縮減封裝體積等優點，然而，現今的覆晶球閘陣列產品朝向細間距和高密度的方向發展，這使得使用底部填膠(Underfill resin)來增加封裝體的可靠度的封裝技術難度顯著提升，帶來一系列問題，包括爬膠、溢膠、包封以及充填不完全等挑戰，進而直接影響產品的品質，降低生產良率。
本研究著重在毛細底部填膠(Capillary Underfill, CUF)封裝製程之分析，儘管現今半導體產業可以採用模流軟體進行CUF分析，但由於涉及的控制參數眾多，例如網格尺寸、點膠重量、點膠時間等，這些參數對模擬準確度有很大的影響，模擬結果常有時間與流動波前無法與實驗結果相符且只能大概定性分析，不能準確定量分析，所以CUF的研究與分析模擬對工程師來說仍是一個重大挑戰。同時，也很少有文獻針對大晶片封裝體(Bumps 數量較多)的案例進行模擬及實驗。
在本研究中，為了找出影響CUF充填流動模擬準確性的關鍵因素，特別針對點膠實驗、點膠路徑、點膠重量、點膠分配時間及大晶片封裝體的案例進行研究。從模擬結果中發現網格尺寸非常重要，所以本論文由理論分析推倒證實網格尺寸與間隙高度、接觸角和凸塊間距有關。也發現點膠的重量會對CUF充填有很大的影響，將相同重量的底部填膠分為多筆進行點膠，隨著點膠次數的增加，單筆重量的減少，不僅使殘餘底部填充樹脂的擴散範圍減小，解決了側面溢出的問題，而且還能忠實呈現了更均勻的流動波前，防止包封的產生，且模擬結果與實驗結果非常一致。然而兩筆點膠路徑時間的分配也會影響充填結果，兩筆膠料間隔時間太短，會導致膠料無法充分流入模型中，造成左右兩側的溢膠產生，間隔時間太長，則會導致包封的產生，在本研究中發現等到第一筆膠料幾乎流入模具中再進行第二筆點膠，有助於解決溢膠及包封的問題，但同時也增加了填充時間。此外，本論文也對大晶片封裝體進行研究，從結果發現模擬與實驗結果也極一致。
綜合上述本研究可歸納出要實現準確的底部填膠模擬需要以下要素：1. 良好的流動模擬軟體 2. 精確測量的材料特性 3. 良好且精細的網格4. 適當的點膠重量 5. 正確的點膠分配時間。 如果上述問題能夠得到妥善處理，就能實現準確的底部填膠模擬。

In the capillary underfill packaging process, resin with specific characteristics such as low viscosity, high flowability, fast curing, and high reliability is utilized to fill the gaps between the substrate and the die. This underfill resin reinforces the connections between metal bumps and the substrate, extending the lifespan and enhancing the reliability of FCBGA (Flip-Chip Ball Grid Array) packages. Despite the availability of flow simulation tools, the development of the underfill process remains a significant challenge for engineers due to the multitude of control parameters involved.
This study aims to identify the key factors influencing the accuracy of underfill flow simulations and explore potential solutions to these challenges. In this study, it is found that necessary ingredients for accurate underfill simulation need to include the following items: 1. Good flow simulation software 2. Accurately measured material properties 3. Good and fine mesh 4. Right amount of dispensed resin 5. Right timing for resin dispensing. The accuracy of the simulation is particularly affected by factors such as overflowing, resin climbing, non-uniform flow, and voids formation, which are influenced by the amount and timing of resin dispensing.
By addressing these factors, this study demonstrates that accurate underfill simulation can be achieved, providing valuable insights into microscale flip-chip underfill physics. This research lays the groundwork for the development of validated models applicable to next-generation high-density flip-chip products.

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