基於二維材料均勻分散的超高熱導複合材料應用於覆晶晶片封裝之研究

Abstract

摩爾定律自1965年由戈登·摩爾提出以來，一直是半導體行業技術進步的指導原則，預測電晶體數量每兩年將增加一倍。然而，隨著技術進步，摩爾定律正面臨著前所未有的瓶頸。首先，電晶體尺寸接近物理極限，難以再縮小。當電晶體尺寸進入奈米級別時，量子效應和隧穿電流等問題變得顯著，影響了電晶體的可靠性和效率。其次，製造工藝的複雜性和成本急劇增加，先進工藝節點需要極紫外光刻（EUV）等昂貴設備，使得每一次技術迭代的投入巨大成本。最後，熱管理成為一大挑戰，密集的電晶體排列導致晶片的散熱問題難以解決，這些瓶頸使得半導體行業試圖尋找新的技術途徑，以繼續推動性能提升和成本降低。散熱的熱管理在現代電子設備中相當重要，特別是在高性能應用和密集的三維積體電路中。隨著電晶體數量和運行速度的不斷增加，熱量的聚集成為一大挑戰。為了有效管理散熱，高導熱材料的應用、創新的封裝設計以及先進的冷卻方法都是關鍵。例如，將石墨烯等高導熱材料引入封裝材料中，可以明顯提高熱導率，從而有效散熱。此外，先進的封裝設計，如通過矽通孔（TSV）技術實現的三維堆疊，不僅增強了熱傳導，還縮短了電信號傳輸的距離。這些熱管理技術，可以大幅提升電子設備的性能和可靠性，確保其在高溫環境下穩定運行。 因應熱管理在電子封裝的重要性，在本篇碩士論文研究中，我們團隊引入並成功研發將碳化矽 (SiC) 填料融入先前成功做出以石墨烯為基底的環氧樹酯複合材料中，大幅提升垂直方向熱傳導率，且依然保有良好的水平熱導特性。在電子封裝中添加碳化矽 (SiC) 填料於環氧樹脂中，可以提升材料的垂直熱導率。環氧樹脂作為常用的封裝材料，其本身的熱導率有限，難以滿足高性能電子元件的散熱需求。通過將碳化矽填料均勻分佈在環氧樹脂中，能夠有效提高整體熱導性能，尤其是垂直方向的熱導率。碳化矽具有優異的熱導率和熱穩定性，能快速將熱量從熱源區域傳導至散熱器，從而減少熱聚集現象，提高電子元件的可靠性和使用壽命。這種特性環氧樹脂不僅能支持更高功率和更密集的封裝設計，還能通過調整SiC填料的濃度和分佈，針對不同應用需求進行熱管理性能的精確調整，達到最佳的散熱效果。此外，為了驗證此材料依然擁有很好的機械特性，我們找到在黏度與熱膨脹係數最適合的範圍，並利用模擬得到此複合材料的熱流途徑。最後，利用此複合材料在矽基板加上助焊劑進行覆晶晶片接合，確保了穩定的電和機械特性的連接。透過此製程也確保了經由毛細現象完全的填充於空隙中，使用石墨烯基底複合材料實現了接近 100% 的填充。這些進展不僅增強了熱能管理和結構完整性，也證明了我們的方法在下一代電子封裝解決方案中的實際可行性。

Since its introduction by Gordon Moore in 1965, Moore's Law has been a guiding principle for technological advancements in the semiconductor industry, predicting that the number of transistors on a chip would double approximately every two years, thereby increasing performance and reducing costs. However, as technology advances, Moore's Law faces unprecedented challenges. Firstly, transistor sizes are approaching their physical limits, making further miniaturization difficult. When transistor sizes reach the nanoscale, issues such as quantum effects and tunneling currents become significant, affecting transistor reliability and efficiency. Secondly, the complexity and cost of manufacturing processes have skyrocketed, with advanced nodes requiring expensive equipment like extreme ultraviolet (EUV) lithography, leading to enormous investments for each technological iteration. Lastly, thermal management has become a major challenge, as densely packed transistors lead to heat dissipation issues. Effective thermal management is crucial in modern electronic devices, especially high-performance applications, and dense 3D ICs. As the number and speed of transistors increase, heat accumulation becomes a significant challenge. Critical strategies for managing heat effectively include using high thermal conductivity materials, innovative packaging designs, and advanced cooling methods. For example, incorporating high thermal conductivity materials like graphene into packaging materials can significantly enhance thermal conductivity, thereby improving heat dissipation. These thermal management techniques can significantly improve the performance and reliability of electronic devices, ensuring stable operation in high-temperature environments. Given the critical role of thermal management in electronic packaging, this master's thesis research introduces and successfully develops a method to incorporate silicon carbide (SiC) filler into a previously developed graphene-based epoxy composite material. This innovation significantly enhances out-of-plane thermal conductivity while maintaining excellent in-plane thermal properties. Adding SiC filler to epoxy resin in electronic packaging can markedly improve the material's out-of-plane thermal conductivity. Epoxy resin, a commonly used packaging material, has limited thermal conductivity, making it insufficient for the heat dissipation needs of high-performance electronic components. By uniformly distributing SiC filler within the epoxy resin, the overall thermal conductivity, particularly in the out-of-plane direction, can be effectively enhanced. SiC possesses excellent thermal conductivity and thermal stability, allowing for the rapid transfer of heat from heat sources to heat sinks, thereby reducing heat accumulation, and improving the reliability and lifespan of electronic components. Furthermore, to ensure that this material retains excellent mechanical properties, we identified the optimal range for viscosity and thermal expansion coefficient and used simulations to determine the heat flow path within the composite material. Finally, we applied this composite material to a silicon substrate with flux for flip-chip bonding, ensuring stable electrical and mechanical connections. This process also ensured the filling of gaps through capillary action, achieving nearly 100% filling with graphene-based composite material. These advancements not only enhance thermal management and structural integrity but also demonstrate the practical feasibility of our approach for next-generation electronic packaging solutions, providing reassurance about the applicability of our research.