高導熱銅基鑽石複材製造及其基板接合

Fabrication of High Thermal Conductive Diamond/Copper Composites and Their Joining with Substrates

吳宜馨(Yi-Hsin Wu)

指導教授 ： 林樹均

國立清華大學/工學院/材料科學工程學系/碩士(2015年)

摘要

利用無壓真空液相燒結製程製備銅基鑽石複材，並獲得高熱傳導係數且熱膨脹係數介於4-7 ppm/K的散熱複材，適當的平整處理之後與常見之電路基板進行接合。
在銅基材中添加單一活性元素鋯以提升潤濕性，並探討活性元素添加量對複材熱性質的影響。實驗中的複材熱傳導係數最高可達608 W/mK，其熱膨脹係數為6.4 ppm/K，介於電子元件的範圍內。本製程簡單、模具亦無損耗問題，在成本考量上極具優勢；利用添加銅鋯薄片的平整處理方式，可有效將複材的表面粗糙度減少一個數量級以上。而實驗中所設計的接合流程能夠有效將銅基複材與電路基板做出完整的接合封裝，並具有良好的拉伸強度。其封裝結構的熱性質表現最優異為銀膠接合氮化鋁組，其熱傳導值最高可達174 W/mK。銀膠組普遍熱性質良好、環氧膠組具有優異的拉伸強度，大於8.34 MPa；石墨膠組的拉伸強度約在1 MPa上下，可利用其來分析拉伸斷面上的膠分布，並推論接合中最脆弱的接合位置。氮化鋁與氧化鋁試片組由膠體中間斷開；而矽試片組屬於另一系統，由膠體與基板界面斷開。200 °C、150 次的高溫熱循環試驗中，發現銅鋯薄片添加可延後複材熱性質的劣化，其中環氧膠的氧化鋁組無衰退情形出現。而85 °C、1000 次的低溫熱循環試驗中，接合封裝的銀膠組可以通過測試，顯示其在實際使用條件下能有良好的可靠性，具有商業潛力。

關鍵字

銅基鑽石複合材料 ； 散熱材料 ； 熱傳導係數 ； 接合封裝

並列摘要

Pressureless liquid phase sintering process was adopted for the fabrication of diamond/Cu composites. After suitable surface treatment these composites were joined with AlN, Si, and Al2O3 substrates by silver, graphite, and epoxy gels. The results show that adding minor active Zr element to enhance the wettability between Cu and diamond, the composites with a high thermal conductivity of 608 W/mK and CTE of 6.4 ppm/K can be achieved by using 300 μm diamonds with the volume fraction of 50 vol%. One order of surface roughness can be reduced through attaching a Cu/Zr flake to the composites before sintering. Packages joined by the silver gel have best performance, reaching 210 W/mK; those joined by epoxy shows excellent tensile strength, larger than 8.34 MPa. The tensile strength of graphite gel is around 1 MPa, providing a suitable condition to observe the distribution of the gel on the fracture surface. In thermal cycle tests carried out at 200 °C with 150 cycles, it was found that Cu/Zr flake addition can postpone the degradation of thermal properties of the composites, and the alumina package joined by epoxy gel has good reliability. While in thermal cycle tests carried out at 80 °C with 1000 cycles, packages joined by silver gel shows great reliability in normal circumstances, showing great commercial potential.

並列關鍵字

Cu-based diamond composite ； heat dissipation ； thermal conductivity ； electronic package

參考文獻

[63] 曾筱婷, "鑽石/銀-鈦基複合材料之熱性質與熱循環可靠性測試", 國立清華大學材料科學工程學系碩士論文, (2014)

[68] 楊曼寧, "電子構裝鑽石/銅鋯複合材之製程及熱性質研究", 國立清華大學材料科學工程學系碩士論文, (2013)

[72] 林資烜, "電子構裝鑽石/錫-鈦複合材之製程及其熱性質", 國立清華大學碩士論文, (2013)

[16] R. M. German, K. F. Hens, and J. L. Johnson, "Power-Metallurgy processing of Thermal Management Materials for Microelectronic Applications", International Journal of Powder Metallurgy, 30 (1994) 205-215.

[9] D. M. Jacobson and S. P. S. Sangha, "Novel Low Expansion Packages for Elecronics", The GEC Journal of Technology, 14 (1997) 48-52.