Cu pillar 범프의 Cu-Sn-Cu 샌드위치 접속구조를 이용한 플립칩 공정
Flip Chip Process by Using the Cu-Sn-Cu Sandwich Joint Structure of the Cu Pillar Bumps
1
조회
0
다운로드
5
인용
0
참고문헌
키워드
초록
Cu pillar 범프를 사용한 플립칩 기술은 솔더범프를 사용한 플립칩 공정에 비해 칩과 기판 사이의 거리를 감 소시키지 않으면서 미세피치 접속이 가능하다는 장점이 있다. Cu pillar 범프를 사용한 플립칩 공정은 미세피치화와 더불 어 기생 캐패시턴스를 억제하기 위해 칩과 기판 사이에 큰 거리가 요구되는 RF 패키지에서도 유용한 칩 접속공정이다. 본 연구에서는 Sn 캡을 형성한 Cu pillar 범프와 Sn 캡이 없는 Cu pillar 범프를 전기도금으로 형성한 후 플립칩 접속하 여 Cu-Sn-Cu 샌드위치 접속구조를 형성하였다. Cu pillar 범프 상에 Sn 캡의 높이를 변화시키며 전기도금한 후, Sn 캡의 높이에 따른 Cu-Sn-Cu 샌드위치 접속구조의 접속저항과 칩 전단하중을 분석하였다. 직경 25 μm, 높이 20 μm인 Cu pillar 범프들을 사용하여 형성한 Cu-Sn-Cu 샌드위치 접속구조에서 10~ 25 μm 범위의 Sn 캡 높이에 무관하게 칩과 기판 사이 의 거리는 44 μm으로 유지되었으며, 접속부당 14 mΩ의 평균 접속저항을 나타내었다.
Abstract
Compared to the flip-chip process using solder bumps, Cu pillar bump technology can accomplish much finer pitch without compromising stand-off height. Flip-chip process with Cu pillar bumps can also be utilized in radiofrequency packages where large gap between a chip and a substrate as well as fine pitch interconnection is required. In this study, Cu pillars with and without Sn caps were electrodeposited and flip-chip-bonded together to form the Cu-Sn- Cu sandwiched joints. Contact resistances and die shear forces of the Cu-Sn-Cu sandwiched joints were evaluated with variation of the height of the Sn cap electrodeposited on the Cu pillar bump. The Cu-Sn-Cu sandwiched joints, formed with Cu pillar bumps of 25-μm diameter and 20-μm height, exhibited the gap distance of 44 μm between the chip and the substrate and the average contact resistance of 14 mΩ/bump without depending on the Sn cap height between 10 to 25 μm.
참고문헌 (19)
- J. H. Choi, "Contact Resistance of the Chip-on-glass Bonded 48Sn-52In Solder Joint", Mater. Trans, 46, pp.1042~1046 (2005)
- J. W. Wan, "Recent Advances in Modeling the Underfill Process in Flip-chip Packaging", Microelectron. J, 38, pp.67~75 (2007)
- T. Braun, "High-temperature Reliability of Flip Chip Assemblies", Microelectron. Reliab., 46, pp.144~154 (2006)
- K. N. Tu, "Under Bump Metallurgy Study for Pb-free Bumping", Mater. Sci. Eng., 34, pp.1~58 (2001)
- J. H. Lau, "Low Cost Flip Chip Technologies", pp.511~ (2000), McGraw-Hill
- J. H. Lau, "Low Cost Flip Chip Technologies", pp.183~ (2000), McGraw-Hill
- U. B. Kang, "A New COG Technique Using Low Temperature Solder Bumps for LCD Driver IC Packaging Applications", IEEE Trans. Comp. Packag. Technol., 27, pp.253~258 (2004)
- 김종웅, "Effect of Bonding Conditions on Conduction Behavior of Anisotropic Conductive Film Interconnection", Metals and Materials International, 14(3), pp.373~379 (2008), 대한금속·재료학회
- B. Banijamali, "Crack Growth- Resistant Interconnects for High-Reliability Microelectronics", Proc. 57th Electron. Comp. Technol. Conf., pp.1880~1886 (2008)
- A. Keigler, "Pattern Effects on Electroplated Copper Pillars", Inter. Wafer-level Packag. Conf. (2006)
- G. T. Lim, "Temperature Effect on Intermetallic Compound Growth Kinetics of Cu Pillar", Sn Bumps, 2009, pp.38(11), 2228~2233
- T. Wang, "Studies on a Novel Flip-Chip Interconnect Structure-Pillar Bump", Proc. Electron. Comp. Technol. Conf., pp.945~949 (2001)
- L-R. Zheng, "Cost and Performance Trade-off Analysis in. Radio and Mixed-Signal System-on-Package Design", IEEE Trans. Adv. Packag., 27, pp.364~375 (2004)
- A. Chandrasekhar, "Accurate RF Electrical Characterization of CSPs Using MCM-D Thin Film Technology", IEEE Trans. Adv. Packag., 27, pp.203~212 (2004)
- E. Beyne, "Multilayer Thin-Film Technology Enabling Technology for Solving High-Density Interconnect and Assembly Problems", Nuclear Inst. Methods Phys. Res. A, 509, pp.191~199 (2003)
- 최정열, "Cu 범프와 Sn 범프의 접속구조를 이용한 RF 패키지용 플립칩 공정", 마이크로전자 및 패키징학회지, 16(3), pp.67~73 (2009), 한국마이크로전자및패키징학회
- C. W. Tan, "Effect of Autoclave Test on At sotropic Conductive Jointf", Microelectron. Reliab., 43, pp.279~285 (2003)
- J. H. Zhang, "Contact Resistance and Adhesion Performance of ACF Interconnections to Aluminum Metallization", Microelectron. Reliab., 43, pp.1303~1310 (2003)
- Y.-T. Hsieh, "Reliability and Failure Mode of Chip-on-film with Non-conductive Adhesive", Proc. Int. Symp. Electron. Mater. Packag., pp.157~160 (2002)