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IC Thermal Management Using Microchannel Liquid Cooling Structure with Various Metal Bumps

금속 범프와 마이크로 채널 액체 냉각 구조를 이용한 소자의 열 관리 연구

  • Won, Yonghyun (Graduate School of Nano-IT-Design, Seoul National Univ. of Science and Technology) ;
  • Kim, Sungdong (Department of Mechanical System Design Engineering, Seoul National University of Science and Technology) ;
  • Kim, Sarah Eunkyung (Graduate School of Nano-IT-Design, Seoul National Univ. of Science and Technology)
  • 원용현 (서울과학기술대학교 나노IT디자인융합대학원) ;
  • 김성동 (서울과학기술대학교 기계시스템디자인공학과) ;
  • 김사라은경 (서울과학기술대학교 나노IT디자인융합대학원)
  • Received : 2016.05.30
  • Accepted : 2016.06.23
  • Published : 2016.06.30

Abstract

An increase in the transistor density of integrated circuit devices leads to a very high increase in heat dissipation density, which causes a long-term reliability and various thermal problems in microelectronics. In this study, liquid cooling method was investigated using straight microchannels with various metal bumps. Microchannels were fabricated on Si wafer using deep reactive ion etching (DRIE), and Ag, Cu, or Cr/Au/Cu metal bumps were placed on Si wafer by a screen printing method. The surface temperature of liquid cooling structures with various metal bumps was measured by infrared (IR) microscopy. For liquid cooling with Cr/Au/Cu bumps, the surface temperature difference before and after liquid cooling was $45.2^{\circ}C$ and the power density drop was $2.8W/cm^2$ at $200^{\circ}C$ heating temperature.

집적회로(Integrated Circuit) 소자의 트랜지스터(transistor) 밀도 증가는 소자에서 발생하는 열 방출(heat dissipation)의 급격한 상승을 초래하여 열 문제를 발생시키고, 이는 소자의 성능과 열적 신뢰성에 영향을 크게 미친다. 열문제의 해결방안 중 본 연구에서는 냉매를 이용한 액체 냉각방법을 연구하였으며, 실리콘 웨이퍼에 관통실리콘비아(through Si via)와 마이크로 채널(microchannel)을 딥 반응성 이온 애칭(deep reactive ion etching)로 구현한 후 유리기판과 어노딕본딩을 통하여 액체 냉각 구조를 제작하였다. 제작된 마이크로 채널 위에 Ag, Cu 또는 Cr/Au/Cu bump를 스크린프린팅(screen printing) 방법으로 형성하였고, 범프의 유무를 통해 액체 냉각 전후의 냉각 모듈의 실리콘 표면온도의 변화를 적외선현미경으로 분석하였다. Cr/Au/Cu bump가 탑재된 액체 냉각 모듈의 경우 가열온도 $200^{\circ}C$에서 냉각 전후의 실리콘 표면 온도 차이는 약 $45.2^{\circ}C$이고, 전력밀도 감소는 약 $2.8W/cm^2$ 이었다.

Keywords

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