Investigation of the effect of heat leak in loop heat pipes with flat evaporator

Shen Chun Wu, Jen Chieh Peng, Shih Ru Lai, Chien Chih Yeh, Yau Ming Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Loop heat pipes (LHPs) have a great potential for applications of electronic cooling due to the advantages of high transfer capacity, low thermal resistance and long transport distances. However, the cylindrical evaporators of loop heat pipes cannot work on a flat thermo-contact surface without saddle. The saddle not only creates an extra thermal resistance but also makes evaporators less isothermal. To avoid the above disadvantages, we adopt the flat evaporators of loop heat pipes. According to the literatures, however, the heat leak problem is more serious in the flat evaporators than the cylindrical evaporators. This problem makes the thermal resistance of flat evaporators higher. Hence this study tries to solve the difficulties and provides two solutions. The first method is to increase the thermal resistance of the wick by raising the wick thickness. The second method, we design a double-decked complex wick, which is composed of the main wick sintered with metal powder and the additional wick made of the low thermal conductivity polymer. The material wick generates higher capillary forces and the polymer has lower thermal conductivity. Such designs can ease the heat leak problem. The results showed that both methods can ease heat leak problem. When the temperature of the evaporators was less than 100°C and the sink temperature was at 30°C. The maximum heat capacity reached 180W with thermal resistance 0.38 K/W ,and the heat flux is 14.32W/cm2.

Original languageEnglish (US)
Title of host publicationIMPACT Conference 2009 International 3D IC Conference - Proceedings
Number of pages4
StatePublished - Dec 1 2009
Externally publishedYes
EventIMPACT Conference 2009 International 3D IC Conference - Taipei, Taiwan, Province of China
Duration: Oct 21 2009Oct 23 2009

Publication series

NameIMPACT Conference 2009 International 3D IC Conference - Proceedings


OtherIMPACT Conference 2009 International 3D IC Conference
Country/TerritoryTaiwan, Province of China


  • Flat evaporator
  • Heat leak
  • Loop heat pipe (LHP)

ASJC Scopus subject areas

  • Hardware and Architecture
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials


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