1998 Fiscal Year Final Research Report Summary
IMMERSION COOLING OF MICROELECTRONIC CHIP WITH MICROCONFIGURED SURFACE
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||KYUSHU UNIVERSITY |
TAKAMATSU Hiroshi KYUSHU UNIVERSITY,INSTITUTE OF ADVANCED MATERIAL STUDY,ASSOCIATE PROFESSOR, 機能物質科学研究所, 助教授 (20179550)
YAMASHIRO Hikaru KYUSHU UNIVERSITY,INSTITUTE OF ADVANCED MATERIAL STUDY,RESEARCH ASSOCIATE, 機能物質科学研究所, 助手 (70239995)
HONDA Hiroshi KYUSHU UNIVERSITY,INSTITUTE OF ADVANCED MATERIAL STUDY,PROFESSOR, 機能物質科学研究所, 教授 (00038580)
|Project Period (FY)
1997 – 1998
|Keywords||Pool Boiling / Silicon Chip / FC-72 / Boiling Incipience / Critical Heat Flux / Heat Transfer Enhancement / Reentrant Cavity / Microconfigured Surface|
Although the recent developments of CMOS technology has resulted in a considerable decrease in the chip-level heat dissipation rate, it is obvious that the heat dissipation rate will increase again to a high level as the packaging density and switching speed of the electronic devices increase. Direct immersion cooling of electronic devices by use of dielectric liquids has been a promising method because of its high cooling potential. However, this is not in practical use mainly due to a high wall superheat required for boiling incipience associated with the use of dielectric liquids with a high wettability.
In the present reasearch, boiling heat transfer of FC-72 from newly developed treated surfaces with micro-reentrant cavities was studied experimentally. The surface structure was fabricated on a silicon chip by use of microelectronic fabrication techniques. Several kinds of treated surfaces with the combinations of three cavity mouth diameters (1.6 IOTAm, 3 mum and 9 mum) and two num
ber densities of the micro-reentrant cavities (8I 1/cm^2 and 96CHI 10^3 1/cm^2) were tested along with a smooth surface. Experiments were conducted at the liquid subcoolings of 3 K and 25 K with degassed and gas-dissolved FC-72. The results were as follows :
(1)While the wall superheat at boiling incipience was strongly dependent on the dissolved gas content, it was little affected by the cavity mouth diameter and the liquid subcooling.
(2)For the degassed FC-72, the boiling incipience superheat was generally higher than the prediction of the heterogeneous nucleation theory which assumed the force balance of an embryonic bubble at the cavity mouth. This suggest that even the reentrant cavity with small mouth such as 1.6 mum is inactive for the liquid with high wettability.
(3)The heat transfer performance of the silicon chip with micro-reentrant cavities was considerably improved over the smooth chip.
(4)The heat transfer performance of the gas-dissolved FC-72 was higher than that of the degassed FC-72. Less
Research Products (4 results)