1990 Fiscal Year Final Research Report Summary
Development of Direct Cooling Technique of Integrated Circuit Junctions
| Project/Area Number |
01850047
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
Thermal engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
HIJUKATA Kunio Tokyo Inst. Tech., Faculty of Engineering, Professor, 工学部, 教授 (60016582)
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| Co-Investigator(Kenkyū-buntansha) |
NAGASAKI Takao Tokyo Inst. Tech., Faculty of Engineering, Assistant, 工学部, 助手 (30155923)
NAKAYAMA Wataru Tokyo Inst. Tech., Faculty of Engineering, Professor, 工学部, 教授 (50221461)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Heat Transfer / Integrated Circuit / Forced Convection / Boiling / Thermal Conduction / Conjugate Heat Transfer |
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| Research Abstract |
Direct cooling techniques of integrated circuit (IC) junctions have been investigated. Firstly, heat transfer from diode junctions in an IC chip, whose surface was cooled by an impinging jet of air, have been investigated. Junction temperature was measured by using its forward bias voltage. Based on the visualization of the chip surface temperature profile by an infrared imager, it was clarified that the temperature increase of each heating element is divided into two parts. One is local temperature increase near each heating element, which depends on each heating rate, and another is the increase of the average temperature of the chip, which depends on the total heat generation in the chip and is determined by the heat resistance between the chip and the ambience. An idealized experiment was also made by using small heating elements on a glass plate. It was clarified that the dependency of heat transfer rate on the air Reynolds number is small, and the thermal interaction between elements occurs when the distance between two elements becomes the same order as the size of heating element.
Secondly, characteristics of boiling heat transfer in R113 have been investigated. It was shown that the heat flux greatly depends on the thermal conductivity of the substrate, and its value is greater than that of the conventional boiling from wide surfaces due to the conduction in the substrate. Temperature fluctuation of element was also observed corresponding to the bubble formation and departure. A numerical analysis was also made on the conjugate problem of heat conduction in the chip and the cooling of its surface, and the heat transfer characteristics was correlated with nondimensional parameters, such as Biot number.
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