JP2845447B2 - Integrated circuit cooling structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an integrated circuit element constituting an electronic apparatus such as an information processing apparatus, and more particularly, to circulating a liquid refrigerant such as water near the integrated circuit element. The present invention relates to a structure for cooling an integrated circuit element by transmitting heat generated in the integrated circuit element to a liquid refrigerant.

[Conventional technology]

Conventionally, as a cooling structure of this type, an example shown in FIG. 3 [S, Octay, H, Sea, Kamala (H.
C. Kammerer) “A Conducted Cooled Module for Hyper Performance LSI
Devices (A Conduction-Cooled Module for H
igh-Performance LSI Devices) "IBM Journal of Research End Development
Vol. 26, No. 1, January 1982 (IBM J.RES.DEVELOP.Vol.26 No.
1 Jan. 1982). A related Japanese document, “The IBM 3081 Thermal Conduction Module that Enables High-Density Packaging of LSIs,” Nikkei Electronics, July 19, 1982.
There is. ], The piston 304 is pressed against the integrated circuit 301 (mounted on the wiring board 302 having the I / O pins 303) by the spring 305 to take heat, and the heat is passed through the space filled with the helium gas 310 to form the hat 306 intervening layer 307. A number of structures have been devised and put into practical use, including a structure for transmitting the heat to the cooling plate 308 through the cooling plate 308 and releasing the heat to the refrigerant 309.

Japanese Patent Application Laid-Open No. 60-160150 discloses an example of a cooling device utilizing a collision jet of a liquid refrigerant. That is, as shown in FIG. 4, the heat generated by the chip 401 mounted on the printed board 402 is transferred to the heat transfer board 403, the deformable heat transfer body 404, and the heat transfer plate 405.
To cool the heat transfer plate 405 by injecting a cold refrigerant from the nozzle 406. The tip of the nozzle 406 is a heat transfer substrate 403,
It is sealed by a cooling header 408 and a bellows 407.

[Problems to be solved by the invention]

In the cooling structure of the conventional integrated circuit described above, in the example of FIG. 3, the piston 304 is brought into contact with the integrated circuit 301 using the spring 305, so that the integrated circuit 301 is always in a state where a force is applied. This may adversely affect the reliability of the connection between the 301 and the wiring board 302. In addition, in order to follow variations in height and inclination generated when the integrated circuit 301 is attached to the wiring board 302, the contact surface of the piston 304 with the integrated circuit 301 is spherical, and a clearance is provided between the hat 306 and the piston 304. However, these reduce the effective heat transfer area and reduce the cooling capacity. In addition, the refrigerant flow in the cooling plate is formed for the purpose of heat transfer by forced convection, and the obtained heat transfer coefficient is about 0.1 to 0.5 W / cm ℃. Then, the cooling capacity is insufficient.

In the example of JP-A-61-160150 (FIG. 4), a thin bellows is used.
Since the 407 is used, it is conceivable that corrosion occurs and a hole is formed in the bellows 407, and the liquid refrigerant leaks.

[Means for solving the problem]

The present invention relates to a cooling structure for an integrated circuit in which a plurality of integrated circuit elements mounted on a wiring board are cooled by a single cooling plate. The liquid refrigerant is vertically impacted on the inner surface of the cooling plate, and the outer surface of the cooling plate includes a cooler opposed to the integrated circuit element via a heat conductive compound.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention. 1
Reference numeral denotes an integrated circuit, and reference numeral 2 denotes a wiring board on which a plurality of integrated circuits 1 are mounted, and a metal frame 3 is attached so as to surround an outer edge thereof. Reference numeral 4 denotes a metal cooler having a liquid refrigerant flow path therein. The cooler 4 is divided into a plurality of header portions 9 and a plurality of cooling portions 13 by partitions 12, and the header portion 9 and the cooling portion 13 are provided with a nozzle 10 and a hole 14 respectively.
, And a plurality of rows of the header section 9 and the cooling section 13 connected in series as described above are provided in parallel. The cooler 4 is fixed to the frame 3 with screws 6 so as to form a minute gap between the cooling plate 5 on the surface facing the integrated circuit 1 and the integrated circuit 1. Integrated circuit 1 and cooling plate 4
Is filled with a thermally conductive compound 7. The thermally conductive compound 7 is made by mixing a thermally conductive material such as metal oxide or boron nitride as a filler with a base material such as silicon oil.

FIG. 2 shows the flow path of the liquid refrigerant in the embodiment of FIG. The liquid refrigerant that has entered the cooler 4 through the refrigerant inlet 8 flows into the header 9 closest to the inlet. From there, it is jetted to the cooling unit 13 through the nozzle 10, collides with the surface facing the integrated circuit 1 and the cooling plate 5, and flows out to the next header through the hole 14. After passing through some of the header portions 9 and the nozzles 10 arranged in series in this way, the refrigerant finally exits the cooler 4 through the refrigerant outlet 11.

The heat generated in the integrated circuit 1 is transmitted to the cooling plate 5 through the heat conductive compound 7. The liquid refrigerant ejected from the nozzle 10 collides with the cooling plate 5 and heat is transferred here. According to the experiment, the jet velocity from the nozzle was 0.5-3.0m /
As a result, a heat transfer coefficient of 1 to 3 w / cm ° C. was obtained. Therefore, in the cooling structure of the present embodiment, by keeping the gap between the cooling plate 5 and the integrated circuit 1 sufficiently small, the thermal resistance from the integrated circuit 1 to the liquid refrigerant can be suppressed to 1 ° C./w or less. .

Further, the heat conductive compound 7 follows variations in height and inclination that occur when the integrated circuit 1 is mounted on the wiring board 2, so that no force is applied to the integrated circuit 1.
Further, if the cooling plate 5 is made of a metal having a high thermal conductivity such as beryllium copper, the increase in the thermal resistance value can be ignored even if the thickness of the cooling plate 5 is increased, and the formation of holes due to corrosion can be prevented. .

〔The invention's effect〕

As described above, the present invention is configured such that the liquid refrigerant ejected from the nozzle collides with the cooling plate on the surface of the cooling device facing the integrated circuit in the cooling device, and the integrated circuit and the cooling plate By filling the gap between them with a heat conductive compound, a high heat transfer coefficient can be obtained, and a cooling structure with high cooling performance and high reliability against corrosion can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, FIG. 2 is a schematic diagram showing a flow path of a liquid refrigerant in the embodiment shown in FIG. 1, and FIGS. 3 and 4 are conventional integrated circuits. It is sectional drawing which shows the cooling structure of a circuit. 1 ... integrated circuit, 2 ... wiring board, 3 ... frame, 4 ...
Cooler, 5 ... screw, 6 ... heat conductive compound, 7
... refrigerant inlet, 8 ... header, 9 ... nozzle, 10 ...
Cooling plate, 11: refrigerant outlet, 12: partition, 13: cooling unit,
301 …… integrated circuit, 302 …… wiring board, 303 …… I / O pin,
304 ... piston, 305 ... screw, 306 ... hat, 307 ...
... intervening layer, 308 ... cooling plate, 309 ... coolant, 401 ... chip, 402 ... printed board, 403 ... heat transfer board, 404 ...
Deformable heat transfer body, 405… Heat transfer plate, 406… Nozzle, 407
…… Bellows, 408 …… Cooling header.

Claims (1)

(57) [Claims] An integrated circuit cooling structure for cooling a plurality of integrated circuit elements mounted on a wiring board by a single cooling plate, wherein a nozzle is passed from a header portion provided inside to a non-flexible cooling portion through a nozzle. The ejected liquid refrigerant collides perpendicularly with the inner surface of the cooling plate, and faces the integrated circuit device by interposing a heat conductive compound that follows variations in height and inclination of the integrated circuit device on the outer surface of the cooling plate. A cooling structure for an integrated circuit, comprising a cooler.