JPS6211510B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling structure for an LSI package.

From the viewpoint of reliability, it is important to maintain the temperature of elements such as large-scale integrated circuits (hereinafter referred to as LSI) that are widely used in electronic devices at a constant temperature.

Conventionally, the cooling structure for LSI packages is such that a heat sink is pressure-bonded or fixed to the back side of the LSI mounting surface of the LSI package board, and this is forcedly cooled by a blower.
It is conducted through the LSI package board to the heat sink, and from the heat sink to the air.

Generally, LSIs have strict temperature limits in order to guarantee their operation, and the temperature of LSIs must be kept below a certain limit. However, with the recent progress in semiconductor technology, the degree of integration of LSIs has increased dramatically, so the amount of heat generated has only increased.
In conventional cooling structures, the thermal resistance from the heat sink to the air is large, and even with the use of a large heat sink and large blower, the current situation is that the temperature of the LSI cannot be kept below the temperature limit.

An object of the present invention is to provide an LSI package cooling structure with excellent cooling capacity.

In order to achieve the above object, an LSI according to the present invention
A package cooling structure is a cooling structure that diffuses and cools the heat generated by a large number of LSI packages mounted on a board. A cooling module is provided that is close to or in contact with a Ni-Ti alloy or Cu-Zn-Al alloy, etc., which is the body, and allows a liquid coolant to flow through the inside, so that when the temperature of the LSI increases, the heat transfer body deforms. The cooling module is configured to be in pressure contact with the cooling module.

According to the above configuration, the object of the present invention is completely achieved.

Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the cooling structure according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG.

A large number of LSIs 1 are mounted on an LSI package board 2, and each of these LSIs 1 has two Ni heat transfer bodies 3, each having a bimetallic structure with a U-shaped cross section.
-Ti alloy or Cu-Zn-Al alloy, etc. is fixed with the opening facing inside. The heat transfer body 3 and the cooling module 7 are sandwiched between frames 8, 8 so as to fix the cooling module 7 with a gap between the heat transfer body 3 and the heat transfer body 3. The cooling module 7 is provided with a supply port 5 and a discharge port 6 for the liquid refrigerant 4, through which the liquid refrigerant 4 flows.

Heat generated from the LSI 1 is transmitted through the LSI package board 2 to the surrounding air through a first path, from the bimetal heat transfer body 3 fixed to the LSI 1, through the cooling module 7, and from the supply port 5 to the discharge port 6. The heat is radiated through two paths, the second path being conducted to the liquid refrigerant 4 that is constantly flowing.

However, since the thermal resistance of the first path, which is transmitted from the LSI package board 2 to the surrounding air, is extremely large, most of the heat is radiated through the second path, that is, from the bimetal heat transfer body 3 through the cooling module 7. Ru.

In the second path from the bimetal heat transfer body 3 to the cooling module 7, most of the paths from the LSI 1 to the bimetal heat transfer body 3 and from the cooling module 7 to the liquid refrigerant 4 are good thermal conductors, so the thermal resistance is kept low. be able to. Since the heat transfer body has a bimetal structure in order to conduct heat from the bimetal heat transfer body 3 to the cooling module 7 with low thermal resistance, when the temperature of the LSI 1 increases, the bimetal heat transfer body 3 deforms and transfers heat to the cooling module 7. being pressed together,
The thermal resistance is low, and the pressure contact force increases in proportion to the rise in the temperature of the LSI 1, making it possible to lower the thermal resistance even further.

Although the heating element has been described above as an LSI, the present invention is similarly applicable to other heating elements. Further, the heat transfer body and the cooling module may be provided in contact with each other from the beginning.

As explained above, the present invention employs a heat transfer body having a bimetal structure in the heat dissipation path of a heat generating element such as an LSI, so that the thermal resistance of the heat dissipation path decreases as the temperature rises, so the temperature of the heat generating element can be kept constant. This has the effect of improving the cooling capacity of the LSI package.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of the cooling structure according to the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. 1...LSI, 2...LSI package board, 3...bimetal heat transfer body, 4...liquid refrigerant, 5...supply port, 6...
Discharge port, 7...cooling module, 8...frame.

Claims (1)

[Claims] 1 In a cooling structure that diffuses and cools the heat generated by a large number of LSI packages mounted on a board, the above-mentioned
One or more heat transfer bodies each having a bimetallic structure are provided on the LSI, and a cooling module that is close to or in contact with the heat transfer body and allows a liquid coolant to flow through the inside thereof is provided, and when the temperature of the LSI rises, the A cooling structure for an LSI package, characterized in that a heat transfer body is configured to deform and come into pressure contact with the cooling module.