JPH0322555A - Cooling device for integrated circuit - Google Patents

Abstract

PURPOSE:To make it possible to follow freely the relative displacements in all directions between integrated circuits and a heat sink by a plurality of second thermal conductors consisting of a plurality of tabular fins to mesh with the fins of first thermal Conductors by a method wherein the second thermal conductors are arranged between a plurality of pairs of the first thermal conductors consisting of a plurality of fins. CONSTITUTION:Heat generated in each integrated circuit 25 is transmitted to the bottom of a base 2a of a first thermal Conductor 2 on the side of the Circuit 25 and thereafter, is transmitted in order to fins 2b, fins 5b and 5c of second thermal conductors 5, fins 3b of a first thermal conductor 3 on the side of a heat sink 26, a base 3a and a cap 28 and is cooled by a cooler 30. In this case, the displacement in a direction X among the relative displacements between the circuits 25 and the sink 26 is absorbed between the first and second conductors 2 and 5 on the side of the circuits 25, the displacement in a direction Y is absorbed between the first and second conductors 3 and 5 on the side of the sink 26 and the displacement in a direction Z is absorbed between a pair of the first thermal conductors 2 and 3 and the second thermal conductors 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an integrated circuit cooling device suitable for cooling heat generated from an integrated circuit. Ru.

[Conventional technology]

Conventionally, large-scale integrated circuits or their packages (
As a means for cooling the heat generated from integrated circuits (hereinafter simply referred to as integrated circuits), air cooling methods using forced convection are often adopted. However, in recent years, due to the improvement in the degree of integration of the elements themselves and the improvement in the packaging density of the elements, the heat generation density has become significantly higher, and the above-mentioned air cooling method can no longer cope with this.

Therefore, it is desired to adopt a liquid cooling system, but in order to do so, it is necessary to absorb various displacements such as warpage of circuit boards, displacement during mounting of integrated circuits, deformation during assembly of the cooling device structure, and thermal deformation. A cooling device that has the ability to efficiently transfer heat from an integrated circuit that generates heat to a cooling section that contains refrigerant or cooling water, and that allows easy attachment and detachment of the cooling section and the mounting section of the integrated circuit. is inconclusive.

Regarding such a cooling device, conventionally, for example, Japanese Patent Application Laid-open No. 5
7-10337 discloses a cooling device as shown in FIGS. 5 to 7. In the figure, reference numerals 21 and 22 denote bases 2la and 22a made of a material with good thermal conductivity such as copper or aluminum, and bases 21a and 22a.
, 22a, and a plurality of fins 2lb, 22b made of the same material, which are integrally molded or bonded to the fins 2lb, 22b, respectively, and are a plurality of pairs of heat conductors formed in a tooth shape. Base 21a
, 22a are integrated circuits 25 mounted on the circuit board 23.
A cap 2 comprising a sink 2G to the surface and heat 1
8 is attached to the inner surface of each. Fin 2lb, 2
2b are engaged with each other so as to face each other with a small gap a in the horizontal direction and a sufficient gap b in the vertical direction. The space within the cap 28 and the minute gap a are filled with a gas having good thermal conductivity, such as helium gas or hydrogen gas.

The heat generated in the integrated circuit 25 is transferred to the thermal conductor 21.
22 and the cap 28, and is transmitted to the cooler 30 and cooled.

In FIG. 5, reference numeral 31 denotes a plurality of lead pins implanted on the bottom surface of the circuit board 23, each of which is electrically connected to the integrated circuit 25.

[Problem to be solved by the invention]

However, according to the above-mentioned conventional technology, the integrated circuit 25 and the heater 1
・The relative displacement in the Z direction and the X direction with respect to the sink 26 is as follows:
As shown in FIG. 7, the fins 2lb and 22b of the pair of heat conductors 21 and 22 are interlocked in a comb-like shape, and the structure allows for free displacement in two directions and the X direction, so that Although it has the ability to absorb displacement, the relative displacement in the Y direction can only be absorbed by the minute gap a between the fins 2lb and 22b. That is, in reality, the ability to absorb relative displacement in the Y direction 3 is small, and the contact thermal resistance increases accordingly, resulting in a problem that the cooling performance deteriorates.

An object of the present invention is to provide a cooling device for an integrated circuit that can freely follow relative displacements of the integrated circuit and the heat sink in all directions.

[Means to solve the problem]

To achieve this purpose, the present invention provides pudding! - A cooling device that cools the heat generated from multiple integrated circuits mounted on a circuit board such as a wiring board or a ceramic board using a heat sink installed at a position facing the integrated circuit mounting surface of the circuit board. , a plurality of pairs of bases each having one attached to the plurality of integrated circuits and the other attached to the heat sink, and a plurality of flat fins integrally formed upright on the plurality of pairs of bases. 1 thermal conductor, a plurality of bases disposed between the plurality of pairs of first thermal conductors and having substantially the same bottom area as the bases of the first thermal conductors; and a plurality of second heat conductors formed of a plurality of flat plate-shaped fins that are formed and mesh with the plurality of pairs of first heat conductor fins.

[Effect]

According to the above configuration, among the relative displacements between the integrated circuit and the heat sink due to thermal deformation of the integrated circuit, deformation of the circuit board on which the integrated circuit is mounted, deformation of the heat sink, etc., displacement in the X direction is are the first thermal conductor and the second thermal conductor on the integrated circuit side.
In the heat conductor, the displacement in the Y direction is the first heat conductor and the second heat conductor on the heat sink side, and the displacement in the Z direction is the first heat conductor and the second heat conductor on the heat sink side.
It is absorbed by the heat conductor and the second heat conductor, respectively.

〔Example〕

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

1 to 3 relate to a first embodiment of the present invention, and parts that are the same as those shown in FIG. 5 are given the same reference numerals, and their explanations will be omitted. The integrated circuit cooling device 1 includes a plurality of pairs of first heat conductors 2 and 3 and a plurality of second heat conductors 5.

The first thermal conductors 2 and 3 of the plurality of pairs are integrally connected to the plurality of pairs of heaths 2a and 3a having a bottom area larger than the surface area of the integrated circuit 25 and the bases 2 a r 3 a J2 upright, for example, perpendicularly. A plurality of flat fins 2b, 3 formed in
It consists of b. The plurality of second thermal conductors 5 are arranged between the plurality of pairs of first thermal conductors 2 and 3, and are arranged between the first thermal conductors 2 and 3.
It consists of a plurality of bases 5a having almost the same bottom area as the bases 2a, 3a of No. 3, and a plurality of flat plate-shaped fins 5b, 5c integrally formed orthogonally to both surfaces of the bases 5a. , the fins 5b, 5c are arranged perpendicularly to each other. Also, one of the first thermal conductor 2 or the second thermal conductor 5
is made of a material that is rich in electrical insulation and has high thermal conductivity, such as SiC material.

The base 2a of one first thermal conductor 2 is placed on the integrated circuit 25, and the base 3a of the other first thermal conductor 3 is placed on the cap 2 with the arrangement direction of the fins 3b orthogonal to the fins 2b.
The fins 5b,
5c are engaged with the fins 2b and 3b of the ↓th thermal conductors 2 and 3 with a sufficient gap d in the vertical direction and a minute gap in the horizontal direction.

Next, the operation of the first embodiment of the present invention will be explained.

The heat generated in the integrated circuit 25 is transferred to the bottom surface of the base 2a of the first heat conductor 2 on the integrated circuit 25 side, and then sequentially to the fin 2b, the fins 5b and 5c of the second heat conductor 5, and the heat sink 26 side. The heat is transmitted to the fins 3b, base 3a, and cap 28 of the first heat conductor 3, and is cooled by the cooler 30.

In this case, among the relative displacements between the integrated circuit 25 and the heat sink 26 due to thermal deformation of the integrated circuit 25, deformation of the circuit board 23, deformation of the heat sink 26, etc., as shown in FIG. The displacement is between the first thermal conductor 2 and the second thermal conductor 5 on the integrated circuit 25 side, and the displacement in the Y direction is between the first thermal conductor 3 and the second thermal conductor 5 on the heat sink 26 side. The displacement in the Z direction is absorbed between the pair of first thermal conductors 2 and 3 and second thermal conductor 5. In this way, the displacement in the direction of the bus can be absorbed, and as a result, the heat generated by the integrated circuit 25 can be transferred to the heat source with high heat transfer performance.
~ can be conveyed to the cap 28 which is the sink 26.

Note that a plurality of first thermal conductors 3 on the heat 1/sink 26 side may be formed integrally, or may be formed integrally with the heat 1/sink 26. Further, the first thermal conductor 2 on the side of the frozen accumulation path 25 may be formed integrally with the integrated circuit 25. Furthermore, the pair of first thermal conductors 2 and 3 may be simultaneously formed integrally with the integrated circuit 25 and the heat sink 26, respectively. As described above, by changing the body shape, contact resistance can be eliminated between each direction without changing the ability to absorb displacement in each direction, and cooling performance is further improved.

Further, in the above-described first embodiment, each fin is shaped to be perpendicular to the base, but it may be shaped to be oblique to the base.

FIG. 4 relates to a second embodiment of the present invention, and the difference from the first embodiment is that the base 2a of a pair of i'th thermal conductors 2 and 3 is
, 3a are not fixed to the surface of the integrated circuit 25 or the inner surface of the cap 28, and the compression spring 8 (the first compression spring 8) whose spring force acts in the direction of mutually repulsive forces between the bases 2a, 3a and the base 5a. The bases 2a and 3a are pressed against the surface of the integrated circuit 25 and the inner surface of the cap 28 by the compression spring 8, and are brought into close contact with each other by frictional force.

Other structures and operations are similar to those shown in the first embodiment.

〔Effect of the invention〕

As described above, according to the present invention, when an integrated circuit is mounted on a circuit board, there are various problems such as uneven tilt or height, warpage of the circuit board, deformation and thermal deformation that occur when assembling the structure of the cooling device. It can freely follow displacement, and the heat generated in the integrated circuit can be efficiently transferred to the heat sink by thermal conduction, resulting in high heat transfer performance and improved cooling performance. .

[Brief explanation of drawings]

Figures 1 to 3 relate to the first embodiment of the wooden invention, in which Figure 1 is a longitudinal cross-sectional view of the cooling device, Figure 2 is an exploded perspective view of the first and second heat conductors, and Figure 3 is an exploded perspective view of the first and second heat conductors. A perspective view showing the meshing state of the first and second heat conductors, and FIG. 4 is a partially cutaway perspective view showing the meshing state of the first and second heat conductors according to the second embodiment of the present invention. , FIG. 5 to FIG. 7 relate to the conventional example, FIG. 5 is a longitudinal sectional view of the cooling device, FIG. 6 is a perspective view of the heat conductor, and FIG. 7 shows the meshing state of a pair of heat conductors. FIG. DESCRIPTION OF SYMBOLS 1... Integrated circuit cooling device, 2, 3... First thermal conductor, 2a, 3a... Base of first thermal conductor 2, 3, 2b,
3b...Fins of the first thermal conductors 2, 3, 5...Second
Thermal conductors, 5a... Base of the second heat conductor 5, 5b, 5c... Fins of the second heat conductor 5.

Claims (3)

[Claims] (1) A cooling device that cools the heat generated from multiple integrated circuits mounted on a circuit board such as a printed wiring board or a ceramic board using a heat sink installed at a position facing the integrated circuit mounting surface of the circuit board. , a plurality of pairs of bases each having one attached to the plurality of integrated circuits and the other attached to the heat sink, and a plurality of flat fins integrally formed upright on the plurality of pairs of bases. 1 thermal conductor, a plurality of bases disposed between the plurality of pairs of first thermal conductors and having substantially the same bottom area as the bases of the first thermal conductors; a plurality of second heat conductors comprising a plurality of flat plate-shaped fins that are formed and mesh with the fins of the plurality of pairs of first heat conductors. (2) The integrated circuit cooling device according to claim 1, wherein a plurality of first thermal conductors on the heat sink side are integrally formed. (3) Claim 1, wherein each of the plurality of pairs of first thermal conductors is formed integrally with the plurality of integrated circuits and the heat sink.
Cooling device for the described integrated circuit.