JP2000323631A - Mounting structure for ic chip substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of assembly parts of an IC chip substrate, and to mount this IC chip substrate on a heat sink in a compact constitution. SOLUTION: A heat conductive grease layer 28 is formed between a substrate 26 on which an IC chip 22 is mounted and a heat sink 40, and the substrate 26 is mounted on the heat sink 40 with a spring 30 constituted of a spiral release edge 34 butted to the substrate for pressurizing the substrate 26 to the heat sink 40 and as cantilever part 32 mounted and fixed to the heat sink 40. The grease layer 28 allows the thermal deformation of the substrate 26, and the free end 34 of the spring 30 is butted to the substrate 26 at the lowermost point of the spiral shape so that, even when the substrate 26 is thermally deformed, the substrate 26 can be continuously pressurized following the deformation. As a result, the IC chip substrate can be mounted on the heat sink in a simple constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for an IC chip substrate, and more particularly, to a mounting structure for mounting an IC chip substrate on a heat sink.

[0002]

2. Description of the Related Art Conventionally, as a mounting structure of this type of IC chip substrate, a heat sink is placed on a module cap of a multi-chip module via a heat conductive grease, and the heat sink is pressed down from above with a predetermined pressing force. (For example, Japanese Patent Application Laid-Open No. 3-149861). In this mounting structure, as a means for pressing the heat sink on the module cap, a coil spring that applies a pressing force to the heat sink using a plate-shaped support material fixed to the clamp material as a reaction force acting material is used. It is said that the use of heat conductive grease can follow the external force on the heat sink, the pressure of the coolant, and the thermal expansion.

[0003]

However, such a mounting structure has a problem that the number of assembling parts is large, the number of assembling steps is increased, and the manufacturing cost is increased. In addition, it is necessary to provide a support material to support the reaction force of the coil spring, and there is a problem that the size is increased.

[0004] One of the objects of the present invention is to reduce the number of parts to be assembled and the manufacturing cost. Another object of the present invention is to reduce the size of the structure for mounting an IC chip substrate.

[0005]

Means for Solving the Problems and Actions and Effects Thereof The mounting structure of the IC chip substrate according to the present invention employs the following means in order to achieve at least a part of the above object.

A first mounting structure for an IC chip substrate according to the present invention is a mounting structure for mounting an IC chip substrate on a heat sink, wherein the heat conductive grease layer interposed between the IC chip substrate and the heat sink is provided. IC
The gist of the present invention comprises a pressing means which presses the chip substrate against the heat sink with a predetermined pressing force and can follow thermal deformation of the IC chip substrate.

In the first structure for mounting an IC chip substrate according to the present invention, the grease layer transmits heat of the IC chip substrate to the heat sink and allows thermal deformation of the IC chip substrate. The IC chip substrate is pressed against the heat sink with a predetermined pressing force while following the deformation. As a result, the heat of the IC chip substrate can be efficiently transmitted to the heat sink, and
It can follow the thermal deformation of the C chip substrate.

In the first structure for mounting an IC chip substrate according to the present invention, the pressing means is a cantilever spring which presses the IC chip substrate at a release end formed in a spiral shape. You can also. In this case, an inexpensive and compact structure can be obtained.

A second mounting structure for an IC chip substrate according to the present invention is a mounting structure for mounting the IC chip substrate on a heat sink, wherein the heat conductive grease layer interposed between the IC chip substrate and the heat sink is provided. IC
The gist comprises a deformation absorbing means capable of absorbing thermal deformation of the chip substrate, and an attaching means for attaching the IC chip substrate to the heat sink via the deformation absorbing means.

[0010] In the second structure for mounting an IC chip substrate according to the present invention, the grease layer transmits heat of the IC chip substrate to the heat sink and allows thermal deformation of the IC chip substrate. The IC chip substrate is attached to the heat sink via deformation absorbing means for absorbing deformation. As a result, the heat of the IC chip substrate can be efficiently transmitted to the heat sink, and the heat deformation of the IC chip substrate can be followed.

In the second structure for mounting an IC chip substrate according to the present invention, the deformation absorbing means includes
It may be rubber interposed between the chip substrate and the mounting means. In this case, an inexpensive and compact structure can be obtained.

[0012]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 shows an embodiment of the present invention.
The IC chip 22 is attached by the mounting structure 20 of the C chip substrate.
FIG. 2 is a cross-sectional view illustrating a state where the substrate 26 of the IC chip 22 is mounted on the heat sink 40 by the mounting structure 20 of the IC chip substrate of the embodiment. It is a top view. IC chip substrate mounting structure 20 of embodiment
As shown in the figure, a heat conductive grease layer 28 is interposed between a substrate 26 to which the IC chip 22 is attached and a heat sink 40, and a spring 30 for pressing the substrate 26 against the heat sink 40.

The grease layer 28 includes a thermally conductive grease,
For example, the substrate 26 is made of high thermal conductive silicon grease.
Is formed around the substrate 26 in addition to the entire lower surface. The grease layer 28 transfers heat of the substrate 26 to the heat sink 40.
And allows thermal deformation of the substrate 26.

The spring 30 is made of an elastic material, for example, carbon steel or spring steel. The spring 30 has a spiral-shaped open end 34 that abuts the substrate 26 and presses the substrate 26 against the heat sink 40, and a bolt 49 together with a lid 48. A cantilever section 32 attached to and fixed to the heat sink 40. The cantilever portion 32 is formed by folding a plate material and is formed in a double shape so that sufficient strength can be obtained for a bending moment acting as a reaction force of the elastic deformation of the open end portion 34. The open end 34 is formed in a spiral shape as described above, and presses the substrate 26 against the heat sink 40 at the lowest point. Therefore, the release end 34
Can follow the displacement even if the contact point is slightly displaced in the vertical and horizontal directions in FIG. 1 due to the thermal deformation of the substrate 26.

The IC chip 22 is attached to a substrate 26 formed of a thermally conductive ceramic (for example, AlN) by a brazing material 24 such as nickel brazing or silver brazing. It is sealed by gel 38. Further, a cooling water passage 42 is formed in the heat sink 40 so that the transferred heat can be cooled by carrying the transferred heat to the outside.

According to the IC chip substrate mounting structure 20 of the embodiment described above, the provision of the grease layer 28 allows the heat of the substrate 26 of the IC chip 22 to be efficiently transmitted to the heat sink 40, and the grease layer 28 And the spring 30, it is possible to follow the thermal deformation of the substrate 26 of the IC chip 22. In addition, since both the grease layer 28 and the spring 30 have a simple configuration, the structure can be made inexpensive and small.

IC chip substrate mounting structure 2 of the embodiment
At 0, the open end 34 of the spring 30 has a spiral shape, but may have any shape as long as it can move in the vertical and horizontal directions in FIG. For example, it may be formed in a coil shape.

IC chip substrate mounting structure 2 of the embodiment
0, the substrate 2 to which one IC chip 22 is attached
Although the structure for attaching the IC chip 6 to the heat sink 40 has been described, the substrate 26B to which the plurality of IC chips 22 are attached may be attached to the heat sink 40B as illustrated in FIG.

Next, an IC according to a second embodiment of the present invention will be described.
The chip substrate mounting structure 120 will be described. FIG. 4 is a cross-sectional view illustrating a state where the substrate 26 of the IC chip 22 is mounted on the heat sink 40 by the IC chip substrate mounting structure 20 of the second embodiment, and FIG.
According to the IC chip substrate mounting structure 20 of the embodiment, the IC
FIG. 6 is a plan view illustrating a state where the substrate 26 of the chip 22 is mounted on the heat sink 40, and FIG. 6 is an enlarged cross-sectional view illustrating a cross section of the mounting portion 130 in the mounting structure 120 of the IC chip substrate according to the second embodiment. It is. FIG.
6A to 6C show the IC of the first embodiment for ease of explanation.
The same components as those of the mounting structure 20 of the chip substrate are denoted by the same reference numerals. Therefore, the description of the same configuration will be redundant and will be omitted.

As shown, the IC chip substrate mounting structure 120 of the second embodiment includes a thermally conductive grease layer 28 interposed between the substrate 26 to which the IC chip 22 is mounted and the heat sink 40, and the substrate 26. Heat sink 40
And an attachment portion 130 to be attached to the camera.

As shown in FIG. 6, the mounting portion 130
A deformation absorbing member 13 made of an elastically deformable material, for example, a rubber material such as fluoro rubber or a lubricating resin such as Teflon, and absorbing thermal deformation of the substrate 26 by its elastic deformation.
2 and mounting bolts 134 for mounting and fixing the substrate 26 to the heat sink 40 via the deformation absorbing member 132.
And As shown in FIG. 6, the deformation absorbing member 132 includes a cylindrical portion 132a and a cylindrical portion 13 formed in a cylindrical shape.
Edge 132 provided outward from the circumference of one end of 2a
b, and is fitted into a through hole 26a provided in the substrate 26 from above and below. Since the deformation absorbing member 132 is made of an elastically deformable material as described above, the elastic deformation of the cylindrical portion 132a can absorb the thermal deformation of the substrate 26 in the left-right direction in FIG. 13
The elastic deformation of 2b can absorb thermal deformation of the substrate 26 in the vertical direction in FIG.

According to the IC chip substrate mounting structure 120 of the second embodiment described above, since the substrate 26 is mounted on the heat sink 40 by the mounting bolt 134 via the deformation absorbing member 132, the substrate 26 of the IC chip 22
Can follow the thermal deformation of In addition, since both the deformation absorbing member 132 and the mounting bolt 134 have a simple configuration, an inexpensive and compact structure can be achieved. Of course,
By providing the grease layer 28, heat of the substrate 26 of the IC chip 22 can be efficiently transmitted to the heat sink 40.

In the IC chip substrate mounting structure 120 of the second embodiment, the deformation absorbing member 132 is formed by two members, but may be formed by one member. Further, in the IC chip substrate mounting structure 120 of the second embodiment, the edges 132b are formed on the upper and lower sides of the deformation absorbing member 132, but the edges 132b may be formed on only one of the upper and lower sides.

In the mounting structure 120 of the IC chip substrate of the second embodiment, the substrate 26 on which one IC chip 22 is mounted is described as the structure for mounting on the heat sink 40. It may be structured to be attached to a heat sink.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a state where an IC chip substrate is mounted on a heat sink by an IC chip mounting structure 20 according to one embodiment of the present invention.

FIG. 2 is a plan view illustrating a state in which an IC chip substrate is attached to a heat sink by an IC chip attachment structure 20 according to the embodiment.

FIG. 3 is an explanatory diagram showing an example of a structure for attaching a substrate 26B to which a plurality of IC chips 22 are attached to a heat sink 40B.

FIG. 4 shows that the substrate 26 of the IC chip 22 is mounted on the heat sink 4 by the IC chip substrate mounting structure 20 of the second embodiment.
It is sectional drawing which illustrates the mode attached to 0.

FIG. 5 shows that the substrate 26 of the IC chip 22 is connected to the heat sink 4 by the IC chip substrate mounting structure 20 of the second embodiment.
It is a top view which illustrates the mode attached to 0.

FIG. 6 is an enlarged cross-sectional view showing an enlarged cross section of a mounting portion 130 in the IC chip substrate mounting structure 120 according to the second embodiment.

[Explanation of symbols]

20 Mounting structure of IC chip substrate of first embodiment, 2
2 IC chip, 24 brazing material, 26 substrate, 26a through hole, 28 grease layer, 30 spring, 32 cantilever, 34 open end, 38 sealing gel, 40 heat sink, 42 cooling water passage, 120 second implementation Example mounting structure of IC chip substrate, 130 mounting part,
132 deformation absorbing member, 132a cylindrical portion, 132b
Rim, 134 mounting bolts.

Claims (4)

[Claims] 1. A mounting structure for mounting an IC chip substrate to a heat sink, comprising: a thermally conductive grease layer interposed between the IC chip substrate and the heat sink; A mounting structure for an IC chip substrate, comprising: pressing means capable of pressing and following thermal deformation of the IC chip substrate. 2. The mounting structure for an IC chip substrate according to claim 1, wherein said pressing means is a cantilever spring which presses said IC chip substrate at a release end formed in a spiral shape. 3. A mounting structure for mounting an IC chip substrate to a heat sink, comprising: a thermally conductive grease layer interposed between the IC chip substrate and the heat sink; and a deformation absorbing member capable of absorbing thermal deformation of the IC chip substrate. Mounting means for mounting the IC chip substrate to the heat sink via the deformation absorbing means. 4. The mounting structure for an IC chip substrate according to claim 3, wherein said deformation absorbing means is rubber interposed between said IC chip substrate and said mounting means.