JP2002368166A - Jointing structure between heat sink and heat-diffusion plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily form a stable and quality jointing structure, and to provide the jointing structure between a heat sink and a thermal diffusion plate where components of superior heat dissipation performance, and which are easily separated, are utilized for recycling at a low cost. SOLUTION: A heat conducting adhesion material layer 4 is sandwiched tightly between a heat sink and a thermal diffusion plate 2, while the heat sink 3 and the thermal diffusion plate 2 are fixed detachably to each other. Preferably, mutual fixing is conducted, using a screwing means 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between a heat sink and a heat diffusion plate used for cooling a heat-generating portion such as a CPU in an electronic device such as a personal computer.

[0002]

2. Description of the Related Art A CPU (10) of an electronic device such as a personal computer is used.
1) is generally fixed on a socket (103) mounted on a circuit board (102) as shown in FIG. 6, but the heat generated from the CPU (101) is efficiently reduced. In order to dissipate heat well, a heat sink (105) is often bonded on the CPU (101). In recent years, as the performance of the CPU (101) has been improved,
Since the amount of heat generated from (101) tends to increase, it has been strongly required to improve the heat radiation performance. In particular, when the heat sink (105) is made of aluminum, it is particularly strongly required to improve the heat radiation performance because the heat generating element is extremely small and the heat is particularly difficult to spread to the end portion. In response to such a demand for improved heat radiation performance, a means for increasing the thickness of the substrate may be considered, but adopting such a means increases the overall height and can respond to recent demands for miniaturization. In addition, there is a problem that the weight is increased due to the increase in the plate thickness, so that the weight cannot be reduced.

[0003] In response to the demand for improved heat radiation performance, FIG.
As shown in the figure, the heat sink (105) and the CPU (10)
A heat diffusion plate (106) having excellent heat conductivity is arranged between 1), and the heat diffusion plate (106) and the heat sink (105) are joined with an adhesive or by soldering. A technique has been adopted.

[0004]

However, the method of joining with the adhesive and the method of joining with soldering are as follows.
In any case, the joining work is not easy, and in this connection, the condition management is technically quite difficult, and it was not easy to produce a stable and high quality joint structure,
The heat dissipation performance was not yet satisfactory.

In recent years, there has been a strong social demand for the recycling of industrial products and the like. However, in the above-mentioned conventional joining method using an adhesive or joining method using soldering, the dissimilar metals joined to each other are not bonded. It is necessary to use a special separation technique to separate the compounds from each other, and this requires a very high cost for the separation, so that there is a problem that they cannot be practically recycled.

The present invention has been made in view of such a technical background, and it is possible to easily form a stable and high-quality joining structure, to have excellent heat radiation performance, and to perform an operation of separating each component. An object of the present invention is to provide a joint structure between a heat sink and a heat diffusion plate which is easy and can be used at low cost for recycling.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors have conducted intensive studies and as a result, sandwiched a heat conductive adhesive material layer in close contact with a heat sink and a heat diffusion plate, and It has been found that the above-described desired joint structure can be formed by adopting a configuration in which the heat-dissipating plate and the heat diffusion plate are removably fixed to each other, and the present invention has been completed.

That is, in the joint structure of the heat sink and the heat diffusion plate according to the present invention, the heat sink and the heat diffusion plate are detachably connected to each other through the heat conductive adhesion material layer disposed therebetween. It is characterized by being fixed.

Since a heat conductive adhesive layer in close contact with the heat sink and the heat diffusion plate is interposed between the heat sink and the heat diffusion plate, heat can be efficiently conducted from the heat diffusion plate to the heat sink, thereby providing excellent heat dissipation performance. Is secured.
Further, since the heat sink and the heat diffusion plate are removably fixed to each other, the heat sink, the heat diffusion plate, and the heat conductive adhesive layer can be easily separated from each other. Can be recycled, and the effective use of resources can be sufficiently achieved.

It is preferable that the heat sink and the heat diffusion plate are removably fixed to each other by screwing means.
Since the heat conductive adhesive layer is sandwiched by being tightened by the screwing means, the heat conductive adhesive layer becomes sufficiently adhered to the heat sink or the heat diffusion plate, and therefore, heat conduction from the heat diffusion plate to the heat sink is performed. This is performed more efficiently, and the heat radiation performance is further improved. In addition, since the fastening is fixed by the screwing means, a stable joining structure can be formed, and both the joining operation and the separating operation are further facilitated, and the recycling operation is further facilitated.

When the heat conductive adhesive layer is made of a heat conductive elastic sheet, the sheet has elasticity. It becomes more fully adhered to the diffusion plate, and also adheres well to the uneven surface, so that efficient heat conduction from the heat diffusion plate to the heat sink is reliably performed, and more excellent The heat radiation performance is reliably ensured. Furthermore, when the heat sink and the heat diffusion plate are separated from each other and recycled, the heat sink, the heat diffusion plate, and the heat conductive elastic sheet can be completely separated from each other. Since there is no residue of the thermally conductive adhesive material layer on the surface, there is also an advantage that these can be provided for recycling in a form with very few impurities. It is particularly preferable to use a heat-conductive silicone rubber sheet as the heat-conductive elastic sheet, since the heat dissipation performance can be further improved and the electrical insulation can be further improved.

In the case where the heat conductive adhesive material layer is formed by hot melting a hot melt type heat conductive resin sheet while sandwiching it between the heat sink and the heat diffusion plate, Even if the surface of the heat diffusion plate has irregularities, the hot melt resin enters the recesses due to the thermal melting, and the heat conductive adhesive material layer can sufficiently adhere to these irregular surfaces. In addition, efficient heat conduction from the heat diffusion plate to the heat sink is reliably performed, and more excellent heat radiation performance is reliably ensured. Further, as described above, when the heat sink and the heat diffusion plate are separated from each other and recycled, no residue of the heat conductive adhesive layer remains on any surface of the heat sink and the heat diffusion plate. There is also an advantage that these can be recycled in a form with little waste. The term “thermal melting” is
The term “thermal softening” is used to mean “thermal softening”.

When the heat conductive adhesive material layer is made of a heat conductive viscous substance, the viscous substance is kept on the surface even if the surface of the heat sink or the heat diffusion plate has irregularities. Since the heat conductive adhesive material layer enters the concave portion and sufficiently adheres to these uneven surfaces, efficient heat conduction from the heat diffusion plate to the heat sink is reliably performed, and more excellent. The heat radiation performance is reliably ensured. As this thermally conductive viscous substance, it is preferable to use thermally conductive grease.

In the case where a recess is formed on the contact surface of the heat diffusion plate with the heat generating portion and the screwed head of the screwing means is buried in the recess, the screwed head is higher than the surface of the heat diffusion plate. Since it does not protrude outward, the screw-in head can be prevented from coming into contact with this heat-generating portion when it is joined to a heat-generating portion such as a CPU, so that there is no structural limitation in design and the degree of freedom in structural design is increased. There are advantages that can be done.

It is preferable to use a heat sink made of aluminum and a heat diffusion plate made of copper. If such a configuration is adopted, heat conduction from the heat diffusion plate to the heat sink via the heat conduction sheet is performed more efficiently, and there is an advantage that the heat radiation performance can be further improved.

[0016]

1 and 2 show a joint structure of a heat sink and a heat diffusion plate according to an embodiment of the present invention. In this embodiment, a heat conductive adhesive material layer (4) made of a heat conductive elastic sheet is sandwiched between the substrate portion (3a) of the heat sink (3) and the heat diffusion plate (2) in a state of being in close contact with these. Thus, a joint structure in which the heat sink (3) and the heat diffusion plate (2) are detachably fixed to each other by using the screwing means (5) is formed.

The heat sink (3) is formed by an extrusion method. As shown in FIG. 2, a plurality of fins (3b) project from one surface of the substrate (3a) at predetermined intervals. A fixing hole (11) is formed in each of the four corners on the other surface of the substrate (3a). On the other hand, the heat diffusion plate (2) is formed in the same shape and the same size as the substrate portion (3a) of the heat sink,
Insertion holes (12) are formed in the four corners, respectively. The heat conductive elastic sheet (4) is
The heat diffusion plate (2) is formed to have substantially the same size as the heat diffusion plate (2).
The corners of the locations are obliquely cut.

As shown in FIG. 2, heat is applied to one surface (the side where the fixing holes are formed) of the substrate portion (3a) of the heat sink (3) via the heat conductive elastic sheet (4). The diffusion plate (2) is overlapped, and a screwing means (5) composed of a tapping screw is inserted through the insertion holes (12), (12), (12), and (12) of the heat diffusion plate (2). 3) Fixing holes (11) (1)
1) By screwing into each of (11) and (11), between the heat sink (3) and the heat diffusion plate (2), a heat conductive adhesive material layer (4) made of a heat conductive elastic material sheet in close contact with these. ) Is sandwiched, and a joint structure is formed in which the heat sink (3) and the heat diffusion plate (2) are fixed to each other by using screwing means (5).

According to the above-mentioned joining structure, the heat sink (3) and the heat diffusion plate (2) can be fixed to each other only by screwing the screwing means (5), so that the joining operation is very simple and easy. . Further, since the fixing state can be released only by unscrewing the screwing means (5), the separating operation is also very simple and easy. Further, since the heat sink (3) and the heat diffusion plate (2) are detachably fixed to each other by using the screwing means (5) and are not bonded to each other as described above, each component (A heat sink, a heat diffusion plate, and a heat conductive adhesive layer) can be easily and surely separated, so that these components can be recycled at a low cost and resources can be effectively used. Can be.

Further, in the above-mentioned joining structure, since the heat conductive adhesive layer (4) is interposed between the heat sink (3) and the heat diffusion plate (2) in a state of being in close contact with the heat sink (3) and the heat diffusion plate (2). ) To the heat sink (3) is efficiently conducted. Further, in the above embodiment, since the heat conductive adhesive material layer (4) is made of a heat conductive elastic sheet, that is, since the sheet has elasticity, the fastening and fixing by the screwing means (5) is performed. At this time, the heat conductive adhesive material layer (4) becomes more sufficiently adhered to the heat sink (3) and the heat diffusion plate (2), and furthermore adheres well to the uneven surface. Efficient heat conduction from the diffusion plate (2) to the heat sink (3) is ensured,
Excellent heat dissipation performance can be ensured.

Further, in this embodiment, the screwing means (5) is used to mutually fix the heat sink (3) and the heat diffusion plate (2), and such a screwing means (5) is used.
The heat conductive adhesive layer (4) is sandwiched between the heat sink (3) and the heat diffusion plate (2), so that the heat conductive adhesive layer (4) is It will be more fully adhered to 2).

Since the heat conductive adhesive layer (4) is disposed between the heat sink (3) and the heat diffusion plate (2) in close contact with the heat sink (3), the heat sink (3) is made of aluminum. But the heat easily spreads to the edge,
Even in such a case, excellent heat radiation performance can be secured.

As a material of the heat sink (3),
For example, aluminum, copper and the like can be mentioned, but from the viewpoint of weight reduction and cost reduction, it is preferable to use aluminum ones. Further, as a material of the heat diffusion plate (2), for example, copper, aluminum or the like can be mentioned, but it is preferable to use a copper-made material because heat diffusion is particularly excellent.

The heat conductive adhesive material layer (4) needs to be interposed between the heat sink (3) and the heat diffusion plate (2) so as to be in close contact with the heat sink (3) and the heat diffusion plate (2). However, as the thermally conductive adhesive material layer (4) that can be in such an intimate contact state, in addition to the thermally conductive elastic sheet used in the above-described embodiment, for example, a thermally conductive adhesive sheet may be used. A material formed of a dense material, or a material formed by hot-melting a hot-melt type thermally conductive resin sheet while sandwiching it between a heat sink (3) and a heat diffusion plate (2) can be used. .

If the heat conductive viscous substance is used, even if the surface of the heat sink (3) or the heat diffusion plate (2) has irregularities, the viscous substance also enters the concave parts and the heat conductive adhesive material layer ( 4) is sufficiently adhered to such an uneven surface. The heat conductive viscous substance is not particularly limited, but it is preferable to use a heat conductive grease, whereby workability can be improved and cost can be reduced.

Further, the hot-melt type thermally conductive resin sheet is hot-melted while being sandwiched between the heat sink (3) and the thermal diffusion plate (2) to form a thermally conductive adhesive material layer (4). When the configuration described above is adopted, even when the surface of the heat sink (3) or the heat diffusion plate (2) has irregularities, the hot-melt resin that has been melted by heat enters the recesses on the surface, so that the heat conductive adhesive layer (4) is sufficiently adhered to these uneven surfaces, and efficient heat conduction from the heat diffusion plate (2) to the heat sink (3) is reliably performed, and more excellent heat dissipation performance is ensured. Will be secured.

The screwing means (5) is not particularly limited as long as the heat sink (3) and the heat diffusion plate (2) can be detachably screwed and fixed. And a nut (see FIG. 4). In the present invention, the means for mutually fixing the heat sink (3) and the heat diffusion plate (2) is not limited to the screwing means (5), and other means can be adopted. Caulking may be employed.

In the above embodiment, the heat sink (3) is formed by extrusion. However, the heat sink (3) is not particularly limited to this. For example, skive cutting as shown in FIG. A skive heat sink (3) formed by processing may be used.

FIG. 3 is a sectional view of a joint structure according to another embodiment. In this embodiment, a recess (10) is formed at each corner of the contact surface of the heat diffusion plate (2) with the heat generating portion, and the screwing means (5) is screwed into the recess (10). The head (5a) is configured to be embedded. If such a configuration is adopted, the screw-in head (5a) does not protrude outward from the heat-generating portion contact surface of the heat diffusion plate (2). Since 5a) can be prevented from contacting the heat generating portion, there is an advantage that there is no structural limitation in design and the degree of freedom in structural design can be increased.

FIG. 5 shows an example in which the joint structure of the heat sink and the heat diffusion plate of the present invention is applied to a semiconductor product. In this semiconductor product, a CPU (51) is fixed on a socket (53) mounted on a circuit board (52), and a heat sink (3) shown in FIG. ) And the heat diffusion plate (2) are joined and integrated with the heat diffusion plate (2) side facing downward. CP
The heat generated from the U (51) is efficiently conducted to the heat sink (3) via the heat diffusion plate (2) and the heat conductive adhesive layer (4) in this order, and is radiated from the heat sink (3).

As described above, the joint structure of the heat sink and the heat diffusion plate according to the present invention can be used in electronic devices such as personal computers.
It is preferably applied for cooling a heat generating part such as PU, but is not particularly limited to such use.

[0032]

According to the joint structure of the heat sink and the heat diffusion plate according to the present invention, the heat conductive adhesion material layer is interposed between the heat sink and the heat diffusion plate in a state of being in close contact with the heat sink and the heat diffusion plate.
Heat is efficiently conducted from the heat diffusion plate to the heat sink, and excellent heat radiation performance can be secured. Further, since the heat sink and the heat diffusion plate are removably fixed to each other, the separation operation can be simplified, and each component can be separated easily and reliably, and these components can be separated at low cost. Because it can be used for recycling,
It can fully contribute to the effective use of resources.

When the heat sink and the heat diffusion plate are detachably fixed to each other by screwing means, the heat radiation performance can be further improved, and the joining operation and the separation operation can be further facilitated. The constituent members can be recycled at lower cost.

In the case where the heat conductive adhesive layer is formed of a heat conductive elastic sheet, it is possible to ensure more excellent heat radiation performance and to recycle each constituent member with less impurities. Can be offered.

When a heat conductive silicone rubber sheet is used as the heat conductive elastic sheet, the heat radiation performance can be further improved and the electric insulation can be improved.

In the case where the heat conductive adhesive layer is formed by hot-melting a hot-melt type heat conductive resin sheet in a state of being sandwiched between a heat sink and a heat diffusion plate, it is more excellent. In addition, the heat radiation performance can be ensured, and each component can be recycled for use with less impurities.

When the heat conductive adhesive layer is made of a heat conductive viscous substance, more excellent heat radiation performance can be ensured.

When a heat conductive grease is used as the heat conductive viscous substance, workability can be improved.

When a recess is formed on the contact surface of the heat diffusion plate with the heat-generating portion, and the screw-in head of the screwing means is embedded in the recess, the screw-in head is higher than the surface of the heat diffusion plate. Since it does not protrude outward, there is an advantage that there is no structural limitation in design at the time of joining with the heat generating portion, and the degree of freedom in structural design can be increased.

When the heat sink is made of aluminum and the heat diffusion plate is made of copper, the heat radiation performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a joint structure according to an embodiment of the present invention.

FIG. 2 is a perspective view similarly showing a separated state.

FIG. 3 is a cross-sectional view showing another embodiment.

FIGS. 4A and 4B are diagrams showing still another embodiment, wherein FIG. 4A is a perspective view, and FIG. 4B is a cross-sectional view taken along line AA in FIG.

FIG. 5 is a diagram showing an example in which the bonding structure of the present invention is applied to a semiconductor product.

FIG. 6 is a diagram showing a conventional joint structure between a heat sink and a heat diffusion plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Heat diffusion plate 3 ... Heat sink 4 ... Thermal conductive adhesive material layer 5 ... Screwing means 5a ... Screw-in head 10 ... Depressed part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 7/20 H01L 23/36 M

Claims (9)

[Claims] 1. A heat sink and a heat spreader, wherein the heat sink and the heat spreader are fixed to each other in a close contact state and removably via a heat conductive adhesive material layer disposed therebetween. Joint structure. 2. The heat sink and the heat diffusion plate are detachably fixed to each other by screwing means.
The bonding structure of the heat sink and the heat diffusion plate according to the above. 3. The joint structure between a heat sink and a heat diffusion plate according to claim 1, wherein the heat conductive adhesive layer is formed of a heat conductive elastic sheet. 4. A joint structure between a heat sink and a heat diffusion plate according to claim 3, wherein a heat conductive silicone rubber sheet is used as said heat conductive elastic sheet. 5. The heat conductive adhesive material layer is formed by hot melting a hot melt type heat conductive resin sheet in a state of being sandwiched between the heat sink and a heat diffusion plate. 3. A joint structure between the heat sink and the heat diffusion plate according to 1 or 2. 6. The joint structure between a heat sink and a heat diffusion plate according to claim 1, wherein the heat conductive adhesive layer is made of a heat conductive viscous substance. 7. A joint structure between a heat sink and a heat diffusion plate according to claim 6, wherein a heat conductive grease is used as said heat conductive viscous substance. 8. The heat diffusion plate according to claim 2, wherein a concave portion is formed on a contact surface of the heat diffusion plate with the heat generating portion, and a screw-in head of the screwing means is embedded in the concave portion. The bonding structure of the heat sink and the heat diffusion plate according to the above. 9. The joint structure between a heat sink and a heat diffusion plate according to claim 1, wherein the heat sink is made of aluminum, and the heat diffusion plate is made of copper.