JP2000332169A - Heat dissipating structure for heat generating object and electronic apparatus having it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat dissipating structure for a heat generating object, and an electronic apparatus having that structure, in which a gap between the heat generating object and a heat dissipating unit can be filled constantly with grease regardless of variation of the gap due to thermal expansion/ contraction. SOLUTION: The heat dissipating structure for a heat generating object comprises a BGA package 15 being mounted on a printed circuit board 11, a unit 21 for dissipating heat generated from the BGA package 15, a resin 17 touching the BGA package 15 and the heat dissipating unit 21 and transferring heat generated from the BGA package 15 to the heat dissipating unit 21, and an elastic member 19 surrounding the heat transfer resin 17 while touching the BGA package 15 and the heat dissipating unit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat dissipation structure for dissipating heat generated by a heating element such as a semiconductor package, and an electronic device such as a personal computer having the same.

[0002]

2. Description of the Related Art In recent years, notebook personal computers, palmtop computers, and the like have become smaller and thinner, and the heat generation in the case has increased with the increase in performance. Various heat radiating means are taken.

As means for radiating the heat of the heating element, a heat radiating unit such as a heat sink or a heat pipe is provided with grease,
Thermal connection members (heat transfer members) such as adhesives and heat conductive sheets
And a method of thermally connecting the heating element to the heating element.
In particular, the connection using grease has excellent heat conductivity and is widely used.

FIG. 13 is a diagram showing a conventional heat connection between a heating element and a heat radiating unit. The electrode 13 of the heating element 12 is connected to the printed circuit board 11 by solder. I
The chip portion 15 of the C package (heating element) 12 is thermally connected to the heat radiation unit 21 via grease (heat transfer member) 17. The heat radiating unit 21 is fixed to the printed circuit board 11 by mounting screws 23.

With such a structure, the IC package 1
Since the heat generated from 2 is transferred to the heat radiating unit 21 side through the grease 17, heat can be radiated.

[0006]

However, in the above method, the heat radiating unit 21 expands and contracts due to heat.
Due to contraction, the distance (gap) between the heating element and the heat radiating unit varies. FIGS. 14A and 14B are diagrams showing a trend of grease accompanying a change in the gap. FIG. 14A shows a case where the gap is narrow, and FIG. 14B shows a case where the gap is wide. As shown in the figure, the heating element 12 and the heat radiation unit 2
When the gap with the gap 1 becomes narrow, the grease 17 is compressed by the top surface of the chip portion 15 and the heat radiation unit 21 and is pushed out from the top surface of the chip portion 15. Also, when the gap between the heating element 12 and the heat radiation unit 21 is widened,
The grease 17 is not filled between the top surface of the chip portion 15 and the heat radiation unit 21 so that a gap is formed.

Therefore, in the present invention, even if the gap between the heating element and the heat radiating unit fluctuates due to expansion and contraction due to heat, it is possible to maintain a state in which the gap is always filled with grease. It is an object to provide a heat dissipation structure and an electronic device having the same.

[0008]

In order to achieve the above object, according to the first aspect of the present invention, a heating element mounted on a printed circuit board, a radiator for radiating heat generated from the heating element, A heat transfer resin that is provided so as to be in contact with the heating element and the heat radiator, and that conducts the heat generated from the heating element to the heat radiator, and that surrounds the heat transfer resin and is provided so as to be in contact with the heat generator and the heat radiator. And an elastic member to be provided.

With such a configuration, it is possible to hold the heat transfer resin on the top surface of the heating element and prevent leakage of the heat transfer resin due to a change in the gap between the heating element and the heat radiating unit.

[0010] In the invention according to claim 3, the heat generating element mounted on the printed circuit board, the heat radiator for dissipating heat generated from the heat generating element and having an opening, and the opening end of the opening are included. One surface, a heat transfer resin in contact with the heating element and conducting heat generated from the heating element, and an elastic member surrounding the heat transmission resin and arranged to be in contact with the heating element and the heat radiator. It is characterized by the following.

With such a configuration, the pressure applied when the gap between the heat generating element and the heat radiating element is reduced can escape to the opening, and the pressure can be dispersed more than when only the elastic member is used. is there.

In the invention according to claim 5, the main body of the electronic device, the printed circuit board, the heating element mounted on the printed circuit board, the radiator for radiating heat generated from the heating element, and the heating element A heat transfer resin that is provided so as to be in contact with the heat radiator and that conducts heat generated from the heat radiator to the heat radiator; and an elastic member that surrounds the heat transfer resin and is arranged to be in contact with the heat radiator and the heat radiator. And characterized in that:

With such a configuration, there is provided an electronic device capable of holding the heat transfer resin on the top surface of the heating element and preventing leakage of the heat transfer resin due to a change in the gap between the heating element and the heat radiation unit. can do.

In the invention according to claim 7, the electronic device has a main body, a printed circuit board, a heating element mounted on the printed circuit board, and an opening for dissipating heat generated from the heating element. A heat radiator, a surface including an opening end of the opening, a heat transfer resin that is in contact with the heat generator, and conducts heat generated from the heat generator, and surrounds the heat transfer resin, and is in contact with the heat generator and the heat radiator. And an elastic member disposed on the second member.

With such a configuration, when the gap between the heat generating element and the heat radiating element becomes narrow, the grease moves to the opening, so that the pressure applied to the heat transfer resin and the elastic member can be reduced. Equipment can be provided.

[0016]

Embodiments of the present invention will be described below.
This will be described with reference to the drawings.

FIG. 1 is a perspective view of a computer according to the present invention. The computer 1 has a main body case 2, a display unit case 3, an LCD panel 4, and a keyboard 5. A keyboard 5 is arranged on the upper surface of the main body case 2. The display case 3 is rotatably connected to the main body case 2 by a hinge 6. An LCD panel 4 is arranged inside the display unit case 3. Although not shown, a printed circuit board on which electronic components are mounted is built in the main body case 2.

FIG. 2, FIG. 3, and FIG. 4 are views showing a first embodiment according to the present invention. FIG. 2 is a side view of the connection between the IC package and the heat radiating unit, FIG. 3 is an enlarged view of the connection portion of FIG. 2, and FIG. The IC package 12 serving as a heating element is fixed to the printed circuit board 11 by connecting the electrodes 13 by soldering. Heat dissipation unit 21
Are fixed to the printed circuit board 11 by spacers 22 and mounting screws 23. The chip portion 15 of the IC package 12 and the heat radiation unit 21 are thermally connected by grease 17. The elastic member 19 made of a heat conductive member is provided on the outer periphery of the top surface of the tip portion 15 so as to surround the grease 17. The elastic member 19 has a height that can fill the maximum gap when the gap between the chip portion 17 and the heat radiation unit 21 is considered to be wide. Therefore, at the time of normal mounting, the elastic member 19 has a shape expanding toward the outside of the chip portion 15.

In FIG. 4, grease 17 is applied on the top surface of the chip portion 15 of the IC package 12. The elastic member 19 is attached to the tip portion 15 so as to surround the grease 17.
It is provided on the outer periphery of the top surface.

With the above configuration, when the gap between the grease 17 and the heat radiating unit 21 becomes narrow as shown in FIG. 5, the elastic member 19 absorbs the pressure received from the heat radiating unit, and Can be prevented from leaking. Further, even when the gap between the grease 17 and the heat radiating unit 21 is widened as shown in FIG. 6, the elastic member 19 expands, so that thermal connection is possible.

By providing the elastic member 19 so as to surround the grease 17 as described above, the grease 17 is held on the top surface of the tip portion 15, and the elastic member 19 is protected against the fluctuation of the gap caused by expansion due to heat. Since the grease 17 can be prevented from leaking, stable thermal connection can be achieved. Further, since a heat conductive member is used as the elastic member 19, heat is also transmitted from the elastic member 19 to the heat radiating unit 21, so that further heat conduction can be expected.

Next, a second embodiment according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 7 is a side view of the connection between the IC package of the present embodiment and the heat dissipation unit. FIG.
FIG. 10 shows a case where the gap between the IC package and the heat dissipation unit is widened, and FIG. 10 shows a case where the heat dissipation unit is inclined.

In this embodiment, in order to reduce the pressure applied to the grease and the elastic member when the gap between the IC package 12 and the heat radiating unit 22 is reduced, an opening is formed in a portion of the heat radiating unit 22 which is in contact with the grease 17. 18 are provided.

By providing the opening 18 in the heat radiating unit 22, even if pressure is applied to the grease and the elastic member, a part of the grease 17 can be moved to the opening 18, so that only the elastic member 19 is used. The grease can be prevented from leaking even when the gap between the IC package 12 and the heat radiating unit 22 is largely changed or when the heat radiating unit 22 is inclined.

Next, a third embodiment according to the present invention will be described with reference to FIG.
1 and FIG. FIG. 11 shows a side view of the connection between the IC package and the heat radiating unit, and FIG. 12 shows a top view of the thermal connection of the IC package of FIG.

In the first embodiment, the outer periphery of the top surface of the chip portion 15 is surrounded by an elastic member 19, whereas in the third embodiment, the entire top surface of the IC package 12 excluding the chip portion 15 is covered. The elastic member 25 is installed, and the tip portion 15
Grease 17 which is a heat transfer resin is applied to the top surface.

With such a structure, the grease 17 can be applied to the entire top surface of the chip portion 15. The grease 17 is surrounded by the elastic member 25 to prevent the grease 17 from leaking and to transfer the heat of the entire IC package 12 to the heat radiation unit 21. Further, the load applied to the IC package is distributed not only to the chip portion 15 but also to the entire IC package 12. Further, the heat radiation unit 21 may be provided with an opening as in the second embodiment.

Further, by using a heat radiating sheet having good heat conductivity as an elastic member, heat can be transmitted not only from the chip portion but also from the entire package to the heat radiating unit. Further, since the load applied from the heat radiating unit is distributed not only to the chip portion but also to the entire IC package, the reliability is improved.

As described above in detail, according to the present invention, it is possible to prevent the leakage of the heat transfer resin such as grease used when transferring the heat of the heating element to the heat radiation unit.

[0030]

According to the invention described in detail above, it is possible to provide a heat radiating structure of a heat generating element which can cope with a change in a gap between the heat generating element and the heat radiating unit due to expansion and contraction by heat. Also,
Has a structure that enables stable thermal connection with grease,
It is possible to provide a heat radiating structure of a heat generating element and an electronic device having the same, which can maintain a state in which grease is appropriately filled in a gap between the heat generating element and the heat radiating unit.

[Brief description of the drawings]

FIG. 1 is a perspective view of a computer according to the present invention.

FIG. 2 is a side view of the connection between the IC package and the heat dissipation unit according to the first embodiment of the present invention.

FIG. 3 is an enlarged view of a connection portion in FIG. 2;

FIG. 4 is a view of the thermal connection portion of the IC package in FIG. 2 as viewed from above.

FIG. 5 is a diagram illustrating a case where a gap between an IC package and a heat radiation unit is narrowed;

FIG. 6 is a diagram showing a case where a gap between an IC package and a heat radiation unit is widened.

FIG. 7 is a diagram of a second embodiment according to the present invention.

FIG. 8 is a diagram illustrating a case where a gap between an IC package and a heat radiating unit is reduced.

FIG. 9 is a diagram illustrating a case where a gap between an IC package and a heat radiation unit is widened.

FIG. 10 is a diagram when the heat radiation unit is inclined.

FIG. 11 is a diagram of a third embodiment according to the present invention.

FIG. 12 is a view of the thermal connection portion of the IC package as viewed from above.

FIG. 13 is a side view of a thermal connection between an IC package and a heat dissipation unit according to a conventional method.

14A is a grease trend diagram when the gap is narrowed, and FIG. 14B is a grease trend diagram when the gap is widened.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Computer 2 ... Body case 3 ... Display part case 4 ... LCD panel 5 ... Keyboard 6 ... Hinge part 11 ... Printed circuit board 12 ... IC package 13 ... Electrode 15 ... Chip part 17 ... Grease 18 ... Opening 19, 25 ... Elastic members 21, 22 Heat dissipation unit 23 Mounting screw 24 Spacer

Claims (8)

[Claims] A heating element mounted on a printed circuit board; a radiator for radiating heat generated from the heating element; and a heating element provided in contact with the heating element and the radiator. And a heat transfer resin that conducts heat generated from the heat transfer member to the heat radiator, and an elastic member that surrounds the heat transfer resin and is provided so as to be in contact with the heat radiator and the heat radiator. Heat dissipation structure of heating element. 2. The heat radiating structure for a heating element according to claim 1, wherein said elastic member is a heat conductive member. 3. A heating element mounted on a printed circuit board, radiating heat generated from the heating element to dissipate heat, having an opening, a surface including an opening end of the opening, and the heating element. A heat transfer resin that is in contact with the heat transfer member and conducts heat generated from the heat generating member; and an elastic member that surrounds the heat transfer resin and is disposed so as to be in contact with the heat generating member and the heat radiator. A heat dissipation structure for a heating element. 4. The heat radiating structure for a heating element according to claim 3, wherein said elastic member is a heat conductive member. 5. A printed circuit board, a heating element mounted on the printed circuit board, a radiator for dissipating heat generated from the heating element, a heat radiator, and a radiator. A heat transfer resin that is provided and conducts the heat generated from the heat generating body to the heat radiator, and an elastic member that surrounds the heat transfer resin and is arranged to be in contact with the heat generator and the heat radiator. An electronic device, comprising: 6. The electronic device according to claim 5, wherein the elastic member is a heat conductive member. 7. A printed circuit board, a heating element mounted on the printed circuit board, a heat radiator having an opening for radiating heat generated from the heating element, and an opening end of the opening. A heat transfer resin that is in contact with one surface and the heat generator and conducts heat generated from the heat generator; and an elastic member that surrounds the heat transfer resin and is arranged to be in contact with the heat generator and the heat radiator. An electronic device comprising: 8. The electronic device according to claim 7, wherein said elastic member is a heat conductive member.