JPH0982859A - Heat sink assembled body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a heat sink assembled body superior in cooling efficiency by a method wherein an electronic component and a circuit board are bridged between first and second heat sinks, are energized in a direction, to which both of those heat sinks apporach each other, and are pinched between both of the sinks. SOLUTION: A heat sink assembled body is provided with a first heat sink 14, a second heat sink 16 and one pair of press springs 18. The heat sink assembled body is used for cooling an electronic component (an MPU chip) 12 mounted on a CPU board 10 which is used as a circuit board. The board 10 and the sink 14 on the opposite side to the board 10 are provided holding the chip 12 between them and the sink 14 and the sink 16 opposing to the sink 14 are provided holding the board 10 and the chip 12 between them. The chip 12 and the board 10 are bridged between the sinks 14 and 16, are energized in a direction, to which the sinks 14 and 16 approach each other, and are pinched between the sinks 14 and 16. Thereby, the heat sink assembled body is made superior in cooling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink assembly which functions as a temperature lowering device suitable for cooling high heat-generating components of electronic equipment such as MPU chips.

[0002]

2. Description of the Related Art For example, an electronic device such as a personal computer includes a large number of electronic components mounted on a circuit board, and some of these electronic components generate heat at a high temperature when they are operated, for example, an MPU. (Microprocessor unit) Chip included. Therefore, the electronic device generally includes a heat sink assembly that functions as a temperature lowering device for cooling such a high heat-generating component.

Conventionally, such a heat sink assembly has been
A heat sink provided on the upper surface side of the electronic component, that is, on the opposite side of the circuit board with the electronic component interposed therebetween, and a holding spring provided on the opposite side of the electronic component with the circuit board interposed therebetween. The heat sink includes a base plate having a flat bottom surface that is in contact with the top surface of the electronic component, and a large number of cooling fins provided upright on the base plate. And
The holding spring has an end portion that penetrates the circuit board and engages with the heat sink, and the heat sink is held in a state of being pressed against the upper surface of the electronic component by the holding spring.

A cooling fan for supplying cooling air to the heat sink is provided near the heat sink. Therefore, the heat from the electronic component is conducted to the cooling fin via the base plate of the heat sink and is radiated from the cooling fin into the cooling air. Thereby, the electronic components are cooled.

[0005]

However, in the above-mentioned conventional heat sink assembly, the urging force of the pressing spring that presses the heat sink against the electronic component directly acts on the circuit board via the electronic component. Therefore, the circuit board may be bent or deformed by the urging force of the pressing spring, and the circuit pattern may be cut.

Further, since the heat sink is held on the electronic parts only by the holding spring, when the circuit board or the heat sink is vibrated or impacted, it cannot be supported only by the holding spring, and the heat sink is displaced. There is also a risk that the heat sink will fall off due to the pressing spring coming off.

Furthermore, in recent electronic devices, the electronic components mounted on the circuit board are becoming higher in density, and the total amount of heat generation is also increasing. Therefore, it is difficult to obtain sufficient cooling efficiency by simply increasing the size of the heat sink.

The present invention has been made in view of the above points, and an object thereof is to provide a heat sink assembly excellent in cooling efficiency. Another object of the present invention is to
An object of the present invention is to provide a heat sink assembly that can be reliably mounted on a high heat-generating component without causing damage to the circuit board and has excellent cooling efficiency.

[0009]

In order to achieve the above object, a heat sink assembly of the present invention according to claim 1 is
A first heat sink provided on the opposite side of the circuit board with an electronic component sandwiched therebetween, and a second heat sink provided opposite to the first heat sink with the circuit board and the electronic component sandwiched therebetween. A bridge installed between the first and second heat sinks and biasing the first and second heat sinks toward each other so that the electronic component and the circuit board are sandwiched between the first and second heat sinks. It is characterized in that it is provided with a force means.

According to the heat sink assembly having the above structure,
The first and second heat sinks are provided by sandwiching the electronic component and the circuit board from both sides, the heat of the electronic component is radiated through the first heat sink, and the heat conducted from the electronic component to the circuit board is the first. The heat is dissipated through the heat sink 2. As a result, the electronic component can be cooled from both sides, and the cooling efficiency can be improved.

According to a third aspect of the heat sink assembly of the present invention, the first heat sink provided on the opposite side of the circuit board with the electronic component interposed therebetween and the circuit board and the electronic component are interposed therebetween. A second heat sink provided to face the first heat sink is sandwiched between the second heat sink and the second heat sink. The first heat sink and the second heat sink are movably connected to each other along a direction in which the first heat sink and the second heat sink are separated from each other. And the electronic component and the circuit board between the first and second heat sinks by urging the first and second heat sinks toward each other. And a biasing means sandwiching the pin.

According to the heat sink assembly having the above structure,
The first and second heat sinks are provided by sandwiching the electronic component and the circuit board from both sides, the heat of the electronic component is radiated through the first heat sink, and the heat conducted from the electronic component to the circuit board is the first. The heat is dissipated through the heat sink 2. The first and second heat sinks are
They are connected to each other by a connecting means that penetrates the circuit board and positioned with respect to the circuit board and the electronic component. Then, the urging force of the urging means acts between the first and second heat sinks via the connecting means.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A heat sink assembly according to an embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIGS. 1 to 4, the heat sink assembly 11 includes a first heat sink 14, a second heat sink 16, and a pair of pressing springs 18. The heat sink assembly 11 is used for cooling the MPU chip 12 mounted on the CPU board 10 as a circuit board. The MPU chip 12 as a high heat generating component is formed in a rectangular parallelepiped shape, and has a bottom surface soldered to a circuit pattern on the CPU board 10, and a bottom surface and a top surface parallel to the CPU boat 10. Further, four through holes 15 are formed on the CPU board 10 outside the MPU chip 12, and each has a through hole M
It is located adjacent to the four corners of the PU chip.

As shown in FIGS. 1 to 4, the first heat sink 14 stands upright on the rectangular first base plate 20 constituting the first base portion and the upper surface of the first base plate. It has a large number of heat radiating rods 22 that are provided and constitute a heat radiating portion, and are made of, for example, aluminum. The first base plate 20 has a size sufficiently larger than the upper surface of the MPU chip 12, and through holes 24 as engaging portions are formed at the four corners thereof. These through holes 24
Are formed in the same arrangement relationship as the through holes 15 of the CPU board 10. The heat dissipation rod 22 has a through hole 24.
It is provided over almost the entire upper surface of the first base plate 20 except the portion.

The second heat sink 16 has a rectangular second base plate 26 as a second base portion having a size slightly larger than that of the first base plate 20, and a lower surface of the second base plate. It has a large number of radiating fins 28 which are erected vertically and constitute a radiating portion, and are made of, for example, aluminum. In addition, the second heat sink 16 includes four support shafts 3 integrally fixed to the second base plate 26.
0, these support shafts are located at the four corners of the second base plate and extend vertically from the upper surface. Further, the four support shafts 30 each functioning as a support member are provided in an arrangement relationship corresponding to the through hole 15 of the CPU board 10,
These through holes 15 and the through holes 2 of the first base plate 20.
4 can be inserted. Furthermore, each support shaft 30 has
An engaging hole 32 for hooking the end portion of the presser spring 18 is formed through and extends in a direction orthogonal to the central axis of the support shaft.

The pair of presser springs 18 are formed by bending a wire into a substantially M-shape, and have a central portion 18a (first engaging portion) that abuts the upper surface of the base plate of the first heat sink 14 and a support shaft. It has a pair of end portions 18b (second engaging portions) that can be engaged with the engaging holes 32 of 30 respectively.

CP of the heat sink assembly 11 having the above-mentioned structure
When assembled to the U board 10, as shown in FIG. 1, the four support shafts 30 of the second heat sink 16 are penetrated from the lower side of the CPU board 10 into the corresponding four through holes 15 to form the second base plate. The upper surface of 26 is brought into contact with the lower surface of the CPU board 10. Subsequently, the upper surface of the MPU chip 12 is covered with the first base plate 20 of the first heat sink 14, and at this time, the tip end portion of each support shaft 30 is inserted into the corresponding engagement hole 32 of the first base plate 20. To do. As a result, the first and second heat sinks 14 and 16 are positioned at predetermined positions with respect to the MPU chip 12.

Thereafter, the pair of presser springs 18 are pressed with the central portions 18a thereof against the upper surface of the first base plate 20, and the both end portions 18b are respectively inserted into the engaging holes 32 of the corresponding two support shafts 30. By being inserted, it is installed between the first heat sink 14 and the second heat sink 16. Thereby, the first and second heat sinks 14,
16 are urged by a pair of pressing springs 18 in a direction in which they approach each other, the lower surface of the first base plate 20, that is, the first contact surface, is in close contact with the upper surface of the MPU chip 12, and the second base plate The upper surface of 26, that is, the second contact surface, is CP
It is held in close contact with the lower surface of the U board 10.

Through the steps described above, the heat sink assembly 11 moves the MPU chip 12 and the CPU board 10 up and down by the first and second heat sinks 14, 16 and particularly by the first and second base plates 20, 26. It is assembled in a predetermined position while being clamped from the.

Each pressing spring 18 is selected to have a predetermined wire diameter and shape so that a predetermined pressing force calculated in advance can be obtained. A cooling fan 3 that supplies cooling air toward the heat sink 11 is provided near the CPU board 10.
4 is provided, and the radiation fins 28 of the second heat sink 16 are formed so as to extend in parallel to the flow direction A of the cooling air.

According to the heat sink assembly 11 configured as described above, the MPU chip 12 can be efficiently cooled by sandwiching the MPU chip 12 between the first and second heat sinks 14 and 16 from above and below. . That is, the heat generated from the MPU 12 is transferred to the heat dissipation rod 22 via the first base plate 20 and is radiated to the atmosphere, and the heat transferred from the MPU chip to the CPU board 10 side is transferred to the second base plate 26. And the radiation fin 28
Heat is dissipated to the atmosphere via. Therefore, these first and second heat sinks 14, 16 allow the MPU chip 1 to
2 can be cooled from both upper and lower sides, and the cooling efficiency is significantly improved.

Further, the first and second heat sinks 1
The reference numerals 4 and 16 are connected to each other via four support shafts 30 as a connecting means, and these support shafts are inserted into through holes 15 formed in the CPU board 10. Therefore, even if vibration, impact, or the like acts on the first or second heat sinks 14, 16, it is possible to prevent the displacement of the first and second heat sinks 14, 16, and
It can be stably held at a predetermined position with respect to the PU chip 12. Similarly, even when vibration, impact, etc. act on the first or second heat sinks 14, 16, these vibrations, impact, etc. do not directly act on the presser spring 18, and the presser spring comes off and the heat sink It is possible to reliably prevent a drop or the like.

Further, each pressing spring 18 is installed between the first heat sink 14 and the second heat sink 16, and in the above embodiment, between the first base plate 20 and the support shaft 30. The urging force is supplied in the closed state. Therefore, the biasing force of these pressing springs 18 is received by the first and second heat sinks 14 and 16 without directly acting on the CPU board 10, so that the CPU board is deformed or the pattern is broken due to the biasing force. And the like can be prevented. Further, since the second base plate 26 of the second heat sink 16 is mounted in surface contact with the lower surface of the CPU board 10, the second base plate 26 can reinforce the CPU board 10. This makes it possible to prevent the CPU board from being deformed more reliably.

According to the heat sink assembly 11 having the above structure, the first and second heat sinks 14 and 16 are connected to the CPU.
Since the assembling is completed simply by hooking the presser spring 18 after stacking on the board 10, efficient assembling is possible.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the support shaft 30 is provided on the first base plate 20,
The second base plate 30 is provided with an engagement hole into which these support shafts fit.
May be provided. Further, the numbers of support shafts and presser springs can be increased or decreased as necessary.

A coil spring may be used as the pressing spring 18 which functions as a biasing means. 6 to 7 show a second spring having a compression coil spring as the presser spring 18.
The embodiment of is shown.

That is, according to the second embodiment, the heat sink assembly 11 is provided with a support sleeve 40 and a fixing screw 42 functioning as a connecting means, instead of the above-mentioned supporting shaft 30, and is held by the connecting means. The spring 18 is combined. The support sleeve 40 that functions as a support member includes the first base plate 20 of the first heat sink 14.
The diameter of the through hole 24 is slightly smaller than that of the through holes 24 formed at the four corners, and the flange 43 is formed at the upper end, that is, the tip. Then, the support sleeve 40 is
The first base plate 20 is slidably inserted into each through hole 24 from above, and the lower end, that is, the base end, is the CPU board 10.
Is in contact with the upper surface of the

On the other hand, screw holes 44 are formed at the four corners of the second base plate 26 of the second heat sink 16 and are located opposite to the through holes 24 of the first base plate 20. Then, each support sleeve 40 is attached to the washer 4 from the upper end thereof.
A long fixing screw 42 is inserted via 5, and the fixing screw is screwed into a screw hole 44 through a through hole 46 formed in the CPU board 10. Therefore, each support sleeve 40 is connected to the second base plate 26 via the CPU board 20.
And the second base plate 26 is held in close contact with the lower surface of the CPU board 10. Then, the first and second heat sinks 14, 16 and in particular the first and second base plates 20, 26 have four support sleeves 4
The first base plate 20 is movable with respect to the MPU chip 12 while being connected to each other by the 0 and the fixing screw 42.

A pressing spring 18 which is a compression coil spring is wound around each support sleeve 40 as a biasing means and is located between the flange 43 and the first base plate 20. Therefore, the first base plate 20 has four holding springs 1
It is pressed against the upper surface of the MPU chip 12 by the urging force of the MPU chip 12 and cooperates with the second base plate 26.
And the CPU board 10 is sandwiched.

The other structure is the same as that of the above-described embodiment, and the same portions are denoted by the same reference numerals and detailed description thereof will be omitted. Also in the heat sink assembly 11 according to the second embodiment configured as described above,
The MPU chip 12 and the first and second heat sinks 1
By sandwiching the MPU chip from above and below with 4, 16, the MPU chip can be efficiently cooled, and even when vibration or impact is applied to the first or second heat sink 14, 16, the pressing spring comes off, and It is possible to reliably prevent the heat sink from falling.

Further, the urging force of each pressing spring 18 acts on the first base plate 20 and also acts on the second base plate 26 via the fixing screw 42. Therefore, the urging force of these pressing springs 18 does not directly act on the CPU board 10, and it is possible to prevent the deformation of the CPU board, the breakage of the pattern, and the like due to the urging force. Further, according to the heat sink assembly 11 having the above configuration, the first
And the second heat sinks 14 and 16 for the CPU board 1
Support sleeve 42 and presser spring 1 after stacking to 0
Since the assembling is completed by mounting 8 and screwing the screw 42, efficient assembling is possible.

[0032]

As described above in detail, according to the present invention, the first and second parts provided so as to sandwich the high heat-generating component therebetween.
By providing the heat sink of (1), it is possible to provide a heat sink assembly having excellent cooling efficiency. Further, according to the present invention, by providing the connecting means for connecting the first and second heat sinks, the circuit board can be reliably mounted on the high heat-generating component without causing damage, and the cooling efficiency is excellent. A heat sink assembly can be provided.

[Brief description of drawings]

FIG. 1 is an exploded side view showing a heat sink assembly according to an embodiment of the present invention.

FIG. 2 is a side view of the heat sink assembly in a state where it is mounted on a CPU board.

FIG. 3 is a plan view of the heat sink assembly in a state where it is mounted on a CPU board.

FIG. 4 is a front view of the heat sink assembly in a state where it is mounted on a CPU board.

FIG. 5 is a side view of the heat sink assembly according to the second embodiment of the present invention.

FIG. 6 is a plan view of a heat sink assembly according to a second embodiment of the present invention.

FIG. 7 is a front view of a heat sink assembly according to a second embodiment of the present invention.

[Explanation of symbols]

 10 ... CPU board 11 ... Heat sink assembly 12 ... MPU chip 14 ... First heat sink 16 ... Second heat sink 18 ... Pressing spring 20 ... First base plate 22 ... Heat dissipation rod 26 ... Second base plate 28 ... Heat dissipation Fin 30 ... support shaft 40 ... support sleeve 42 ... fixing screw

Claims (7)

[Claims] 1. A heat sink assembly for cooling electronic components mounted on a circuit board, comprising: a first heat sink provided on the opposite side of the circuit board with the electronic component interposed therebetween; A second heat sink provided opposite to the first heat sink with a component sandwiched between the first heat sink and the second heat sink;
And a biasing means that biases the second heat sink toward each other so as to sandwich the electronic component and the circuit board between the first and second heat sinks, and a heat sink assembly. 2. The first heat sink includes a first base portion having a first contact surface in contact with the electronic component,
A plurality of heat radiating portions provided upright on the first base portion, wherein the second heat sink is in surface contact with the circuit board and is opposed to the second contact surface substantially in parallel with the first contact surface. The heat sink assembly according to claim 1, further comprising: a second base portion having a contact surface and a plurality of heat radiating portions provided upright on the second base portion. 3. A heat sink assembly for cooling electronic components mounted on a circuit board, comprising: a first heat sink provided on the opposite side of the circuit board with the electronic component interposed therebetween; A second heat sink provided to face the first heat sink with a component interposed therebetween and a second heat sink extending through the circuit board along a direction in which the first heat sink and the second heat sink are brought into contact with and separated from each other. The connecting means movably connected to the first and second heat sinks is installed between the first and second heat sinks.
And a biasing means for biasing the second heat sink toward each other so as to sandwich the electronic component and the circuit board between the first and second heat sinks, and a sheet sink assembly. . 4. The connecting means extends through the circuit board from the engaging hole formed in the first heat sink and the second heat sink, and is slidably inserted into the engaging hole. 4. The heat sink assembly according to claim 3, wherein the biasing means is provided between the support member and the first heat sink. 5. The first heat sink includes a first base portion having a first contact surface in contact with the electronic component,
A plurality of heat radiating portions provided upright on the first base portion, wherein the second heat sink is in surface contact with the circuit board and is opposed to the second contact surface substantially in parallel with the first contact surface. A second base portion having a contact surface and a plurality of heat dissipation portions provided upright on the second base portion, and the connecting means is formed on the first base portion of the first heat sink. An engaging hole and a support shaft extending from the second base portion of the second heat sink through the circuit board and slidably inserted into the engaging hole. The heat sink assembly according to claim 3, wherein the means is provided between the support shaft and the first heat sink. 6. The urging means engages with the support shaft between a first engaging portion that abuts against the first base portion and between the first base portion and the circuit board. The heat sink assembly according to claim 5, further comprising a second engaging portion. 7. The first heat sink includes a first base portion having a first contact surface in contact with the electronic component,
A plurality of heat radiating portions provided upright on the first base portion, wherein the second heat sink is in surface contact with the circuit board and is opposed to the second contact surface substantially in parallel with the first contact surface. A second base portion having a contact surface and a large number of heat dissipation portions provided upright on the second base, and the connecting means is formed on the first base portion of the first heat sink. A support sleeve having an engagement hole, a base end abutting on the circuit board, and a tip end extending from the first base portion, and the support sleeve slidably inserted through the engagement hole, and the tip end. A fixing screw that is inserted into the support sleeve from the side and is screwed into the second base portion through the circuit board and that fixes the support sleeve, and the biasing means is wound around the support sleeve. Of the first base portion and the support sleeve. The heat sink assembly according to claim 3, characterized in that it has a coil spring positioned between an end.