JP6883498B2 - Heatsink - Google Patents

Description

The present invention relates to a radiator that dissipates heat generated from electronic components.

A radiator (heat sink) is used to dissipate heat generated from electronic components that generate a large amount of heat, such as thyristors and power transistors. For example, there has been proposed a radiator having a plurality of heat sinks erected on a mounting substrate at predetermined intervals and having a tubular body inserted into through holes formed in each of the heat sinks. In this radiator, cooling air is blown from an air-cooling fan arranged opposite to the heat sink to the tubular body, and cooling air is blown from another air-cooling fan arranged on the side surface between adjacent heat sinks (patented). See Document 1).

Further, a radiator for cooling a microprocessor used in an electronic device or the like has been proposed. For example, a box-shaped radiator having a bottom surface in contact with the surface of a microprocessor, four side surfaces having ventilation holes, and an air cooling fan on the ceiling surface has been proposed (see Patent Document 2).

Japanese Unexamined Patent Publication No. 10-4165 Japanese Unexamined Patent Publication No. 10-294582

However, although the conventional radiator can obtain a sufficient heat dissipation effect (air cooling performance), the production efficiency is poor due to the complicated structure, and the occupied area on the circuit board is large, which limits the degree of freedom in circuit design. There are various inconveniences such as being done.

An object of the present invention is to provide a radiator capable of efficiently dissipating heat generated from electronic components with a simple configuration and reducing the occupied area on a circuit board.

The present invention provides the following radiators.

That is, the radiator according to the embodiment of the present invention has the following configuration.
A radiator that abuts on an electronic component mounted on a circuit board erected so that the substrate surface is parallel to the vertical direction and dissipates heat generated from the electronic component.
By switching on / off of the air cooling fan arranged so as to blow the cooling air in the horizontal direction of the substrate surface, the horizontal air flow is received at right angles to the horizontal air flow generated by the horizontal cooling air when the air cooling fan is turned on. a first wind receiving heat radiating surface, the first wind receiving radiating surface substantially perpendicular to such a bent form Rutotomoni, second receiving that swept the orthogonal the rising air against updraft generated around during off Has a wind radiating surface,
A first through hole through which the horizontal airflow can pass is formed on the first wind receiving and radiating surface, while a second through hole through which the updraft can pass is formed on the second wind receiving and radiating surface. Consists of boards ,
It has legs that extend from the heat sink, allow the heat sink to be installed on the circuit board, and separate the heat sink from the circuit board.
The leg portion extends from the first wind receiving and heat radiating surface .

According to this configuration, when the air cooling fan is turned on, at least one of the plurality of wind receiving and radiating surfaces (the first wind receiving and radiating surface) is substantially orthogonal to the air flow direction of the cooling air of the air cooling fan, while the air cooling fan is turned off. Sometimes the other surface (second wind receiving and radiating surface) that is not substantially orthogonal to the airflow direction of the cooling air of the air cooling fan is substantially the direction of the naturally occurring airflow such as the updraft that exists when the air cooling fan is off. Orthogonal. Since a through hole through which the airflow can pass is formed on the wind receiving and radiating surface orthogonal to each airflow direction, the airflow is downstream from the through hole formed on the wind receiving and radiating surface without retaining the airflow. Passes through and exhibits excellent heat dissipation efficiency. Moreover, other surfaces that are not substantially orthogonal to the airflow direction (surfaces that are bent and formed with respect to the wind receiving and radiating surface) also contribute to improving the heat radiating capacity of the heat radiating plate as secondary heat radiating surfaces. As a result, heat generated from the electronic components can be effectively dissipated regardless of whether the air cooling fan is operating or not. Further, since the radiator itself has a simple and compact configuration composed of a plurality of bent wind receiving and radiating surfaces, it is excellent in production efficiency and can occupy a relatively small area on the circuit board.
Further, according to this configuration, when the air cooling fan is turned off, an updraft is generated around the heat sink due to the heated air around the heat sink including heat generated by the electronic components. In this case, the second wind-receiving heat-dissipating surface of the heat-dissipating plate, which is substantially orthogonal to the updraft, allows air to pass downstream from the second through hole formed in the second wind-receiving heat-dissipating surface without retaining the airflow. Therefore, it exhibits excellent heat dissipation efficiency, which in turn greatly contributes to improving the heat dissipation capacity of the heat sink. Further, since the other surface (first wind receiving heat radiating surface) formed by bending continuously with the second wind receiving heat radiating surface is not orthogonal to the air flow, it contributes to the heat radiating capacity of the heat radiating plate as a secondary heat radiating surface. ..
Further, according to this configuration, the heat radiating plate is installed on the circuit board by the legs on which the first wind receiving surface is formed, and a gap is formed between the circuit board and the heat radiating plate. The air can be efficiently passed downstream. As a result, the cooling efficiency of electronic components is improved. Further, an electronic component having a height lower than the height of the gap can be mounted in the gap between the heat sink and the circuit board. That is, the area occupied by the radiator on the circuit board can be reduced, and the mounting efficiency of electronic components can be improved.

Further, in the above configuration, it is preferable not to have through holes (first and second through holes) in a predetermined region of the heat sink on which the electronic component is mounted.

According to this configuration, since the heat radiating plate and the electronic component are brought into surface contact with each other, the heat generated by the electronic component can be efficiently transferred to the heat radiating plate to dissipate heat.

According to the radiator of the present invention, it is possible to efficiently dissipate heat generated from electronic components with a simple configuration, and it is possible to reduce the occupied area on the circuit board.

It is a perspective view which shows the whole structure of the radiator of this invention. It is a front view of the radiator of this invention. It is a left side view of the radiator of this invention. It is a right side view of the radiator of this invention. It is a rear view of the radiator of this invention. It is a top view of the radiator of this invention. It is a schematic diagram which shows the cooling of an electronic component by the radiator of this invention. It is a perspective view from the front side of the radiator of the modification. It is a perspective view from the front side of the radiator of another modification. It is a perspective view from the back side of the radiator of another modification. It is a perspective view from the front side of the radiator of another modification. It is a perspective view from the back side of the radiator of another modification. It is a schematic diagram which shows the cooling of an electronic component by a radiator of another modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the radiator 1 of the present embodiment includes a heat sink 2 and legs 3 extending from the heat sink 2.

As shown in FIGS. 2 to 4, the heat radiating plate 2 has two surfaces, a large rectangular first surface 2A and a small second surface 2B bent from one side edge of the first surface 2A. Have. The first surface 2A and the second surface 2B function as the wind receiving and heat radiating surfaces of the present invention. Further, the heat sink 2 has a third surface 2C smaller than the second surface 2B formed by bending from the other side edge of the first surface 2A.

In the present embodiment, one thin plate of galvanized steel sheet is bent and formed from the first surface 2A to the second surface 2B and the third surface 2C which are the bases by press working. As the galvanized steel sheet, for example, a galvanized steel sheet having a thickness of 1 mm and having excellent solder wettability is used. The material of the heat radiating plate 2 is not limited to the galvanized steel sheet, and various metals such as aluminum and copper having excellent thermal conductivity can be used.

As shown in FIG. 2, the first surface 2A of the heat radiating plate 2 has three in the first region in which a plurality of through holes 4 are formed in approximately one-third of the upper side and in approximately two-thirds of the lower side. It has a second region in which the through hole 5 of the above is formed. The through hole 4 in the first region is formed in a two-dimensional shape having two upper and lower stages by punching. As will be described later, the through hole 4 allows an updraft generated around the through hole 4 to pass through. In the present embodiment, the through hole 4 is set as follows. The triangle formed by connecting the centers of the two adjacent upper through holes 4 and the lower one through hole 4 between the two through holes 4 is set to be an equilateral triangle. For example, in the present embodiment, a through hole 4 having a diameter of 4 mm is formed on the first surface 2A having a width of about 51 mm. The distance (pitch) between the centers of these through holes 4 is set to 6 mm. The diameter, number, pitch, etc. of the through holes 4 are appropriately set and changed depending on the material, shape, dimensions, material thickness, and the like of the heat radiating plate 2 to be used.

In the second region, three through holes 5 are formed by burring from the front side, and a flange 6 is formed on the back side as shown in FIGS. 5 and 6. That is, the through hole 5 is for fixing the electronic component 7 to the heat sink 2 with the screw 8. The number, position, and dimensions of the through holes 5 are appropriately changed according to the electronic component 7 to be mounted. Further, in the present embodiment, one electronic component 7 is mounted on the first surface 2A. For example, two or more electronic components 7 having the same shape or electronic components 7 having different shapes as described later are used. It is also possible to attach two or more (see FIG. 8).

The second surface 2B of the heat radiating plate 2 is bent so as to be orthogonal to the first surface 2A from one side edge of the first surface 2A. The second surface 2B is set at a height approximately half that of the first surface 2A, and through holes 4 having the same shape as the first surface 2A are formed in a vertical row at equal intervals. Further, the leg portion 3 extends below the second surface 2B.

The third surface 2C of the heat radiating plate 2 is bent so as to be orthogonal to the first surface 2A from the other side edge of the first surface 2A. The third surface 2C is set to a height of approximately one-eighth that of the first surface 2A. In this embodiment, the through hole 5 is not formed on the third surface 2C. A leg portion 3 having the same shape as the second surface 2B extends below the third surface 2C.

The legs 3 are configured to protrude from the lower end of the heat radiating plate 2 by a predetermined length, so that the heat radiating plate 2 can be installed on the circuit board 12. When the radiator 1 is installed on the circuit board 12, a gap is formed between the lower end of the first surface 2A and the circuit board 12 by a pair of legs 3 facing each other at both side ends of the first surface 2A.

Further, the leg portion 3 has a through hole 9 and a protrusion 10. The through hole 9 is smaller than the through hole 4. The through hole 9 functions as follows. When the radiator 1 is mounted on the circuit board 12 and soldered, the through holes 9 prevent heat diffusion to the heat sink 2, and thus suppress the temperature drop of the soldered portion. That is, the through hole 9 suppresses a decrease in the solder wettability of the leg portion 3.

The protrusion 10 is formed in the lower part of the leg 3, and as shown in FIG. 1, is inserted into the installation hole 13 formed through the circuit board 12 in the same manner as the lead terminal of the electronic component 7. A tapered notch 11 (see FIGS. 3 and 4) that engages with the installation hole 13 is formed in the protrusion 10 at positions facing each other in the width direction. In the present embodiment, one leg is not provided with a surface having a through hole 4, but a surface having a through hole 4 that functions as a wind receiving and radiating surface is provided like the other legs 3. The leg portion 3 may extend from the surface.

In the present embodiment, notches 14 are formed at one location on each side edge of the first surface 2A of the heat sink 2, and at each one location on the second surface 2B and the third surface 2C. These notches 14 are for preventing distortion of the heat radiating plate 2 that occurs when the second surface 2B and the third surface 2C are bent. If distortion is unlikely to occur depending on the material and bending angle of the heat radiating plate 2, the notch 14 may not be provided.

Next, the heat dissipation of the electronic component 7 by the radiator 1 of the above embodiment will be described with reference to FIG. 7.

<Example>
In the embodiment, one air cooling fan (not shown) is installed. The radiator 1 is attached to the circuit board 12 in an upright posture. Further, the radiator 1 is arranged so that the first surface 2A of the heat sink 2 is substantially parallel to the airflow direction of the cooling air with respect to the airflow direction of the cooling air from the air cooling fan. Therefore, the second surface 2B and the third surface 2C of the heat radiating plate 2 are substantially orthogonal to the airflow direction of the cooling air. Further, the third surface 2C in which the through hole 4 is not formed is arranged on the upstream side in the airflow direction. As a result, the second surface 2B, which has a larger area than the third surface 2C, is exposed to the cooling air after the first surface 2A, and the secondary heat dissipation by the first surface 2A is hindered by the second surface 2B. It is suppressed. At this time, the first surface 2A is the top surface. The air-cooling fan is switched on and off by a control unit such as a CPU (central processing unit) according to the temperature detected by a temperature sensor (not shown).

When the air-cooling fan is on (operated), the radiator 1 receives the cooling air blown from the air-cooling fan on the second surface 2B that functions as the wind receiving and radiating surface, and the through hole 4 formed in the second surface 2B. Let the cooling air pass downstream from. When the air cooling fan is off (stopped), the heated air around the radiator 1 including heat generated from the electronic component 7 becomes an updraft and passes through the through hole 4 on the first surface 2A. That is, the second surface 2B is substantially orthogonal to the airflow direction of the cooling air from the air cooling fan, and the first surface 2A is substantially orthogonal to the updraft. As described above, in the present embodiment, through holes through which airflow can pass are formed on the wind receiving and radiating surfaces extending in different directions, that is, the first surface 2A and the second surface 2B, and the air cooling fan can be switched on / off. Since each of the airflows associated with the airflow is received and the airflow is passed through the through hole without staying, the heat generated from the electronic component 7 can be effectively dissipated.

In the present embodiment, when the air cooling fan is on, the heat generated from the electronic component 7 is secondarily dissipated from the first surface 2A, which is the mounting surface of the electronic component 7, and the first surface 2A to the second surface 2A. It is transmitted to the surface 2B and the third surface 2C, and is efficiently dissipated from the second surface 2B, which is mainly the wind receiving and radiating surface. When the air cooling fan is off, the heat generated from the electronic component 7 is mainly dissipated from the first surface 2A. Since a plurality of through holes are formed on the first surface 2A, the updraft generated around the heat sink 2 does not stay, but smoothly passes to the downstream side in the airflow direction (upward direction), and the heat dissipation efficiency. Can be enhanced.

Further, as described above, the radiator 1 of the present embodiment can improve the heat dissipation efficiency of the electronic component 7 with a simple configuration. Since the radiator 1 has a simple structure in which one heat sink 2 is bent to provide a plurality of wind receiving and radiating surfaces, the production efficiency is excellent and the occupied area on the circuit board can be reduced.

Further, since the radiator 1 is mounted on the circuit board 12 by the legs 3 and a gap is provided between the first surface 2A and the circuit board 12, the radiator 1 rises between the circuit board 12 and the radiator 1. In addition to allowing the passage of airflow, it is also possible to mount an electronic component 7 having a height lower than the height of the gap on the circuit board 12.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as it is described in the claims. For example, the following embodiments are also included.

(1) In the above embodiment, the leg portion 3 forms a gap between the circuit board 12 and the first surface 2A of the heat radiating plate 2, but a gap may not be formed. For example, as shown in FIG. 8, the lower portion of the first surface 2A expands so as to come into contact with or approach the circuit board 12. Further, a plurality of through holes 4 are formed in a region (third region) below the mounting surface of the electronic component 7. This makes it possible to increase the surface area (heat dissipation area) of the first surface 2A while allowing the passage of airflow near the surface of the circuit board 12. In the present embodiment, the size of the through holes 4 formed in the third region is set to be the same as that of the first region, but the sizes may be different, and the number of through holes 4 is also different. You may be.

(2) In the above embodiment, only two surfaces are provided, which function as a wind receiving heat radiating surface and a secondary heat radiating surface, but the number may be three or more. For example, as shown in FIGS. 9 and 10, the second surface 2B is extended to the same height as the first surface 2A, and the upper and lower portions of the first surface 2A are extended and bent toward the back side to form a fourth surface. The surface 2D and the fifth surface 2E are formed. The depth length of the back surface side of the fourth surface 2D and the fifth surface 2E is set to be the same as that of the second surface 2B. In this embodiment, the through holes 4 are not formed on the fourth surface 2D and the fifth surface 2E.

According to this configuration, when the radiator 1 of the modified example is installed on the circuit board 12 in the same posture as the radiator 1 shown in FIG. 7, and the air cooling fan is turned off (stopped), the fourth surface 2D and the first Since the fifth surface 2E is not orthogonal to the updraft, the heat dissipation efficiency is inferior to that of the first surface 2A, but it contributes to the improvement of the heat dissipation capacity of the heat sink as a secondary heat dissipation surface. Further, when the air cooling fan is turned on (operated), the fourth surface 2D and the fifth surface 2E are arranged orthogonal to the air flow direction of the cooling air of the air cooling fan, and are exposed to the cooling air to increase the heat dissipation efficiency. Contribute to.

(3) In each of the above embodiments, the through hole 4 formed in the heat radiating plate 2 is formed by punching, but as shown in FIGS. 11 and 12, a notch is made in a substantially arc shape to form a notched portion. May be bent to the back side to form the cooling fin 15.

According to this configuration, the area of the heat radiating plate is expanded by the cooling fins 15, so that the heat radiating efficiency of the radiator 1 is improved. Therefore, the heat dissipation efficiency is further improved by the synergistic effect with the cooling effect obtained by passing the cooling air through the through hole 4.

(4) In each of the above embodiments, the configuration when one air-cooling fan is installed has been described, but it is also possible to deal with the case where a plurality of air-cooling fans are installed. For example, the radiator 1 is configured as follows. Hereinafter, description will be given with reference to FIG.

In the present embodiment, the air cooling fans are installed at two places, the first surface 2A which is the base of the heat sink 2 is orthogonal to the flow direction of the cooling air from one of the first air cooling fans, and the second surface 2B is The radiator 1 is installed on the circuit board 12 so as to be orthogonal to the flow direction of the cooling air from the other second air cooling fan. The circuit board 12 is installed in an upright posture. Therefore, in FIG. 13, the fourth surface 2D is the top surface.

The shapes of the first surface 2A, the second surface 2B, and the fourth surface 2D are substantially square. Through holes 4 are formed in a two-dimensional shape on each surface 2A, 2B, and 2D. The electronic component 7 is mounted on the second surface 2B. The through hole 4 is not formed in the mounting portion of the electronic component 7 on the second surface 2B.

In the present embodiment, the leg portion 3 is shown because the same leg portion as the protrusion 10 of the above embodiment is provided on the second surface 2B and the fourth surface 2D, but is embedded in the circuit board 12. Absent.

Next, the operation of cooling the electronic component 7 by the radiator 1 of the present embodiment will be described. When only the first air-cooling fan is turned on, the first surface 2A receives the cooling air blown from the first air-cooling fan, and the cooling air is passed through the through hole 4 to the downstream side. That is, the cooling air that has passed through the through hole 4 flows into the space surrounded in four directions by the first surface 2A, the second surface 2B, the fourth surface 2D, and the circuit board 12. After that, the cooling air passes through the through holes 4 of the second surface 2B and the fourth surface 2D in the direction not having the heat radiating plate 2 (radiating surface) and diffuses to the outside.

On the other hand, when only the second air-cooling fan is turned on, the second surface 2B receives the cooling air blown from the second air-cooling fan and allows the cooling air to pass through the through hole 4 to the downstream side. The cooling air that has passed through the through hole 4 passes through the through hole 4 and the like and diffuses to the outside, as in the case of operating the first air cooling fan.

When both the first air cooling fan and the second air cooling fan are turned off, the air in the space surrounded by the first surface 2A, the second surface 2B, the fourth surface 2D, and the circuit board 12 in four directions becomes an electronic component. The temperature is raised by the heat generated by 7 or the like to form an updraft, which passes through the through hole 4 on the fourth surface 2D. That is, the air does not stay in the space but passes through the through hole 4 on the fourth surface 2D and diffuses to the outside.

As described above, the air does not stay in the space surrounded by the heat sink 2 and the circuit board 12 and is smooth regardless of whether one of the air cooling fans is operating or both air cooling fans are stopped. The heat generated from the electronic component 7 can be efficiently dissipated.

Further, when the product provided with the circuit board 12 can be installed vertically or horizontally, or when it is portable, even if the top surface of the product changes, the air that becomes an updraft generated when the air cooling fan is stopped. Can be passed through the through hole 4 while receiving the air on any of the three surfaces. That is, the heat generated from the electronic component 7 can be efficiently dissipated regardless of the posture and the installation state of the product.

(5) In each of the above embodiments, the other second surface 2B and the fourth surface 2D are bent at right angles to the first surface 2A which is the base of the heat radiating plate 2, but the bending angle is limited to a right angle. Instead, the settings are appropriately changed so that the cooling air and the receiving and radiating surface are orthogonal to each other according to the circuit design and the installation angle of the air cooling fan.

1 Heat sink 2 Heat sink 2A 1st surface 2B 2nd surface 2C 3rd surface 3 Leg 4 Through hole 5 Through hole 6 Flange 7 Electronic component 8 Screw 9 Through hole 10 Protrusion 11 Notch 12 Circuit board 13 Installation hole 14 Notch

Claims (2)

A radiator that abuts on an electronic component mounted on a circuit board erected so that the substrate surface is parallel to the vertical direction and dissipates heat generated from the electronic component.
By switching on / off of the air cooling fan arranged so as to blow the cooling air in the horizontal direction of the substrate surface, the horizontal air flow is received at right angles to the horizontal air flow generated by the horizontal cooling air when the air cooling fan is turned on. a first wind receiving heat radiating surface, the first wind receiving radiating surface substantially perpendicular to such a bent form Rutotomoni, second receiving that swept the orthogonal the rising air against updraft generated around during off Has a wind radiating surface,
A first through hole through which the horizontal airflow can pass is formed on the first wind receiving and radiating surface, while a second through hole through which the updraft can pass is formed on the second wind receiving and radiating surface. Consists of boards ,
It has legs that extend from the heat sink, allow the heat sink to be installed on the circuit board, and separate the heat sink from the circuit board.
A radiator characterized in that the legs extend from the first wind receiving heat radiating surface. Radiator according to claim 1, characterized in that it does not have the first and second through-holes in a predetermined area of the heat radiating plate for mounting the electronic component.

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