JPH05327247A - Heat radiating structure for printed-board unit - Google Patents

Abstract

PURPOSE:To cause heat generated in a printed-board unit to be efficiently transferred to a front plate and to be radiated. CONSTITUTION:A heat radiating structure is provided with a printedboard unit 12 that has heating components 27 and a heat-conductive member 19 for causing heat generated by the heating components to be transferred to a front side of the unit, and a heat-transfer member 22 having a pressure contact means 23 for bringing the heat-transfer member into pressed contact with a front plate 25 that is located at the front end of the heat-conductive member 19 and is removably attached to the front surface of the printed-board unit 12.

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 a printed board unit. An electronic / communication device or the like has a device configuration in which a large number of printed board units are mounted in a housing to form a device circuit.

According to such a device configuration, in order to mount a large number of printed board units having circuit functions at a higher density without enlarging the entire apparatus, they are mounted on the printed board unit. It is important to efficiently remove the heat generated from heat-generating components such as LSI to maintain the temperature inside the device at a predetermined temperature or lower. Further, the same is required when mounting the device at a high density in order to miniaturize it.

On the other hand, since the above-mentioned device is operated continuously for a long period of time, it is necessary to use a movable part such as an electric fan to cool the inside of the device by means of heat radiation, so that the reliability of the electric fan and the space and electric power therefor are increased. Therefore, it is not desirable to use it, and it is preferable to perform heat radiation cooling by natural ventilation.

[0004]

2. Description of the Related Art Electronic / communication devices, etc. (hereinafter simply referred to as devices) adapted to perform heat radiation cooling by natural ventilation
In general, the configuration as shown in the schematic view of FIG. 9 is adopted. That is, FIG. 9A is a side sectional view of FIG.
As shown in the front view of the figure, the shelves 2 are accommodated in a vertically long multi-stage (three stages in the figure) at intervals inside the vertically long casing 1.
A guide plate 3 for cooling air is attached diagonally rearward and upward in the left direction in the figure at the space.

A large number of printed circuit board units 5 are vertically arranged in parallel inside the shelves 2, and the lateral intervals between the printed circuit board units 5 in each stage depend on the amount of heat generated by the printed circuit board units 5. The interval width is set.
A heat generating component such as an LSI (not shown) is mounted on the printed board unit 5, and the heat generated from these is radiated mainly to the space except for being transferred to the printed board.

This radiated heat is conducted to the air outside the casing that enters from the front along the upper surface of the guide plate 3 below the shelves 2 and raises the temperature of the air, whereby the air rises upward. Then, it flows out along the lower surface of the upper guide plate 3 to the outside of the rear surface of the housing 1.

In this way, the upper and lower shelves 2, 2 are partitioned by the guide plate 3 so that cooling air for cooling and heating does not mix, and the cool air from the outside of the front surface is taken into the sheerf 2 and the temperature is raised by natural convection. The air is configured to flow out to the outside back surface of the housing along the path indicated by arrow A.

Since it is necessary to set a large opening for taking in outside air and a large discharge port according to the amount of heat generated by the printed board unit 5, the sheerf 2,
The height interval between the upper and lower sides of the two is increased, and the overall height is increased. In order to reduce this, it is necessary to reduce the number of printed circuit board units 5 accommodated per shelf, but this goes against high-density mounting.

[0009]

The problem with the above-mentioned prior art is that when the number of printed circuit board units accommodated in the shelves is increased, the inlet / outlet of the cooling air is made larger (higher), but this also naturally occurs. There is a limit and it cannot be increased (high) indefinitely. On the contrary, it is required to mount more printed board units. Cooling by forced ventilation with an electric fan or the like is not preferable for the above reason.

In view of the above, it is an object of the present invention to provide a heat dissipation structure for a printed board unit in which the inlet and outlet of the cooling air are minimized so that heat is actively dissipated. ..

[0011]

Means for Solving the Problems The object of the present invention to solve the above problems is to provide a printed board unit having a heat-generating component and a heat-conducting member for transmitting the heat generated by the heat-generating component to the front side. A heat transfer member provided at a front end of the heat conductive member and press-contacted with a front plate detachably attached to the front surface of the printed board unit.

The heat transfer member has a tubular metal body joined to the heat transfer member and a heat transfer surface slidably fitted to the metal body and in contact with the front plate in a pressure contact state. And consist of.

The heat conducting member is preferably a heat pipe.

[0014]

According to the above-mentioned gist of the present invention, the heat generated inside is conducted to the heat conducting member, and the front end of the heat conducting member is brought into pressure contact with the front plate attached to the front surface of the printed board unit to transfer the heat. , Efficiently dissipate heat from the front plate.

Further, by providing the heat transfer member at the front end of the heat transfer member, a reliable pressure contact state can be obtained even if there is a gap error with the front plate. Furthermore, by using a heat pipe as the heat conducting member, a more efficient heat conducting state can be obtained.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cooling structure for a printed board unit according to the present invention will be described in detail with reference to the drawings based on a specific embodiment based on the structure.

FIG. 1 is a basic side sectional view (a) of a heat dissipation structure of a printed board unit according to the present invention and a front view (b) taken along the line BB. In addition, in the figure (a), the illustrated surface is a side surface, the right-hand side is a front surface, the left-hand side is a back surface, the upper side is an upper side, the front side is a lower side,
Called. In FIG. 1, a printed circuit board unit 12 is vertically inserted into the shell 11 from the front side, and a connector 15 is electrically connected to a back board 13 on the rear side by plug-in connection.

Cooling air guide plates 16 and 17 are arranged obliquely rearward and upward, respectively, on the upper and lower portions of the shelves 11. On the upper part of the printed board unit 12, a heat conductive member 19 is fixedly mounted in a horizontal posture from the front surface to the back surface along the printed board. This heat conducting member 19
A heat absorption plate 21 is attached in a vertical position at key points (five in the figure).

An internal member of a heat transfer member 22 which is extendable in a front-rear direction and fitted and slidable is attached to the front end portion of the heat transfer member 19, and the front surface of the external member of the heat transfer member 22 is internally provided. Front plate 2 indicated by phantom lines by the press-contact means 23
It is pressed against the back surface of No. 5. A high heat-generating component 27 such as an LSI is mounted on the printed board unit 12.

With the above structure, L
The ambient air is heated by the heat generated from the SI 27 and the like, and the air rises along the printed board. The rising air flows out along the lower surface of the upper guide plate 16 to the outer rear surface side of the shell 11 as shown by an arrow C, so that the external cooling air flows along the upper surface of the lower guide plate 17 from the lower front surface. Introduced and replenished.

Due to such a flow of the cooling air, the air that is heated and rises contacts the heat absorbing plate 21, and the heat absorbing plate 21 absorbs a considerable amount of heat. The heat is transmitted from the heat absorbing plate 21 to the heat conducting member 19 and is transmitted to the front plate 25 via the heat transmitting member 22 at the front end portion. From the wide front plate 25, the space and the shell 11 or the housing in which the space is fixed. Conduct heat dissipation to.

Since the front plate 25 is radiatively cooled as described above, the heat conducting member 19 has a low temperature,
The heat is efficiently absorbed by the heat absorption plate 21. The heat conduction member 19, the heat absorption plate 21, and the heat transfer member 22 are made of, for example, copper, copper alloy, aluminum and its alloy material having a low heat resistance, and are composed of a combination of a plate material, a bar material, a tube material and the like. However, if the heat conducting member 19 is a known heat pipe, the most preferable aspect can be obtained. Further, in order to make the heat absorption plate 21 positively absorb the heat, it is also possible to obtain a preferable result by forming a rough surface having a good emissivity or a surface state such as black.

FIG. 2 (a) is a view of the shell 11 from the front. The printed board units 12 are vertically arranged and plugged in horizontally in parallel. Heat absorption plate 2
The size of No. 1 is changed according to the amount of heat generated, and similarly, the interval between the printed board units 12 is also changed. The position of the heat transfer member 22 in the height direction is set to be on a constant line.

Screw holes 26 are provided at the left and right ends of the shelves 11, and a front plate 25-1 having a narrow height shown in FIG. The heat transfer member 22 is in pressure contact with the front plate 25-1 to radiate heat. This front plate 25-1
Along with the heat radiation, each of the printed board units 12 functions to prevent the printed board units 12 from coming out of the shelves 11.

Instead of the narrow front plate 25-1 (c)
A larger heat radiating area can be obtained by mounting the front plate 25-2 having a height covering the entire front opening of the shelves 11 shown in the figure with the screws 27. This front plate 25-2 is a display of each function of the printed board unit 12,
It is also used as having a function to attach parts for control operation. Of course, it also has a function of preventing each printed board unit 12 from coming off.

Regarding the heat dissipation function of the front plates 25-1 and -2, in order to further improve the function, the front plate 25 has a large number of fins 28 on the front side as shown in FIG. By setting the value to -3, the heat dissipation capability is further increased. Further, the material of the front plate is preferably an aluminum material or the like having a low thermal resistance, but a structural steel plate or the like is low in cost and economical.

A preferred first embodiment of the heat transfer member will be described below with reference to FIG. FIG. 4A is a side cross-sectional view, and FIG. 4B is a DD arrow view as seen from the front side.

In the figure, a heat transfer member 30 has a cylindrical metal body 31 joined to the heat conduction member 19 by means such as press-fitting or soldering, and is slidably fitted to the metal body 31 and is attached to the front side. The heat transfer surface 32 and the through hole 33 include a compression coil spring 34 and a heat transfer body 37 in which a C-shaped retaining ring 35 for locking the spring 34 is fitted in a groove 36.

On the back side, a pin 38 is press-fitted into a hole penetrating the heat transfer body 37 in the radial direction. The tip of the pin 38 is fitted in the vertical groove 39 of the metal body 31 to prevent mutual rotation and the metal body 31. The heat transfer body 37 is prevented from slipping out of due to the compression reaction force of the spring 34.

The front view of the heat transfer surface 32 is vertically long and formed to have a narrow width in the horizontal direction, as is apparent from FIG. This is suitable for making the mounting intervals of the printed board units high. A heat transfer rubber sheet 41 is interposed between the front surface of the heat transfer surface 32 and the front plate 25 that is in contact therewith, so that the entire surface is effectively adhered.

The conduction heat of the heat conduction member 19 is transmitted in the direction of the arrow E, is transmitted to the joined metal body 31, and is transmitted to the heat transfer body 37 fitted thereto. Since the heat transfer body 37 is pressed against the front side by the pressure of the spring 34 between the C-shaped retaining ring and the metal body 31, the heat transfer surface 32 is pressed against the front plate 25 and the heat is transferred to the front plate 25. Heat is generated and front plate 25
The heat is radiated from the space. Further, heat is also conducted to the shelves 11 and heat is also dissipated from the shelves.

When the front plate 25 is removed, the pins 38 come into contact with the ends of the vertical grooves 39 of the metal body 31, and the heat transfer body 37 is protected from being separated from the metal body 31. Even if there is a slight inclination between the heat transfer surface 32 and the front plate 25 due to the interposition of the heat transfer rubber sheet 41,
The two are effectively in close contact with each other for heat conduction.

The presence of the compression coil spring 34 as the pressure contact means prevents a slight positional error in the front-back direction between the heat transfer member 30 (22) provided in each of the multiple printed board units 21 and the front plate 25. All the heat transfer surfaces 32 function so as to come into pressure contact with the front plate 25.

The metal body 31 and the heat transfer body 37 are formed of a metal having good heat conduction, for example, copper, copper alloy, aluminum and alloys thereof, and the fitting portion is provided with heat to improve heat transfer. It is preferable to supply conductive grease or the like, and the sliding movement of the fitting portion can be suitably performed.

A second preferred embodiment of the heat transfer member will be described below with reference to FIG. FIG. 5A is a side cross-sectional view, and FIG. 5B is a view taken along the line FF as viewed from the front side.

In the figure, a heat transfer member 50 is a cylindrical metal body 51 joined to the heat transfer member 19 by means such as press fitting or soldering, and is slidably fitted to the metal body 51 and is attached to the front side. It comprises a heat transfer surface 52 and a heat transfer body 55 in which a compression coil spring 54 is fitted in a hole 53 whose rear end is opened.

On the back side, a screw 57 is screwed into a screw hole in the radial direction of the heat transfer body 55, and is located so that the tip end contacts the back end of the metal body 51. This prevents the heat transfer body 55 from coming off from the metal body 51 due to the compression reaction force of the spring 54. Further, a radial through hole 58 is provided in the vicinity of the bottom of the hole 53 of the heat transfer body 55 so that the hole 53 communicates with the outside.

A heat transfer rubber sheet 59 is inserted between the heat transfer surface 52 and the front plate 25 in contact therewith so that the entire surface is effectively adhered. The conduction heat of the heat conduction member 19 is transmitted in the direction of arrow E, and the metal body 51 is joined.
Is transmitted to the heat transfer body 55 which is fitted to the heat transfer body 55.
The heat transfer body 55 is the spring 5 between the bottom of the hole 53 and the metal body 51.
Since it is pressed to the front side by the pressure of 4, the heat transfer surface 5
2 is pressed against the front plate 25 to transfer heat to the front plate 25, and the heat is radiated from the front plate 25 to the space. Part of the heat is also conducted to the shelves 11, and the heat is also dissipated from the shelves.

When the front plate 25 is removed, the screw 57 abuts on the end surface of the metal body 51, and the heat transfer body 55 is protected from being separated from the metal body 51. The heat transfer rubber sheet 59 is made of the same material as that of the embodiment shown in FIG. 4 and functions similarly.

The metal body 51 and the heat transfer body 55 are also shown in FIG.
The same material and the same operation as in the above embodiment are performed. The same applies to the supply of heat conductive grease or the like to the fitting portion. In addition,
The through hole 58 of the heat transfer body 55 is for allowing air to flow in and out of the space in the hole 53 in a sealed state.

The heat transfer rubber sheets 41 and 59 do not necessarily have to be rubber, and the same action and effect can be obtained even if they are bladder bodies filled with a heat transfer liquid material. ..

A preferred embodiment of the connecting portion between the heat conducting member 19 and the heat absorbing plate 21 will be described below with reference to FIG. FIG. 6A is a side sectional view, and FIG. 6B is an arrow GG.
It is the figure seen from. In the figure, on a surface of the heat absorbing plate 21 through which the heat conducting member 19 penetrates, a combined body 60 in which a flange portion 61 is connected to the heat absorbing plate 21 by spot welding 62 is attached.

The combined body 60 is integrally formed with a sleeve 63 which extends in the axial direction of the central portion of the flange portion 61 and in which the heat conducting member 19 is closely fitted. The sleeve 63 is axially extended from one open end. The notch groove 65 is formed at a plurality of locations (four locations in the figure).

A coil spring 67 is provided around the sleeve 63.
Is fitted in the expanded state. Therefore, the winding spring 67 acts to reduce the sleeve 63 toward the center by the cut groove 65 in an attempt to reduce it.

Since the combined body 60 has a large heat transfer area to the heat conducting member 19, the heat from the heat absorbing plate 21 can be efficiently transferred to the heat conducting member 19. Further, although the sleeve 63 is in close contact with the heat conducting member 19, it is only in contact with the heat conducting member 19, so that the sleeve 63 can slide in the axial direction. Therefore, the position of the heat absorption plate 21 with respect to the heat conduction member 19 can be moved and set to an arbitrary position in the length direction.

The material of the joint body 60 is copper, which has good thermal conductivity,
It is preferably formed from aluminum or an alloy thereof. One embodiment of a preferred mode of direct thermal coupling between the heat generating component 27 and the heat absorbing plate 21 will be described below with reference to FIG. 7. FIG. 7A is a side view, and FIG. 7B is a view seen from the direction of arrow H-H. In the figure, the legs 72 of the heat absorbing plates 21 arranged on the left and right of the LSI 27, which is a heat generating component mounted and mounted on the printed board 71, are attached to the printed board 71 with screws 73.

Between the heat absorbing plates 21 and 21, a connecting plate 75 formed in a U-shape is attached by heat absorbing plates 21 and 21 and screws 77 by both leg portions 76 and 76 thereof. Then, the coupling plate 75 and the heat dissipation device 78 of the LSI 27 are provided.
A heat transfer rubber sheet 79 is inserted between and under pressure contact.

The heat generated by the LSI 27 is transmitted from the heat dissipation device 78 integrated with the LSI 27 to the coupling plate 75 via the heat transfer rubber sheet 79, and the legs 76 and 76 of the heat absorption plate 2 are transmitted.
1, 21 and is transferred to the heat conducting member 19 as described above.
Through the heat transfer member 22 to the front plate 25 to be radiated.

This coupling plate 75 is made of a material having good thermal conductivity,
For example, it is formed of copper, copper alloy, aluminum and its alloy material. The rubber sheet 79 may also be the bladder described above, but other heat transfer compounds and the like are also applicable.

One embodiment of a preferred embodiment applicable for indirect heat absorption of the heat absorption plate 21 of FIG. 1 will be described below with reference to FIG. 8A is a plan view,
(B) The figure is a side view. In the figure, the heat absorbing plate 80 in this embodiment has a large number of heat absorbing fins (fins) 81 formed in parallel in the vertical direction, and is fixed to the heat conducting member 19 penetrating in the horizontal direction by press fitting or soldering. Attached to. However, it is of course preferable to apply the combination embodiment of FIG.

It is needless to say that the present invention can be applied to each of the embodiments and modes described above, but by combining them arbitrarily or intentionally, heat dissipation can be more efficiently performed. It goes without saying that this is included.

In the above embodiments, the cross section of the heat transfer member is illustrated as a circle, but the present invention is not limited to this, and may be any shape such as square, oval, elliptical or rectangular. I will get it. Further, as the press-contact means, other elastic bodies can be applied instead of the coil spring, and various kinds such as a leaf spring can be applied.

[0053]

As described above in detail, according to the heat dissipation structure of the printed board unit of the present invention, the printed board unit is provided with the heat conducting member for transmitting the heat generated by the heat producing component to the front side. Since a heat transfer member having a pressure contact means is provided at the front end portion of and the end surface of this heat transfer member is pressed against the front plate, the heat generated by the heat generating component is conducted and radiated from the front plate. It enables high-density mounting of the device.

The operability is simple and easy because the pressure contact state with the conductive component and the separated state are automatically established according to the attachment / detachment of the surface plate. By sharing heat generation by natural convection of internal air and heat dissipation from the surface plate, it is possible to set the vertical spacing of the shelves to a minimum, and the practical effect that solved the conventional problems is extremely high. It is remarkable.

[Brief description of drawings]

FIG. 1 is a basic diagram of a heat dissipation structure of the present invention.

FIG. 2 is a front view of the shelf of FIG.

[Fig. 3] Front plate for improving heat dissipation function

FIG. 4 is a first embodiment of the heat transfer member.

FIG. 5: Second embodiment of heat transfer member

FIG. 6 is an example of a joint between a heat conducting member and a heat absorbing plate.

FIG. 7 is an example of coupling the heat generating component and the heat absorbing plate.

FIG. 8: One example of heat absorbing plate

FIG. 9 is an explanatory diagram of a conventional heat dissipation structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 11 Shelf 12 Printed board unit 16,17 Induction plate 19 Heat conduction member 21 Heat absorption plate 22 Heat transfer member 23 Pressure contact means 25 Front plate 27 Heat generation part 30,50 Heat transfer member 31,51 Metal body 32,52 Transfer Heat surface 34, 54 Spring 37, 55 Heat transfer element 38 Pin 41, 59 Heat transfer rubber sheet 60 Combined body 61 Flange 63 Sleeve 65 Cut groove 67 Winding spring 75 Coupling plate 80 Heat absorption plate 81 Fin (fin)

Claims (3)

[Claims] 1. A printed board unit (12) comprising a heat-generating component (27) and a heat-conducting member (19) for transmitting heat generated by the heat-generating component to the front side, and a front end of the heat-conducting member (19). A heat transfer member (22) provided with a pressure contact means (23) for pressure contact with a front plate (25) detachably attached to the front surface of the printed board unit (12). The heat dissipation structure of the printed circuit board unit. 2. The heat transfer member (22) (30) is slidably fitted to a cylindrical metal body (21) joined to the heat conduction member (19). And front plate (2
5. The heat dissipation structure for a printed circuit board unit according to claim 1, further comprising: a heat transfer body (37) having a heat transfer surface (32) in pressure contact with the heat transfer body (37). 3. The heat dissipation structure for a printed circuit board unit according to claim 1, wherein the heat conducting member (19) is a heat pipe.