JP2002016388A - Heat sink and method for radiating heat from plug-in type device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink and method for radiating heat from a plug-in type device by which the heat generated from a heat generating element mounted on the printed board of a card which can be inserted into and pulled out of an enclosure fixed on a rack, etc., can be radiated easily and efficiently to the outside of the enclosure and, in addition, can prevent malfunctions caused by static electricity and does not deteriorate the EMC characteristic. SOLUTION: The heat sink radiates the heat generated from a plug-in type device provided with at least one card which can be inserted into and pulled out from the enclosure and has the printed board 1, a front panel 2 installed to one end section of the board 1, and a connector 7 for backboard installed to the other end section of the board 1. The heat sink is provided with a micro heat pipe 8 one end of which is thermally connected to the heat generating element 6 provided on the printed board 1, and the other end of which is thermally connected to the front panel 2 through a prescribed route and transfers the heat from the heat generating element 6 to a prescribed portion of the front panel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiating device and a heat radiating method for a plug-in type device in which a card having a front panel at an end of a printed circuit board is inserted into a housing.

[0002]

2. Description of the Related Art A plug-in type device usually has a housing in which at least one printed circuit board is removably mounted, and a front panel is attached to one end of each printed circuit board. A heating element such as a semiconductor element is mounted on the printed circuit board, the degree of integration of the semiconductor element is increased, and the amount of heat generation is large. For example, air is blown in a vertical direction to lower the temperature inside the housing. FIGS. 4 and 5 show a conventional plug-in type device. FIG. 4 shows a conventional plug-in type device in an installed state.

FIG. 5 is a diagram showing a card formed of a printed circuit board to which a front panel is attached. As shown in FIG. 4, this is a plug-in type device in which a card having a front panel 32 attached to one end of a printed board 31 is mounted on a housing 34. The housing 34 is mounted on a rack 35 or the like installed in a vertical direction. The card is composed of one or more cards, and each card has a mechanism that can be inserted and removed in the front-rear direction. Further, each card is fitted to the back board of the housing by a connector 37 shown in FIG.

Conventionally, as shown in FIG. 5, a connector 38 for outputting a signal or the like from a printed circuit board 31 and an alarm LED (Lig) are provided on a front panel 32 of each card.
ht Emitting Diode) 39 and the like are arranged side by side. In addition, the IC in the printed circuit board serves as the front panel
Display, protection from dust, protection against human body such as electric shock, protection from electromagnetic wave, and the like. Further, as shown in FIG. 4, there is a front panel 32 in which metal pieces 33 are attached to both sides of the front panel 32 in order to further enhance electromagnetic wave protection.

[0005] Various demands for the performance of the plug-in type device have been increased, and accordingly, the number of components directly arranged on the front panel has been increased. As mentioned above,
In a plug-in type device, the amount of heat generated by a heating element mounted on a printed circuit board increases, and various cooling methods are employed in order to maintain high performance. Conventionally, in a plug-in type device, as a general method for lowering the temperature of components in the device, a heat sink is installed on the heating element, and the heat generated by the heating element is radiated into the housing. For example, a forced air cooling system using a fan or the like is used, or a mounting space is widened by dispersing the mounting density of the heat-generating components on the printed circuit board to avoid heat concentration.

[0006]

However, the heat dissipation method of the conventional plug-in type device has the following problems. In other words, the method of dissipating heat by disposing a heat sink on the heating element has an effect of efficiently dissipating heat from a heat generating source, but has a limit in heat dissipation capacity. Furthermore, in the case of a plug-in type device, since the card is inserted and removed, there is almost no place that becomes a heat radiating part, and even when radiating heat inside the housing, processing such as radiating heat to the part with a small mounting density of the heating element Was needed. In addition, heat is easily dissipated by disposing an electronic component serving as a heating element close to the front panel. However, there is a risk of malfunction due to static electricity when a device is operated by a person. Therefore, it is necessary to keep the heating element away from the front panel. Was.

Therefore, it is necessary to treat the components around the heat sink so as not to be affected by heat.
It was necessary to increase the space such as dispersing the component mounting density on the printed circuit board. Further, if an external air intake for cooling is provided in the apparatus, noise also enters, so that there is a problem that EMC (Electromagnetic Compatibility) characteristics of a high-performance system are deteriorated.

Accordingly, it is an object of the present invention to easily and efficiently radiate heat of a heating element mounted on a printed circuit board of a card which can be inserted into and removed from a housing fixed to a frame or the like, to the outside of the housing and to generate static electricity. An object of the present invention is to provide a heat radiating device and a heat radiating method for a plug-in type device that do not prevent malfunction and degrade EMC characteristics.

[0009]

Means for Solving the Problems The present inventor has made intensive studies to solve the above-mentioned conventional problems. as a result,
At least one insertable card having a printed circuit board, a front panel provided at one end of the printed circuit board, and a backboard connector provided at another end of the printed circuit board. By specifying a predetermined portion of the front panel that does not deteriorate the EMC characteristics of the plug-in type device, and transferring the heat of the heating element on the printed circuit board to the specified predetermined portion of the front panel by the micro heat pipe, It has been found that the heat of the heating element can be effectively radiated by using the predetermined portion as a part of the heat sink.

The present invention has been made based on the above findings, and a first aspect of the heat radiating device of the plug-in type device according to the present invention is provided on a printed board and one end of the printed board. A heating element on the printed circuit board of a plug-in type device having at least one insertable / removable card having a front panel and a backboard connector provided at another end of the printed circuit board. A plug having a micro heat pipe, one end of which is thermally connected, and the other end of which is thermally connected to the front panel via a predetermined path to transfer heat of the heating element to a predetermined portion of the front panel. It is a heat radiator of an in-type device.

In a second aspect of the heat radiating device of the plug-in type device according to the present invention, a metal piece thermally connected to the front panel is provided on at least one side of the card. A heat radiator for a plug-in type device, wherein the transferred heat is further transferred to the metal piece.

In a third aspect of the heat radiating device of the plug-in type device according to the present invention, the micro heat pipe is bent three-dimensionally, and is closely connected to the predetermined portion of the front panel which can be used as a heat radiating portion. A heat radiating device for a plug-in type device, characterized in that

A first aspect of the heat radiation method for a plug-in type device according to the present invention is directed to a printed circuit board, a front panel provided at one end of the printed circuit board, and a front panel provided at another end of the printed circuit board. A predetermined portion of the front panel of a plug-in type device having at least one insertable / removable card having a backboard connector, and a micro heat pipe between the heating element and the front panel. A path to be connected is specified, one end of the micro heat pipe is thermally connected to the heating element on the printed circuit board, and the other end of the micro heat pipe is thermally connected to the front panel via the predetermined path. And a heat radiation method for a plug-in type device, in which heat of the heating element is moved to a predetermined portion of the front panel to radiate heat.

According to a second aspect of the heat radiation method for a plug-in type device of the present invention, a metal piece thermally connected to the front panel is provided on at least one side of the card and moved to the front panel. A method for radiating heat of a plug-in type device, wherein the generated heat is further transferred to the metal piece and radiated.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a heat radiating device and a heat radiating method of a plug-in type device according to the present invention will be described in detail. The plug-in type device according to the present invention includes at least one of a printed circuit board, a front panel provided at one end of the printed circuit board, and a backboard connector provided at another end of the printed circuit board. One end is thermally connected to the heating element on the printed circuit board and the other end is thermally connected to the front panel of the plug-in type device equipped with two insertable cards. Is a heat radiator of a plug-in type device provided with a micro heat pipe moving to a predetermined portion of the device.

That is, in the plug-in type device according to the present invention, at least one insertable and removable card including a printed circuit board and a front panel is mounted on a housing fixed to a frame or the like and provided with a backboard via a connector. It is a device to be performed. There is a limitation that the rear side of the housing cannot be used as a heat radiating portion for radiating heat from a heating element mounted on a printed circuit board in the housing in order to avoid affecting the arrangement of other devices and the like. The plug-in type device of the present invention can be mounted on the printed circuit board in the housing without deteriorating the EMC characteristics of the high-performance system as well as dissipating heat in the situation where the heat radiation part is limited as described above. And a heat radiating device capable of efficiently radiating the heat from the generated heating element.

FIG. 1 is a view for explaining a heat radiating device of a plug-in type device according to the present invention. As shown in FIG. 1, in one embodiment of the plug-in type device of the present invention, two insertable / extractable cards including a printed circuit board 1 and a front panel 2 are mounted on a housing 4 vertically fixed by a frame 5. Has been charged. Each card is mounted on the housing 4 by a backboard connector (not shown) provided at an end.

The heat radiating device of the plug-in type device according to the present invention is further provided with a metal piece thermally connected to the front panel on at least one side of the above-mentioned card. The generated heat is further transferred to the metal pieces. Preferably, the metal strip is a front panel of a card arranged next to the card. In that case, if an electromagnetic shielding member (metal or the like) is provided so as to fill the gap between the two front panels, heat transfer becomes easy, and the heat radiation effect of the heating element is further enhanced.

FIG. 2 is a diagram showing a card mounted on the housing of the plug-in type device of the present invention. A front panel 2 is provided at one end of the printed circuit board 1.
A heat sink 9 having radiation fins is mounted on a heating element 6 such as a semiconductor element mounted on a printed circuit board. The micro heat pipe 8 arranged in contact with the heating element extends through the predetermined space of the card along the printed circuit board 1 to the front panel 2 and is fixed to the back surface of the predetermined portion 12 on the upper part of the front panel by the fixing bracket 11. Have been. A back board connector 7 is provided at the other end of the printed circuit board.

In the plug-in type device of the present invention, as described above, the front panel has many functions such as display of the contents of the IC in the printed circuit board, protection from dust, protection against human body such as electric shock, and protection from electromagnetic waves. It is required to demonstrate. In general, it is very difficult to achieve both heat dissipation measures and prevention of EMC degradation. That is, in the plug-in type device of the present invention, while fully exhibiting these many functions described above,
In addition, by making a limited part function for heat dissipation,
The heat of the heating element mounted on the printed circuit board is efficiently radiated to the outside of the housing without deteriorating the characteristics of the EMC.

For this reason, a predetermined portion of the front panel, which is capable of sufficiently performing many functions while allowing a limited portion thereof to function for heat radiation, is specified.
Furthermore, it is important that the micro heat pipe disposed in contact with the heating element extends through a predetermined space of the card and along a printed circuit board to a predetermined portion of the front panel.

In FIG. 2, the micro heat pipe 8 is arranged symmetrically with respect to the heating element 6 having a high calorific value, but another micro heat pipe 8 'is arranged on another heating element 6' shown in FIG. Alternatively, it may extend through a predetermined space to the back surface of the predetermined portion 12 at the upper portion of the front panel and be fixed.
Since the micro heat pipe has a small outer diameter and is excellent in workability, it is easy to dispose such a three-dimensional gap.

FIG. 3 is a diagram showing another embodiment of the card mounted on the housing of the plug-in type device of the present invention.
In FIG. 3, a front panel 2 is provided at one end of a printed circuit board 1. On a heating element 6 such as a semiconductor element mounted on the printed circuit board 1, a heat sink 9 having a radiation fin is placed. The micro heat pipe 8 arranged in contact with the heating element extends through the predetermined space of the card along the printed circuit board 1 to the front panel 2 and is fixed to the back surface of the predetermined portion 12 on the upper part of the front panel by the fixing bracket 11. Have been. A back board connector 7 is provided at the other end of the printed circuit board.

As shown in FIG. 3, many functions such as display of the contents of the IC in the printed circuit board, protection from dust, protection against human body such as electric shock, and protection from electromagnetic waves are sufficiently exhibited, and furthermore, the characteristics of EMC are further improved. A predetermined portion 12 of the front panel that can function for heat dissipation without deteriorating the heat path, and furthermore, a path of the micro heat pipe 8 capable of transferring heat from the heating element mounted on the printed circuit board. To identify.

As shown in FIG. 3, in the heat radiating device of the plug-in type device according to the present invention, the micro heat pipe 8 is three-dimensionally bent so as to pass the path specified as described above, and the front panel is bent. Is closely connected to a predetermined portion 12 that can be used as a heat radiating portion. In addition,
In the heat radiation device of the plug-in type device of the present invention,
As shown in FIGS. 2 and 3, another heat sink may be further provided on the heating element.

As described above, the micro heat pipe connected to the heating element and a predetermined portion of the front panel through a predetermined path is connected to the heat-removable card including the printed circuit board on which the heating element is mounted and the front panel. By mounting the heat sink provided in contact with the body, the heat of the heating element is dissipated by a route moved above the printed circuit board by convection of air and a route moved to the front panel by the micro heat pipe. As a result, a predetermined portion of the front panel that is in direct contact with the outside air can be used as a part of the heat sink without impairing the sufficient function of the front panel that performs multiple functions as described above, and the heat dissipation effect can be reduced. Can be enhanced.

Further, in order to reduce thermal resistance between the micro heat pipe and the heat sink and between the micro heat pipe and the front panel, a heat conductive sheet may be provided between the micro heat pipe and the front panel. Further, in the plug-in type device of the present invention, the radiator may be provided with a Peltier element. For example, when the heating element uses a Peltier element such as an LD (Laser Diode) module, the heat dissipation effect of the Peltier element can be further enhanced by drawing the micro heat pipe directly below the LD module. If the housing of the Peltier element LD module cannot be dropped on the frame GND, an insulating heat conductive sheet is sandwiched between the micro heat pipe and the housing of the LD module, or an insulation is provided between the micro heat pipe and the front panel. It is preferable that the screw used for fixing the type heat conductive sheet is resin screw.

As described above, in the heat radiation method for a plug-in type device according to the present invention, a predetermined portion of the front panel which does not deteriorate EMC characteristics is specified, and a micro heat pipe is provided between the heating element and the front panel. The micro heat pipe is closely connected to the specified predetermined portion of the front panel through the specified path.

That is, at least one pluggable plug having a printed circuit board, a front panel provided at one end of the printed circuit board, and a backboard connector provided at another end of the printed circuit board. Of a front panel that does not degrade the EMC characteristics of a plug-in type device equipped with a simple card, specifies a path connecting a heating element to the front panel with a micro heat pipe, and specifies a heating element on a printed circuit board. The other end of the micro heat pipe is thermally connected to the front panel through a predetermined path, and the heat of the heating element is transferred to the upper part of the front panel for heat radiation. I do.

The material of the container of the micro heat pipe according to the present invention may be any material such as copper, aluminum, copper alloy, aluminum alloy, etc., which is excellent in heat conductivity and easy to bend. As the working fluid sealed in the container, water, alternative Freon, acetone, methanol, helium, nitrogen, ammonia, sodium, or the like can be used. The working fluid can be selected in consideration of the compatibility with the material of the container from the above.

The heat radiating device of the plug-in type device of the present invention can be applied to, for example, an optical amplification repeater used in an optical wavelength division multiplexing transmission system or the like. Conventionally, optical amplifier repeaters have large power consumption and are required to save space, and heat dissipation of the optical amplifier repeater has been a major issue. By using this, the heat radiation effect can be enhanced without deteriorating the EMC characteristics of the optical amplification repeater. Furthermore, optical amplification repeaters generally have many unmanned stations,
Due to the maintenance, it is difficult to employ the forced air cooling system. By using the heat radiating device of the plug-in type device of the present invention, a high heat radiation effect can be obtained without employing the forced air cooling system. Hereinafter, the heat radiating device and the heat radiating method of the plug-in type device according to the present invention will be described in more detail with reference to examples.

[0032]

EXAMPLE 1 As shown in FIG. 1, two insertable / removable cards having a front panel attached to one end of a printed circuit board were inserted into a case vertically fixed by a frame. A plug-in type device of the invention was prepared. The size of the housing was 30 cm long × 20 cm wide × 40 cm high. The upper and lower surfaces of the housing have an open shape so that convection of air is possible. The other surface of the housing is closed.

A front panel is provided at one end of the printed circuit board of each card. A heat sink having radiation fins is mounted on a heating element such as a semiconductor element mounted on a printed circuit board. Sites on the front panel that did not degrade the EMC characteristics of the plug-in type device were previously investigated and identified. The micro heat pipe arranged in contact with the heating element extends through the predetermined space of the card to the front panel along the printed circuit board, and is three-dimensionally bent so as to be a specified portion which does not deteriorate the EMC characteristics. The end of the micro heat pipe was fixed to the back surface of the portion 4 cm from the upper end of the front panel with a fixing bracket. The other end of the printed circuit board is provided with a connector for a backboard.

The micro heat pipe is made of copper (C102
0) made of a round container having a diameter of 3 mm, and pure water as a working fluid is sealed in the container.
The heating value of the heating element on the printed circuit board of each card is about 25W
Met. When such a card was inserted into the housing and the plug-in type device was operated to measure the temperature of the component to be cooled in the housing, the temperature was about 40 ° C. Further, when the EMC characteristics of the plug-in type device were examined, it did not deteriorate as compared with the EMC characteristics of a comparative example described later.

COMPARATIVE EXAMPLE 1 For comparison, an insertable / removable 2 without a micro heat pipe having a front panel attached to one end of a printed circuit board in a case vertically fixed by a frame.
A plug-in type device for comparison with three cards was prepared. The size of the housing is 30cm long x 20cm wide
× The height was 40 cm. The upper and lower surfaces of the housing have an open shape so that convection of air is possible. The other surface of the housing is closed.

A front panel is provided at one end of the printed circuit board of each card. A heat sink having radiation fins is mounted on a heating element such as a semiconductor element mounted on a printed circuit board. The heating value of the heating element on the printed circuit board of each card was about 25 W. When such a card was inserted into the housing and the plug-in type device was operated to measure the temperature of the component to be cooled in the housing, the temperature was about 50 ° C.

As apparent from the above description, according to the plug-in type device of the present invention, the housing temperature can be maintained without deteriorating the EMC characteristics due to the natural air cooling opening of the plug-in type device. The operation was maintained to such an extent that the operation was not affected, and a high heat radiation effect was obtained. On the other hand, without a micro heat pipe,
In Comparative Example 1 in which heat is released by convection of air, the temperature inside the housing is high, which hinders the operation of the plug-in type device.

That is, by investigating in advance a portion of the front panel that does not degrade the EMC characteristics of the plug-in type device and fixing the end of the micro heat pipe to that portion, only vertical air convection is possible. It is proved that effective heat dissipation can be performed even for a plug-in type device that cannot dissipate heat backward, without deteriorating its performance.

[0039]

As described above, according to the present invention, heat of a heating element mounted on a printed circuit board of a card that can be inserted into and removed from a housing fixed to a frame or the like is easily and efficiently radiated out of the housing. In addition, it is possible to provide a heat radiating device and a heat radiating method of a plug-in type device which do not prevent malfunction due to static electricity and degrade EMC characteristics, and have high industrial use value.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a heat radiating device of a plug-in type device according to the present invention.

FIG. 2 is a diagram showing a card mounted on a housing of the plug-in type device of the present invention.

FIG. 3 is a diagram showing another embodiment of a card mounted on the housing of the plug-in type device of the present invention.

FIG. 4 is a diagram showing a conventional plug-in type device in an installed state.

FIG. 5 is a diagram illustrating a card including a printed circuit board to which a front panel is attached.

[Explanation of symbols]

 1. Printed circuit board 2. Front panel 3. Metal piece 4. Housing 5. Frame 6. Heating element 7. Backboard connector 8. Micro heat pipe 9. Heat sink 10. 10. Plug-in type device Fixing bracket 12. Predetermined part on top of front panel 31. Printed circuit board 32. Front panel 33. Metal piece 34. Housing 35. Frame 36. Air convection direction 37. Connector 38. Connector 39. LED

Claims (5)

[Claims] At least one pluggable connector having a printed circuit board, a front panel provided at one end of the printed circuit board, and a backboard connector provided at another end of the printed circuit board. One end is thermally connected to a heating element on the printed circuit board, and the other end is thermally connected to the front panel via a predetermined path, so that the heating element A heat radiator for a plug-in type device, comprising a micro heat pipe for transferring heat to a predetermined portion of the front panel. 2. The method according to claim 1, further comprising: a metal piece thermally connected to the front panel on at least one side of the card, wherein heat transferred to the front panel is further transferred to the metal piece. The heat radiating device for a plug-in type device according to claim 1, wherein 3. The micro heat pipe according to claim 1, wherein the micro heat pipe is bent three-dimensionally, and is closely connected to the predetermined portion of the front panel which can be used as a heat radiating portion. Heat dissipation device for plug-in type devices. 4. At least one pluggable plug having a printed circuit board, a front panel provided at one end of the printed circuit board, and a backboard connector provided at another end of the printed circuit board. A predetermined portion of the front panel of a plug-in type device equipped with a simple card, a path connecting the heating element and the front panel with a micro heat pipe, and a heating element on the printed circuit board. One end of the micro heat pipe is thermally connected, the other end of the micro heat pipe is thermally connected to the front panel via the predetermined path, and heat of the heating element is moved to a predetermined portion of the front panel. Heat dissipation method for plug-in type devices. 5. The method according to claim 5, further comprising: a metal piece thermally connected to the front panel on at least one side of the card, wherein the heat transferred to the front panel is further transferred to the metal piece and radiated. The method for radiating heat of a plug-in type device according to claim 4, characterized in that: