JP2016046345A - Electronic apparatus and wireless access point - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus including a heat dissipation mechanism capable of dissipating heat of a heat source body stably.SOLUTION: An electronic apparatus 10 includes an electronic component 20 as a heat source body, a heat conductive sheet 30, a buffer member 40, and a housing 50 as a heat dissipation member. The electronic component 20 includes an electronic component which generates heat by driving. The buffer member 40 is arranged between the electronic component 20 and housing 50, while being applied with a predetermined pressing force by the electronic component 20 and housing 50. The heat conductive sheet 30 is arranged on the surface of the electronic component 20 opposite from the buffer member 40, and has a first part 301 in contact with the electronic component 20, a second part 302 located between the buffer member 40 and housing 50, in contact with the housing 50, and a third part 303 for conducting heat between the first part 301 and second part 302.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device including a heat source body that generates heat by driving and a wireless access point.

  Some electronic devices currently in practical use include elements and electronic units that generate large amounts of heat. Hereinafter, these elements and electronic units that generate large amounts of heat are referred to as heat source bodies. For this reason, the electronic device provided with such a heat source body is provided with a heat dissipation mechanism.

  In the electronic device disclosed in Patent Document 1, a high thermal conductive sheet is disposed across three surfaces of the HDD that is a heat source. This high thermal conductive sheet is routed to the inner wall of the housing. A cooler is disposed in a portion of the high thermal conductive sheet that contacts the casing. The cooler cools the high heat conductive sheet, and the electronic unit dissipates heat through the high heat conductive sheet.

JP 2008-310855 A

  However, the high thermal conductive sheet may be deformed depending on the temperature history or aging, and desired heat dissipation characteristics may not be obtained.

  For example, in the configuration described in Patent Document 1, since the high heat conductive sheet is routed from the position where the heat source body is arranged in the housing to the inner wall of the housing, when the high heat conductive sheet is deformed, The contact state or the contact state with respect to the housing changes, and the heat dissipation characteristics deteriorate.

  The objective of this invention is providing the electronic device provided with the thermal radiation mechanism which can thermally radiate a heat source body stably.

  The electronic device of the present invention includes a heat source body, a heat radiating member, a buffer member, and a heat conductive sheet. The heat source body includes an electronic component that generates heat when driven. The buffer member is disposed between the heat source body and the heat radiating member with a predetermined pressing force applied by the heat source body and the heat radiating member. The heat conductive sheet has first, second, and third portions. The first portion is disposed on the surface of the heat source body opposite to the buffer member and is in contact with the heat source body. The second portion is disposed between the buffer member and the heat radiating member, and is in contact with the heat radiating member. The third part conducts heat between the first part and the second part.

  In this configuration, the state where the heat conductive sheet is in contact with the heat source body and the heat radiating member is maintained by the buffer member. Thereby, heat dissipation is stably maintained.

  Moreover, the heat conductive sheet of the electronic device of this invention is further arrange | positioned between a heat source body and a buffer member, and further has a 4th part which contact | connects a heat source body and a buffer member.

  In this configuration, the heat conductive sheet comes into contact with the heat source body in a more stable state. Thereby, heat dissipation is performed more stably.

  Moreover, in the electronic device of this invention, the heat conductive sheet is wound around the heat source body and the heat radiating member. In this structure, a heat conductive sheet can be arrange | positioned easily.

  In the electronic device of the present invention, the heat conductive sheet is wound around the entire circumference of the heat source body and the buffer member. With this configuration, the heat dissipation efficiency can be further improved.

  In the electronic device of the present invention, the heat conductive sheet is composed of a single sheet in which the first portion, the second portion, and the third portion are integrated.

  In this configuration, the structure of the heat conductive sheet can be simplified, and installation on the heat source body and the heat radiating member can be facilitated.

  Moreover, in the electronic device of this invention, the 4th part is integrated with the 1st part, the 2nd part, and the 3rd part.

  In this structure, a heat conductive sheet can be arrange | positioned easily and efficiently, and an arrangement | positioning state can be maintained stably.

  Moreover, in the electronic device of this invention, the heat radiating member is a housing in which the heat source body and the buffer member are disposed.

  In this configuration, since the casing is a heat dissipation member, the shape of the electronic device can be reduced in size, and the heat dissipation efficiency is improved.

  In the electronic device of the present invention, the heat source body and the buffer member are disposed in a space sealed by the housing. Even with such a shape, the heat source body can be effectively dissipated.

  In the present invention, the heat source includes an electric circuit element constituting a wireless communication circuit, and the electronic device is a wireless access point. With this configuration, thermal runaway and failure of the wireless access point can be suppressed.

  According to this invention, the heat source body can be radiated stably. Thereby, the thermal runaway and failure of the element and electronic unit which are heat source bodies can be suppressed, and a highly reliable electronic device can be realized.

The top view and 1st side view which show the thermal radiation structure of the electronic device which concerns on the 1st Embodiment of this invention The 2nd side view and sectional drawing of the 2nd side which show the heat dissipation structure of the electronic device which concerns on the 1st Embodiment of this invention The graph which shows the thermal radiation characteristic in the thermal radiation structure of the electronic device which concerns on the 1st Embodiment of this invention, and the thermal radiation structure of a comparative example The figure explaining the attachment aspect of the heat conductive sheet of the electronic device which concerns on the 1st Embodiment of this invention. 1st side view of the electronic device which concerns on the 2nd Embodiment of this invention 1st side view of the electronic device which concerns on the 3rd Embodiment of this invention The 2nd side view of the electronic equipment concerning a 4th embodiment of the present invention.

  An electronic apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a plan view showing a heat dissipation structure of an electronic device according to the first embodiment of the present invention. FIG. 1B is a first side view showing the heat dissipation structure of the electronic device according to the first embodiment of the present invention. FIG. 2A is a second side view showing the heat dissipation structure of the electronic device according to the first embodiment of the present invention. FIG. 2B is a cross-sectional view of the second side surface showing the heat dissipation structure of the electronic device according to the first embodiment of the present invention.

  As shown in FIGS. 1 and 2, the electronic device 10 according to the first embodiment of the present invention includes an electronic component 20, a heat conductive sheet 30, a buffer member 40, a housing 50, and a main circuit board 60.

  The electronic component 20 includes a circuit board 21 and a cover 22. An electric circuit element is mounted on the circuit board 21, and a circuit pattern for connecting the mounted electric circuit element is formed. The cover 22 is installed so as to cover a region where the electric circuit element is mounted on the surface of the circuit board 21.

  When the electric circuit element is driven by being supplied with power, the electric circuit element realizes a predetermined function like an electric circuit but generates heat. For example, the electric circuit element is a resistor, a transistor, an integrated circuit element (IC), or the like. The number of electric circuit elements mounted on the circuit board 21 may be one or plural. This heat is transmitted to the circuit board 21 and the cover 22. For this reason, the electronic component 20 becomes a heat source body. In this case, the circuit board 21 on which the electronic circuit elements are mounted is likely to be hotter than the cover 22. Further, the cover 22 can be omitted. In this case, only the circuit board 21 on which the electric circuit element is mounted corresponds to the electronic component 20 and becomes a heat source body.

  The part of the circuit board 21 where the cover 22 is disposed, that is, the outer shape of the electronic component 20 serving as a heat source body is a rectangular parallelepiped.

  The circuit board 21 is arranged in parallel to the main circuit board 60. The circuit board 21 includes an external connection terminal at the end of the flat plate surface. This external connection terminal is attached to a connector 61 mounted on the main circuit board 60. With this configuration, the electronic component 20 is fixed and electrically connected to the main circuit board 60 with the back surface 202 of the electronic component 20 parallel to the front surface of the main circuit board 60.

  The shape of the buffer member 40 is the same rectangular parallelepiped as the electronic component 20. The area of the buffer member 40 in plan view is substantially the same as the area of the electronic component 20 in plan view. The buffer member 40 is made of a material having low elasticity. It is preferable that the buffer member 40 is excellent in moisture resistance and heat resistance.

  The buffer member 40 is disposed between the housing 50 and the surface of the electronic component 20 (the surface on which the electric circuit element on the circuit board 21 is mounted and the cover 22 is disposed). At this time, the buffer member 40 is disposed such that substantially the entire back surface of the buffer member 40 faces substantially the entire surface 201 of the electronic component 20. In addition, the buffer member 40 is disposed so that the surface 401 of the buffer member 40 faces the inner wall surface of the housing 50.

  The housing 50 is made of a material having high thermal conductivity. For example, the housing 50 is made of aluminum. Therefore, the housing 50 functions as a heat radiating member.

  The heat conductive sheet 30 is made of a material having high heat conductivity and flexibility. For example, the heat conductive sheet 30 is made of a graphite sheet.

  The heat conductive sheet 30 is a sheet-like member. The heat conductive sheet 30 is disposed so as to be in contact with substantially the entire back surface of the electronic component 20. This portion corresponds to the first portion 301 of the heat conductive sheet 30. The heat conductive sheet 30 is disposed so as to be sandwiched between the surface of the buffer member 40 and the housing 50. This portion corresponds to the second portion 302 of the heat conductive sheet 30. The heat conductive sheet 30 is disposed so as to be in contact with substantially the entire left side surface and right side surface of the electronic component 20 facing each other and the left side surface and right side surface of the buffer member 40 facing each other. This portion corresponds to the third portion 303 of the heat conductive sheet 30. The heat conductive sheet 30 is disposed so as to be sandwiched between the front surface of the electronic component 20 and the back surface of the buffer member 40. This portion corresponds to the fourth portion 304 of the heat conductive sheet 30.

  Since the buffer member 40 is sandwiched between the electronic component 20 and the housing 50 in a compressed state, the buffer member 40 is sandwiched between the surface of the electronic component 20 and the back surface of the buffer member 40 in the heat conductive sheet 30. The part (fourth part 304) is in contact with substantially the entire surface of the electronic component 20. Further, a portion (second portion 302) sandwiched between the surface of the buffer member 40 and the housing 50 in the heat conductive sheet 30 is in contact with substantially the entire surface of the housing 50.

  The left side surface and right side surface of the electronic component 20 in the heat conductive sheet 30 and the left side surface and the right side surface of the buffer member 40 (the third portion 303) are in contact with the back surface of the electronic component 20 (the first side). Part 301), a part sandwiched between the surface of the buffer member 40 and the housing 50 (second part 302), a part sandwiched between the surface of the electronic component 20 and the back surface of the buffer member 40. It is connected to the (fourth portion 304) as a heat conduction path.

  Thus, the heat conductive sheet 30 is arrange | positioned so that the whole outer periphery connected with the surface which the electronic component 20 mutually opposes, a back surface, and the mutually opposing left side surface and right side surface may be touched. The heat conductive sheet 30 is in contact with the inner wall surface of the housing 50.

  With this configuration, heat generated from the electronic component 20 is efficiently conducted to the housing 50 by the heat conductive sheet 30. The housing 50 releases the conducted heat to the outside. Thereby, even if the electronic component 20 exists in the housing | casing 50, it can thermally radiate effectively. Therefore, runaway or failure due to heat of the electronic component 20 can be suppressed, and the highly reliable electronic device 10 can be realized. In particular, even when the heat generation amount of the circuit board 20 is large, by using this configuration, heat is applied to the housing 50 from the first portion 301 of the heat conductive sheet 30 via the third portion 303 and the second portion 302. Is efficiently conducted and can effectively dissipate heat.

  Further, the buffer member 40 is held in a compressed state between the electronic component 20 and the housing 50. Thereby, the heat conductive sheet 30 is stably fixed, and it can suppress that the heat conductive sheet 30 deform | transforms with the change of temperature or time, and the adhesiveness with respect to the electronic component 20 falls. In particular, by providing the fourth portion 304, the deformation of the heat conductive sheet 30 can be suppressed more reliably and stably. Therefore, the electronic component 20 can be radiated stably and continuously, and the highly reliable electronic device 10 can be realized.

  FIG. 3 is a graph showing the heat dissipation characteristics of the heat dissipation structure of the electronic device according to the first embodiment of the present invention and the heat dissipation structure of the comparative example. The vertical axis of the graph is the temperature of the electronic component, and the horizontal axis of the graph is the time. FIG. 3 shows a temperature transition in a state where power is continuously supplied through the power supply to the electronic component at time “0”.

  The heat dissipation structure of the comparative example is a structure in which a buffer member is not provided, the electronic component and the housing are separated from each other, and a heat conductive sheet is disposed so as to connect them.

  As shown in FIG. 3, in the configuration of the comparative example, the temperature rises and the temperature rises and falls and is not stable. However, by using the configuration of the present invention, the temperature rise is lower than the configuration of the comparative example, and becomes a constant temperature earlier than the comparative example. In addition, the temperature can be maintained at a constant level with little fluctuation. Thus, by providing the configuration of the present invention, heat can be radiated stably and efficiently.

  In addition, by using a low elastic material for the buffer member 40, the compressive stress applied to the electronic component 20 can be reduced, and the failure of the electronic component 20 can be suppressed. Thereby, the electronic device 10 with higher reliability can be realized.

  Further, by using a material having low elasticity for the buffer member 40, the distance between the electronic component 20 and the housing 50 can be made flexible. Thereby, even if there is variation in the distance between the electronic component 20 and the housing 50, the electronic component 20 and the housing 50 can be reliably thermally connected using the heat conductive sheet 30.

  Furthermore, by using the configuration of the present embodiment, it is possible to prevent the main heat generation portion of the electronic component 20 from contacting the main circuit board 60 with a large area. Thereby, it is possible to prevent the heat generated by the electronic component 20 from being conducted to the main circuit board 60. As described above, by using the configuration of the present embodiment, the electronic component 20 can be radiated efficiently and stably, and the heat of the electronic component 20 can be prevented from being conducted to the main circuit board 60 unnecessarily. Thereby, the electronic device 10B with higher reliability can be realized.

  The above-described heat conductive sheet 30 is disposed on the electronic component 20 and the buffer member 40 as described below. FIG. 4 is a view for explaining an attachment mode of the heat conductive sheet of the electronic device according to the first embodiment of the present invention.

  First, as shown in FIG. 4A, one end Ed31 of the heat conductive sheet 30 is arranged in accordance with a ridge formed by the surface and side surfaces of the electronic component 20. Next, the heat conductive sheet 30 is wound around the electronic component 20 so that the front surface, the right side surface, and the back surface of the electronic component 20 are in close contact with each other.

  Next, as illustrated in FIG. 4B, the buffer member 40 is installed on the surface of the electronic component 20 with the heat conductive sheet 30 interposed therebetween. At this time, it is preferable that the left side surface of the electronic component 20 and the left side surface of the buffer member 40 be arranged flush with each other. Then, the heat conductive sheet 30 is attached to the electronic component 20 and the buffer member 40 so as to be in close contact with the left side surface of the electronic component 20 and the left side surface of the buffer member 40.

  Next, as shown in FIG. 4C, the heat conductive sheet 30 is wrapped around the buffer member 40 so that the surface of the buffer member 40 is in close contact with the right side surface, and further, on the right side surface of the electronic component 20, The other end of the heat conductive sheet 30 is brought into close contact with the heat conductive sheet 30 that is already mounted.

  By attaching the heat conductive sheet 30 in this way, the heat conductive sheet 30 can be disposed in close contact with both the outer peripheral surface of the electronic component 20 and the outer peripheral surface of the buffer member 40. Thereby, the electronic device 10 with high heat dissipation efficiency and high reliability can be realized, and the electronic device 10 can be manufactured by an easy method. Moreover, by winding the heat conductive sheet 30 in a shape sandwiched between the electronic component 20 and the buffer member 40, the heat conductive sheet 30 can be reliably and stably fixed. A decrease in adhesion to the electronic component 20 can be suppressed.

  Next, an electronic component according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a first side view of an electronic apparatus according to the second embodiment of the present invention.

  The electronic device 10A according to the present embodiment is different from the electronic device 10 according to the first embodiment in the shape of the heat conductive sheet 30A. Other configurations are the same as those of the electronic apparatus 10 according to the first embodiment.

  The heat conductive sheet 30A is obtained by omitting the fourth portion of the heat conductive sheet 30 according to the first embodiment. In this case, the front surface of the electronic component 20 and the back surface of the buffer member 40 abut. Even with such a configuration, the heat generated in the electronic component 20 can be effectively and stably dissipated in the housing 50 as in the first embodiment.

  Next, an electronic apparatus according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a first side view of an electronic apparatus according to the third embodiment of the present invention.

  The electronic device 10B according to the present embodiment differs from the electronic device 10 according to the first embodiment in the configuration of the buffer member 40B and the housing 50B and the arrangement mode of the heat conductive sheet 30B. Other configurations are the same as those of the electronic apparatus 10 according to the first embodiment.

  The buffer member 40B includes a first buffer member 41B and a second buffer member 42B. The first buffer member 41 </ b> B is disposed on the surface of the electronic component 20. The second buffer member 42 </ b> A is disposed on the right side surface of the electronic component 20.

  The heat conductive sheet 30B is disposed in close contact with the entire outer periphery of the electronic component 20, and is disposed in close contact with substantially the entire outer periphery of the buffer member 40B.

  The housing 50B includes a top wall 51B and a side wall 52B. The top wall 51B faces the surface of the electronic component 20 with the first buffer member 41B interposed therebetween. The side wall 52B faces the side surface of the electronic component 20 with the second buffer member 42B interposed therebetween.

  The buffer member 40B is sandwiched in a compressed state between the electronic component 20 and the housing 50B.

  A portion in contact with the back surface of the electronic component 20 corresponds to the first portion 301B of the heat conductive sheet 30B. A portion sandwiched between the buffer member 41B and the housing 50B corresponds to the second portion 302B of the heat conductive sheet 30B. A portion in contact with the left side surface of the electronic component 20 and the buffer member 41B and a portion in contact with the buffer member 42B correspond to the third portion 303B of the heat conductive sheet 30B. The portion sandwiched between the surface of the electronic component 20 and the buffer member 41B and the portion sandwiched between the right side surface of the electronic component 20 and the buffer member 42B correspond to the fourth portion 304B of the heat conductive sheet 30B. .

  Even with such a configuration, similarly to the first embodiment, the heat generated by the electronic component 20 can be efficiently conducted to the housing 50B via the heat conductive sheet 30B, and the housing 50B. Can be emitted from the outside. Furthermore, in the electronic device 10A of the present embodiment, heat can be conducted to the two wall surfaces of the housing 50B and heat can be radiated from the two wall surfaces, so that the electronic component 20 can be radiated more effectively.

  Next, an electronic apparatus according to a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a second side view of the electronic apparatus according to the fourth embodiment of the present invention.

  The electronic device 10C according to the present embodiment is different from the electronic device 10 according to the first embodiment in the installation mode of the electronic component 20 with respect to the main circuit board 60. Other configurations are the same as those of the electronic apparatus 10 according to the first embodiment.

  The end of the electronic component 20 of the electronic device 10 </ b> C according to this embodiment that is opposite to the end that is attached to the connector 61 is supported by a support member 62 that is disposed on the surface of the main circuit board 60. With this configuration, the electronic component 20 can be more stably fixed.

  Note that the electronic devices described in the above embodiments may be required to have environment resistance and dust resistance. In this case, the inside of the housing is preferably sealed. In such a case, the configuration of the present invention works more effectively. For example, when considering dust resistance and the like, it is preferable to seal the inside of the housing, but since the heat radiating fan or the like cannot be installed by sealing the inside of the housing, the heat dissipation is generally lowered. However, it is possible to effectively dissipate heat by using the configuration of the present invention. Therefore, an electronic device having excellent heat dissipation performance and environmental resistance and high reliability can be realized.

  Further, the electronic device shown in each of the above-described embodiments is, for example, a wireless access point. In this case, the electronic component 20 that is a heat generation source is a circuit module for wireless communication including an IC for wireless communication and a PA (power amplifier). Since the circuit module for wireless communication needs to widen a communicable range and enable continuous communication without interruption, the energization time is long and the power consumption increases. Therefore, the circuit module for wireless communication has a large amount of heat generation, and the possibility of thermal runaway or failure is increased as compared with other circuit modules. For this reason, by providing the configuration of the present invention, the circuit module for wireless communication can be effectively radiated and a highly reliable wireless access point can be realized.

  Further, the wireless access point is installed in an environment where an unspecified number of persons enter and exit. Further, the installation position is often specified, and the installation position may be easily affected by the external environment. Therefore, the wireless access point is easily affected by dust, temperature, humidity, and the like. However, by using the above-described case with the inside sealed, both the environment resistance (sealing property) and heat dissipation of the wireless access point can be increased, which is useful.

  In each of the above-described embodiments, the case in which the housing is used as the heat radiating member has been described. However, a heat radiating plate having high thermal conductivity can be used separately from the housing.

  Moreover, in each above-mentioned embodiment, although the aspect using one heat conductive sheet was shown, the aspect which winds one heat conductive sheet for each electronic component and buffer member can also be used.

  In each embodiment described above, a buffer member for fixing the position may be disposed between the electronic component and the main circuit board. In this case, the buffer member may have a high thermal conductivity when the main circuit board has a heat dissipation effect, and may have a low thermal conductivity when the main circuit board does not have a heat dissipation effect.

10, 10A, 10B, 10C: Electronic device 20: Electronic component 21: Circuit board 22: Cover 30, 30A, 30B: Thermal conductive sheet 40, 40B: Buffer member 41B: First buffer member 42B: Second buffer member 50, 50B: Housing 51B: Top wall 52B: Side wall 60: Main circuit board 61: Connector 62: Support member

Claims (9)

A heat source body including electronic components that generate heat by driving;
A heat dissipating member;
Between the heat source body and the heat radiating member, a buffer member disposed in a state where a predetermined pressing force is applied by the heat source body and the heat radiating member,
A first part that is disposed on the surface of the heat source body opposite to the buffer member and is in contact with the heat source body, a second part that is disposed between the buffer member and the heat dissipation member, and is in contact with the heat dissipation member; And a heat conductive sheet having a third portion that conducts heat between the first portion and the second portion;
With electronic equipment. The electronic device according to claim 1,
The heat conductive sheet is
A fourth portion disposed between the heat source body and the buffer member and in contact with the heat source body and the buffer member;
Electronics. The electronic device according to claim 1 or 2,
The heat conductive sheet is wound around the heat source body and the heat radiating member,
Electronics. The electronic device according to claim 3,
The heat conductive sheet is
Wound around the entire circumference of the heat source body and the buffer member,
Electronics. The electronic device according to claim 3 or claim 4,
The heat conductive sheet is composed of one sheet in which the first portion, the second portion, and the third portion are integrated.
Electronics. The electronic device according to claim 5,
The fourth part is integrated with the first part, the second part, and the third part,
Electronics. The electronic device according to any one of claims 1 to 6,
The heat dissipation member is a housing in which the heat source body and the buffer member are disposed.
Electronics. The electronic device according to claim 7,
The heat source body and the buffer member are disposed in a space sealed by the housing,
Electronics. A configuration of the electronic device according to claim 7 or claim 8,
The heat source body includes an electric circuit element constituting a wireless communication circuit,
Wireless access point.

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