JP6511973B2 - Electronics - Google Patents

Description

  The present invention relates to an electronic device.

In recent years, downsizing and thinning of electronic devices have been required. On the other hand, in the electronic device, the surface temperature becomes high due to the heat generated by the electronic component such as the CPU incorporated in the housing, giving a feeling of discomfort or injury to a person, or causing discoloration in the place where the electronic device was installed. Etc. may adversely affect the peripherals of electronic devices.
Heretofore, as a method for preventing the surface of the housing of the electronic device from becoming high temperature, for example, a metal heat dissipation plate is used which widens the space between the heat generating electronic component (heat generating component) and the housing. Methods have been proposed to diffuse the heat generated by

  Further, for example, in Patent Document 1, a printed wiring board is provided as an electromagnetic induction heating cooker having a structure for effectively cooling a heat-generating component mounted on the printed wiring board by an air flow from a cooling fan, An opening for passing the cooling air is provided, the heat generating component to be cooled is mounted on the printed wiring board in the vicinity of the opening, and part of the air flow from the cooling fan is the lower surface of the printed wiring board The electromagnetic induction heating cooker is proposed that is configured to cool the heat-generating component mounted in the vicinity after passing through the opening of the printed wiring board through the space between the solder surface and the bottom of the housing It is done.

JP 2005-63777 A

However, the method of widening the space between the heat generating electronic component (heat generating component) and the housing is a method that does not meet the demand for downsizing and thinning of the electronic device, and the method of using a metal heat sink When the electronic device has a wireless communication function, the method may have an adverse effect on the function.
In addition, the invention described in Patent Document 1 aims to supply a fresh (low-temperature) air flow to the heat-generating component, and between the back surface of the printed wiring board and the bottom surface of the housing, The ability to lower the surface temperature of the case was not sufficient, mainly because air flows only partially.

  An object of the present invention is to provide an electronic device capable of suppressing an increase in surface temperature of a housing while achieving downsizing and thinning of the electronic device in view of the conventional problems.

  An electronic device according to an aspect of the present invention includes a box-shaped casing provided with an inlet and an outlet and having a minimum height dimension, a substrate on which a heat generating component accommodated in the casing is mounted, and An electronic device comprising a cooling fan housed in a housing, wherein the substrate is housed in the housing in a direction parallel to a bottom plate of the housing, and the air inlet is the housing And the first space on the bottom plate side and the second space on the opposite side of the bottom plate by the substrate over substantially the entire interior space of the housing. The exhaust gas such that the air taken in from the air intake circulates from the end on the air intake side of the first space to the other end and then flows into the second space, The position of the mouth is set.

  According to the present invention, it is possible to provide an electronic device in which the surface temperature of the housing does not become high even if it is miniaturized or thinned.

It is the perspective view which looked at the set top box which concerns on one Embodiment of this invention from the bottom side. It is a disassembled perspective view of FIG. It is the top view except the cover part of the set top box shown in FIG. It is the sectional view on the AA line of FIG. It is the BB sectional drawing of FIG. It is a perspective view which shows an example of the mounting state of a set top box. It is the top view except the cover part of the set top box concerning one embodiment of a reference invention. It is CC sectional view taken on the line of the set top box shown in FIG.

<Overview of Embodiments of the Present Invention>
Hereinafter, the outline of the embodiment of the present invention will be listed and described.
(1) The electronic device of the present embodiment is provided with a box-shaped casing having an intake port and an exhaust port and having a minimum height dimension, a substrate on which a heat generating component accommodated in the casing is mounted, and An electronic device comprising a cooling fan housed in a housing, wherein the substrate is housed in the housing in a direction parallel to a bottom plate of the housing, and the air inlet is the housing And the first space on the bottom plate side and the second space on the opposite side of the bottom plate by the substrate over substantially the entire interior space of the housing. The exhaust gas such that the air taken in from the air intake circulates from the end on the air intake side of the first space to the other end and then flows into the second space, The position of the mouth is set.

  According to the electronic device of the present embodiment, the inside of the housing provided with the intake port and the exhaust port is partitioned into the first space and the second space by the substrate on which the heat generating component is mounted, and from the intake port The air taken into the housing flows from the end on the inlet side of the first space to the other end in the first space sandwiched between the substrate and the bottom plate of the housing. It flows into the second space and is further exhausted through the exhaust port. Therefore, the air flow cools the heat-generating component and also removes the heat diffused from the heat-generating component to the bottom plate. As a result, in the present embodiment, the temperature of the bottom plate can be prevented from becoming high.

(2) The electronic device according to the present embodiment closes the gap between the inner surface of the side wall provided with the intake port and the end portion of the substrate, and the air taken in from the intake port enters the second space. It is preferable that a sealing member for suppressing movement is provided.
In this case, the air taken into the housing through the intake port passes through the first space through the gap between the inner surface of the side wall provided with the intake port and the end of the substrate. Therefore, it is possible to reliably prevent the flow into the second space. Therefore, in the present embodiment, it can be reliably avoided that the temperature of the bottom plate becomes high.

(3) In the electronic device according to the present embodiment, the guide member is configured to prevent the air flowing in the first space from leaking laterally to the second space in the direction intersecting the flowing direction of the air. Preferably, it is provided on the inner surface of the bottom plate.
In this case, the air taken into the housing through the air inlet leaks laterally to the second space in a direction intersecting with the flow direction of the air while flowing through the first space. Can be suppressed. Therefore, in the present embodiment, it can be reliably avoided that the temperature of the bottom plate becomes high.

(4) In the electronic device according to the present embodiment, preferably, the cooling fan is a sirocco fan, and the sirocco fan is disposed at a position where the intake portion is close to the heat-generating component and overlaps the heat-generating component. .
In this case, the heat-generating component can be more reliably cooled while contributing to thinning of the housing.

<Details of the Embodiment of the Present Invention>
The details of the embodiments of the present invention will be described below with reference to the drawings.
Here, the details of the embodiment of the present invention will be described by taking a set top box which is an example of the embodiment of the present invention as an example.
The set top box is a terminal device that is connected to a television and enables movie content and the like distributed via a broadband IP (internet protocol) network to be viewed on the television screen.

FIG. 1 is a perspective view of a set top box according to an embodiment of the present invention as viewed from the bottom side.
FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a plan view of the set top box shown in FIG. 4 is a cross-sectional view taken along line A-A of FIG. 1, and FIG. 5 is a cross-sectional view taken along line B-B of FIG.

As shown in FIGS. 1 to 5, the set top box 1 includes a housing 2, a circuit board 3 housed in the housing 2, and a cooling fan 4.
The housing 2 is made of resin, and a box-shaped housing 21 having an opening at the top and having a minimum height dimension is integrally formed with a flat cover 22 for closing the top opening of the housing 21.
The casing 2 is composed of a plurality of pores aligned along one side of the bottom plate 23 at the corner portion of the bottom plate 23 and the side wall 24 a of the storage portion 21, and intake air for taking in air from the outside into the casing 2. A mouth 25 is provided. Further, the housing 2 is provided with an exhaust port 26 for discharging the air circulated in the housing 2 to the outside at the central portion of the upper side of the side wall 24 b adjacent to the side wall 24 a of the housing portion 21.

  As shown in FIGS. 3 and 5, two substantially parallel guides are provided on the inner surface of the bottom plate 23 of the storage portion 21 from the side wall 24a side provided with the intake port 25 toward the side wall 24c side facing the side wall 24a. The members 27a and 27b are provided by integral molding. The guide members 27 a and 27 b are members having a role of regulating the flow of air taken into the housing 2 and a role of supporting the circuit board 3, which will be described in detail later.

As shown in FIGS. 3 to 5, in the housing portion 21 of the housing 2, the circuit board 3 on which the electronic components such as the CPU (central processing unit 31 composed of semiconductor elements) are mounted on the top surface is housed. . Further, a heat sink 32 is attached to the upper surface of the CPU 31.
The circuit board 3 is supported by the guide members 27a and 27b, and is stored sideways so as to be substantially parallel to the bottom plate 23 in a state of being separated from the bottom plate of the storage portion 21.

The circuit board 3 has a rectangular shape in a plan view as shown in FIG. 3, and the length in the longitudinal direction (the length in the direction from the side wall 24a to the side wall 24c of the storage portion 21) is the side wall 24a and the side wall It is slightly shorter than the distance to 24c.
Further, the length of the circuit board 3 in the short direction (the length in the direction from the side wall 24b to the side wall 24d of the storage portion 21) is longer than the distance between the guide members 27a and 27b. It is slightly shorter than the distance.
In the set top box 1, the area of the circuit board 3 is about 70 to 95% of the area of the cut surface when the internal space of the housing 2 is cut along the same horizontal plane as the circuit board 3.

Therefore, in the set top box 1, the upper space (second space) U on the upper surface side of the circuit board 3 and the lower space (first It is divided by the circuit board 3 into a space L).
At this time, the lower space L has a height (distance between the bottom plate 23 and the circuit board 3) smaller (shorter) than the height of the upper space U (distance between the lid 22 and the circuit board 3). In the set top box 1, the circuit board 3 is accommodated so as to be closer to the bottom plate 23 than the lid 22.

From the viewpoint of reducing the thickness of the set top box 1, it is preferable that the lower space L has a lower height (the circuit board 3 approaches the bottom plate 23). On the other hand, when the height of the lower space L is low, the heat of the heat generating component such as the CPU 31 is easily transmitted to the bottom plate 23, and the temperature of the bottom plate 23 tends to be high.
Therefore, in the set top box 1 of the present embodiment, the height of the lower space L is normally set to about 1 to 8 mm in order to prevent the temperature of the outer surface of the bottom plate from becoming high while achieving thinning. Is preferable, and about 3 to 5 mm is more preferable.

As shown in FIGS. 3 and 5, a plate-like sealing member 28 is provided in the housing portion 21 to close the gap between the inner surface of the side wall 24 a and the end of the circuit board 3.
Since the sealing member 28 is provided, in the set top box 1, the air taken into the housing 2 from the outside through the air inlet 25 is a gap between the inner surface of the side wall 24 a and the end of the circuit board 3. It is suppressed from flowing into the upper space U, and flows in the lower space U reliably.

As shown in FIGS. 2, 4 and 5, a sirocco fan is attached as the cooling fan 4 to the inside of the lid 22 of the housing 2, and the air discharged from the side of the cooling fan 4 (sirocco fan) is exhausted. A guide tunnel 29 for guiding into the mouth 26 is attached.
The sirocco fan is positioned such that the axial direction is substantially perpendicular to the circuit board 3 and right above the CPU 31 (the sheet sink 32) (that is, a position overlapping the CPU 31), and the intake portion of the sirocco fan is the heat sink 32. It is attached close to the top surface. By attaching the cooling fan 4 in this manner, thinning of the housing 2 is achieved while the CPU 31 is reliably cooled.
The guide tunnel 29 has a taber shape in which the opening area on the cooling fan 4 side is small and the opening area on the exhaust port 26 side is large.

In the set top box 1, an electronic component mounted on a circuit board such as the CPU 31 is a heat generating component that generates heat when driven, and in particular, the CPU 31 is a main heat generating component.
On the other hand, in the set top box 1, the air taken into the housing 2 cools the heat generating components such as the CPU 31 and the like, and prevents the surface temperature of the housing 2, especially the outer surface temperature of the bottom plate 23 from rising. be able to. I will explain this in more detail.

In the set top box 1, the air taken into the housing 2 from the air inlet 25 first flows into the lower space L in the housing 2, as shown by the arrow in FIG. After flowing from the side wall 24 a side to the side wall 24 c side substantially from end to end, it flows into the upper space U through the gap between the circuit board 3 and the side wall 23 c, and then the cooling fan 4 located right above the CPU 31 And, it is exhausted to the outside from the exhaust port 26 through the guide tunnel 29.
When such a flow of air occurs in the internal space of the housing 2, the heat of the CPU 31 (heat sink 32) is dissipated to the outside along the flow of air, and the CPU 31 is cooled. At the same time, the air flows from the end on the intake port 25 side to the other end in the lower space L, whereby the heat diffused from the CPU 31 toward the bottom plate 23 of the housing 2 is also a bottom plate along the air flow. It will be missed from 23. As a result, it can be avoided that the outer surface temperature of the bottom plate 23 becomes high as described above. Furthermore, in the case where the bottom plate 23 side is a mounting surface when mounting on a desk or the like, heat can be prevented from being transmitted to the desk or the like.

Further, in the set top box 1, by providing the sealing member 28 and the guide members 27a and 27b, only a part of the air introduced from the air intake can flow in the lower space L from the end to the end. The outer surface temperature of the bottom plate of the housing can be lower than that of the set top box configured in the above.
This is because, when the sealing member 28 is provided, the air introduced from the intake port 25 does not flow directly into the upper space U without flowing through the lower space L, and the guide members 27a and 27b are provided. The air introduced from the intake port does not leak laterally through the gap between the circuit board 3 and the side walls 24b and 24d while flowing through the lower space L and does not flow into the upper space U. It is considered that the flow velocity of air flowing in L can be increased.

As described above, the set top box 1 can be used by placing it on a desk or the like with the bottom plate 23 side as a placement surface, whereby heat is transmitted to the desk or the like, and adverse effects due to heat such as discoloration of the desk Can be avoided.
FIG. 6 is a perspective view showing an example of the set state of the set top box.
As shown in FIG. 6, the set top box 1 can also be used by being placed vertically with the bottom plate 23 facing vertically, using a dedicated stand 41.

  Although not shown, the set top box 1 is appropriately provided on the side walls 24 a to 24 d of the housing 2 with a connector connection portion for connecting to an external terminal or a power supply, a power switch, and the like.

(Other embodiments)
In the first embodiment, the sealing member 28 is provided to prevent air taken into the housing 2 from the intake port 25 from flowing directly into the upper space U without flowing through the lower space L. However, in order to achieve the above object without providing the sealing member 28, the circuit board 3 is housed in the housing 2 so that the end on the side wall 24a of the circuit board 3 abuts on the side wall 24a. It may be

In the first embodiment, by providing the guide members 27a and 27b, air is prevented from flowing from the lower space L into the upper space U through the gap between the end of the circuit board 3 and the side wall 24b or the side wall 24d. However, instead of providing the guide members 27a and 27b, a sealing member may be provided in the gap between the end of the circuit board 3 and the side wall 24b or the side wall 24d to suppress the above-described air flow.
In addition, the circuit board 3 may be housed in the housing 2 so that the end thereof abuts on the side wall 24 b or the side wall 24 d. Also in this case, air can be suppressed from flowing from the lower space L into the upper space U through the gap between the end of the circuit board 3 and the side wall 24 b or the side wall 24 d.

In the first embodiment, the intake port 25 is provided at the corner portion of the bottom plate 23 and the side wall 24a, but the position at which the intake port is provided is not limited to the corner portion, and is lower than the circuit board in the side wall Any position is acceptable.
In the first embodiment, the exhaust port is provided on the side wall 24b adjacent to the side wall 24a provided with the intake port, but the position at which the exhaust port is provided is not limited to this, and the other positions are not limited. It may be provided on any side wall or lid.

  In the first embodiment, the sirocco fan is provided as the cooling fan, but instead of the sirocco fan, another cooling fan such as an axial flow fan may be provided.

In the case of the electronic device according to the embodiment of the present invention, it is preferable that the dimension (height dimension) in the direction perpendicular to the bottom plate be sufficiently smaller than the dimensions of each side of the bottom plate. In the case of a set top box, the height dimension of the housing is preferably about 1.5 to 8 cm, and more preferably about 2 to 4 cm.
The housing of such a height dimension is thin, and the surface temperature of the housing tends to be high. Therefore, by providing the configuration of the present invention, an increase in the surface temperature of the housing (particularly, the surface temperature of the bottom plate) is avoided. It is suitable for

  The electronic device according to the embodiment of the present invention is not limited to the set top box, and the substrate on which the heat generating component is mounted is housed in a box-like housing and it is necessary to avoid the temperature rise on the housing surface. Any electronic device is acceptable.

  The embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is not limited to the embodiments described above, and includes all modifications within the scope equivalent to the configuration described in the claims.

[Supplementary Note]
Hereinafter, the invention (reference invention) disclosed as a reference will be described.
Like the present invention described in the claims, this reference invention aims to provide an electronic device capable of suppressing an increase in surface temperature of a housing while achieving downsizing and thinning of the electronic device. It is an invention to be The above reference invention is as follows.

A box-like housing provided with an inlet and an outlet and having a minimum height dimension;
A substrate mounted with a heat generating component housed in the housing;
An electronic device comprising: a cooling fan housed in the housing;
The housing has at least two guide members provided on the inner surface of the bottom plate for supporting the substrate.
The substrate is accommodated on the guide member and accommodated in the housing in a direction parallel to the bottom plate of the housing.
The air inlet is provided at a position lower than the substrate in the housing,
The electronic device wherein the position of the exhaust port is set so that the air taken in from the intake port is exhausted after being circulated throughout the space surrounded by the substrate, the bottom plate and the guide member.

  Also in the electronic device according to such a reference invention, the air taken into the housing from the air inlet is exhausted after flowing through the entire space under the substrate surrounded by the substrate, the bottom plate and the guide member. . Therefore, the air flow removes heat diffused from the heat-generating component to the bottom plate side. As a result, in the present embodiment, the temperature of the bottom plate can be prevented from becoming high.

Embodiments of the reference invention will be described with reference to the drawings.
FIG. 7 is a plan view of a case (housing unit) excluding the cover of the set top box according to the embodiment of the reference invention. FIG. 8 is a cross-sectional view of the set top box shown in FIG. 7 taken along the line C-C. In addition, in FIG. 7, the cooling fan attached to the cover part is described by the imaginary line.
As shown in FIGS. 7 and 8, the set top box 101 includes a housing 102, a circuit board 103 housed in the housing 102, and a cooling fan 104. The housing 102 is formed by integrating the housing portion 121 and the lid portion 122. The circuit board 103 is housed in the housing portion 121.
As shown in FIG. 7, the circuit board 103 has a rectangular shape in plan view, and the area thereof is as small as about 20 to 30% of the area of the bottom plate 123 of the housing portion 121 of the housing 102. A CPU 131 is mounted on the top surface of the circuit board 103, and a heat sink 132 is attached to the top surface of the CPU 131.

The circuit board 103 is provided on two guide members 127a and 127b parallel to each other, which are provided on the inner surface of the bottom plate 123, and a guide member 127c connected to respective ends of the two guide members 127a and 127b. It is supported and housed horizontally so as to be substantially parallel to the bottom plate 123 in a state of being separated from the bottom plate 123.
Therefore, in the set top box 101, a space (hereinafter referred to as a board lower space L) surrounded by the circuit board 103, the bottom plate 123, and the guide members 127a to 127c is provided below the circuit board 103.
Further, the bottom plate 123 is provided with an air inlet 125 composed of a plurality of pores. The air inlet 125 is provided at a position close to the guide member 127 c so as to penetrate the bottom plate 123 and communicate with the lower space L of the substrate.

The set top box 101 includes a cooling fan 104 and a guide tunnel 129, and a lid 122 provided with an exhaust port 126.
The positions of the cooling fan and the exhaust port in the lid portion are not particularly limited. For example, the cooling fan may be located just above the substrate (CPU).

In the set top box 101, the air taken into the housing 102 from the air inlet 125 flows through the entire lower space L of the substrate and then is exhausted. Therefore, the heat diffused from the CPU 131 to the bottom plate 123 is removed by the air flow. As a result, in the set top box 101, the temperature of the bottom plate 123 can be prevented from becoming high.
In the reference invention, the items described in the embodiment of the present invention can be applied as needed.

DESCRIPTION OF SYMBOLS 1 set top box 2 case 3 circuit board 4 cooling fan 21 accommodation part 22 lid part 23 bottom plate 24a-24d side wall 25 intake port 26 exhaust port 27a, 27b guide member 28 sealing member 29 guide tunnel 31 CPU
32 heatsink 41 dedicated stand

Claims (3)

A box-like housing provided with an inlet and an outlet;
A substrate mounted with a heat generating component housed in the housing;
An electronic device comprising: a cooling fan housed in the housing;
The substrate is accommodated in the housing in a direction parallel to the bottom plate of the housing,
The air inlet is provided at a position lower than the substrate on a side wall of the housing,
The internal space of the housing is divided substantially by the substrate into a first space on the bottom plate side and a second space on the opposite side of the bottom plate by the substrate,
The position of the exhaust port is set such that the air taken in from the intake port flows from the end on the intake port side of the first space to the other end and then flows into the second space. Yes,
The lid of the housing includes the cooling fan and a guide tunnel for guiding air from the cooling fan to the exhaust port,
An electronic device , wherein an intake portion of the cooling fan is close to an upper surface of a heat sink attached to the upper side of the heat-generating component . The electronic device according to claim 1, wherein the cooling fan is located directly above the heat generating component. The electronic device according to claim 1, wherein the heat sink has a flat top surface.

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