JP2014224952A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism that can efficiently radiate heat generated in a wireless communication substrate mounted on an electronic apparatus without affecting the communication performance of the wireless communication substrate.SOLUTION: An electronic apparatus includes a wireless communication substrate 211, a resin-made member 213 that is arranged to cover an element mounting surface of the wireless communication substrate 211, a frame member 204 that is thermally connected with one end of the wireless communication substrate 211, a metallic exterior member 214 that is attached to the resin-made member 213, and heat radiation means 316 having elasticity, thermal conductivity, and non-conductivity, held by the resin-made member 213, and compressed by the wireless communication substrate 211 and exterior member 214 to thermally connect the wireless communication substrate 211 with the exterior member 214.

Description

  The present invention relates to an electronic device including an imaging device such as a digital camera or a digital video camera and a mobile terminal such as a smartphone or a tablet terminal, and more particularly to an electronic device having a wireless communication function.

  In an electronic device such as an imaging device such as a digital camera or a mobile terminal such as a smartphone, image quality and functionality are increasing, and the amount of heat generated by elements mounted on a circuit board tends to increase. Conventionally, as a technique for efficiently radiating heat generated in a circuit board, the circuit board and the main frame are fixed with screws, and a sheet metal higher than the thermal conductivity of the main frame and the exterior member is provided between the main frame and the exterior member. A sandwiching technique has been proposed (Patent Document 1). In this proposal, heat generated in the circuit board can be efficiently radiated to the outside through the screw, the main frame, the sheet metal, and the exterior member.

JP 2011-023647 A

  By the way, with the spread of wireless technology in recent years, electronic devices equipped with wireless communication boards such as wireless LAN and infrared communication are increasing. Such electronic devices have a large data capacity for storing images captured by high-pixel image sensors on a network or transferring them to other devices, and high-temperature heat is generated from the wireless communication board during transmission and reception. To do.

  However, since the heat dissipation structure of Patent Document 1 uses a metal sheet metal, it cannot be applied to an electronic device on which a wireless communication board is mounted. That is, if a metal member is arranged around the wireless communication board, the wireless signal from the antenna is hindered, and stable communication performance cannot be maintained.

  Therefore, an object of the present invention is to provide a mechanism that can efficiently dissipate heat generated in a wireless communication board mounted on an electronic device without affecting the communication performance of the wireless communication board.

  In order to achieve the above object, an electronic apparatus according to the present invention includes a wireless communication board, a resin member disposed so as to cover an element mounting surface of the wireless communication board, and one end of the wireless communication board. A frame member that is thermally connected, a metal exterior member that is attached to the resin member, and has elasticity, thermal conductivity, and non-conductivity, and is held by the resin member, and the wireless communication board And heat radiating means for thermally connecting the wireless communication board and the exterior member by being compressed by the exterior member.

  ADVANTAGE OF THE INVENTION According to this invention, the heat | fever generated with the radio | wireless communication board mounted in an electronic device can be thermally radiated efficiently, without affecting the communication performance of a radio | wireless communication board.

It is the perspective view which looked at the digital camera which is an example of the embodiment of the electronic device of the present invention from the front side (subject side). It is a disassembled perspective view of the digital camera shown in FIG. It is a perspective view which shows the principal part of the internal structure of a digital camera. (A) is a perspective view which shows the state by which the wireless LAN board | substrate was screw-fixed to the main frame, (b) is the perspective view seen from the back surface side of (a). It is a perspective view which shows the state which removed the exterior cover of the front side of a digital camera. It is the perspective view which looked at the upper surface part of the exterior cover from the back side. It is the perspective view which looked at the exterior cover of the front side from the back side. (A) is the perspective view which looked at the state which attached heat dissipation rubber to a crevice and a holding hole, respectively from the surface (appearance surface) side of the upper surface part of an exterior cover, (b) is a perspective view which looked at (a) from the back side. It is. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view of a digital camera, which is an example of an embodiment of an electronic apparatus according to the invention, viewed from the front side (subject side). FIG. 2 is an exploded perspective view of the digital camera shown in FIG.

  As shown in FIG. 1, the digital camera 100 of the present embodiment is provided with a lens barrel 102, a strobe light emission window 105, an AF auxiliary light window 106, and the like on the front side of the camera body 101. On the upper surface of the camera body 101, a power button 103, a release button 104, and the like are provided.

  As shown in FIG. 2, a main frame 204, a flexible board 209, a main board 210, and a wireless LAN board 211 are provided inside the camera body 101. Here, the wireless LAN board 211 corresponds to an example of a wireless communication board of the present invention, and the main frame 204 corresponds to an example of a frame member of the present invention.

  The lens barrel 102, the strobe unit 202, and the battery storage unit 203 are fixed to the main frame 204 with screws. On the flexible substrate 209, various operation switches 205, a battery connector 206, a USB connector 207, and an AF auxiliary light LED 208 are mounted. The AF auxiliary light LED 208 is disposed at a position corresponding to the AF auxiliary light window 106, and the light emitting unit of the strobe unit 202 is disposed at a position corresponding to the strobe light emitting window 105.

  The exterior cover 213 is made of a synthetic resin and forms an exterior of the left side surface portion and the upper surface portion as viewed from the front side of the camera body 101. The exterior covers 214 and 215 are both made of an aluminum alloy having excellent thermal conductivity, the exterior cover 214 forms an exterior on the front side of the camera body 101, and the exterior cover 215 is an exterior on the back side of the camera body 101. Form. A display unit 212 such as an LED is provided on the back side of the camera body 101. Here, the exterior cover 213 corresponds to an example of a resin member of the present invention, and the exterior cover 214 corresponds to an example of a metal exterior member of the present invention.

  FIG. 3 is a perspective view showing the main part of the internal structure of the digital camera 100. As shown in FIG. 3, the flexible substrate 209 is electrically connected to the connector 217 of the main substrate 210 disposed on the front left side of the camera body 101 and is a wireless LAN substrate disposed on the upper surface portion of the camera body 101. It is electrically connected to the connector 211a of 211.

  Further, the flexible substrate 209 extends below the wireless LAN substrate 211 to the front right side of the camera body 101, and is then branched into two. One of the flexible boards 209 branched into two is held in the battery housing part 203 via the battery connector 206, and the other is electrically connected to the connector 216a of the strobe board 216.

  The flexible board 209 that passes below the wireless LAN board 211 is spaced apart from the wireless LAN board 211, so that radio waves emitted from the wireless LAN board 211 are absorbed by the copper foil pattern of the flexible board 209. Is avoiding.

  The wireless LAN board 211 is formed with a fastening hole 211b for fixing the screw to the main frame 204 and a positioning hole 211c that is positioned and fitted to a boss 102a provided in the lens barrel 102. The lens barrel 102 is provided with ribs 102b and 102c for supporting the wireless LAN substrate 211.

  4A is a perspective view showing a state in which the wireless LAN board 211 is screw-fixed to the main frame 204, and FIG. 4B is a perspective view seen from the back side of FIG. 4A. As shown in FIG. 4, the main frame 204 has a plate surface portion 204a orthogonal to the photographing optical axis and an orthogonal surface to the plate surface portion 204a, and the wireless LAN board 211 is screw-fixed on the upper surface portion of the camera body 101. And a plate surface portion 204b.

  On the back surface of the wireless LAN substrate 211, a copper foil pattern 211d is formed for ground connection with the main frame 204 via the plate surface portion 204b. In the present embodiment, the plate surface portion 204a and the plate surface portion 204b are integrally formed, but the plate surface portion 204a and the plate surface portion 204b may be formed separately.

  Further, when the wireless LAN substrate 211 is screw-fixed to the plate surface portion 204b of the main frame 204, the region of the copper foil pattern 211d of the wireless LAN substrate 211 contacts the plate surface portion 204b and is thermally connected. Thereby, the heat generated in the wireless LAN board 211 is transmitted to the plate surface portion 204b of the main frame 204, and the heat transmitted to the plate surface portion 204b is transmitted to the plate surface portion 204a.

  The plate surface portion 204 a is a plate material having a relatively large area that is disposed between the lens barrel 102 and the display panel 21. For this reason, the plate surface portion 204a has a sufficient heat capacity and is not exposed to the external surface, so that the photographer who touches the exterior of the camera body 101 does not feel uncomfortable even if the temperature of the main frame 204 itself rises. As a result, the temperature of the wireless LAN board 211 can be lowered, but the temperature is lowered only in the range in contact with the plate surface portion 204b and in the vicinity thereof, and the temperature at a position away from the plate surface portion 204b is not lowered.

  As shown in FIG. 4A, at the position away from the fastening hole 211b of the wireless LAN board 211, that is, at the center in the width direction of the end opposite to the fastening hole 211b of the wireless LAN board 211, An antenna pattern 211h for transmitting and receiving is formed. If the plate surface portion 204b screw-fixed in the fastening hole 211b is close to the antenna pattern 211h, the radio wave radiation state is adversely affected. Therefore, the plate surface portion 204b has a necessary minimum area, and the distance from the antenna pattern 211h is reduced. Secured.

  Therefore, in order to lower the temperature at a position away from the plate surface portion 204b of the wireless LAN substrate 211, an air layer for heat insulation is secured between the heat generating portion of the wireless LAN substrate 211 and the exterior of the upper surface portion of the camera body 101. There is a need to.

  In FIG. 4A, a shield member 211e is a member that covers a plurality of semiconductor elements mounted on the wireless LAN substrate 211. When a large amount of data is transmitted / received by connecting the camera body 101 to another camera or public wireless LAN by the wireless LAN function, heat generated from each semiconductor element is transmitted to the shield member 211e.

  Therefore, as described above, it is necessary to provide an air layer for heat insulation by separating the distance between the shield member 211e and the exterior of the upper surface portion of the camera body 101. However, in order to secure the distance between the wireless LAN board 211 and the flexible board 209 disposed below the wireless LAN board 211 while reducing the size of the camera itself, the shield member 211e and the exterior of the upper surface of the camera body 101 are used. It is difficult to secure a sufficient distance.

  FIG. 5 is a perspective view showing a state in which the exterior cover 214 on the front side of the digital camera 100 is removed. In FIG. 5, the exterior cover 213 is made of synthetic resin as described above, and forms the exterior of the left side surface portion and the upper surface portion when viewed from the front side of the camera body 101. A portion of the exterior cover 213 that forms the exterior of the upper surface portion of the camera body 101 (hereinafter referred to as the upper surface portion 213 p of the exterior cover 213) is disposed at a position that covers the upper side of the element mounting surface of the wireless LAN substrate 211. The synthetic resin exterior cover 213 is suitable for covering the wireless LAN substrate 211 because it does not absorb radio waves.

  In addition, the wireless LAN substrate 211 increases the width dimension α of the upper surface portion 213p of the outer cover 213 and secures the front and back side aluminum outer covers 214, The antenna pattern 211h is not covered with 215. As a result, the boundary portion 213h between the upper surface portion 213p of the synthetic resin exterior cover 213 and the aluminum alloy exterior covers 214 and 215 is also disposed at a position away from the antenna pattern 211h.

  Here, as described above, since a sufficient distance between the shield member 211e and the upper surface portion 213p of the exterior cover 213 cannot be secured, the temperature rise due to the heat transmitted from each semiconductor element to the shield member 211e during wireless LAN communication. Concerned. Therefore, in the present embodiment, in order to diffuse the heat transmitted from each semiconductor element to the shield member 211e throughout the camera, the wireless LAN board 211 and the exterior cover 214 on the front side are thermally connected via the heat radiation rubbers 316 and 317. To do. Details will be described below.

  FIG. 6 is a perspective view of the upper surface portion 213p of the exterior cover 213 as viewed from the back surface side. As shown in FIG. 6, a recess 213 a that houses the shield member 211 e is provided on the back surface of the upper surface portion 213 p of the exterior cover 213. In addition, ribs 213n project from the side portions on the front side of the camera body 101 in the width direction of the back surface of the upper surface portion 213p, and a recess 213e that holds the heat radiation rubber 316 is provided. The heat radiation rubber 316 is fixed and held in the recess 213e by adhesion or the like.

  In the rib 213n, a holding hole 213b for holding the microphone is formed, and a holding hole 213k for holding the heat radiation rubber 317 is formed. Further, on both sides in the width direction of the back surface of the upper surface portion 213p of the exterior cover 213, there are provided an engagement projection 213c and an engagement projection 213d that respectively engage with the exterior cover 214 on the front side and the exterior cover 215 on the back side. It has been.

  The heat radiating rubbers 316 and 317 are both composed of rubber members having elasticity, thermal conductivity, and non-conductivity that do not easily affect radio waves, and the heat radiating rubber 316 is an example of the first heat radiating member of the present invention. The heat radiation rubber 317 corresponds to an example of the second heat radiation member of the present invention.

  An engagement hole 213f is formed in the bottom surface of the recess 213e that holds the heat radiation rubber 316. The engaging claw 214a (see FIG. 7) of the outer cover 214 on the front side engages with the engaging hole 213f from the front surface side (rear surface side in the drawing) of the upper surface portion 213p of the outer cover 213. The engaging claw 214a protrudes from the bottom surface of the recess 213e when the engaging claw 214a is engaged with the engaging hole 213f.

  FIG. 7 is a perspective view of the front-side exterior cover 214 as seen from the back side. As shown in FIG. 7, at the boundary portion 213h of the exterior cover 214 with the upper surface portion 213p of the exterior cover 213, an engagement claw 214a that engages with an engagement hole 213f of the upper surface portion 213p, and a plurality of arm portions 214c, 214d.

  Each of the arm portions 214c and 214d has an engagement hole. The engagement hole of the arm part 214c engages with the engagement protrusion 213c of the upper surface part 213p of the exterior cover 213, and the engagement hole of the arm part 214d engages with the engagement protrusion (not shown) of the upper surface part 213p.

  8A is a perspective view of the state where the heat radiating rubber 316 and the heat radiating rubber 317 are attached to the concave portion 213a and the holding hole 213k, respectively, as viewed from the surface (appearance surface) side of the upper surface portion 213p of the exterior cover 213. FIG. ) Is a perspective view of FIG. 8A viewed from the back side.

  As shown in FIG. 8, when the heat radiation rubber 316 is attached to the recess 213e, the engagement hole 213f is completely covered with the heat radiation rubber 316. This prevents light from the AF auxiliary light LED 208 disposed below the wireless LAN board 211 from leaking outside through the gap of the engagement hole 213f. From the viewpoint of light shielding, the heat radiation rubber 316 is preferably colored in a color other than white.

  9 is a cross-sectional view taken along line AA in FIG. Referring to FIG. 9, in a state in which the exterior cover 214 is incorporated in the exterior cover 213, the heat radiation rubber 316 is formed on the substrate surface at the end opposite to the fastening hole 211 b of the wireless LAN substrate 211 in the width direction of the camera body 101. It abuts on the side portion 211f on the front side (exterior cover 214 side).

  The side portion 211f is sufficiently away from the antenna pattern 211h, and the heat radiating rubber 316 is made of a material that hardly affects radio waves, and thus does not affect the communication performance of the wireless LAN.

  Further, since a copper foil pattern for ground connection is provided inside and on the back side of the wireless LAN board 211, the side portion 211f with which the heat radiating rubber 316 contacts is not located near the center of the wireless LAN board 211. However, a sufficient heat transfer effect can be obtained.

  As shown in FIG. 6, the inclined rib 213 j protrudes into the engagement hole 213 f of the upper surface portion 213 p of the exterior cover 213 with which the engagement claw 214 a of the exterior cover 214 is engaged, as shown in FIG. It is installed. Further, the inner wall surface of the engagement hole 213f facing the inclined rib 213j is flush with the surface 213q of the boundary portion 213h of the upper surface portion 213p of the outer cover 213 and the outer cover 214 as shown in FIG. Has been.

  In a state where the engaging claw 214a of the outer cover 214 is engaged with the engaging hole 213f of the upper surface portion 213p, the engaging claw 214a is flush with the inner wall surface facing the tip of the inclined rib 213j and the inclined rib 213j. Is sandwiched between the upper surface portion 213p and the surface 213q. This prevents the exterior cover 214 from being detached from the exterior cover 213 due to an impact caused by dropping or the like.

  Further, the distal end portion 214b of the engaging claw 214a protrudes from the bottom surface of the concave portion 213e of the upper surface portion 213p and comes into contact with the heat radiation rubber 316.

  As a result, the wireless LAN substrate 211 and the exterior cover 214 are thermally connected via the heat radiation rubber 316. As a result, the heat transmitted from each semiconductor element of the wireless LAN substrate 211 to the shield member 211e is transmitted to the exterior cover 214 having a large area via the heat radiation rubber 316 and dispersed, and the temperature of the upper surface portion 213p of the exterior cover 213 increases. Is suppressed.

  Further, the tip 214b of the engaging claw 214a that contacts the heat radiation rubber 316 protrudes into the recess 213e and is separated from the appearance surface by a distance β. Therefore, even if a part of the heat radiating rubber 316 is sandwiched between the engaging claw 214a and the surface 213q of the upper surface portion 213p described above, the heat radiating rubber 316 does not jump out to the appearance.

  Returning to FIG. 6, the heat radiation rubber 317 is fixed and held in the holding hole 213k by adhesion or the like. In such a holding state, both ends of the heat radiation rubber 317 protrude from the holding hole 213k.

  The positioning of the heat radiation rubber 317 with respect to the holding hole 213k is not particularly performed in this embodiment. The heat radiation rubber 317 is fixed only to the upper side surface 213m of the holding hole 213k, and a gap is formed between the heat releasing rubber 317 and the holding hole 213k. Accordingly, the heat radiating rubber 317 can be deformed so that the other end follows the deformation of one end while being held in the holding hole 213k.

  A region 214e corresponding to the holding hole 213k on the back side of the outer cover 214 is in contact with the heat radiating rubber 317 at one end of the heat radiating rubber 317 whose both ends protrude from the holding hole 213k, and the heat radiating rubber 317 is compressed. To do. Further, the side surface portion 211 g in the width direction of the wireless LAN substrate 211 is brought into contact with the heat radiating rubber 317 at the other end of the heat radiating rubber 317 to compress the heat radiating rubber 317.

  As a result, the wireless LAN substrate 211 and the exterior cover 214 are thermally connected via the heat radiation rubber 317. As a result, the heat transmitted from each semiconductor element of the wireless LAN substrate 211 to the shield member 211e is transmitted to the exterior cover 214 having a large area via the heat radiating rubber 317 and dispersed, and the temperature of the upper surface portion 213p of the exterior cover 213 increases. Is suppressed.

  Further, since the heat radiation rubber 317 is made of a material that does not easily affect radio waves, the influence on the wireless LAN communication is small. Further, since a copper foil pattern for ground connection is provided inside and on the back side of the wireless LAN board 211, sufficient heat transfer is possible even if the contact part of the heat radiation rubber 317 is the side part 211g of the wireless LAN board 211. An effect is obtained.

  10 is a cross-sectional view taken along line BB in FIG. Referring to FIG. 10, exterior cover 214 is attached after exterior cover 213. Therefore, even when the heat radiating rubber 317 is separated from the side surface portion 211g of the wireless LAN board 211 when the outer cover 213 is attached, the heat radiating rubber 317 is pushed back when the outer cover 214 is attached to the wireless LAN board 211. It contacts the side surface portion 211g. Thereby, the thermal connection between the wireless LAN board 211 and the exterior cover 214 can be stably performed.

  In addition, by ensuring that the axial width γ of the holding hole 213k of the heat radiation rubber 317 is longer than the distance δ between the side surface portion 211g of the wireless LAN board 211 and the contact region 214e of the exterior cover 214, a reliable thermal connection is ensured. can do.

  As described above, in the present embodiment, heat generated by the wireless LAN board 211 mounted on the digital camera 100 can be efficiently radiated without affecting the communication performance of the wireless LAN board 211.

  The configuration of the present invention is not limited to that exemplified in the above embodiment, and the material, shape, dimensions, form, number, arrangement location, and the like can be changed as appropriate without departing from the scope of the present invention. It is.

  For example, in the above-described embodiment, the case where the front-side exterior cover 214 and the wireless LAN board 211 are thermally connected is illustrated, but the present invention is not limited to this, and the rear-side exterior cover 215 and the wireless LAN board 211 are thermally connected. You may let them.

  Further, in the above embodiment, the antenna built-in type wireless LAN substrate 211 is exemplified, but the antenna may be formed independently by a flexible substrate or the like.

101 Camera body 204 Main frame 211 Wireless LAN board 213 Exterior cover 214 Exterior cover 316, 317 Heat radiation rubber

Claims (7)

A wireless communication board;
A resin member arranged to cover the element mounting surface of the wireless communication board;
A frame member thermally connected to one end of the wireless communication board;
A metal exterior member attached to the resin member;
It has elasticity, thermal conductivity, and non-conductivity, is held by the resin member, and is compressed by the wireless communication board and the exterior member, so that the wireless communication board and the exterior member are An electronic device comprising: heat dissipating means for heat connection. The heat dissipating means has a first heat dissipating member,
The electronic apparatus according to claim 1, wherein the first heat dissipation member is compressed by a substrate surface at the other end of the wireless communication substrate and the exterior member.   The resin member has a recess for holding the first heat radiating member. An engagement hole is formed in the bottom surface of the recess, and the engagement claw is formed in the exterior member in the engagement hole. The electronic apparatus according to claim 2, wherein when the first engaging member and the second engaging member are engaged with each other, a tip end portion of the engaging claw compresses the first heat radiating member. The wireless communication board has a built-in antenna,
The electronic apparatus according to claim 2, wherein the first heat radiating member is disposed at a position away from the antenna. The heat dissipation means includes a second heat dissipation member,
5. The electronic apparatus according to claim 1, wherein the second heat radiating member is compressed by a side surface portion in a width direction of the wireless communication substrate and the exterior member. The resin member has a holding hole for holding the second heat radiating member,
The second heat radiating member is held in the holding hole so that both ends protrude from the holding hole, the outer member abuts against one end of the second heat radiating member, and the outer member is The second heat radiating member is compressed, the side surface portion in the width direction of the wireless communication board is in contact with the other end portion of the second heat radiating member, and the side surface portion in the width direction of the wireless communication board is the first side. The electronic device according to claim 5, wherein the heat radiating member is compressed.   The electronic apparatus according to claim 6, wherein a gap is formed between the holding hole and the second heat radiating member held in the holding hole.

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