JP4770933B2 - Wireless communication device - Google Patents

Description

  The present invention relates to a device such as an RFID reader / writer, for example, and relates to a wireless communication apparatus in which a circuit board with a large amount of heat generated is mounted in a housing and radiates heat from the electronic component. It is.

  In an electronic device that mounts an electronic component that generates a large amount of heat, heat is generated to prevent the temperature inside the housing or the temperature of the electronic component itself from exceeding the allowable temperature of the electronic component due to heat generated from the electronic component. Physically connect the surface of the board on which the major electronic components with a large amount are mounted to the housing with metal parts with good thermal conductivity, and conduct heat efficiently to the entire housing, which is a radiator. Spread. For example, Patent Document 1 discloses a conventional wireless communication electronic device. According to the technology described in Patent Document 1, the housing of the wireless communication electronic device has a cylindrical shape, Radiation fins are provided on the surface, and a part of the inner wall surface of the housing is brought into close contact with the bottom surface of the board (metal base) to which the heat generating electronic parts are attached, so that the heat generated by the electronic parts passes through the board. The structure that flows to the housing is adopted.

JP-A-7-74657

  According to the conventional technique described in Patent Document 1, the heat dissipation efficiency is good due to heat conduction from the electronic component that generates heat in the portion of the inner wall surface of the cylindrical housing that is in contact with the substrate (metal base). There is a problem that the heat dissipation efficiency is lowered in the non-contact portion. Specifically, in the inner wall surface portion of the inner wall surface of the cylindrical housing that faces the portion in contact with the substrate, heat dissipation from the electronic components that generate heat depends on heat transfer and heat radiation via air. For this reason, the heat radiation efficiency is lower than the heat conduction in the portion in contact with the substrate. Moreover, in order to improve the heat conduction to the whole radiation fin provided in the outer surface of the cylindrical housing | casing of patent document 1, the method of increasing the thickness of a housing | casing and reducing the heat conduction resistance of the circumferential direction However, according to such a method, there is a problem in that the external dimensions and mass of the electronic device increase.

  The present invention has been made to solve the above-described problems. An electronic component, etc., to which a large amount of heat generated by wireless communication is attached is housed in a housing, and the efficiency of the electronic component is reduced. An object of the present invention is to obtain a wireless communication device that can perform heat dissipation well.

According to a first aspect of the present invention, a wireless communication apparatus includes a case for radiating heat generated from a high-frequency electronic component, and an electric circuit unit housed in the case. The electric circuit unit includes the high-frequency electronic component. An attached circuit board; a frame to which the circuit board is attached; a block member provided on the surface of the circuit board and connected to the inner wall of the case 1 to conduct heat generated from the high-frequency electronic component to the case; An inner plate which is provided on the back surface of the circuit board and is connected to the frame and conducts heat generated from the high-frequency electronic component to the frame; and an inner wall of the case which is provided on the frame and faces the inner wall of the one. And a plate member connected to conduct from the frame to the case.

  A wireless communication apparatus according to a second aspect of the present invention is the wireless communication apparatus according to the first aspect of the present invention, wherein the case is a rectangular tube having a hollow rectangular cross section.

  According to a third aspect of the present invention, in the wireless communication apparatus according to the first aspect of the present invention, the plate member is a plate material bent into a Z shape.

  According to a fourth aspect of the present invention, there is provided a wireless communication apparatus including a case for radiating heat generated from high-frequency electronic components and control circuit components, and an electric circuit unit housed in the case. A first circuit board to which high-frequency electronic components are attached; a second circuit board to which the control circuit parts are attached; a frame to which these circuit boards are attached; and a case provided on the surface of the first circuit board. A member connected to an inner wall of the block, the block member having a portion for conducting heat generated from the high-frequency electronic component to the case, and an inner wall of the case provided on the frame and facing the inner wall of the case And a plate member that is connected to conduct heat generated on the second circuit board to the case.

  According to a fifth aspect of the present invention, in the wireless communication apparatus according to the fourth aspect of the present invention, the block member further includes a portion that shields the electronic component attached to the first circuit board. is there.

  A radio communication apparatus according to a sixth aspect of the present invention is the radio communication apparatus according to the fourth or fifth aspect of the present invention, wherein the case is a rectangular tube having a hollow rectangular cross section.

  According to a seventh aspect of the present invention, in the wireless communication apparatus according to the fourth or fifth aspect of the present invention, the plate member is a plate material bent into a Z shape.

  According to the first aspect of the present invention, the heat generated in the high-frequency electronic component on the circuit board is conducted to the case by the block member, the internal plate, and the plate member, so that the generated heat is efficiently a heat radiator. Can be conducted to the whole.

  According to the invention described in claim 2, since the case has a rectangular tube shape, it can be manufactured at a low cost. According to the invention described in claim 3, the plate member can be bent in a Z-shape. Adhesiveness between the plate member and the inner wall of the case is improved by using the plate material, and heat conduction can be improved.

  According to the fourth aspect of the present invention, heat generated in the high-frequency electronic component on the first circuit board is conducted to the case by the block member, and heat generated on the second circuit board is conducted to the case by the plate member. The generated heat can be efficiently conducted to the entire case, which is a radiator. According to the invention of claim 5, the block member can also serve as a shield for the electronic component.

  According to the invention described in claim 6, since the case has a rectangular tube shape, it can be manufactured at a low cost. According to the invention described in claim 7, the plate member can be bent in a Z-shape. Adhesiveness between the plate member and the inner wall of the case is improved by using the plate material, and heat conduction can be improved.

It is an external view showing the external shape of the radio | wireless communication apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing showing the AA cross section of the radio | wireless communication apparatus shown in FIG. It is sectional drawing showing BB cross section of the radio | wireless communication apparatus shown in FIG. FIG. 3 is an external view illustrating an outer shape of a left side surface of the electric circuit unit 6. It is sectional drawing showing CC cross section of the electric circuit unit 6 shown in FIG. It is an external view showing the external appearance seen from the D side of the electric circuit unit 6 shown in FIG. FIG. 3 is an external view illustrating an outer shape of a right side surface of the electric circuit unit 6. It is an external view showing the external shape of the left side surface of the electric circuit unit 13 of the radio | wireless communication apparatus which concerns on Embodiment 2 of this invention. It is sectional drawing showing EE cross section of the electric circuit unit 13 shown in FIG. It is an external view showing the external appearance seen from the F side of the electric circuit unit 13 shown in FIG.

  Embodiment 1

  A wireless communication apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1A and 1B are external views showing the outer shape of a wireless communication apparatus according to Embodiment 1 of the present invention. FIG. 1A is a left side view, FIG. 1B is a front view, and FIG. is there. In FIG. 1, 1 is a housing, 2 is a case for storing a circuit board to which electronic components are attached, 3 is a front panel, 4 is a back panel, and 5 is a connector for connecting an antenna cable. The case 2 has a rectangular tube shape (the cross section AA is a hollow rectangular cross section) with the front and back sides opened and the left and right side surfaces, the top surface, and the bottom surface closed, and the case 2 is drawn or extruded. The square pipe to be formed can be made by cutting out with a predetermined dimension in the axial direction. By such a processing method, the case 2 can be manufactured at low cost. The wireless communication apparatus according to the first embodiment is a casing 1 composed of a case 2, a front panel 3, and a rear panel 4, and an electric circuit unit housed in the casing 1, and includes a connector 5, electronic components, and the like. The circuit board and the electric circuit unit composed of members such as a frame are provided. 2 is a cross-sectional view showing the AA cross section of the wireless communication apparatus shown in FIG. 1, and FIG. 3 is a cross-sectional view showing the BB cross section of the wireless communication apparatus shown in FIG. In FIG. 2, 6 is an electric circuit unit housed in the case 2, and is fixed to the bottom surface 2a of the case 2 at the bottom surface portion 6a. As for the configuration inside the electric circuit unit 6, 7 is a circuit board to which the connector 5 and electronic components are attached, 8 is a U-shaped frame for attaching the circuit board 7, and 9 is heat generated by the circuit board 7. Is a block member that conducts heat to one side surface 2b of the case 2, 10 is an internal plate that is provided between the circuit board 7 and the frame 8, and that conducts heat generated in the circuit board 7 to the frame 8 side, and 11 is a frame. 8 is a plate member that conducts heat from the circuit board 7 transmitted to 8 to the other side surface 2 c of the case 2.

  4 is an external view showing the outer shape of the left side surface of the electric circuit unit 6, FIG. 5 is a cross-sectional view showing a CC section of the electric circuit unit 6 shown in FIG. 4, and FIG. 6 is an electric circuit unit shown in FIG. 6 is an external view showing the external shape viewed from the D side, and FIG. 7 is an external view showing the external shape of the right side surface of the electric circuit unit 6. On the left side of the electric circuit unit 6 shown in FIG. 4, there is a block member 9 provided on the circuit board 7. This block member 9 is a high-frequency electron such as an amplifier 12 which is an electronic component that generates heat as shown in FIG. It is provided so as to cover the parts. In an RFID reader / writer, which is a wireless communication device, heat is generated greatly in a modulator (including an amplifier 12) that amplifies a high-frequency signal and a modulator that generates a radio wave transmitted from an RFID antenna. In order to dissipate heat, a block member 9 is provided on the circuit board 7 so as to cover the high frequency electronic component.

  As shown in FIG. 5, the internal plate 10 is provided between the circuit board 7 and the frame 8. Specifically, when the surface of the circuit board 7 to which the block member 9 is attached is the front surface, an electronic circuit 13 (for example, a high-frequency component such as a modulator or a local signal generation circuit) is mounted on the back surface of the circuit board 7. An internal plate 10 is provided to conduct heat generated from the electronic circuit 13 to the frame 8 side. Further, the plate member 11 is a Z-shaped member formed by bending a sheet metal as shown in FIG. 6, has a step in the thickness direction, is outside the frame 8, and is formed on the inner plate 10. It is attached near the attachment part. FIG. 7 shows the plate member 11 provided on the right side surface of the electric circuit unit 6.

  The assembly of the electric circuit unit 6 composed of the above parts will be described. A groove is provided in the block member 9 so that the outer shape does not interfere with high-frequency electronic components such as the amplifier 12 having the largest heat generation amount provided on the surface of the circuit board 7 (see FIG. 7). In order to reduce heat transfer resistance in the gap between the high-frequency electronic component and the block member 9, an elastic body having a good thermal conductivity is compressed and sandwiched by an appropriate amount, and the block member 9 is attached to the circuit board 7. The plate member 11 and the internal plate 10 are attached to the frame 8, and an elastic body having a good thermal conductivity is also attached to the surface of the internal plate 10 that contacts the electronic circuit 13. The electric circuit unit 6 is assembled by attaching the circuit board 7 to the frame 8 to which the plate member 11 and the internal plate 10 are attached. The electric circuit unit 6 is inserted into the case 2, and the bottom surface portion 6a of the electric circuit unit 6 is fixed to the bottom surface portion 2a of the case 2 with fastening parts such as screws (see FIG. 2). Further, the male member is inserted from the right side surface and the left side surface of the case 2 and screwed to the female screw of the block member 9 and the plate member 11, so that the block member 9 and the plate member 11 are in close contact with the inner wall surface of the case 2. The plate member 11 is a plate component formed by bending, and is elastically deformed and is brought into close contact with the inner surface of the case 2 by fastening to the case 2 with screws. Finally, the front panel 3 is attached to the front surface of the case 2 and the rear panel 4 is attached to the rear surface to complete the assembly.

  As described above, the path that conducts heat generated by the electronic components mounted on the circuit board 7 inside the case 2 to the case 2 that is a radiator is formed on the surface side of the circuit board 7 to which the block member 9 is attached. Furthermore, by providing the back side of the circuit board 7 to which the internal plate 10 is attached, it is possible to efficiently and more uniformly conduct heat to the entire case 2 around the circuit board 7. The Z-shaped plate member 11 is dimensioned so that the gap between the electric circuit unit 6 and the left and right inner walls of the case 2 becomes as small as possible when the electric circuit unit 6 is inserted into the case 2. By setting the height of the step, rattling when the electric circuit unit 6 is assembled in the case 2 can be suppressed, the adhesion between the plate member 11 and the inner wall surface of the case 2 is increased, and heat is increased. The conductivity can be further improved. In addition, high frequency electronic components are distributed and arranged on the circuit board 7, and a block member 9 (which also serves as a heat sink) is arranged at a location of an electronic component (amplifier 12 or the like) that generates the largest amount of heat. By providing the internal plate 10 at a location of an electronic component (such as a modulator or a local signal generation circuit) that generates a large amount of heat, heat can be dissipated by effective heat conduction of heat generated in a distributed manner on the circuit board 7.

  Embodiment 2

  A radio communication apparatus according to Embodiment 2 of the present invention will be described with reference to FIGS. 8 is an external view showing the outer shape of the left side surface of the electric circuit unit of the radio communication apparatus according to Embodiment 2 of the present invention, and FIG. 9 is a cross-sectional view showing the EE cross section of the electric circuit unit shown in FIG. 10 is an external view showing the outer shape of the electric circuit unit shown in FIG. 8 viewed from the F side. The electric circuit unit 13 according to the second embodiment of the present invention shown in FIGS. 8 to 10 is substituted for the electric circuit unit 6 in the first embodiment, and the embodiment is described with reference to FIGS. Since the configuration of the case 2 of the electric circuit unit described in 1 and the method of attaching the electric circuit unit 13 to the case 2 are the same as those in the first embodiment, the description thereof is omitted.

  Regarding the configuration of the electric circuit unit 13 shown in FIGS. 8 to 10, reference numeral 14 denotes a first circuit board to which a connector 5 and high-frequency electronic components are attached, and 15 denotes a second circuit board to which a control circuit and a signal processing circuit are attached. A circuit board 16 is a U-shaped frame for attaching the first circuit board 14 and the second circuit board 15, and 17 conducts heat generated in the first circuit board 14 to one side 2 b of the case 2. A block member 18 is a plate member that conducts heat generated in the first circuit board 15 to the other side surface 2 c of the case 2.

  On the left side surface of the electric circuit unit 13 shown in FIG. 8, there is a block member 17 provided on the first circuit board 14. The block member 17 has a concave portion 17a for electromagnetic shielding and a medium for heat conduction. It consists of a real part 17b. As shown in FIG. 9, a solid portion 17a is located immediately below a portion where a high-frequency electronic component such as an amplifier 12 which is a heat-generating electronic component is provided, and medium / high-frequency electronic components such as a frequency converter 19 and a synthesizer are located. The shape and position of the block member 17 are determined so that the concave portion 17a is positioned so as to cover the provided portion. In the first circuit board 14 shown in FIG. 9, high-frequency electronic components such as the amplifier 12 with large heat generation are provided on the substrate surface 14b side, and medium / high-frequency electronic components such as a frequency converter 19 and a synthesizer are provided on the substrate 14a side. ing. When the high-frequency electronic components with large heat generation such as the amplifier 12 and the middle / high-frequency electronic components such as the frequency converter 19 are arranged on the same substrate surface 14a side, the shape of the solid portion 17b is the block member shown in FIG. As shown in FIG. 9, the high-frequency electronic component such as the amplifier 12 has a recess that does not interfere with the outer shape, and an elastic body having good thermal conductivity is sandwiched between the bottom surface of the recess and the amplifier 12, so that the thermal conductivity is increased. It becomes good.

  Next, heat dissipation by the plate member 18 will be described. Compared to the first embodiment, the electric circuit unit according to the second embodiment has a larger mounting area by the provision of two circuit boards, and thus heat generation by electronic components is dispersed. The first circuit board 14 is mainly provided with medium and high frequency electronic circuits, whereas the second circuit board 15 is mounted with a control circuit such as a CPU 20, a signal processing circuit, and the like. Even in such a control circuit or signal processing circuit, when the processing speed is increased and the circuit scale is further increased, the amount of generated heat cannot be ignored, and some kind of heat dissipation mechanism is required. As shown in FIG. 9, an elastic body 21 having good heat conduction characteristics is provided on the upper surface of a control circuit component or signal processing circuit component that generates heat, such as the CPU 20, and is sandwiched between plate members 18. The plate member 18 is a Z-shaped member formed by bending a sheet metal as shown in FIGS. 9 and 10, and has a step in the thickness direction. Further, the plate 16 is screwed or spot welded to the inner surface of the frame 16. It has a seating surface for mounting by etc.

  The assembly of the electric circuit unit 6 composed of the above parts will be described. The plate member 16 is attached to the frame 16. An elastic body 21 having good heat conduction characteristics is attached to the upper surface of a control circuit component such as a CPU 20 or a signal processing circuit component, and the second circuit board 15 is inserted into the frame 16 and screwed. At this time, the elastic body 21 is pressed by the plate member 18 to increase the adhesion, and the heat transfer resistance from the control circuit component such as the CPU 20 or the signal processing circuit component to the plate member 18 is reduced, and the heat conductivity is improved. . The block member 17 is attached to the first circuit board 14 and the first circuit board 14 is screwed to the frame 16 to assemble the electric circuit unit 13. The electric circuit unit 13 is inserted into the case 2, and the bottom surface portion 13a of the electric circuit unit 13 is fixed to the bottom surface portion 2a of the case 2 with fastening parts such as screws (see FIG. 2). Further, by inserting male screws from the right side surface and the left side surface of the case 2 and screwing them to the female screws of the block member 17 and the plate member 18, the block member 17 and the plate member 18 are brought into close contact with the inner wall surface of the case 2. The plate member 18 is a plate component formed by bending, and is elastically deformed and is brought into close contact with the inner surface of the case 2 by being fastened to the case 2 with screws. Finally, the front panel 3 is attached to the front surface of the case 2 and the rear panel 4 is attached to the rear surface to complete the assembly.

  As described above, a path is ensured in which the heat generated by the electronic components mounted on the first circuit board 14 and the second circuit board 15 in the case 2 is thermally conducted to the case 2 that is a radiator. That is, a path for radiating heat from the first circuit board 14 to the left side of the case 2 via the block member 17 and a path for radiating heat from the second circuit board 15 to the right side of the case 2 via the plate member 18 are obtained. The heat generated in the electric circuit unit 13 can be efficiently and more uniformly conducted to the entire case 2. Further, the block member 17 has a solid portion 17b and a concave portion 17a, and the concave / high portion 17a can electromagnetically shield the medium / high frequency electronic circuit. The Z-shaped plate member 18 is dimensioned so that the gap between the electric circuit unit 13 and the left and right inner walls of the case 2 becomes as small as possible when the electric circuit unit 13 is inserted into the case 2. By setting the height of the step, rattling when the electric circuit unit 13 is assembled in the case 2 can be suppressed, the adhesion between the plate member 18 and the inner wall surface of the case 2 is increased, and heat is increased. The conductivity can be further improved.

DESCRIPTION OF SYMBOLS 1 Case 2 Case 6, 13 Electric circuit unit 7 Circuit board 8, 16 Frame 9, 17 Block member 10 Internal plate 11, 18 Plate member 14 1st circuit board 15 2nd circuit board

Claims (7)

A case for radiating heat generated from a high-frequency electronic component, and an electric circuit unit housed in the case, wherein the electric circuit unit includes a circuit board to which the high-frequency electronic component is attached, and a frame to which the circuit board is attached. A block member provided on the surface of the circuit board and connected to the inner wall of the case 1 to conduct heat generated from the high-frequency electronic component to the case; and provided on the back surface of the circuit board on the frame. An internal plate that conducts heat generated from the high-frequency electronic component to the frame and is connected to an inner wall of the case that is provided on the frame and faces the inner wall of the one, and transfers heat from the frame to the case. A wireless communication device comprising a conducting plate member.   The wireless communication apparatus according to claim 1, wherein the case is a rectangular tube having a hollow rectangular cross section.   The wireless communication apparatus according to claim 1, wherein the plate member is a plate material bent into a Z shape.   A case for dissipating heat generated from the high-frequency electronic component and the control circuit component; and an electric circuit unit housed in the case, wherein the electric circuit unit includes a first circuit board to which the high-frequency electronic component is attached; A second circuit board to which the control circuit component is attached, a frame to which these circuit boards are attached, and a member provided on the surface of the first circuit board and connected to the inner wall of the case 1, A block member having a portion that conducts heat generated from the high-frequency electronic component to the case, and an inner wall of the case that is provided on the frame and faces the inner wall of the first, and is connected to the second circuit board. A wireless communication device comprising: a plate member that conducts generated heat to the case. The wireless communication apparatus according to claim 4, wherein the block member further includes a portion that shields an electronic component attached to the first circuit board.   6. The wireless communication apparatus according to claim 4, wherein the case is a square tube having a hollow rectangular cross section.   6. The wireless communication apparatus according to claim 4, wherein the plate member is a plate material bent into a Z shape.

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