JP2020035339A - RF communication device - Google Patents

Abstract

To provide a technique capable of suppressing reduction in processing performance of an RF circuit due to heat generation in an RF communication device.SOLUTION: A RF communication device includes: a housing; a patch antenna; a RF circuit; a metal plate; a heat conductor; a heat conduction sheet; and an inner member. The patch antenna includes an element, a ground substrate having a first and a second surfaces, and a power supply unit. The RF circuit includes at least one heat-generating element and is provided in a range opposed to the second surface. The metal plate is provided in a range opposed to an upper surface of the circuit and has a first and a second main surfaces, and its surface area is larger than that of the RF circuit. The heat conductor is provided between the upper surface of the circuit and the first main surface and thermally connects the at least one heat-generating element and the metal plate. One end of the heat conduction sheet is in contact with the second main surface, and the other end of the heat conduction sheet extends outwardly from a range opposing the second surface and contacts with the inner member.SELECTED DRAWING: Figure 1

Description

  The technology disclosed in this specification relates to an RF communication device that can execute RF communication with an RF tag.

  2. Description of the Related Art An RF communication device capable of executing RF communication including writing information to the RF tag, reading information from the RF tag, and the like by emitting radio waves to the RF tag is known. Such an RF communication device includes an antenna for emitting and receiving radio waves, an RF circuit for executing RF communication by causing the antenna to emit radio waves, and a housing for housing the antenna and the RF circuit. The RF circuit includes a heat generating element that generates heat as RF communication is performed. For this reason, it has been known that the RF circuit becomes high in temperature with the execution of RF communication using the RF communication device.

  On the other hand, in the technique disclosed in Patent Literature 1, the heat generating portion in which the antenna and the RF circuit are housed and the grip portion gripped by the user at the time of use are provided separately from each other, so that the housing is not used. In this case, the user is prevented from touching the heat-generating portion that has become hot.

JP-A-2006-6201

  However, it is also known that the processing performance of the RF circuit decreases when the temperature becomes high. In the technique of Patent Document 1, no consideration is given to suppressing a decrease in the processing performance of the RF circuit due to heat generation.

  This specification provides a technique capable of suppressing a decrease in processing performance of an RF circuit due to heat generation in an RF communication device.

  An RF communication device disclosed in this specification is a housing, a patch antenna provided in the housing, and provided in the housing, electrically connected to the patch antenna, and causing the patch antenna to emit radio waves. An RF circuit that executes RF communication by the above, a metal plate provided in the housing, a heat conductor provided in the housing and having heat conductivity and electrical insulation, and a heat conductor provided in the housing. A heat conductive sheet having conductivity, and an internal member provided in the housing, wherein the patch antenna has a plate-shaped element having conductivity, and a plate-shaped element arranged in a range opposed to the element. A ground substrate, having a first surface facing the element and a second surface opposite to the first surface, wherein the first surface and the second surface are electrically conductive. The layer with The ground substrate, and a power supply unit having conductivity and electrically connecting the element and the ground substrate, and the RF circuit is configured to execute the RF communication. In addition to including at least one heat-generating element that generates heat, the heat-generating element is provided in an area facing the second surface, and is electrically connected to the ground substrate. A first main surface that is provided in a range opposing the circuit upper surface, which is a surface that does not oppose the two surfaces, and that opposes the circuit upper surface; and a second main surface opposite to the first main surface. , A surface area of which is equal to or greater than a surface area of the RF circuit, wherein the heat conductor is provided between the circuit upper surface and the first main surface, and a first contact surface that contacts the at least one heat generating element. And a first side opposite to the first contact surface. A contact surface, having a second contact surface in contact with the first main surface, thermally connecting the at least one heat generating element and the metal plate, One end is in contact with the second main surface, and the other end of the heat conductive sheet extends outward from a region facing the second surface and is in contact with the internal member.

  According to the above configuration, the metal plate is provided in an area facing the circuit upper surface of the RF circuit, and the metal plate and the heat generating element are thermally connected to each other through the heat conductor having thermal conductivity and electrical insulation. Have been. Then, one end of the heat transfer sheet is in contact with the second main surface of the metal plate. Thereby, the heat generated in the heat generating element is transmitted to the heat conductive sheet via the metal plate, so that the heat of the RF circuit can be radiated to the heat conductive sheet. The other end of the heat conductive sheet is in contact with the internal member. Thereby, the heat of the RF circuit can be dissipated to the internal member via the heat conductor, the metal plate, and the heat conductive sheet. Therefore, in the RF communication device, it is possible to suppress a decrease in the processing performance of the RF circuit due to heat generation.

  The heat conductor may have elasticity, and may be pressed against the at least one heat generating element by the metal plate.

  According to this configuration, the heat conductor can be brought into close contact with the first main surface of the metal plate and the heat generating element. Even when the surface area of the heat generating element of the RF circuit is relatively small, it is possible to sufficiently secure the contact area between the heat conductor and the heat generating element and the contact area between the heat conductor and the first main surface. it can. Therefore, the heat of the RF circuit can be efficiently radiated to the heat conductive sheet and the internal member.

  The thickness and the width between the one end and the other end of the heat conductive sheet may be uniform.

  If a place with a small thickness or a place with a small width is formed on the heat conductive sheet, the heat transfer performance at that place will be lower than that at other places, and the heat transfer will be stagnant at that place, and the entire heat conductive sheet Heat transfer performance may be reduced. On the other hand, according to the above configuration, since the thickness and the width from one end to the other end of the heat conductive sheet are uniform, a portion where the heat transfer performance is lower than other portions is not formed. As a result, the heat conductive sheet can exhibit uniform heat transfer performance from one end to the other end. The heat conductive sheet can exhibit high heat transfer performance.

  The internal member may be an internal substrate including at least one metal layer, and the other end of the heat conductive sheet may be in contact with one surface of the internal substrate.

  Generally, metal exhibits high thermal conductivity. That is, the internal substrate including at least one metal layer can exhibit relatively high heat dissipation performance. Therefore, according to this configuration, it is possible to appropriately suppress a decrease in the processing performance of the RF circuit due to heat generation. Also, in particular, when the internal substrate is a substrate on which a control circuit different from the RF circuit is mounted, for example, a substrate for another use in the housing can be used for heat radiation, so that the dedicated substrate for heat radiation is used. It is not necessary to provide an internal member.

  The internal substrate may include a plurality of the metal layers and at least one via hole that thermally connects each of the plurality of metal layers.

  According to the above configuration, heat transmitted to the internal substrate can be conducted to each of the plurality of metal layers of the internal substrate through the via hole, so that the internal substrate can exhibit higher heat radiation performance.

  A plate-shaped RF substrate provided in the housing, the RF substrate further comprising: a front surface provided in a range opposed to the second surface; and a back surface opposite to the surface. A circuit is provided on the back side surface, and the metal plate extends from an end of the first portion disposed at a position facing the RF circuit and an end of the first portion toward the ground substrate. A second portion bent in a direction, and a tip of the second portion may be inserted or inserted into the RF board.

  According to the above configuration, the RF circuit is provided on the back surface of the RF board. The RF circuit can be appropriately fixed in the housing. According to the above configuration, the tip of the second portion of the metal plate is inserted or inserted into the RF board. Since the heat transmitted from the RF circuit to the RF board is transmitted to the metal plate, the heat of the RF circuit can be efficiently radiated to the heat conductive sheet and the internal member.

  The RF circuit is disposed on the second surface, and the metal plate extends from a first portion disposed at a position facing the RF circuit and an end of the first portion, and is provided on the ground substrate. A second portion bent in a direction toward the head, and a tip of the second portion may be inserted or inserted into the ground substrate.

  According to the above configuration, the RF circuit is provided on the second surface of the ground substrate. The RF circuit can be appropriately fixed in the housing. Further, according to the above configuration, the tip of the second portion of the metal plate is inserted or inserted into the ground substrate. Since the heat transmitted from the RF circuit to the ground substrate is transmitted to the metal plate, the heat of the RF circuit can be efficiently radiated to the heat conductive sheet and the internal member.

  When the direction in which the RF circuit and the element oppose each other is defined as a first direction, and a direction perpendicular to the first direction is defined as a second direction, the thermal conductivity of the heat conductive sheet is such that the thermal conductivity in the second direction is It may be larger than the thermal conductivity in the first direction.

  According to this configuration, the heat conductive sheet can conduct more heat in the second direction than in the first direction. Therefore, more of the heat of the RF circuit can be dissipated toward the internal member. That is, according to the above configuration, higher heat dissipation performance can be realized.

  The element, the ground substrate, and the power supply unit may further have thermal conductivity.

  According to this configuration, the heat of the RF circuit can be dissipated to the patch antenna. Therefore, in the RF communication device, it is possible to suppress a decrease in the processing performance of the RF circuit due to heat generation.

1 shows an outline of an RF communication apparatus 10 according to a first embodiment. FIG. 3 is an explanatory cross-sectional view of the RF module 20 according to the first embodiment. FIG. 4 shows a cross-sectional explanatory view of the RF module 20 of the second embodiment. FIG. 6 is an explanatory cross-sectional view of an RF module 20 according to a third embodiment. FIG. 7 is an explanatory cross-sectional view of an RF module 20 according to a fourth embodiment.

(First embodiment)
The RF (Radio Frequency) communication device 10 illustrated in FIG. 1 is a communication device that can execute RF communication with an RF tag (not illustrated). RF communication refers to communication for reading and writing RF tag data in a non-contact manner using radio waves (or electromagnetic fields). The RF communication device 10 according to the present embodiment is a communication device that employs a so-called radio wave method for performing RF communication by radiating and receiving radio waves. The RF communication device 10 is a portable device that can be carried by an operator.

  As shown in FIG. 1, the RF communication device 10 has a housing 11 and an RF module 20 provided in the housing 11. The housing 11 has a main body 11a, a grip 11b, and a module housing 11c. The main body 11a is a case that forms the main body of the RF communication device 10. A control board (for example, an internal board 100 described later) and the like are housed in the main body 11a. A display unit 14 for displaying various information is provided on the upper surface of the main unit 11a. Operation buttons 15 are provided on both side surfaces of the main body 11a. The operator can input various instructions (for example, an instruction to read an RF tag) by pressing the operation button 15.

  The grip part 11b is a grip-shaped member provided on the lower surface of the main body part 11a. The operator can grip the RF communication device 10 by gripping the grip 11b. The operation button 16 is also provided at a position in the gripping portion 11b at which the operator holding the gripping portion 11b can operate with the index finger. The operator can also input various instructions (for example, an RF tag reading instruction) by pressing the operation button 16. That is, the RF communication device 10 of the present embodiment can be used as a gun type device.

  The module accommodating portion 11c is a member provided to be connected to the upper end portion of the main body portion 11a, and is a member for accommodating the RF module 20 for executing the RF communication. The module accommodating portion 11c is provided to extend to the lower surface side of the main body 11a.

  Subsequently, the configuration of the RF module 20 of the present embodiment will be described with reference to FIG. The RF module 20 is a communication module for executing RF communication with a surrounding RF tag (not shown). The RF module 20 includes a patch antenna 22, an RF board 24, a metal plate 26, and a first heat conductor 27. An RF circuit 23 is provided on the RF board 24.

  The patch antenna 22 is an antenna for emitting and receiving a radio wave for RF communication in accordance with an instruction from the RF circuit 23 provided on the RF board 24. The patch antenna 22 may be called a microstrip antenna. The patch antenna 22 includes a ground substrate 30, a power supply unit 40, and an element 50. The ground substrate 30 and the element 50 are arranged in parallel with each other. The power supply unit 40 electrically connects the ground substrate 30 and the element 50.

  The ground substrate 30 is a conductor plate on the minus side of the patch antenna 22. The ground substrate 30 is also called a ground plane. As shown in FIG. 2, the ground substrate 30 includes a resin layer 31 and first and second metal layers 32 and 34 provided on both surfaces of the resin layer 31.

  The resin layer 31 is a resin layer having electrical insulation. The first metal layer 32 is a metal layer provided so as to cover the surface of the resin layer 31 on the side facing the element 50. The second metal layer 34 is a metal layer provided to cover the surface of the resin layer 31 on the side opposite to the element 50. The surface of the ground substrate 30 on which the first metal layer 32 is provided and the surface of the ground substrate 30 on which the second metal layer 34 is provided may be referred to as “first surface” and “second surface”, respectively. Good. In the present embodiment, the first metal layer 32 and the second metal layer 34 are made of a metal having electrical conductivity and thermal conductivity (for example, Cu, Al or the like), but in other examples, the first metal layer 32 and the second Instead of the two-metal layer 34, a layer made of another material having electrical conductivity and thermal conductivity may be provided. In another example, a layer made of another material having only conductivity may be provided. Generally speaking, the first metal layer 32 and the second metal layer 34 need only be made of a material having at least conductivity.

  A plurality of pillars 36 are provided inside the resin layer 31. Each pillar 36 is a cylindrical metal member, and one end is connected to the first metal layer 32 and the other end is connected to the second metal layer 34. That is, the first metal layer 32 and the second metal layer 34 are electrically and thermally connected by the pillar 36. In this embodiment, the pillars 36 are also made of a metal having thermal conductivity (for example, Cu, Al or the like). However, in other examples, the pillars 36 may be formed of other materials having thermal conductivity.

  A power supply circuit 37 is formed inside the resin layer 31. The power supply circuit 37 electrically connects the power supply unit 40 and a connector 38 provided on the surface of the second metal layer 34.

  The power supply unit 40 is a metal columnar member. One end of the power supply unit 40 is fixed to the first metal layer 32 of the ground substrate 30 and is electrically connected to the power supply circuit 37. The other end of the power supply unit 40 is electrically connected to the element 50. Thereby, the power supply unit 40 and the first metal layer 32 and the power supply unit 40 and the element 50 are also thermally connected. In this embodiment, the power supply unit 40 is made of a metal having conductivity and heat conductivity (e.g., Cu, Al, or the like). In another example, the power supply unit 40 is formed of another material having conductivity and heat conductivity. You may. In another example, it may be formed of another material having only conductivity. Generally speaking, the power supply unit 40 may be made of a material having at least conductivity.

  The element 50 is a metal plate member. The element 50 is a member also called a patch, and is a member for emitting and receiving radio waves. As described above, the element 50 is provided in parallel with the ground substrate 30.

  The patch antenna 22 of the present embodiment has the above configuration. Therefore, the ground substrate 30, the power supply unit 40, and the element 50 are electrically connected via the connector 38, the power supply circuit 37, the power supply unit 40, and the element 50. Further, the ground substrate 30, the power supply unit 40, and the element 50 are also thermally connected via the second metal layer 34, the pillar 36, the first metal layer 32, the power supply unit 40, and the element 50. ing.

  The RF substrate 24 is a resin substrate. The RF substrate 24 has a front side surface 24a facing the ground substrate 30 and a back side surface 24b opposite to the front side surface 24a. The front side surface 24a of the RF substrate 24 has a second metal layer 34 of the patch antenna 22 via a second heat conductor 25 made of a material (for example, resin or rubber) having thermal conductivity and electrical insulation. Is stuck on the surface. That is, the front surface 24 a of the RF substrate 24 is in surface contact with the surface of the second metal layer 34 via the second heat conductor 25.

  An RF circuit 23 is provided on a rear side surface 24 b of the RF board 24. In this embodiment, the RF circuit 23 is provided only on the rear side surface 24b of the RF substrate 24, and is not provided on the front side surface 24a. The RF circuit 23 is a circuit that is electrically connected to the patch antenna 22 and executes RF communication by causing the patch antenna 22 to emit radio waves. The RF circuit 23 includes a plurality of heat-generating elements (for example, power devices) 28 that generate heat as RF communication is performed. Each exothermic element 28 has a relatively small surface area.

  A connector 29 that is electrically connected to the RF circuit 23 is further provided on the rear side surface 24 b of the RF board 24. As shown in FIG. 2, a connector 29 provided on the RF board 24 and a connector 38 of the patch antenna 22 are electrically connected via a wiring 39. Thereby, the RF circuit 23 and the patch antenna 22 are electrically connected. The RF circuit 23 can execute RF communication by causing the patch antenna 22 to emit radio waves.

  The metal plate 26 is a member made of a metal (for example, Cu, Al, or the like) having conductivity and heat conductivity. The metal plate 26 includes a first portion 26-1 disposed at a position facing the RF circuit 23, and a second portion extending from an end of the first portion 26-1 and bending in a direction toward the ground substrate 30. 26-2. The first portion 26-1 is a circuit upper surface that is a surface of the RF circuit 23 that does not face the back surface 24 b of the RF circuit 23 (in other words, a surface that does not face the second surface of the ground substrate 30). Are provided in a range opposing to. The first portion 26-1 has a first main surface 26a facing the circuit top surface, and a second main surface 26b opposite to the first main surface 26a. The surface area of the first portion 26-1 is equal to or larger than the surface area of the RF circuit 23. That is, the metal plate 26 covers the RF circuit 23.

  The tip of the second portion 26-2 of the metal plate 26 is inserted into the RF board 24. That is, the tip of the second portion 26-2 penetrates the RF board 24. The tip of the second portion 26-2 is fixed on the front side surface 24a of the RF board 24 by solder or the like (not shown). In another example, the tip of the second portion 26-2 does not need to penetrate the RF board 24, and may be inserted into the RF board 24.

  The first heat conductor 27 has thermal conductivity and electrical insulation, and is formed of a material having elasticity (eg, resin, rubber, or the like). That is, the first heat conductor 27 of the present embodiment is formed of the same material as the second heat conductor 25. The first heat conductor 27 is provided between the circuit upper surface of the RF circuit 23 and the first main surface 26 a of the metal plate 26, and is pressed against the plurality of heat generating elements 28 by the metal plate 26. . Thus, the first heat conductor 27 is fixed by being sandwiched between the plurality of heat generating elements 28 of the RF circuit 23 and the first portion 26-1 of the metal plate 26. More specifically, the first heat conductor 27 is urged by its own elasticity in a direction toward each of the plurality of heat generating elements 28 and the metal plate 26, and the plurality of heat generating elements 28 and the metal plate 26 And close contact with each other. The first heat conductor 27 has a first contact surface 27a that contacts the plurality of heat-generating elements 28, and a second contact surface 27b opposite to the first contact surface 27a. The second contact surface 27b contacts the first main surface 26a of the metal plate 26. That is, the first heat conductor 27 thermally connects the plurality of exothermic elements 28 and the metal plate 26. As a result, heat of the plurality of heat-generating elements 28 generated during execution of the RF communication is transmitted to the metal plate 26 via the first heat conductor 27.

  As shown in FIG. 2, a heat conductive sheet 90 is attached to the metal plate 26 of the RF module 20. The heat conductive sheet 90 is a sheet member having heat conductivity. One end of the heat conductive sheet 90 is attached to the second main surface 26b of the metal plate 26 and is in surface contact with the metal plate 26. The other end of the heat conductive sheet 90 is attached to a metal layer 102 provided on the surface of the internal substrate 100, and is in surface contact with the metal layer 102 on the surface.

  The heat conductive sheet 90 is a sheet material made of graphite. That is, the thermal conductivity sheet 90 has a difference in thermal conductivity between the vertical direction (vertical direction) and the creeping direction (horizontal direction) perpendicular to the vertical direction. In other words, it may be said that the heat conduction performance of the heat conduction sheet 90 is anisotropic. The direction in which the RF circuit 23 and the element 50 oppose each other (that is, the horizontal direction in the drawing) is defined as a first direction, and the direction orthogonal to the first direction (that is, the vertical direction in the drawing) is defined as a second direction. Sometimes, the thermal conductivity in the second direction is higher than the thermal conductivity in the first direction. Thus, the heat transmitted from the metal plate 26 to one end of the heat conductive sheet 90 is efficiently transmitted to the internal substrate 100. Further, the heat conductive sheet 90 has a uniform thickness and width from one end to the other end.

  The internal substrate 100 is a substrate provided in the housing 11. The internal substrate 100 is, for example, a substrate on which another control circuit different from the RF circuit 23 is mounted. The internal substrate 100 has a plurality of metal layers 102 and a plurality of resin layers 104. Further, the internal substrate 100 further has a plurality of via holes 106 for electrically and thermally connecting the metal layers 102. Each metal layer 102 is made of a metal having conductivity and heat conductivity, such as Cu. The via hole 106 is also formed of the same material as the metal layer 102. In this embodiment, the other end of the heat conductive sheet 90 is attached to the metal layer 102 exposed on the surface of the internal substrate 100.

  Subsequently, the movement of heat in the present embodiment will be described. With the execution of the RF communication, the plurality of exothermic elements 28 of the RF circuit 23 generate heat. The heat of the RF circuit 23 is transmitted to one end of the heat conductive sheet 90 via the first heat conductor 27 and the first portion 26-1 of the metal plate 26, and is transmitted via the RF board 24 and the second heat conductor 25. And transmitted to the second metal layer 34 of the ground substrate 30. In addition, part of the heat transmitted to the RF board 24 and the second heat conductor 25 is transmitted to one end of the heat conductive sheet 90 via the second portion 26-2 and the first portion 26-1 of the metal plate 26. . The heat transmitted to the second metal layer 34 is also transmitted to the pillar 36, the first metal layer 32, the power supply 40, and the element 50. Thereby, the heat of the RF circuit 23 can be radiated to the patch antenna 22 as well.

  On the other hand, most of the heat transmitted to one end of the heat conductive sheet 90 is transmitted to the metal layer 102 exposed on the surface of the internal substrate 100 along the second direction. The remaining part of the heat transmitted to one end of the heat conductive sheet 90 is radiated from the heat conductive sheet 90 along the first direction. The heat transmitted to the metal layer 102 on the surface of the internal substrate 100 is transmitted to each metal layer 102 via each via hole 106. Thus, the heat of the RF circuit 23 can be radiated to the internal substrate 100 via the first heat conductor 27, the metal plate 26, and the heat conductive sheet 90.

  As described above, in the present embodiment, since the heat of the RF circuit 23 is transmitted to the heat conductive sheet 90 via the first heat conductor 27 and the metal plate 26, the heat of the RF circuit 23 is radiated to the heat conductive sheet 90. can do. The other end of the heat conductive sheet 90 is in contact with the internal substrate 100. Thus, the heat of the RF circuit 23 can be radiated to the internal substrate 100 via the first heat conductor 27, the metal plate 26, and the heat conductive sheet 90. Therefore, according to the present embodiment, in the RF communication device 10, a decrease in the processing performance of the RF circuit 23 due to heat generation can be suppressed.

  In the present embodiment, the first heat conductor 27 has elasticity, and is pressed against the plurality of heat generating elements 28 by the metal plate 26. Therefore, the first heat conductor 27 can be brought into close contact with the first main surface 26 a of the metal plate 26 and the plurality of heat generating elements 28. Further, even when the surface area of the heat-generating element 28 is relatively small as in this embodiment, the contact area between the first heat conductor 27 and the heat-generating element 28, A sufficient contact area of the first main surface 26a with the metal plate 26 can be secured. Therefore, the heat of the RF circuit 23 can be efficiently radiated to the heat conductive sheet 90 and the internal substrate 100.

  Further, in this embodiment, the thickness and the width from one end to the other end of the heat conductive sheet 90 are formed uniformly. If a place with a small thickness or a place with a small width is formed on the heat conductive sheet 90, the heat transfer performance at that place is reduced as compared with the other places, and the heat transfer is stagnated at that place, so that the heat transfer sheet 90 The overall heat transfer performance may be reduced. On the other hand, in the present embodiment, since the thickness and the width from one end to the other end of the heat conductive sheet 90 are uniform, a portion where the heat transfer performance is lower than other portions is not formed. As a result, the heat conductive sheet 90 can exhibit uniform heat transfer performance from one end to the other end. The heat conductive sheet 90 can exhibit high heat transfer performance.

  Further, in this embodiment, the internal substrate 100 includes a plurality of metal layers 102, and the other end of the heat conductive sheet 90 is in contact with the metal layer 102 on the surface of the internal substrate 100. Generally, metal exhibits high thermal conductivity. That is, the internal substrate 100 including the plurality of metal layers 102 can exhibit relatively high heat dissipation performance. Therefore, according to the present embodiment, it is possible to appropriately suppress a decrease in the processing performance of the RF circuit 23 due to heat generation. Further, in particular, since the internal substrate 100 is a substrate on which a control circuit different from the RF circuit 23 is mounted, a substrate for another use in the housing 11 can be used for heat radiation. It is not necessary to provide the member.

  In the present embodiment, the internal substrate 100 includes a plurality of via holes 106 for thermally connecting each of the plurality of metal layers 102. Since the heat transmitted to the internal substrate 100 can be conducted to each of the plurality of metal layers 102 of the internal substrate 100 via the via hole 106, the internal substrate 100 can exhibit higher heat radiation performance.

  Further, in this embodiment, the RF circuit 23 is provided on the rear side surface 24 b of the RF substrate 24. The RF circuit 23 can be appropriately fixed in the housing 11. Further, in this embodiment, the tip of the second portion 26-2 of the metal plate 26 is inserted into the RF board 24. Since the heat transmitted from the RF circuit 23 to the RF board 24 is transmitted to the metal plate 26, the heat of the RF circuit 23 can be efficiently radiated to the heat conductive sheet 90 and the internal substrate 100. Further, since the RF circuit 23 is covered with the metal plate 26, the influence of noise generated from the RF circuit 23 on other devices can be reduced.

  In the present embodiment, the thermal conductivity of the heat conductive sheet 90 is higher in the second direction than in the first direction. Thereby, the heat conductive sheet 90 can conduct more heat in the second direction than in the first direction. Therefore, of the heat of the RF circuit 23, more heat can be dissipated toward the internal substrate 100. That is, in this embodiment, higher heat dissipation performance can be realized.

  In this embodiment, the element 50, the ground substrate 30, and the power supply unit 40 have thermal conductivity. Thereby, as described above, the heat of the RF circuit 23 can be radiated to the patch antenna 22 as well. Therefore, in the RF communication device 10, a decrease in the processing performance of the RF circuit 23 due to heat generation can be suppressed.

  In the ground substrate 30 of the present embodiment, the surface on the side where the first metal layer 32 is provided and the surface on the side where the second metal layer 34 is provided respectively correspond to the “first surface” and the “second surface”. "Is an example. The first thermal conductor 27 is an example of a “thermal conductor”.

(Second embodiment)
Next, a second embodiment will be described with reference to FIG. 3, focusing on differences from the first embodiment. The basic configuration of the RF communication device 10 of the second embodiment is also the same as that of the first embodiment (see FIG. 1), but as shown in FIG. And different. In FIG. 3, the elements common to the first embodiment are indicated by the same reference numerals as those in FIG. A detailed description of elements common to the first embodiment is omitted.

  As shown in FIG. 3, in the RF module 20 of the present embodiment, the RF circuit 23 is provided directly on the surface of the second metal layer 34 of the ground substrate 30 of the patch antenna 22. That is, in the RF module 20 of the present embodiment, the RF board 24, the second heat conductor 25, the connector 29, the connector 38, and the wiring 39 are omitted. The RF circuit 23 is electrically connected to the power supply circuit 37 via the second metal layer 34. Thus, the RF circuit 23 and the patch antenna 22 are electrically connected. The RF circuit 23 can execute RF communication by causing the patch antenna 22 to emit radio waves.

  The tip of the second portion 26-2 of the metal plate 26 is inserted into the ground substrate 30. The tip of the second portion 26-2 is fixed to the first metal layer 32 of the ground substrate 30 by solder or the like (not shown).

  In the present embodiment, the heat of the RF circuit 23 generated with the execution of the RF communication is transmitted to one end of the heat conductive sheet 90 via the first heat conductor 27 and the first portion 26-1 of the metal plate 26. At the same time, it is directly transmitted to the second metal layer 34 provided with the RF circuit 23. The heat transmitted to the second metal layer 34 is transmitted to the pillar 36, the first metal layer 32, the power supply unit 40, and the element 50. Further, a part of the heat transmitted to the first metal layer 32 and the second metal layer 34 (that is, the heat transmitted to the ground substrate 30) is reduced to the second portion 26-2 and the first portion 26-1 of the metal plate 26. Through one end of the heat conductive sheet 90. Then, the heat transmitted to one end of the heat conductive sheet 90 is transmitted to the internal substrate 100. That is, also in this embodiment, the heat of the RF circuit 23 can be radiated to the heat conductive sheet 90 and the internal substrate 100. Therefore, in the RF communication device 10, a decrease in the processing performance of the RF circuit 23 due to heat generation can be suppressed.

  Further, in this embodiment, the RF circuit 23 is provided on the second surface of the ground substrate 30 (that is, the surface on which the second metal layer 34 is provided). The RF circuit 23 can be appropriately fixed in the housing 11. In this embodiment, the tip of the second portion 26-2 of the metal plate 26 is inserted into the ground substrate 30. As described above, since the heat transmitted from the RF circuit 23 to the ground substrate 30 is transmitted to the metal plate 26, the heat of the RF circuit 23 can be efficiently radiated to the heat conductive sheet 90 and the internal substrate 100.

  In addition, according to the present embodiment, it is not necessary to separately provide an RF board for mounting the RF circuit 23, so that a space corresponding to the RF board can be omitted. Therefore, the RF module 20 and the RF communication device 10 can be downsized.

(Third embodiment)
The third embodiment shown in FIG. 4 is a modification of the first embodiment (see FIG. 2). Also in this embodiment, a part of the configuration of the RF module 20 is different from that of the first embodiment. Specifically, as shown in FIG. 4, the shape of the metal plate 26 is different from that of the first embodiment. In FIG. 4, elements common to the above embodiments are denoted by the same reference numerals as those in the above drawings. In addition, a detailed description of elements common to the above embodiments will be omitted.

  As shown in FIG. 4, the metal plate 26 of the present embodiment is a metal plate-like member, and does not have a portion corresponding to the second portion 26-2 of the metal plate 26 of the first embodiment. The metal plate 26 is adhered to the first heat conductor 27 and the plurality of heat generating elements 28 with an adhesive.

  In the present embodiment, the heat of the RF circuit 23 generated during the execution of the RF communication is transmitted to one end of the heat conductive sheet 90 via the first heat conductor 27 and the metal plate 26, and the RF board 24 and the 2 The heat is transmitted to the second metal layer 34 of the ground substrate 30 via the heat conductor 25. The heat transmitted to the second metal layer 34 is transmitted to the pillar 36, the first metal layer 32, the power supply unit 40, and the element 50. On the other hand, the heat transmitted to one end of the heat conductive sheet 90 is transmitted to the internal substrate 100. That is, also in this embodiment, the heat of the RF circuit 23 can be radiated to the heat conductive sheet 90 and the internal substrate 100. Therefore, in the RF communication device 10, a decrease in the processing performance of the RF circuit 23 due to heat generation can be suppressed.

(Fourth embodiment)
The fourth embodiment shown in FIG. 5 is a modification of the second embodiment (see FIG. 3). Also in this embodiment, a part of the configuration of the RF module 20 is different from that of the second embodiment. Specifically, as shown in FIG. 5, the shape of the metal plate 26 is different from that of the second embodiment. Note that, in FIG. 5 as well, elements common to the above-described embodiments are denoted by the same reference numerals as those in the above-described drawings. In addition, a detailed description of elements common to the above embodiments will be omitted.

  As shown in FIG. 5, the metal plate 26 of the present embodiment is a plate member made of metal, and is similar to the metal plate 26 of the third embodiment (see FIG. 4). That is, the metal plate 26 of the present embodiment also has no portion corresponding to the second portion 26-2 (see FIG. 2).

  In this embodiment, the heat of the RF circuit 23 generated during the execution of the RF communication is transmitted to one end of the heat conductive sheet 90 via the first heat conductor 27 and the metal plate 26, and the RF circuit 23 is provided. Directly to the second metal layer 34. The heat transmitted to the second metal layer 34 is transmitted to the pillar 36, the first metal layer 32, the power supply unit 40, and the element 50. On the other hand, the heat transmitted to one end of the heat conductive sheet 90 is transmitted to the internal substrate 100. That is, also in this embodiment, the heat of the RF circuit 23 can be radiated to the heat conductive sheet 90 and the internal substrate 100. Therefore, in the RF communication device 10, a decrease in the processing performance of the RF circuit 23 due to heat generation can be suppressed.

  Although specific examples of the technology disclosed in the present specification have been described above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Modifications of the above embodiment are listed below.

(Modification 1) In each of the above embodiments, the first heat conductor 27 is formed of an elastic material having thermal conductivity and electrical insulation. The present invention is not limited to this, and the first heat conductor 27 may be formed of a material having no elasticity. In this case, the first heat conductor 27 does not have to be pressed against the plurality of heat generating elements 28 by the metal plate 26. Generally speaking, the thermal conductor only needs to have at least thermal conductivity and electrical insulation.

(Modification 2) In each of the above embodiments, the thickness and width from one end to the other end of the heat conductive sheet 90 are formed uniformly. The thickness and width from one end to the other end of the heat conductive sheet 90 are not limited thereto, and may not be uniform.

(Modification 3) In each of the above embodiments, the other end of the heat conductive sheet 90 is attached to the surface of the internal substrate 100. The present invention is not limited to this, and the other end of the heat conductive sheet 90 may be in contact with any other member in the housing 11. Generally speaking, the other end of the heat conductive sheet extends outward from the range between the RF circuit and the element, and only needs to be in contact with an internal member provided in the housing.

(Modification 4) In each of the above embodiments, the internal substrate 100 further includes a plurality of metal layers 102 and a plurality of via holes 106 for electrically and thermally connecting the metal layers 102. . The present invention is not limited to this, and the via holes 106 need not be electrically connected between the metal layers 102 as long as the metal layers 102 can be thermally connected. In another example, the via hole 106 in the internal substrate 100 may be omitted. In still another example, the internal substrate 100 may include only one metal layer 102.

(Modification 5) In each of the above embodiments, when the direction in which the RF circuit 23 and the element 50 face each other is the first direction, and the direction orthogonal to the first direction is the second direction, the heat conductive sheet 90 The thermal conductivity in the two directions is higher than the thermal conductivity in the first direction. The thermal conductivity of the heat conductive sheet 90 is not limited to this, and the thermal conductivity in the first direction may be equal to the thermal conductivity in the second direction. In this case, the heat conductive sheet 90 may be formed of a material (for example, a metal such as Al or Cu) having the same thermal conductivity in the first direction and the second direction.

  In addition, the technical elements described in the present specification or the drawings exhibit technical utility singly or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology illustrated in the present specification or the drawings simultaneously achieves a plurality of objects, and has technical utility by achieving one of the objects.

10: RF communication device 11: housing 11a: main body 11b: gripper 11c: module housing 14: display 15: operation button 16: operation button 20: RF module 22: patch antenna 23: RF circuit 24: RF board 24a: Front side surface 24b: Back side surface 25: Second heat conductor 26: Metal plate 26-1: First portion 26-2: Second portion 26a: First main surface 26b: Second main surface 27: First heat Conductor 27a: first contact surface 27b: second contact surface 28: heat generating element 29: connector 30: ground substrate 31: resin layer 32: first metal layer 34: second metal layer 36: pillar 37: power supply circuit 38 : Connector 39: Wiring 40: Feeding part 50: Element 90: Thermal conductive sheet 100: Internal board 102: Metal layer 104: Resin layer 106: Via hole

Claims (9)

An RF communication device,
A housing,
A patch antenna provided in the housing,
An RF circuit provided in the housing, electrically connected to the patch antenna, and performing RF communication by causing the patch antenna to radiate radio waves,
A metal plate provided in the housing,
A heat conductor provided in the housing and having heat conductivity and electrical insulation,
A heat conductive sheet provided in the housing and having heat conductivity,
An internal member provided in the housing,
With
The patch antenna,
A plate-shaped element having conductivity,
A plate-like ground substrate disposed in a range opposed to the element, comprising a first surface opposed to the element, and a second surface opposite to the first surface. A ground substrate on which a conductive layer is formed on a surface and a surface of the second surface;
A power supply unit having conductivity and electrically connecting the element and the ground substrate,
With
The RF circuit includes at least one heat-generating element that generates heat with the execution of the RF communication, is provided in a range facing the second surface, and is electrically connected to the ground substrate,
The metal plate,
In the RF circuit, a first main surface facing the circuit upper surface, which is provided in a range facing the circuit upper surface, which is a surface not facing the second surface, and a first main surface opposite to the first main surface. And two main surfaces, the surface area of which is equal to or greater than the surface area of the RF circuit,
The heat conductor is provided between the circuit top surface and the first main surface, and has a first contact surface that contacts the at least one heat-generating element, and a second contact surface opposite to the first contact surface. A contact surface, having a second contact surface in contact with the first main surface, thermally connecting the at least one heat generating element and the metal plate;
One end of the heat conductive sheet is in contact with the second main surface,
The other end of the heat conductive sheet extends outward from a region facing the second surface, and is in contact with the internal member.
RF communication device.   The RF communication device according to claim 1, wherein the heat conductor has elasticity and is pressed against the at least one heat-generating element by the metal plate.   The RF communication device according to claim 1, wherein a thickness and a width of the heat conductive sheet from the one end to the other end are uniform. The internal member is an internal substrate including at least one metal layer,
4. The RF communication device according to claim 1, wherein the other end of the heat conductive sheet is in contact with one surface of the internal substrate. 5.   The RF communication device according to claim 4, wherein the internal substrate includes a plurality of the metal layers and at least one via hole that thermally connects each of the plurality of metal layers. Further comprising a plate-like RF substrate provided in the housing,
The RF substrate,
A front surface provided in a range opposed to the second surface,
A back side opposite to the surface,
The RF circuit is provided on the back side surface,
The metal plate,
A first portion disposed at a position facing the RF circuit; and a second portion extending from an end of the first portion and bending in a direction toward the ground substrate,
The RF communication device according to claim 1, wherein a tip of the second portion is inserted or inserted into the RF board. The RF circuit is disposed on the second surface;
The metal plate,
A first portion disposed at a position facing the RF circuit; and a second portion extending from an end of the first portion and bending in a direction toward the ground substrate,
The RF communication device according to claim 1, wherein a tip of the second portion is inserted or inserted into the ground substrate.   When the direction in which the RF circuit and the element oppose each other is defined as a first direction, and a direction perpendicular to the first direction is defined as a second direction, the thermal conductivity of the heat conductive sheet is such that the thermal conductivity in the second direction is The RF communication device according to any one of claims 1 to 7, wherein the RF communication device has a thermal conductivity greater than the first direction thermal conductivity. The RF communication device according to any one of claims 1 to 8, wherein the element, the ground substrate, and the power supply unit further have thermal conductivity.

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