JP2008108937A - Heat dissipation structure of inductance component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipation structure of inductance component which can dissipate internally generated heat well and can utilize electromagnetic energy stored in the core in the circuit of other system. <P>SOLUTION: A choke coil 1 is constituted of E-type cores 103, 103, a winding body 101, and a heat spreader 5. The heat spreader 5 is formed of a material excellent in heat dissipation properties and has a substantially planar U-shape wherein the legs 8 and 9 becoming the distal ends can make electrical connection with an electric circuit formed on a substrate. The heat spreader 5 dissipates heat in the choke coil 1 to the outside and, in the inventive arrangement, it is wound around the core 3 of the E-type core 103 and can be regarded as a coil coupled magnetically with the winding body 101. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure for an inductance component formed by winding a conductive member.

  For example, an inductance component used as a choke coil or the like is provided with various heat dissipation measures in order to suppress a high temperature state due to heat generation in the winding portion. As an example, in the transformer disclosed in Patent Document 1, a heat radiating plate is interposed between coil layers, whereby heat inside the transformer is conducted to the heat radiating plate and radiated to the outside.

  FIG. 5 shows an application of the prior art disclosed in Patent Document 1 to a choke coil. The figure shows a state where the choke coil mounted on the substrate is viewed from the cross-sectional direction of the substrate. The choke coil 100 is configured by mounting a pair of E-shaped cores 103 and 103 made of a magnetic material on a winding body 101 in which a winding as a conductive member is wound around a resin bobbin, for example. Further, in this choke coil 100, a heat radiating plate 104 excellent in heat dissipation (thermal conductivity) is sandwiched between the upper surface of the winding body 101 and the inner surface of the E-shaped core 103 opposed thereto. The heat radiating plate 104 is formed with two legs 105 and 105 that extend slightly from the main body sandwiched inside the choke coil 100 in the horizontal direction with respect to the substrate 107 and then hang down so as to approach the substrate 107. Yes.

The choke coil 100 is placed on the substrate 107, and a terminal (not shown) protruding from the lower surface side of the winding body 101 is soldered and connected (surface mounted) to a mounting pad provided on the surface of the substrate 107. On the substrate 107, a mold 106, which is a heat radiating filler having excellent heat dissipation, is filled in order to dissipate heat generated on the surface of the substrate 107. The mold 106 is filled to such an extent that the lower end portions of the leg portions 105 and 105 protruding from the choke coil 100 are filled, and thermal connection between the leg portions 105 and 105 and the mold 106 is achieved. Due to the thermal connection, heat generated in the choke coil 100 is radiated through the heat radiating plate 104 and the mold 106.
JP 7-226323 A

  By the way, in an electric circuit constituting an electronic device or the like, for example, current detection or an auxiliary power source may be required. Conventionally, when such a need arises, for example, a current transformer, an auxiliary power source device, or the like It was necessary to add these parts to the electric circuit. On the other hand, reduction of the number of parts in a product is an important issue, and efficient circuit design for that purpose is always required.

  Accordingly, in view of the above-described problems, the present invention provides a heat dissipation structure for an inductance component that can dissipate heat generated internally and can use electromagnetic energy generated in the inductance component in another circuit. With the goal.

  In Claim 1 in this invention, it is a heat dissipation structure of the inductance components comprised from the wound electroconductive member and the heat sink thermally connected to the said electroconductive member, Comprising: The said heat sink is electroconductive. It is formed in a discontinuous annular shape having a pair of end portions by opening a part of a plate-like member having an end. It is configured by electrical connection.

  In this way, since a current flows through the conductive member, a voltage can be induced in the heat sink provided only for heat dissipation in the conventional inductance component, and therefore the induced voltage is transferred to another electric circuit. Can be supplied.

  According to a second aspect of the present invention, a core made of a magnetic material is provided, and the conductive member and the heat radiating plate are wound around the core.

  If it does in this way, the magnetic coupling with a conductive member and a heat sink will become strong with a core, and the electric energy induced by a heat sink can be increased.

  According to a third aspect of the present invention, the substrate is a metal base substrate.

  If it does in this way, since a heat sink is thermally connected to the metal base board excellent in heat dissipation, the heat of an inductance component can be efficiently radiated.

  According to a fourth aspect of the present invention, the substrate is filled with a heat radiation filler.

  If it does in this way, since a heat sink and a board | substrate are thermally connected to the filler for heat dissipation excellent in heat dissipation, the heat | fever of an inductance component can be thermally radiated efficiently.

  According to claim 1 of the present invention, it is possible to provide a heat dissipation structure for an inductance component that can dissipate the heat generated inside well and can use electromagnetic energy generated in the inductance component in a circuit of another system. it can.

  According to claim 2 of the present invention, it is possible to provide a heat dissipation structure for an inductance component that can use electromagnetic energy stored in the core in a circuit of another system.

  According to claim 3 of the present invention, it is possible to provide a heat dissipation structure for an inductance component that is more excellent in heat dissipation by improving the heat dissipation of the substrate.

  According to the fourth aspect of the present invention, it is possible to provide a heat dissipation structure for an inductance component that is more excellent in heat dissipation due to the action of the heat dissipation filler.

  Hereinafter, preferred embodiments of a heat dissipation structure for an inductance component according to the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the same location as a prior art example, and since description of a common part overlaps, it abbreviate | omits as much as possible.

  FIG. 1 is an exploded perspective view showing the structure of a choke coil 1 as an inductance component in the present invention. The choke coil 1 includes a pair of E-shaped cores 103 and 103 made of a magnetic material, and a winding body 101 formed by, for example, winding a winding as a conductive member around a cylindrical bobbin having a center hole 2; It is comprised from the heat sink 5 which consists of metals, such as copper, which was excellent in heat dissipation (thermal conductivity). The E-shaped cores 103 and 103 are formed in a flat plate-shaped main portion by projecting a cylindrical core portion 3 at the central portion on one side and outer wall portions 4 and 4 at both end portions on one side. . The winding body 101 is configured by, for example, winding a winding as a conductive member around a resin bobbin, and the winding is electrically connected to the bobbin constituting the winding body 101, For example, it has a terminal 101a for electrical connection (surface mounting) to a mounting pad provided on a substrate such as a printed circuit board by, for example, soldering.

  The heat radiating plate 5 is formed by forming a material excellent in heat radiating property (thermal conductivity) into a substantially U-shaped plate shape, and is formed in a discontinuous substantially annular shape having a through hole 7 formed in the center. It comprises a portion 6 and leg portions 8 and 9 as end portions extending horizontally outward from both ends of the winding portion 6 with a notch 10 provided in communication with the through hole 7 therebetween. The leg portions 8 and 9 are slightly bent from the both ends of the winding portion 6 in the horizontal direction on the same plane as the winding portion 6 and then bent so as to hang down. Electrical connection (surface mounting) to a mounting pad provided on a substrate (not shown) by soldering or the like is possible. The shape of the heat sink 5 needs to be a shape that takes into account interference with surrounding components when mounted on the substrate, but in order to improve heat dissipation, its surface area should be as large as possible. preferable. In the example shown in FIG. 1, two adjacent corners of the winding part 6 are chamfered, and the leg part 8 becomes thicker from the notch 10 until the outer diameter of the winding part 6 is reached in order to increase the surface area. On the other hand, the leg portion 9 is formed so as to be much thinner than the leg portion 8 in order to avoid surrounding parts, and has the same width as the winding portion 6.

  The choke coil 1 is configured by attaching a heat sink 5 and a pair of E-shaped cores 103 and 103 to a winding body 101. Specifically, the winding body 101 and the heat sink 5 are arranged so that the center hole 2 and the through hole 7 are aligned and overlapped so that the center hole 2 and the through hole 7 are coaxial. The core portions 3 and 3 of the E-shaped cores 103 and 103 are inserted into the hole 2 and the through-hole 7 from above and below, respectively, and the core portions 3 and 3 and the outer wall portions 4 and 4 of the opposing E-shaped cores 103 and 103 are connected to each other. The assembly shown in FIG. As a result, the heat sink 5 is sandwiched between the upper surface of the winding body 101 and the inner surface of the E-shaped core 103 facing the choke coil 1. The heat radiating plate 5 radiates the heat inside the choke coil 1 to the outside. In the configuration of this embodiment, the heat radiating plate 5 is wound around the core portion 3 of the E-shaped core 103 and simultaneously with the winding body 101. It can be regarded as a magnetically coupled one turn auxiliary winding.

  FIG. 3 is a perspective view showing the choke coil 1 mounted on the substrate 107. In the figure, the assembled choke coil 1 is mounted on a substrate 107, and a terminal 101a protruding from the lower surface side of the winding body 101 is soldered to a mounting pad provided on the surface of the substrate 107 (surface Has been implemented). At this time, the legs 8 and 9 of the heat sink 5 extending from the choke coil 1 are also soldered (surface mounted) to the mounting pads 20 and 20 provided on the surface of the substrate 107, similarly to the terminal 101a. . The circuit pattern connected to the mounting pads 20, 20 forms a circuit line of a different system from the circuit pattern connected to the winding body 101 that originally functions as the terminal 101 a and thus the choke coil. For example, a printed circuit board or the like is generally used as the substrate 107, but it is preferable to use a metal base substrate excellent in heat dissipation. In this case, since the heat radiating plate 5 is thermally connected to the metal base substrate having excellent heat dissipation, the heat of the choke coil 1 can be efficiently radiated through the substrate 107. Although not shown, like the conventional example, the substrate 107 is filled with a mold 106 which is a heat dissipating filler having excellent heat dissipation in order to dissipate heat generated on the surface of the substrate 107.

  FIG. 4 shows a general circuit configuration of a power factor correction circuit using a step-up chopper circuit, which is incorporated in, for example, a power supply device as one usage mode of the choke coil 1. In the figure, a rectifier circuit 34 comprising, for example, a diode bridge as a rectifier is connected to both ends of a commercial power supply 31 corresponding to an AC power supply, and an AC power supply voltage from the commercial power supply 31 is rectified to obtain input terminals 32, 33 is supplied to the boost chopper circuit 35 at the subsequent stage. This step-up chopper circuit 35 connects a series circuit of a choke coil 1 (winding body 101) and a drain-source of a MOSFET 37, which is a switching element, between input terminals 32 and 33 serving as output terminals of a rectifier circuit 34. A series circuit of a parallel circuit of the rectifier diode 38, the thyristor 26 and the resistor 27 and an output capacitor 39 made of, for example, an electrolytic capacitor is connected between both ends of the MOSFET 37, that is, between the drain and source. The gate of the thyristor 26 is connected to the output of a gate trigger circuit 25 in which both ends of the heat radiating plate 5 constituting the choke coil 1, that is, the legs 8 and 9 are connected to the input side.

  When the MOSFET 37 is on, excitation energy is stored in the choke coil 1 by a full-wave rectified direct current from the rectifier circuit 34. When the MOSFET 37 is off, the excitation energy stored in the choke coil 1 is stored in the rectifier circuit. The output voltage Vo higher than the input side of the step-up chopper circuit 35 is generated between the output terminals 42 and 43 provided between both ends of the output capacitor 39 by being superimposed on the input voltage Vi generated between the output terminals 34. I have to.

  On the other hand, 41 is a PFC control unit that switches the MOSFET 37 by supplying a pulsed drive voltage to the gate of the MOSFET 37. The PFC control unit 41 monitors the output voltage Vo as a feedback signal, and switches the MOSFET 37 so that the output voltage Vo is constant, so that the current waveform taken in via the choke coil 1 is supplied from the commercial power supply 31. It approaches the sinusoidal voltage waveform to improve the input power factor.

  In the step-up chopper circuit 35, the heat radiating plate 5 is used for detecting the current flowing through the winding body 101, and functions as a so-called current transformer. That is, a current detection voltage is induced in the heat sink 5 when a current flows through the winding body 101. This current detection voltage is input to the gate trigger circuit 25 that performs on / off control of the thyristor 26. The thyristor 26 is provided together with the resistor 27 as a circuit for preventing an inrush current to the output capacitor 39.

  The operation of the inrush current prevention circuit will be described. While electric power is normally supplied from the commercial power supply 31, current always flows through the choke coil 1, and a current detection voltage is induced in the heat sink 5. Since no voltage is induced in the heat sink 5 of the choke coil 1 until the MOSFET 37 is operated after the input is turned on, the current from the power source at the time of turning on the input is the rectifier circuit 34 → winding body 101 → rectifier diode 38 → resistor 27 The inrush current is suppressed by the resistance of the resistor 27. Next, when the MOSFET 37 performs a switching operation (starts boosting), a voltage is induced in the heat sink 5 and the gate voltage of the thyristor 26 reaches the trigger level by the gate trigger circuit 25. As a result, the thyristor 26 is turned on. The current flowing through 27 flows through thyristor 26. As long as the MOSFET 37 is switching, current flows through the thyristor 26.

  As described above, in the choke coil 1 of the present embodiment, an inductance component including the winding body 101 as a wound conductive member and the heat sink 5 thermally connected to the winding body 101 is used. In the heat dissipation structure, the heat radiating plate 5 is formed in a discontinuous annular shape having legs 8 and 9 as a pair of end portions by opening a part of a conductive plate-like member. The leg portions 8 and 9 of the heat radiating plate 5 are electrically connected to a gate trigger circuit 25 corresponding to an arbitrary electric circuit by mounting on the substrate 107.

  In this way, since a current flows through the winding body 101, a voltage can be induced in the heat radiating plate 5 provided only for heat dissipation in the conventional inductance component. It can be supplied to the trigger circuit 25. Therefore, it is possible to provide a heat radiating structure for an inductance component that can radiate heat generated in the interior well and can use electromagnetic energy generated in the choke coil 1 in another circuit.

  In this embodiment, the E-shaped cores 103 and 103 made of a magnetic material are provided, and the winding body 101 and the heat sink 5 are wound around the E-shaped cores 103 and 103.

  In this way, the magnetic coupling between the winding body 101 and the heat sink 5 is strengthened by the E-shaped cores 103, 103, and the amount of power induced in the heat sink 5 can be increased.

  Furthermore, in this embodiment, it is desirable that the substrate 107 is a metal base substrate.

  If it does in this way, since the heat sink 5 is thermally connected to the metal base board | substrate excellent in heat dissipation, the heat | fever of an inductance component can be thermally radiated efficiently. Therefore, it is possible to provide a heat dissipation structure for an inductance component that is more excellent in heat dissipation.

  In this embodiment, the substrate 107 is filled with a mold 106 as a heat radiating filler.

  In this way, since the heat radiating plate 5 and the substrate 107 are thermally connected to the mold 106 having excellent heat dissipation, the heat of the choke coil 1 can be efficiently radiated. Therefore, by the action of the mold 106, it is possible to provide a heat dissipation structure for an inductance component that is more excellent in heat dissipation.

  In addition, this invention is not limited to the said Example, It can change in the range which does not deviate from the meaning of this invention. In addition to the above-described current detection, the voltage induced in the heat sink 5 may be used as an auxiliary power source for other electronic components, for example. In addition to the choke coil, the inductance component includes various coil components such as a transformer, and the structure thereof is not particularly limited.

It is a disassembled perspective view which shows each component which comprises the inductance component in the Example of this invention. It is a perspective view which shows the state after an assembly of an inductance component same as the above. It is a perspective view which shows the inductance component of the state mounted in the board | substrate same as the above. It is a circuit diagram which shows the example of 1 circuit using an inductance component same as the above. It is a front view which shows a mode that the inductance component in a prior art example was mounted in the board | substrate.

Explanation of symbols

1 Choke coil (inductance component)
5 Heat sink 8, 9 Leg (end)
25 Gate trigger circuit (arbitrary electrical circuit)
101 Winding body (conductive member)
103 E-shaped core
106 Mold (Heat dissipation filler)
107 substrate

Claims (4)

A heat dissipation structure for an inductance component comprising a wound conductive member and a heat dissipation plate thermally connected to the conductive member, wherein the heat dissipation plate is a part of a conductive plate-like member Is formed in a discontinuous annular shape having a pair of end portions, and both ends of the heat sink are electrically connected to an arbitrary electric circuit by mounting on a substrate. A heat dissipation structure for an inductance component. The heat dissipation structure for an inductance component according to claim 1, further comprising a core made of a magnetic material, wherein the conductive member and the heat dissipation plate are wound around the core. 3. The heat dissipation structure for an inductance component according to claim 1, wherein the substrate is a metal base substrate. The heat dissipation structure for an inductance component according to claim 1, wherein a heat dissipation filler is filled on the substrate.

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