JP2017195326A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, when an inductance component such as a resonance coil or transformer is attached to a housing, a projection for pressing cores to a metallic cover is required and reduction in size and improvement in heat dissipation are hindered.SOLUTION: In a power supply device, an inductance component and a printed circuit board 3 are arranged on a base plate 1, a heat transfer sheet 5 having compressibility is provided on the upper surface of a core 2a of the inductance component, and by fixing a metal flat plate 4 to the base plate 1 using a screw or the like, the heat transfer sheet 5 is pressurized and the core 2a and a core 2b are fixed to each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device holding inductance components such as a transformer, a resonance coil, and a choke coil.

  The switching power supply is provided with a heat radiating portion in the holding structure of the inductance component. Conventionally, a metal base plate is provided with a columnar projection, a top plate portion of a metal cover is fastened to the columnar projection, a projection is formed on the top plate portion of the cover, and the core of the transformer is sandwiched between the base plate and the projection A power supply apparatus is disclosed (for example, see Patent Document 1). In this power supply device, the projecting portion formed on the cover is in press contact with the core of the transformer, and a heat transfer sheet is provided between the projecting portions to contact the core. Thereby, the temperature rise of a transformer is suppressed and the loss of a power supply device is suppressed.

JP 2007-6635 A

FIG. 2 is a diagram illustrating an inductance component holding structure in the conventional power supply device disclosed in Patent Document 1. In FIG.
In FIG. 2, a transformer as an inductance component is composed of upper and lower cores 2a and 2b and a printed circuit board 3 forming a coil. The heat radiating base plate 1 releases the heat generated by the core 2b. The metal cover 6 has a protrusion 6a for cooling the core 2a. The protrusion 6a protrudes to the core 2a side of the metal cover 6, and the metal cover 6 is fixed to the base plate 1 by screwing, so that the protrusion 6a presses the upper surface of the core 2a, and the core 2a and the core 2b Is retained. In this way, the core 2a and the core 2b are sandwiched between the metal cover 6 and the base plate 1, and heat is radiated from both the upper and lower surfaces of the core 2a and the core 2b.

  This holding structure has a problem that it is necessary to increase the projecting dimension of the projecting portion 6a in order to secure a force for pressing the core against the base plate 1, and this hinders a reduction in the height of the apparatus.

  The heat transfer sheet 5 is provided to reduce the thermal resistance between the upper core 2 a and the metal cover 6. Since the dimension of the protrusion 6a is large, there is a problem that the thickness of the heat transfer sheet 5 increases and a sufficient cooling effect cannot be obtained.

  Furthermore, there is a problem that work for forming the projecting portion 6a of the metal cover 6 is generated, which hinders cost reduction.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a power supply device having a holding structure for an inductance component that is small in size and excellent in heat dissipation characteristics at low cost.

  The power supply device according to the present invention includes a base plate, a protrusion attached to the pace plate, a metal flat plate held on the protrusion by screw fastening, a lower core in contact with the base plate, and a lower core. An upper core that is in contact with each other, a printed circuit board that is disposed between the upper core and the lower core and forms a coil that forms an inductance component together with the upper core and the lower core, the metal flat plate, and the upper core A highly compressible heat transfer sheet disposed between the cores and compressed by the screw fastening.

  According to the present invention, a power supply device having a holding structure for an inductance component that is small in size and excellent in heat dissipation characteristics can be provided at low cost.

It is a figure explaining the holding structure of the inductance component of the power supply device by Embodiment 1 of this invention. It is a figure explaining the holding structure of the inductance component of the conventional power supply device.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an inductance component holding structure in a power supply device according to Embodiment 1 of the present invention. The power supply device according to the first embodiment includes inductance components such as a transformer, a resonance coil, and a choke coil, and constitutes a switching power supply, for example. In FIG. 1, the power supply device according to the first embodiment includes a heat radiating base plate 1, an upper core 2 a, a lower core 2 b, a printed board 3, a metal flat plate 4, and a heat transfer sheet 5. The cores 2a and 2b and the printed board 3 constitute, for example, a transformer as an inductance component.

  The base plate 1 is formed with a protrusion 6. The protrusion 6 may be formed separately from the base plate 1. The base plate 1 is a heat radiating base plate that releases heat generated by the core 2b. A plurality of columnar or plate-like protrusions (heat sinks) (not shown) may be formed on the back surface of the base plate 1. The printed circuit board 3 is arranged around the cores 2a and 2b, and a coil pattern 3b constituting a transformer is formed. The coil pattern 3b of the printed circuit board 3 is sandwiched between the cores 2a and 2b and accommodated in the holes 2c formed in the cores 2a and 2b. The printed circuit board 3 is held on the base plate 1 by screws or the like. The heat transfer sheet 5 has compressibility. As the heat transfer sheet 5, for example, a phase change sheet using a phase change material made of special silicone that changes phase by heat is used. The phase change sheet changes its phase and melts by heat generated from the heating element and changes from a solid sheet to a liquid fluid body, so that the thermal resistance is lowered and the sheet is highly compressible.

  The core 2a and the core 2b constitute a transformer by sandwiching the printed board 3 on which a coil pattern is formed. The core 2b is disposed in contact with the base plate 1, and the heat transfer sheet 5 is disposed on the upper surface of the core 2a. The metal flat plate 4 is fixed to the upper surface of the protrusion 6 of the base plate 1 and fastened with screws 7.

  The heat transfer sheet 5 is sandwiched between the metal flat plate 4 and the core 2a. The heat transfer sheet 5 is pressed and fixed by the fastening force of the screws 7. At the same time, the core 2 a and the core 2 b are fixed together by the fastening force of the screw 7. At this time, by compressing the compressible cooling sheet 5 with an appropriate force, the required vibration resistance performance and heat dissipation performance can be secured in the holding structure of the core 2a and the core 2b. Further, unlike the holding structure for the inductance component in the conventional power supply device shown in Patent Document 1, it is not necessary to provide a large-sized protrusion on the metal flat plate 4.

  In the transformer according to the first embodiment, an I-type core is used as the core 2b, and the core 2b is positioned by the concave shape provided in the base plate 1. Further, by using an E-type core for the core 2a and positioning the printed circuit board 3 through the hole 2c, the assemblability can be improved. Further, by applying heat radiation grease between the core 2 b and the base plate 1, the heat dissipation can be further improved.

  As described above, since the power supply device according to the first embodiment does not require a protruding portion on the metal flat plate 4, the distance between the core 2a and the metal flat plate 4 is shortened, and the miniaturization can be realized. Moreover, when the said distance becomes short, the thickness of the heat-transfer sheet | seat 5 becomes thin, and a more favorable heat dissipation effect can be acquired because thermal resistance becomes small. Furthermore, since the protrusion of the metal flat plate 4 is not necessary, cost reduction can be realized.

  DESCRIPTION OF SYMBOLS 1 Base plate, 2a core (upper core), 2b core (lower core), 3 printed circuit board, 4 metal flat plate, 5 heat transfer sheet, 6 metal cover, 6a protrusion part, 7 screw

Claims (1)

A base plate;
A protrusion attached to the pace plate;
A metal flat plate held on the protrusion by screw fastening;
A lower core in contact with the base plate;
An upper core in contact with the lower core;
A printed circuit board that is disposed between the upper core and the lower core and forms a coil that forms an inductance component together with the upper core and the lower core;
A highly compressible heat transfer sheet disposed between the metal flat plate and the upper core and compressed by the screw fastening;
Power supply unit with

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