JP2016119395A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device capable of enhancing heat dissipation of a heating component, while reducing noise.SOLUTION: A power supply device includes a substrate mounting one or a plurality of heating components such as a FET, a diode, a transformer and a coil, a fixing member for fixing the substrate, and a lid attached to the fixing member and covering the substrate. The lid can be attached to the fixing member. An electromagnetic shield is provided between the lid and heating component. The electromagnetic shield is configured to cover the periphery of a heating component, especially a component becoming a noise generation source, such as a switching element.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power supply device including one or a plurality of heat generating components.

  A power supply device such as a DC / DC converter has a heat generating component such as a circuit board, a switching element such as an FET and a diode mounted on the circuit substrate, or a heat generating component such as a transformer or a choke coil. In order to improve the reliability of the power supply device, it is important to take measures against heat radiation of such heat generating components.

  For example, a component carrier configured to include a heat generating component mounted on a wiring board, a heat sink attached to the component carrier so as to be able to transfer heat, and a case for accommodating the wiring board and the component carrier by exposing the heat sink to the surface An electronic control device for a vehicle is disclosed (see Patent Document 1).

JP 2005-251861 A

  However, in the apparatus of Patent Document 1, the case only has an opening for exposing the heat sink, and hardly contributes to heat dissipation measures for the heat-generating component. On the other hand, it is conceivable to use a case as a heat dissipation measure for heat-generating components mounted on a circuit board, but because there are various shapes and sizes of heat-generating components, some heat-generating components could be dissipated in the case. However, it is insufficient for heat dissipation measures for other heat-generating components having different shapes and sizes. Further, no consideration is given to noise generated from heat-generating components such as switching elements.

  This invention is made | formed in view of such a situation, and it aims at providing the power supply device which can improve the thermal radiation of a heat-emitting component, reducing a noise.

  A power supply device according to an embodiment of the present invention includes a substrate on which one or a plurality of heat generating components are mounted, a fixing member that fixes the substrate, and a lid that is attached to the fixing member and covers the substrate. It is an apparatus, Comprising: An electromagnetic shielding part is provided between the said cover part and the said heat-emitting component.

  According to the present invention, it is possible to improve the heat dissipation of the heat-generating component while reducing noise.

It is explanatory drawing which shows an example of the circuit structure of the power supply device of this Embodiment. It is principal part sectional drawing which shows the 1st Example of the structure of the power supply device of this Embodiment. It is a schematic diagram which shows the example of fixation with the cover and electromagnetic shielding part of the power supply device of this Embodiment. It is a cross-sectional view which shows an example of the structure of the electromagnetic shielding part of the power supply device of this Embodiment. It is principal part sectional drawing of the electromagnetic shielding part vicinity of the power supply device of this Embodiment. It is principal part sectional drawing which shows the 2nd Example of the structure of the power supply device of this Embodiment.

[Description of Embodiment of Present Invention]
(1) A power supply device according to an embodiment of the present invention includes a substrate on which one or more heat generating components are mounted, a fixing member that fixes the substrate, a lid that is attached to the fixing member and covers the substrate. A power supply device comprising: an electromagnetic shield part between the lid part and the heat generating component.

  The power supply device includes a substrate on which one or a plurality of heat generating components are mounted, a fixing member that fixes the substrate, and a lid that is attached to the fixing member and covers the substrate. The heat generating component is, for example, a switching element such as an FET or a diode, or a component such as a transformer or a choke coil. The power supply device includes an electromagnetic shield portion between the lid portion and the heat generating component. The electromagnetic shield part can be configured to cover one or a plurality of heat generating components. When the lid portion is attached to the fixing member, the lid portion can be brought into thermal contact with the heat-generating component via the electromagnetic shield portion. Moreover, since the electromagnetic shield part is provided between the cover part and the heat-generating component, noise generated from the heat-generating component (for example, high-frequency noise due to switching) is shielded and leaked to the outside. Can be reduced. Furthermore, since the heat generating component comes into thermal contact with the lid portion via the electromagnetic shield portion, heat from the heat generating component can be released to the outside using the lid portion (particularly the entire lid portion). The heat dissipation of the heat generating component can be improved.

(2) In the power supply device according to the embodiment of the present invention, the plurality of heat generating components have different separation dimensions from the surface of the substrate, and the electromagnetic shield portion is formed from the surface of the substrate of the plurality of heat generating components. It has a different thickness according to the separation dimension.

  The plurality of heat generating components have different separation distances from the surface of the substrate, and the electromagnetic shield portion has a different thickness according to the distance between the plurality of heat generation components from the surface of the substrate. For example, when the height dimension of the heat-generating component from the board surface is relatively large, the thickness of the electromagnetic shield part is reduced. When the height dimension of the heat-generating part from the board surface is relatively small, the electromagnetic shield part Increase the thickness. As a result, one or a plurality of heat-generating components can reduce noise at the electromagnetic shield part regardless of the shape and size (particularly the height dimension from the substrate surface), and the separation between the lid part and the substrate surface. Since a dimension can be made into a required dimension, a common cover part can be used irrespective of the shape and size of a heat-emitting component, and common use of components can be achieved.

  In addition, regardless of the height dimension of the heat generating component from the substrate surface, the heat generating component and the lid can be brought into heat conductive contact via the electromagnetic shield, so the cover (particularly the entire cover) is used. Thus, heat from the heat generating component can be released to the outside, and heat dissipation of the heat generating component can be improved.

(3) In the power supply device according to the embodiment of the present invention, the heat generating component and the electromagnetic shield portion are separated from each other, and an insulating sheet having elasticity is provided between the heat generating component and the electromagnetic shield portion. The thickness of the insulating sheet is larger than the distance between the heat generating component and the electromagnetic shield part.

  The heat generating component and the electromagnetic shield portion are separated from each other, and an insulating sheet having elasticity is provided between the heat generating component and the electromagnetic shield portion. And the thickness of an insulating sheet is larger than the separation dimension of a heat-emitting component and an electromagnetic shielding part. When an insulating sheet having a thickness larger than the distance between the heat generating component and the electromagnetic shield portion is mounted between the heat generating component and the electromagnetic shield portion, the elastic insulating sheet is pressed by the heat generating component and the electromagnetic shield portion. Thereby, the contact pressure between a heat-emitting component and a cover part can be increased, thermal resistance can be reduced, and the heat dissipation effect can be further improved.

(4) The power supply device according to the embodiment of the present invention includes a heat radiating portion between the lid portion and the electromagnetic shield portion.

  A heat radiating portion is provided between the lid portion and the electromagnetic shield portion. For example, a metal sheet, an insulating sheet, or the like can be used for the heat dissipation unit. Thereby, the heat dissipation effect from an electromagnetic shielding part to a cover part can be heightened.

[Details of the embodiment of the present invention]
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments. FIG. 1 is an explanatory diagram illustrating an example of a circuit configuration of the power supply apparatus 100 according to the present embodiment. Hereinafter, a DC / DC converter will be described as an example of the power supply device 100 of the present embodiment. However, the present embodiment is not limited to the DC / DC converter, and may have a heat generating component. For example, the present invention can be applied to other power supply devices, electric devices, or electronic devices. That is, the power supply device of this embodiment includes an electric device and an electronic device having a heat generating component.

  In FIG. 1, reference numeral 1 indicates an input terminal, and reference numeral 2 indicates an output terminal. The power supply apparatus 100 converts a relatively high DC voltage input to the input terminal 1 into a relatively low DC voltage, and outputs it from the output terminal 2.

  The power supply apparatus 100 includes a capacitor 11, four FETs 10, a control unit 12 that controls switching of the FET 10, a transformer 13, two diodes 14, a coil (also referred to as a choke coil) 15, a capacitor 16, and the like. Each FET 10, each diode 14, transformer 13, coil 15, and the like are heat generating components. Further, the input side of the transformer 13 is referred to as a primary side, and the output side is referred to as a secondary side. In the transformer 13, the input side and the output side are electrically insulated, and the primary side and the secondary side are electrically insulated.

  When the control unit 12 controls the on / off of each FET 10 at a required switching frequency, an alternating current is generated in the primary winding of the transformer 13. The alternating current stepped down by the transformer 13 is rectified by the diode 14, smoothed by the coil 15 and the capacitor 16, and direct current is output via the output terminal 2.

  FIG. 2 is a cross-sectional view of an essential part showing a first example of the structure of the power supply apparatus 100 of the present embodiment. In FIG. 2, reference numeral 20 denotes a metal housing 20 as a fixing member. Note that the casing 20 may be made of a synthetic resin having heat dissipation characteristics, for example, polyphenylene sulfide (PPS) resin, polycarbonate (PC) resin, or the like, if required strength can be ensured. An input terminal 1 and an output terminal 2 are provided at both ends of the housing 20 via insulating parts (not shown).

  The substrate 31 is mounted with an FET 10 and a diode 14 as heat-generating components. Further, another electronic component 311 having a relatively small amount of heat generation is mounted on the substrate 31. A bus bar 32 is arranged on the surface opposite to the mounting surface of the substrate 31. The bus bar 32 is made of metal, for example, and a metal case of the FET 10 and the diode 14 is attached thereto. An insulating sheet 33 is interposed between the bus bar 32 and the housing 20. When the FET 10 and the diode 14 are fixed on the substrate 31, the bus bar 32 may be omitted. The substrate 31, the bus bar 32, and the insulating sheet 33 are fixed to the housing 20.

  A transformer 13 and a coil 15 are mounted on the surface of the housing 20. Note that the transformer 13 and the coil 15 may be mounted on the substrate 31.

  The cover 40 serving as a lid is made of metal, and can cover the substrate 31, the transformer 13, the coil 15, the input terminal 1, the output terminal 2, and the like. The cover 40 may be made of a synthetic resin having heat dissipation characteristics, such as polyphenylene sulfide (PPS) resin or polycarbonate (PC) resin. The cover 40 can be attached to the housing 20 by tightening the screw 62. The method of attaching the cover 40 to the housing 20 is not limited to the screw 62, and the cover 40 may be fitted into the housing 20 or may be fitted.

  An electromagnetic shield 51 is provided between the cover 40 and the FET 10. Further, an electromagnetic shield part 52 is provided between the cover 40 and the diode 14. The electromagnetic shield 51 may be configured to individually cover each FET 10 or may be configured to cover a plurality of FETs 10 together. Moreover, the electromagnetic shield part 52 may be comprised so that each diode 14 may be covered individually, and you may comprise so that the several diode 14 may be covered collectively. That is, the electromagnetic shield portions 51 and 52 can be configured to cover one or a plurality of heat generating components.

  When the cover 40 is attached to the housing 20, the cover 40 can be brought into thermal conductive contact with the FET 10 and the diode 14 via the electromagnetic shield portions 51 and 52. Further, since the electromagnetic shield portions 51 and 52 are provided between the cover 40 and the FET 10 and the diode 14, noise (for example, high frequency noise due to switching) generated from the FET 10 and the diode 14 is shielded and leaked to the outside. This can suppress noise and reduce noise. Furthermore, since the FET 10 and the diode 14 are in heat conductive contact with the cover 40 via the electromagnetic shield portions 51 and 52, the heat from the heat-generating component is transferred to the outside using the cover 40 (particularly the entire cover 40). The heat can be released and the heat dissipation of the heat-generating component can be improved.

  An insulating sheet 36 is provided between the transformer 13 and the cover 40, and an insulating sheet 38 is provided between the coil 15 and the cover 40. The insulating sheets 35 to 38 have a function of insulating the primary side and the secondary side of the power supply device 100.

  Further, the plurality of heat generating components have different separation dimensions from the surface of the substrate 31, and the electromagnetic shield portions 51 and 52 have different thicknesses according to the separation dimensions of the plurality of heat generating components from the surface of the substrate 31.

  As shown in FIG. 2, assume that the height dimension of the FET 10 from the surface of the substrate 31 is h1, the height dimension of the diode 14 from the surface of the substrate 31 is h2, and h1> h2. In this case, the thickness of the electromagnetic shield 51 with respect to the FET 10 (more precisely, the thickness between the cover 40 and the insulating sheet 35 of the electromagnetic shield 51) is t1, and the thickness of the electromagnetic shield 52 with respect to the diode 14 (more accurately). In this case, if the thickness between the cover 40 and the insulating sheet 37 of the electromagnetic shield portion 52 is t2, t1 <t2.

  That is, when the height dimension of the heat generating component from the surface of the substrate 31 is relatively large, the thickness of the electromagnetic shield portion is reduced, and when the height dimension of the heat generating component from the surface of the substrate 31 is relatively small. Increase the thickness of the electromagnetic shield. As a result, the one or more heat generating components can reduce noise by the electromagnetic shield portions 51 and 52 regardless of the shape and size (particularly the height dimension from the substrate surface), and the cover 40 and the substrate 31. The distance from the surface can be a required dimension. In the example of FIG. 2, since the thickness of the electromagnetic shield is adjusted so that (t1 + h1) = (t2 + h2), the common cover 40 (for example, the top of the cover 40) can be used regardless of the shape and size of the heat generating component. The plate can be made flat, and the parts can be shared.

  In addition, the heat generating component and the cover 40 can be brought into heat conductive contact via the electromagnetic shield portion regardless of the height dimension of the heat generating component from the surface of the substrate 31. Therefore, the cover 40 (particularly the entire cover 40). The heat from the heat-generating component can be released to the outside by using the so that heat dissipation of the heat-generating component can be improved.

  FIG. 3 is a schematic diagram showing an example of fixing the cover 40 and the electromagnetic shield part 51 of the power supply apparatus 100 of the present embodiment, and FIG. 4 is an example of the structure of the electromagnetic shield part 51 of the power supply apparatus 100 of the present embodiment. FIG. In FIG. 4, reference numeral 101 denotes a connection terminal of the FET 10, and the connection terminal 101 is electrically connected to a circuit pattern (not shown) on the substrate 31. 3 and 4 exemplify only the electromagnetic shield 51, the method for fixing the electromagnetic shield 52 to the cover 40 is the same. As shown in FIGS. 3 and 4, the electromagnetic shield 51 has a box shape with an opening on one side, and can accommodate the FET 10 inside so as to cover the FET 10 mounted on the substrate 31 from the periphery and the upper side. Make.

  The electromagnetic shield 51 can be fixed to the cover 40 by inserting a screw 61 through an insertion hole (not shown) provided in the cover 40 and screwing it into the screw hole of the electromagnetic shield 51. By fixing the cover 40 to which the electromagnetic shield portions 51 and 52 are fixed to the housing 20, the heat generating component is pressed by the cover 40, and the heat of the heat generating component is changed to the insulating sheets 35 to 38, the electromagnetic shield portions 51 and 52, and the like. Can be conducted to the cover 40 through the cover, and heat can be radiated by the cover 40 as a whole.

  Moreover, since the electromagnetic shield parts 51 and 52 cover the circumference | surroundings of FET10 and the diode 14, respectively, it can suppress that noise leaks outside simultaneously with heat dissipation.

  FIG. 5 is a cross-sectional view of the main part in the vicinity of the electromagnetic shield 51 of the power supply device 100 according to the present embodiment. As shown in FIG. 5, the FET 10 as the heat generating component and the electromagnetic shield part 51 are separated by an appropriate length (dimension indicated by reference sign d), and the insulating sheet 35 having elasticity between the FET 10 and the electromagnetic shield part 51. Is provided. The thickness of the insulating sheet 35 (the dimension indicated by the symbol t) is larger than the separation dimension d of the FET 10 and the electromagnetic shield part 51. When the insulating sheet 35 thicker than the separation dimension d of the FET 10 and the electromagnetic shielding part 51 is mounted between the FET 10 and the electromagnetic shielding part 51, the insulating sheet 35 having elasticity is pressed by the FET 10 and the electromagnetic shielding part 51. The Thereby, the contact pressure between FET10 and the electromagnetic shielding part 51 can be increased, a thermal resistance can be made small and the thermal radiation effect can be improved further.

  FIG. 6 is a cross-sectional view of an essential part showing a second example of the structure of the power supply device 100 of the present embodiment. The difference from the first embodiment illustrated in FIG. 2 is that heat dissipating parts 53 and 54 are provided. As shown in FIG. 6, in the second embodiment, a heat radiating portion 53 is mounted between the cover 40 and the electromagnetic shield portion 51, and a heat radiating portion 54 is mounted between the cover 40 and the electromagnetic shield portion 52. It is. For example, a metal sheet, an insulating sheet, or the like can be used for the heat radiation units 53 and 54. Thereby, the heat dissipation effect from the electromagnetic shield parts 51 and 52 to the cover 40 can be enhanced.

  As described above, according to the present embodiment, since not only the housing 20 but also the cover 40 can be used as a heat dissipation path as a heat dissipation path for the heat generating component, the heat dissipation effect can be improved, and the power supply device The overall size can be reduced. In addition, among the heat generating components, components that generate noise, such as switching elements, are covered with an electromagnetic shield portion, and the electromagnetic shield portion is thermally conductively fixed to the cover 40, so that noise reduction and heat dissipation measures are taken. Can also be done. Further, even if the height dimension of the heat generating component mounted on the substrate 31 or the housing 20 is different, the thickness of the electromagnetic shield is varied according to the height dimension of the heat generating component, so that the required heat generating component The cover 40 can be brought into thermal contact with the cover 40, and a heat dissipation measure for all necessary heat generating components can be realized by the cover 40. Further, each heat-generating component can be brought into thermal contact with the cover 40 to increase the heat radiation area. Furthermore, the cover 40 can be formed in a simple shape such as a flat top plate, for example, and can be shared.

  The embodiments and examples disclosed above should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments and examples but by the scope of claims, and is intended to include all modifications and variations within the meaning and scope equivalent to the scope of claims. .

1 Input terminal 2 Output terminal 10 FET (Heat generation component)
11, 16 Capacitor 12 Control unit 13 Transformer (heat generating component)
14 Diode (heat generation component)
15 Coil (Heat generation part)
20 Housing (fixing member)
31 Substrate 32 Bus bar 33 Insulating sheet 35, 36, 37, 38 Insulating sheet 40 Cover (lid)
51, 52 Electromagnetic shield part 53, 54 Heat radiation part

Claims (4)

A power supply device comprising: a substrate on which one or a plurality of heat generating components are mounted; a fixing member that fixes the substrate; and a lid that is attached to the fixing member and covers the substrate,
A power supply apparatus comprising an electromagnetic shield part between the lid part and the heat generating component. The plurality of heat generating components have different separation dimensions from the surface of the substrate,
The electromagnetic shield part is
2. The power supply device according to claim 1, wherein the plurality of heat generating components have different thicknesses according to a separation dimension from a surface of the substrate. The heat generating component and the electromagnetic shield part are separated from each other,
An insulating sheet having elasticity between the heat-generating component and the electromagnetic shield part;
3. The power supply device according to claim 1, wherein a thickness of the insulating sheet is larger than a distance between the heat generating component and the electromagnetic shield part. The power supply device according to any one of claims 1 to 3, further comprising a heat radiating portion between the lid portion and the electromagnetic shield portion.

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