JP4775108B2 - Power electronics - Google Patents

Description

  The present invention relates to a power electronic device intended for a switching power supply, an inverter, a power factor correction circuit, and the like, and more particularly to a cooling structure for a heat generating component such as a power semiconductor element, a transformer, and a reactor constituting the circuit.

  As is well known, switching power supplies such as DC-DC converters, inverters, and power factor correction circuit devices include power semiconductor elements (switching elements such as IGBTs), high-frequency transformers, electromagnetic components such as reactors, rectifier diodes, and smoothing capacitors. These components are mounted on a printed board and housed in a housing.

  Here, in the configuration of the conventional power electronic device, a heat sink is attached to the power semiconductor element that is a heat generating component so as to dissipate the heat generated by the semiconductor element, and the heat generating component such as a transformer and a reactor is cooled in the housing. The wind is guided and cooled (see, for example, Patent Document 1), and the assembly structure of the main part is shown in FIG. 2 as a schematic diagram.

2A and 2B, 1 is a power semiconductor element (switching element) 1 a is a terminal lead of the semiconductor element 1, 2 is a heat sink for heat dissipation attached to the power semiconductor element 1, and 2 a is formed on the heat sink 2. The radiation fins 3 are electromagnetic parts of a transformer (or reactor) in which a winding (primary winding) 3b and a winding (secondary winding) 3c are wound around a magnetic body (for example, a cylindrical toroidal core) 3a. Is a printed circuit board on which the power semiconductor element 1 and the electromagnetic component 3 are mounted, and 5 is a heat transfer paste applied to the overlapping surface between the semiconductor element 1 and the heat sink 2, as shown by the arrows in the figure for this circuit assembly. Cooling air is blown to cool the heat generating parts.
Japanese Patent Laid-Open No. 11-346069 (page 1-2, FIG. 1)

  By the way, the above-described conventional cooling method has the following problems in terms of cooling performance. That is, the power semiconductor element 1 is provided with a heat sink 2 made of a metal such as aluminum having high thermal conductivity, so that a high cooling capacity can be secured. However, an electromagnetic component 3 such as a transformer, a reactor, etc. 3a has an iron loss and windings 3b and 3c have a copper loss), and the cooling efficiency is lower than that of the semiconductor element 1. Therefore, conventionally, the magnetic component 3a having a large iron core cross-sectional area is used for the electromagnetic component 3, and the windings 3b and 3c are formed of strands having a large wire diameter. Although measures are taken to suppress the increase, the electromagnetic component 3 is increased in size and cost.

  The present invention has been made in view of the above points, and a power electronic device having an improved assembly structure capable of effectively cooling heat-generating components such as a transformer and a reactor by skillfully utilizing a heat sink attached to a power semiconductor element. The purpose is to provide.

To achieve the above object, according to the present invention, in a power electronic device including a power semiconductor element and electromagnetic components such as a transformer and a reactor, a heat sink is combined with the power semiconductor element to dissipate heat generated by the semiconductor element. In what I did,
Shall heat transfer coupling the electromagnetic component to the heat sink, the concrete constituting in the manner as follows follow.
(1) Using the magnetic body of the electromagnetic component as a wound iron core, an extension is formed on the heat sink, and the magnetic body of the electromagnetic component composed of the wound iron core is fitted into the extension of the heat sink to couple heat transfer to (claim 1).
(2) In the preceding item (1), the heat sink and the winding of the electromagnetic component are coupled in a heat transfer manner through an electrically insulating high thermal conductive material (claim 2).
(3) In the preceding item (1) or (2), the heat sink and the magnetic body of the electromagnetic component are coupled in a heat transfer manner through a high thermal conductive material ( Claim 3 ).
(4) In the preceding item (3), an electrically insulating heat transfer paste or heat transfer sheet is used as the high heat conductive material.
(5) In any one of the above (1) to (4), constitutes a winding of an electromagnetic component of the extension of the heat sink as a current path (claim 5).

  According to the above configuration, the heat generated by the electromagnetic component can be efficiently radiated to the heat sink by using the heat sink of the power semiconductor element. In addition, since the heat sink is shared by the semiconductor element and the electromagnetic component, it is not necessary to add a new cooling component, and the cost of the device can be reduced and the cooling performance can be improved as compared with the conventional cooling method.

  Further, by constructing the extension formed on the heat sink as a conductive path so as to also serve as the winding of the electromagnetic component, the assembly structure of the device is simplified.

  Hereinafter, an embodiment of the present invention will be described based on the example shown in FIG. In addition, in the figure of an Example, the same code | symbol is attached | subjected to the member corresponding to FIG. 2, and the description is abbreviate | omitted.

  That is, in the assembly structure of the illustrated embodiment, a heat sink (for example, made of aluminum) 2 attached to the upper surface of the power semiconductor element 1 is extended sideways, and leg portions that stand downward at both ends of the extension portion 2b. The terminal 2c, 2d is formed, and the leg-like terminal 2b, 2c is inserted into the through hole of the printed board 4 or screwed together with the terminal lead 1a of the semiconductor element 1. The extension 2b of the heat sink 2 is formed by removing the heat dissipating fins 2a at the intermediate portion, and then fitting a magnetic body 3a to be a split wound core (toroidal core) into the extension 2b. The electromagnetic component (transformer) 3 is configured with the portion 2b as a primary winding and the winding 3c wound around a magnetic body (toroidal core) 3b as a secondary winding.

  And with respect to the said circuit assembly, between the extension part surrounding surface of the heat sink 2, the magnetic body 3a of the electromagnetic component 3, and the coil | winding 3c, an electrically insulating heat-transfer paste (as a heat-transfer material with high heat conductivity) ( Alternatively, a soft plastic heat transfer sheet) 5 is filled without gaps, and the heat generated by the electromagnetic component 3 is transferred to the heat sink 2 via the heat transfer paste 5 to be dissipated.

  According to the above assembly structure, the heat (iron loss of the magnetic body 3a, copper loss of the winding 3c) generated in the electromagnetic component 3 due to energization can be dissipated to the heat sink 2, whereby the power semiconductor element 1 Similarly, the electromagnetic component 3 can be efficiently cooled to suppress a transient temperature rise.

  In the illustrated embodiment, the primary winding of the electromagnetic component (transformer) 3 is configured by using the extended portion 2b of the heat sink 2 as a conductive path with a terminal. However, the present invention is not limited to this structure. Of course, the electromagnetic component (transformer) 3 may be formed by winding the winding 3b around the magnetic body 3a in the same manner as the electromagnetic component 3 shown in FIG. Moreover, when the electromagnetic component 3 is a reactor, the winding wound around the magnetic body 3a is set as one set.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembly structure diagram schematically showing a main part of a power electronic device according to an embodiment of the present invention, wherein (a) and (b) are a side view and a plan view, respectively. FIG. 2 is an assembly structure diagram schematically showing main parts of a conventional power electronic device, where (a) and (b) are a side view and a plan view, respectively.

DESCRIPTION OF SYMBOLS 1 Power semiconductor element 2 Heat sink 2b Extension part 3 Electromagnetic component 3a Magnetic body 3b, 3c Winding 4 Printed board 5 Heat-transfer paste (electrically insulating high heat conductive material)

Claims (5)

Power semiconductor device, and a transformer, a power electronic device equipped with a magnetic component, such as a reactor, in that so as to radiate the heat generated by the semiconductor element by combining a heat sink in power semiconductor devices, magnetic properties of the electromagnetic component A power electron comprising: a body as a wound iron core; an extension portion formed in the heat sink; and a magnetic body of an electromagnetic component composed of the wound iron core fitted into the extension portion of the heat sink to couple heat conductively machine. 2. The power electronic device according to claim 1, wherein the heat sink and the winding of the electromagnetic component are thermally coupled through an electrically insulating heat transfer material. 3. The power electronic device according to claim 1, wherein the heat sink and the magnetic body of the electromagnetic component are thermally coupled through a heat transfer material. 4. 4. The power electronic device according to claim 3, wherein the heat transfer material is a heat transfer paste or a heat transfer sheet having high thermal conductivity. 5. The power electronic device according to claim 1, wherein a winding of an electromagnetic component is formed by using an extension portion of the heat sink as an energizing path. 6.

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