JP2001359280A - Power supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce exclusive space for a power supply apparatus, to improve heat radiation efficiency and to protect the other electronic components from noises generated by a transformer, etc. SOLUTION: Both a transformer and an inductor are, or one of them is, attached to a main circuit board, on which various electronic components are mounted. A heat radiation means and a sub-circuit board are erected on both the sides of both the transformer and the inductor or one of them. The heat radiation means and the sub-circuit board are bridged by a heat radiating metal member, above both the transformer and the inductor or one of them and both the transformer and the inductor are, or one of them is, surrounded by the main circuit board, the heat radiation means, the sub-circuit board and the heat radiating metal member on four sides. A switching semiconductor device is attached to the heat-radiating metal member and a rectifying semiconductor device is attached to the heat-radiating means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device that surrounds four sides of a transformer by combining a main circuit board with a sub-circuit board or a heat radiation fin.

[0002]

2. Description of the Related Art Generally, except for a large-capacity power supply device, many electronic devices such as a switching semiconductor element, a diode, a capacitor, and a resistor are mounted on a circuit board. In this case, each electronic component is generally arranged on a circuit board in a planar manner. However, when the size of the circuit board is severely restricted, the main circuit board and the control circuit board are divided into a two-story structure, or the electronic terminals of the snubber circuit are connected to the lead terminals of the switching semiconductor element. Various structures have been proposed, such as those for fixing a snubber circuit board on which components are mounted.

[0003]

The switching frequency of a switching power supply has been increasing year by year, and the transformer has been considerably reduced in size due to improvements in core materials and the like. Until a few years ago, transformers were said to be the tallest of the electronic components mounted on circuit boards,
In recent years, in the case of a device having a relatively large output current, a radiating means such as a radiating fin for radiating heat generated by a switching semiconductor element or a diode on the secondary side is often taller than a transformer.

Accordingly, in such a case, the present invention arranges a part of electronic components in a space above the transformer in order to reduce the size of the main circuit board, thereby increasing the heat dissipation of the transformer and at the same time dissipating the heat of the heat dissipation means. It is a main object to provide a structure that surrounds a transformer in order to increase efficiency and minimize adverse effects of a switching noise generated by the transformer on a power supply circuit.

[0005]

Means for Solving the Problems Claim 1 of the present invention,
In order to solve the above-described problem, in a power supply device including a main circuit including a transformer and / or an inductor, a switching semiconductor element, and a diode, the transformer and / or the inductor are connected to various electronic devices. Attached to a main circuit board on which components are mounted, a heat dissipation means and a sub-circuit board are arranged on both sides of one or both of the transformer and the inductor so as to stand on the main circuit board, and the heat dissipation means and the sub-circuit board And bridging with a heat dissipating metal member above the transformer and / or the inductor,
The transformer and / or the inductor are surrounded by the main circuit board, the heat radiating means, the sub circuit board, and the heat dissipating metal member, and the switching semiconductor element is mounted on the heat dissipating metal member. And a power supply device in which a semiconductor element for use is attached to the heat radiating means.

According to a second aspect of the present invention, in order to solve the above problem, in the first aspect, the heat dissipating metal member is locked to the heat dissipating means and the sub-circuit board. Is provided.

According to a third aspect of the present invention, in order to solve the above problem, in the first or second aspect, an electronic component of a primary side circuit connected to the primary winding of the transformer is mounted. And a primary circuit board disposed above the heat-dissipating metal member and engaged with the sub-circuit board.

According to a fourth aspect of the present invention, there is provided a power supply device including a main circuit including at least one of a transformer and an inductor, a switching semiconductor element, and a diode. Mount one or both of the inductors on the main circuit board,
A letter-shaped sub-circuit metal substrate is placed on the main circuit board on either or both sides of the transformer and the inductor, and the upper side of the sub-circuit metal substrate is attached to the heat radiating means. Surrounding the transformer and / or the inductor with the main circuit board, the heat radiating means, and the sub-circuit metal board, mounting the switching semiconductor element on the sub-circuit metal board, and mounting the diode on the heat radiating means. A power supply device is provided.

According to a fifth aspect of the present invention, there is provided a power supply device according to the fourth aspect, wherein the switching semiconductor element is mounted on an electrical insulating layer on an upper side surface of the sub-circuit metal substrate. Things.

According to a sixth aspect of the present invention, there is provided a power supply device including a main circuit including at least one of a transformer and an inductor, a switching semiconductor element, and a diode. Both or one of the inductors is mounted on the main circuit board, and a U-shaped sub-circuit metal board composed of two side walls and an upper side is arranged on the main circuit board so as to surround the transformer, The switching semiconductor element is attached to an upper side of the sub-circuit metal board located above and / or one of the transformer and the inductor, and an electronic component forming a snubber circuit of the switching semiconductor element is mounted on one of the sub-circuit metal boards. And a power supply device in which the diode is mounted on the other side wall of the sub-circuit metal substrate. .

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, in the sixth aspect, the switching semiconductor element and the diode are provided in an area where a metal surface of the sub-circuit metal substrate is covered with an electric insulating layer. A power supply device to which one or both are attached is provided.

[0012] An eighth aspect of the present invention is directed to any one of the first to seventh aspects in order to solve the above problem.
The main circuit board surrounding the four sides of the transformer, the heat radiating means, the sub-circuit board, and the heat radiating metal member form a wind tunnel, and a power supply device is provided in which a heat radiating fan is located in front of or behind the wind tunnel. Things.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, FIG. 1 shows a circuit example of a general single-ended type power supply. A primary winding N1 of a transformer T includes a MOSFET Tr
1,... Trn are connected in parallel, and each MOSFE
.. Tn, between the source and the drain of the Tr.
n are connected in parallel. A plurality of rectifier diodes D1 and flywheeling diodes D2 connected in parallel are connected to the secondary winding N2 of the transformer T. Other electronic components are omitted.

FIG. 2 shows the structure of the power supply circuit shown in FIG. 1 according to one embodiment of the present invention, and 1 is a main circuit board on which various electronic components are directly mounted except for electronic components to be described later. Is a transformer corresponding to the transformer Tr in FIG.
It is mounted and connected on a circuit pattern of the main circuit board 1. Reference numeral 3 denotes a switching semiconductor element whose lead terminal 3a is connected to the circuit pattern of the sub-circuit board 4, and corresponds to the MOSFET Tr in FIG. Other MOS
The switching semiconductor elements corresponding to the FETs Tr2,..., Trn are mounted in a line in a row toward the back of the paper of the switching semiconductor element 3, although not shown. The sub-circuit board 4 is substantially upright with respect to the main circuit board 1 beside the transformer 2, and the transformer 2
On the side surface, a plurality of electronic components 5 constituting the snubber circuits S1,... Sn for each MOSFET shown in FIG. 1 are mounted and connected to a circuit pattern. The sub circuit board 4 is mechanically fixed to the main circuit board 1 by a plurality of connecting means 6 for connecting the circuit pattern to the circuit pattern of the main circuit board 1. However, the connecting means 6 may of course be provided with a fixing means only for mechanically fixing in addition to the means having the function of electrically and mechanically connecting.

The main body of the plurality of switching semiconductor elements 3 to which the lead terminals 4 a are fixed to the sub-circuit board 4 are screws,
Alternatively, a heat-dissipating metal plate 8 such as an aluminum plate having good heat conduction is attached by a first fixing means 7 such as caulking or press-fitting via an electric insulating sheet (not shown). The heat-dissipating metal plate 8 has an L-shape.
The short side of the character shape is fixed to the sub-circuit board 4 by a screw or a second fixing means 9 such as caulking or press-fitting.
The other side of the heat-dissipating metal plate 8 is fixed to the upper end of the heat-dissipating means 10 such as a heat-dissipating fin by a screw or a third fixing means 11 such as caulking or press-fitting. Then, a diode 12 corresponding to the rectifying diode D1 shown in FIG. 1 is screwed on the outer surface of the heat radiating means 10 via an electric insulating sheet (not shown) by a fourth fixing means 13 such as caulking or press fitting. The lead terminals 12a are fixed and connected to the circuit pattern of the main circuit board 1. Although not shown, if necessary, a diode corresponding to the flywheeling diode D2 shown in FIG. 1 is also fixed to the outer surface of the heat radiating means 10 via an electric insulating sheet.

Therefore, the transformer 2 has a main circuit board 1 and a sub circuit board 4
, The metal plate 8 for heat dissipation and the heat dissipation means 10, and these four members form an air tunnel. As shown in FIG. 3, the power supply housing wall 14 corresponding to the front or back of the wind tunnel
Is provided on the power supply housing wall portion opposite to the power supply housing wall where the heat release fan 15 is located by disposing the heat radiation fan 15 at a position corresponding to the air discharge hole. The air flowing into the housing from the vent hole is guided by the wind tunnel and is discharged to the outside by the radiating fan 15 at a relatively high flow rate. Therefore, the transformer 2 in the wind tunnel
In addition, not only the electronic components 5 forming the snubber circuit but also the heat radiation efficiency of the heat radiation metal plate 8 and the heat radiation means 10 forming the wind tunnel are improved. In this embodiment, the transformer 2, the switching semiconductor element 3, the rectifier diode 12, and the electronic components 5 forming the snubber circuit, etc., which generate a particularly large amount of heat, are located in the wind tunnel or the heat-dissipating metal plate 8 forming the wind tunnel, Since it is fixed at 10, the temperature rise of the power supply device can be greatly restricted.

Further, the transformer 2 which is a source of large switching noise in the power supply device is housed in the wind tunnel, and is mounted on the main circuit board 1 by the heat dissipating metal plate 8 and the heat dissipating means 10. Since various electronic components are protected from noise generated by the transformer 2, the possibility that electronic components such as semiconductor ICs malfunction due to noise can be reduced. Although the sub circuit board 4 does not have a noise shielding function, there is no problem because the sub circuit board 4 is located at one end of the main circuit board 1 and there are no electronic components on the right side of the sub circuit board 4 in the drawing. In this embodiment, if there is a space in the wind tunnel due to a difference in height between the transformer 2 and the heat radiation means 10, the switching semiconductor element 3 may be located in the wind tunnel.

The second embodiment shown in FIG. 4 uses a sub-circuit metal substrate 14 made of a metal material bent at substantially 90 degrees as the sub-circuit substrate, and also serves as the heat-dissipating metal plate 8 shown in FIG. It is characterized by having. A circuit pattern is formed on the vertical portion 14a of the sub-circuit metal substrate 14 similarly to the heat-dissipating metal plate 8 shown in FIG. Its vertical part 1
The lower portion of 4a is electrically and mechanically connected to the main circuit board 1 by connection means 6. Sub circuit metal substrate 1
An electric insulating layer (not shown) is formed on the horizontal portion 14b only in the area where the switching semiconductor element 3 is mounted. Alternatively, although not shown, a thick surface copper foil layer to which the lead terminals of the switching semiconductor element 3 are brazed may be formed on an electric insulating layer extending to the vertical portion 14a. Of course, this surface copper foil layer is
Circuit pattern. And the horizontal part 1
4b is fixed to the heat radiating means 10 by the fixing means 11 as in the first embodiment. As a result, a wind tunnel surrounding the four surroundings of the transformer 2 is formed, and the same effect as described above can be obtained.

In this embodiment, the step of mechanically connecting the sub-circuit board 4 and the heat dissipating metal plate 8 as in the first embodiment becomes unnecessary, and the switching semiconductor element 3 is connected to the sub-circuit metal board 14. And electronic components for the snubber circuit are mounted, so that they can be handled as one component, which is practically convenient.

Next, in a third embodiment shown in FIG. 5, a sub-circuit metal substrate 24 made of a metal material bent in a U-shape is used as the sub-circuit substrate, and the heat-dissipating metal plate of the first embodiment is used. 8 and the heat radiating means 10. As in the above-described embodiment, an electronic component 5 constituting a snubber circuit or the like is connected to one vertical portion, and a diode 12 corresponding to the rectifier diode D1 in FIG.
Are attached by a fixing means via an electrically insulating layer.
In addition, the switching semiconductor element 3 and other electronic components (not shown) are attached to the horizontal portion by a fixing means via an electric insulating layer as required, and are connected to a circuit pattern. In FIG. 5, the lead terminal 1 of the diode 12 is shown.
2a is connected to the circuit pattern of the main circuit board 1, but the surface copper foil layer (not shown) of the sub-circuit metal board 24
May be connected. It is also possible to use a surface-mount type switching semiconductor element 3 or diode 12 and solder it to an electrode pad (not shown) formed on a thick circuit pattern of the sub-circuit metal substrate 24. is there.

FIG. 6 shows a basic circuit configuration of a general boost converter. In place of a power supply having a circuit configuration as shown in FIG.
Similar effects can be obtained by applying the present invention to a boost converter as shown in the figure. The same symbols as those shown in FIG. 1 indicate the corresponding members. When the current capacity is substantially the same, the inductor L has substantially the same size as the transformer 2 in FIG. 1 and the switching semiconductor element Tr generates substantially the same heat.
The heat radiating means (not shown) of the switching semiconductor element Tr may be taller than the inductor L. In such a case, the structure shown in FIGS. 2 to 5 can be used for the inductor L as described above.

[0022]

As described above, according to the present invention, the space above the transformer or the inductor can be used effectively, so that the space occupied by the power supply can be reduced, and the wind tunnel is formed around the four surroundings of the transformer or the inductor. As a result, the heat radiation efficiency can be improved, and at the same time, other electronic components can be protected from the generated noise.

[Brief description of the drawings]

FIG. 1 shows an example of a general power supply circuit.

FIG. 2 is a diagram for explaining one embodiment of a power supply device according to the present invention.

FIG. 3 is a partial cross-sectional view for explaining a structure of a power supply device according to the present invention.

FIG. 4 is a diagram for explaining another embodiment of the power supply device according to the present invention.

FIG. 5 is a diagram for explaining another embodiment of the power supply device according to the present invention.

FIG. 6 is a diagram showing an example of another power supply circuit to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main circuit board 2 ... Transformer 3 ... Switching semiconductor element 4 ... Sub-circuit board 5 ... Electronic components 6 ... Connection means 7, 9, 11, 13 ... Fixed Means 8: Heat dissipating metal plate 10: Heat dissipating means 12: Diode 14: Power supply housing wall 16: Heat dissipating fan

Claims (8)

[Claims] 1. A power supply device comprising a main circuit including at least one of a transformer and an inductor, a switching semiconductor element, and a diode, wherein various electronic components include at least one of the transformer and the inductor. Attached to the mounted main circuit board, a heat radiating means and a sub circuit board are arranged on both sides of one or both of the transformer and the inductor so as to stand on the main circuit board, and the heat radiating means and the sub circuit board are A bridge is formed by a heat dissipating metal member above and / or the transformer and / or the inductor, so that the transformer and / or the inductor are connected to the main circuit board, the heat dissipating means, the sub circuit board and the heat dissipating means. And the switching semiconductor element is attached to the heat dissipating metal member, and the rectifying semiconductor element is attached to the heat dissipating means. The power supply device, characterized in that was. 2. The power supply device according to claim 1, wherein the heat dissipating metal member is locked to the heat dissipating means and the sub-circuit board. 3. The heat dissipation metal member according to claim 1, wherein a primary circuit board on which electronic components of a primary circuit connected to the primary winding of the transformer are mounted. A power supply device disposed above and engaged with the sub-circuit board. 4. A transformer and / or an inductor.
A power supply device having a main circuit including a switching semiconductor element and a diode, wherein at least one of the transformer and the inductor is mounted on a main circuit board, and a heat radiating means and an inverted L-shaped sub-circuit metal board are mounted on the main circuit board. And both sides of one or both of the transformer and the inductor are arranged so as to stand on the main circuit board, and the upper side of the sub-circuit metal board is attached to the heat radiating means, and both or one of the transformer and the inductor is mounted. A power supply, wherein the four sides are surrounded by the main circuit board, the heat radiating means, and the sub-circuit metal board, the switching semiconductor element is mounted on the sub-circuit metal board, and the diode is mounted on the heat radiating means. apparatus. 5. The power supply device according to claim 4, wherein the switching semiconductor element is mounted on an electrical insulating layer on an upper side surface of the sub-circuit metal substrate. 6. A transformer and / or an inductor.
A power supply device including a main circuit including a switching semiconductor element and a diode, wherein at least one of the transformer and the inductor is mounted on a main circuit board, and a U-shape including two side walls and an upper side is provided. A sub-circuit metal substrate is arranged on the main circuit board so as to surround the transformer, and the switching semiconductor element is disposed on an upper side of the sub-circuit metal substrate located above at least one of the transformer and the inductor. Mounting, an electronic component forming a snubber circuit of the switching semiconductor element is mounted on one side wall of the sub-circuit metal substrate, and the diode is mounted on the other side wall of the sub-circuit metal substrate. Power supply. 7. The power supply according to claim 6, wherein one or both of the switching semiconductor element and the diode are attached to a surface area of a metal surface of the sub-circuit metal substrate covered with an electric insulating layer. apparatus. 8. The heat circuit according to claim 1, wherein the main circuit board surrounding the four sides of the transformer, the heat radiating means, the sub circuit board, and the metal member for heat radiating form a wind tunnel. A power supply device, wherein a heat dissipation fan is located in front of or behind a wind tunnel.