JP5896928B2 - Coil device - Google Patents

Description

  The present invention relates to a coil device used for a power supply device or a transformer.

  A coil device used for a power supply device, a transformer, or the like may be configured with a coil using a printed wiring board in order to reduce the thickness of a magnetic component. In this case, there is a problem that the printed wiring board is heated by the heat generated by the coil, and may exceed the heat resistance temperature of the printed wiring board. Conventionally, as a countermeasure for such a problem, an apparatus has been proposed in which heat generated in a printed wiring board constituting a coil is radiated to a housing through an insulating sheet having heat dissipation (for example, Patent Document 1).

JP 2011-77328 A

  However, the conventional device disclosed in Patent Document 1 is generated from the coil pattern of the printed wiring layer other than the lowest printed wiring layer closest to the housing when the coil pattern of the coil device is provided over a plurality of layers. Heat is dissipated to the housing through the base material of the printed wiring board, but generally the base material of the printed wiring board has a low heat transfer coefficient and cannot efficiently transmit heat. For example, a printed wiring board including a coil pattern may have to be formed of a base material having high heat resistance.

  In this case, there is a problem that the cost of the entire apparatus is increased compared to the case where a normal heat-resistant base material is used for the printed wiring board, and the control circuit is a printed wiring board using a normal heat-resistant base material. However, there is a problem that additional cost and mounting space are required for a member used to connect two substrates, a substrate including a coil pattern and a substrate including a control circuit. .

  The present invention has been made to solve the above-described problems in the conventional coil device, and is generated in a layer other than the lowest layer when the coil device is constituted by a coil pattern formed on a printed wiring board. An object of the present invention is to provide a coil device that can efficiently dissipate the generated heat to the metal casing.

The coil device according to the present invention comprises :
A coil device comprising: a metal casing; a core portion fixed to the metal casing; and a printed wiring board that is magnetically coupled to the core portion and has a coil pattern used as a coil winding. There,
The printed wiring board is composed of at least two printed wiring layers of a lowermost layer disposed closest to the metal casing and a layer other than the lowermost layer,
The lowermost layer and the printed wiring layer other than the lowermost layer each include the coil pattern,
Each coil pattern of the printed wiring layer of the layer other than the lowermost layer and the lowermost layer is electrically connected via an electrical connection portion provided in each of the coil patterns ,
Before SL and the electrical connecting portion provided on the coil pattern of the bottom layer of the printed wiring layer, wherein the electrical connecting portion provided on the coil pattern of the printed wiring layer of the lowermost other layers may be overlaid directly And is connected by a through-hole penetrating each of the electrical connection portions, and dissipates heat between the electrical connection portion and the metal casing in the lowermost printed wiring layer. The sheet is placed ,
It is characterized by that.

According to the coil device according to the present invention, the printed wiring board is configured by at least two printed wiring layers including a lowermost layer disposed closest to the metal casing and a layer other than the lowermost layer, and the lowermost layer. The printed wiring layers other than the lowermost layer are each provided with the coil pattern, and the coil patterns of the printed wiring layers other than the lowermost layer and the lowermost layer are respectively provided in the respective coil patterns. are electrically connected via the connecting portion, the said electrical connection portion provided on the coil pattern of the bottom layer of the printed wiring layer, the provided coil pattern of the printed wiring layer of the lowermost other layers the The electrical connection portions are electrically connected by being directly stacked and connected by through holes penetrating the respective electrical connection portions. Runode heat radiation sheet is not disposed between the in the electrical connection to the layer and the metal housing, the through-hole and the heat radiating sheet heat generation caused by the coil pattern of at least the lowermost layer other than the printed wiring layer The heat can be radiated to the metal casing, and the heat can be effectively radiated, and a small and inexpensive coil can be obtained.

It is a perspective view which shows the coil apparatus by Embodiment 1 of this invention. It is a disassembled perspective view which shows the coil apparatus by Embodiment 1 of this invention. It is a disassembled perspective view which shows the coil apparatus by Embodiment 2 of this invention. It is a disassembled perspective view which shows the coil apparatus by Embodiment 3 of this invention.

  Hereinafter, the case where the coil apparatus of this invention is used for a power supply device is demonstrated based on drawing. In the figure, the same or corresponding parts are denoted by the same reference numerals. Of course, the coil device of the present invention can also be applied to a coil device of a transformer.

Embodiment 1 FIG.
1 is a perspective view showing a coil device according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view showing the coil device according to Embodiment 1 of the present invention. 1 and 2, a coil device 100 applied to a power supply device includes a metal casing 1 provided with heat radiating fins 80 and an E shape in which a bridge portion 21 described later is fixed to the metal casing 1. The core 2, the I-type core 3 that bridges the open portion of the E-type core 2, the printed wiring board 4, and the heat dissipating sheets 62 and 5 having insulation properties. The E-shaped core 2 and the I-shaped core 3 constitute a core portion 20 in the coil device 100.

The E-shaped core 2 bridges a cylindrical central leg portion 22, a pair of side leg portions 23 and 24 facing each other with the central leg portion 22 interposed therebetween, and the central leg portion 22 and the side leg portions 23 and 24. It is comprised from the bridge part 21 to do. The metal housing 1 includes projecting portions 60 and 6 (described later) formed upward with the core portion 20 in between.

The printed wiring board 4 is configured as a multilayer printed wiring board having two printed wiring layers of a lowermost printed wiring layer 401 disposed on the most metal casing 1 side and a printed wiring layer 402 other than the lowermost layer. Has been. The printed wiring layer 402 other than the lowermost layer is disposed on the lowermost printed wiring layer 401. Of course, the printed wiring board 4 is not limited to two layers, but may be a multiphase printed wiring board including at least the two layers described above.

  A coil pattern 8 and a coil pattern 7 are formed on the lowermost printed wiring layer 401 and the printed wiring layer 402 other than the lowermost layer constituting the printed wiring board 4, respectively. In the first embodiment, the printed wiring board 4 is composed of two printed wiring layers as described above, and the number of turns of the coil is two turns. A pair of through holes 11 for incorporating the pair of side legs 23 and 24 of the E-shaped core 2 in the lowermost printed wiring layer 401 constituting the printed wiring board 4 and the printed wiring layer 402 other than the lowermost layer, 12 is provided.

  The coil pattern 7 in the printed wiring layer 402 other than the lowest layer is formed from the coil end portion 41 to the winding end portion 72 via the winding start portion 71, and the central portion is formed by the central leg portion 22 of the E-shaped core 2. It is penetrated. The coil pattern 7 forms one turn of the coil. The winding start part 71 and the winding end part 72 of the coil pattern 7 exist on the same side with respect to the core part 20. An electrical connection portion 73 is provided at the winding end portion 72 of the coil pattern 7.

  The electrical connection portion 73 provided at the winding end portion 72 of the coil pattern 7 is electrically connected to the electrical connection portion 83 provided at the winding start portion 81 of the coil pattern 8 in the lowermost printed wiring layer 401. It is connected. The coil pattern 8 formed in the lowermost printed wiring layer 401 extends from the winding start portion 81 provided with the electrical connection portion 83 to the coil end portion 45 via the winding end portion 82. The central portion of the coil pattern 8 is penetrated by the central leg portion 22 of the E-shaped core 2. The coil pattern 8 forms one turn of the coil. The coil pattern 7 of the printed wiring layer 402 other than the lowermost layer and the coil pattern 8 of the printed wiring layer 401 of the lowermost layer are electrically connected by the respective electrical connection portions 73 and 83, so that a two-turn coil is formed. Will be composed.

  The electrical connection portion 73 of the coil pattern 7 and the electrical connection portion 83 of the coil pattern 8 are electrically connected by being overlapped. Furthermore, the electrical connection portion 73 of the coil pattern 7 and the electrical connection portion 83 of the coil pattern 8 are connected by a large number of through holes 44 penetrating them. These through holes 44 have an inner peripheral surface plated with copper and have good thermal conductivity.

The protrusion 60 formed on the metal housing 1 is provided at a position corresponding to the electrical connection portion 83 of the lowermost printed wiring layer 401. The protruding portion 6 formed in the metal casing 1 is provided at a position corresponding to the coil outer side portion 46 protruding from the core portion 20 of the lowermost printed wiring layer 401. The heat radiating sheet 62 is disposed between the electrical connection portion 83 and the surface of the protruding portion 60 in the lowermost printed wiring layer 401. The heat dissipating sheet 5 is disposed between the coil outer portion 46 and the surface of the protruding portion 6 in the lowermost printed wiring layer 401.

  In the coil device according to Embodiment 1 of the present invention configured as described above, when a current is passed through the coil patterns 7 and 8, the coil patterns 7 and 8 generate heat. The coil pattern 8 is formed on the lowermost printed wiring layer 401 of the printed wiring board 4, and the heat generated in the coil pattern 8 is an insulating heat dissipating sheet 62 disposed on the lower surface of the electrical connection portion 83. The heat is radiated to the projecting portion 60 of the metal casing 1 via.

  On the other hand, heat generated in the coil pattern 7 formed on the printed wiring layer 402 other than the lowermost layer is first transferred to the electrical connection portion 73. Next, the heat is transmitted to the electrical connection portion 83 of the lowermost printed wiring layer 401 through the through hole 44 and further radiated to the protruding portion 60 of the metal casing 1 through the heat radiation sheet 62. As described above, the inner surface of the through hole 44 is plated with copper and has good thermal conductivity.

In the coil device according to the first embodiment of the present invention, the coil outer portion 46 of the coil pattern 8 in the lowermost printed wiring layer 401 is connected to the protrusion 6 of the metal casing 1 via the heat dissipation sheet 5. The heat that is placed on the surface and is generated in the coil pattern 8 is radiated from the coil outer portion 46 of the coil pattern 8 to the protruding portion 6 through the heat dissipation sheet 5.

  The description of the circuits connected to both ends of the coil patterns 7 and 8 will be omitted. However, in an actual coil device, for example, a coil device of a transformer, for example, a circuit constituting a control device other than the illustrated one. Is connected.

  According to the coil device according to the first embodiment of the present invention configured as described above, the heat generated in the coil patterns 7 and 8 provided on the printed wiring board 4 is efficiently radiated to the metal casing 1. This eliminates the need to use a highly heat-resistant base material for the base material of the printed wiring board 4 and eliminates the need to increase the coil size for heat dissipation, thereby obtaining a small and inexpensive coil. be able to.

  In the first embodiment, the metal casing 1 has the heat radiation fins 80 for air cooling. However, for example, a water channel may be formed for water cooling. Although not shown in the first embodiment, some members may be added to the top of the I-shaped core 3 for the purpose of fixing the entire core portion 20 to the metal casing 1.

  Furthermore, in the first embodiment, the configuration of the core unit 20 is such that the E-shaped core 2 is arranged in the lower part and the I-shaped core 3 is arranged in the upper part, but the I-shaped core 3 is arranged in the lower part and the E-shaped core 2 is arranged in the upper part. Other configurations such as a configuration in which an E-shaped core is disposed in both the lower part and the upper part may be used.

  In the first embodiment, the through hole 44 has been described with respect to the case where the inner peripheral surface is plated with copper. However, for example, by filling the through hole 44 with a material having a high thermal conductivity, further heat dissipation is achieved. Thus, the temperature increase of the coil patterns 7 and 8 can be further suppressed. As the substance filling the through hole 44, for example, thermally conductive grease, soldering material, or the like can be considered.

  Further, in the first embodiment, the number of layers of the printed wiring board 4 is two, and the case where a two-turn coil is configured has been described. However, the present invention is not limited to this, and other layers and turns But it can be applied as well. In the first embodiment, the heat dissipation path passing through the two heat dissipation sheets 62 and 5 has been described. However, when only one of the heat dissipation paths is provided for space reasons, the other heat dissipation path is omitted. May be.

Embodiment 2. FIG.
3 is an exploded perspective view showing a coil device according to Embodiment 2 of the present invention. In FIG. 3, a winding start portion 66 corresponding to the winding start of the coil pattern 7 is provided with a number of through holes 67 connected to the coil vicinity pattern 84 located in the vicinity of the coil pattern 8. A through hole 44 similar to that in the first embodiment is formed in the electrical connection portion 73 of the coil pattern 7.

A through hole 44 similar to that in the first embodiment is formed in the electrical connection portion 83 corresponding to the start of winding of the coil pattern 8. Further, the above-described through-hole 67 is provided in the above-described coil vicinity pattern 84 located in the vicinity of the coil pattern 8. The winding start portion 66 of the coil pattern 7 and the coil vicinity pattern 84 are connected by a through hole 67. The inner peripheral surfaces of these through holes 44 and 67 are plated with copper.

  The metal casing 1 has a protruding portion 64 and a protruding portion 6 that are formed upward along the E-shaped core 2 of the core portion 20. The upper surface of the protruding portion 64 corresponds to the through hole existence region 63 that covers all the lower surfaces of the through hole 44 and the through hole 67 of the coil pattern 8. The heat radiating sheet 65 is inserted between the upper surface of the projecting portion 64 and the lower surface of the coil pattern 8. The heat dissipation sheet 5 is inserted between the upper surface of the protruding portion 6 and the lower surface of the coil outer side portion 46 of the coil pattern 8. Other configurations are the same as those in the first embodiment.

  In the coil device according to Embodiment 2 of the present invention, the heat generated in the coil pattern 8 is made of metal via the insulating heat dissipating sheet 65 present on the lower surface of the electrical connection portion 83 of the coil pattern 8. Heat is radiated to the protrusion 64 of the housing 1. Further, the heat generated in the coil pattern 7 is transmitted from the electrical connection portion 73 to the electrical connection portion 83 of the coil pattern 8 through the through hole 44, and further radiated to the protruding portion 64 through the heat radiation sheet 65. At the same time, through the through hole 67, the coil pattern 8 near the coil pattern 8 is reached, and the heat is radiated to the protrusion 64 of the metal casing 1 through the heat dissipation sheet 65.

  As described above, according to the coil device according to the second embodiment of the present invention, the heat generated in the coil patterns 7 and 8 provided on the printed wiring board 4 is efficiently radiated to the metal casing 1. In addition to eliminating the need to use a highly heat-resistant substrate as the substrate of the printed wiring board 4, there is no need to increase the coil size for heat dissipation, and a small and inexpensive coil can be obtained. Can do. Of course, the coil device according to the second embodiment can be variously modified as in the case of the coil device according to the first embodiment.

Embodiment 3 FIG.
4 is an exploded perspective view showing a coil device according to Embodiment 3 of the present invention. In FIG. 4, the coil outer portion 46 of the coil pattern 8 exists on the opposite side of the winding start portion 81 and the winding end portion 82 with respect to the core portion 20, and the pattern width 47 is the inner side of the core of the coil pattern 8. The pattern width 48 is larger. The coil outer portion 46 of the coil pattern 8 is divided into a connection portion 51 that is directly connected to the coil pattern 8 and a non-connection portion 52 that is not connected. Among these, the non-connection portion 52 not directly connected to the coil pattern 8 is provided with a through hole 54, and the outside of the coil protruding from the core portion 20 in the coil pattern 7 of the printed wiring layer 402 other than the lowermost layer. Connected to the section 55. The through hole 44 is provided in the electrical connection portion 73 of the coil pattern 7 and the electrical connection portion 83 of the coil pattern 8 as in the case of the first and second embodiments.

In the coil device according to the third embodiment of the present invention, the heat generated in the coil pattern 7 is transmitted to the non-connected portion 52 that is not directly connected to the coil pattern 8 via the through hole 54. Next, heat is radiated to the projecting portion 6 of the metal casing 1 through the insulating heat radiating sheet 5. The heat generated in the coil pattern 8 is radiated from the connecting portion 51 directly connected to the coil pattern 8 to the protruding portion 6 of the metal casing 1 through the heat dissipation sheet 5 having insulation properties. Of course, the coil device according to the third embodiment can be variously modified as in the case of the coil device according to the first embodiment. Similarly to the first and second embodiments, the metal housing 1 is provided with a protrusion 60 corresponding to the electrical connection portion 83 of the coil pattern 8, and the electrical connection portion 73 of the coil pattern 7 and the coil Of course, the electrical connection portion 83 of the pattern 8 may be connected by the through hole 44, and a heat radiation sheet may be provided between the protruding portion 60 and the electrical connection portion 83.

  As described above, according to the coil device according to the second embodiment of the present invention, the heat generated in the coil patterns 7 and 8 provided on the printed wiring board 4 can be efficiently radiated to the metal casing 1. It becomes possible to obtain a small and inexpensive coil without the need to use a highly heat-resistant base material for the base material of the printed wiring board 4 and the need to increase the coil size for the purpose of heat dissipation. it can. In Embodiment 3, since the area of the portion where the through hole is provided can be increased, better heat dissipation than in Examples 1 and 2 can be obtained.

  In the present invention, the embodiments can be appropriately modified or omitted within the scope of the invention.

100 coil device, 1 metal case , 80 heat radiation fin, 20 coil part, 2 E-shaped core, 21 bridging part, 22 central leg part, 23, 24 side leg part, 3 i-shaped core, 4 printed wiring board, 62, 5, 65 Heat radiation sheet, 60, 6, 64 Protruding part, 401 Bottom layer printed wiring layer, 402 Bottom layer printed wiring layer, 7, 8 Coil pattern, 11, 12 Through hole, 41, 45 Coil end Part, 71, 81, 66 Winding start part, 72, 82 Winding end part, 73, 83 Electrical connection part, 44, 67, 54 Through hole, 46, 55 Coil outer part, 84 Coil near pattern, 63 Through hole existence Area, 47, 48 Pattern width, 51 connection part, 52 non-connection part.

Claims (6)

A coil device comprising: a metal casing; a core portion fixed to the metal casing; and a printed wiring board that is magnetically coupled to the core portion and has a coil pattern used as a coil winding. There,
The printed wiring board is composed of at least two printed wiring layers of a lowermost layer disposed closest to the metal casing and a layer other than the lowermost layer,
The lowermost layer and the printed wiring layer other than the lowermost layer each include the coil pattern,
Each coil pattern of the printed wiring layer of the layer other than the lowermost layer and the lowermost layer is electrically connected via an electrical connection portion provided in each of the coil patterns ,
Before SL and the electrical connecting portion provided on the coil pattern of the bottom layer of the printed wiring layer, wherein the electrical connecting portion provided on the coil pattern of the printed wiring layer of the lowermost other layers may be overlaid directly And is connected by a through-hole penetrating each of the electrical connection portions, and dissipates heat between the electrical connection portion and the metal casing in the lowermost printed wiring layer. The sheet is placed ,
The coil apparatus characterized by the above-mentioned. The coil vicinity pattern located in the vicinity of the coil pattern in the lowermost printed wiring layer, and the portion that becomes the winding start of the coil pattern in the printed wiring layer other than the lowermost layer are the coil vicinity pattern and Connected by a through hole penetrating a coil pattern winding start portion in a printed wiring layer other than the lowermost layer,
A heat dissipation sheet is disposed between the coil vicinity pattern and the metal casing.
The coil device according to claim 1. The portion separated from the coil pattern in the lowermost printed wiring layer and the electrical connection portion in the coil pattern of the printed wiring board other than the lowermost layer via the core portion. The opposing parts are connected by through holes that penetrate the respective parts,
Between the part separated from the coil pattern of the lowermost printed wiring layer and the metal casing, a heat dissipation sheet is disposed.
The coil device according to claim 1 or 2, wherein The core part includes a central leg part and a pair of side leg parts that are located on both sides of the central leg part and are magnetically coupled to the central leg part,
The coil pattern formed in each of the lowermost printed wiring layer and the printed wiring layer other than the lowermost layer has a central portion penetrated by the central leg portion of the core portion, and at least a part of the outer peripheral portion is It is arranged inside a pair of side legs of the core part,
The coil device according to any one of claims 1 to 3, wherein Between at least a part of the coil pattern of the lowermost printed wiring layer other than the part disposed inside the pair of side legs of the core part and the metal casing Heat dissipation sheet is placed,
The coil device according to claim 3. The heat-dissipating sheet is disposed on the surface of the protruding portion formed in the metal casing.
The coil device according to any one of claims 1 to 5, wherein

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