JP7636463B2 - transformer - Google Patents

Description

The present invention relates to a transformer including a two-layer substrate having a first coil pattern and a second coil pattern, and a core that electromagnetically couples the first coil pattern and the second coil pattern.

Conventionally, a transformer is known that includes a substrate on which a first spiral coil pattern, an insulating base material, and a second spiral coil pattern are laminated, and a core that electromagnetically couples the first coil pattern and the second coil pattern. In such a transformer, in order to electrically connect to the inner peripheral ends of the first coil pattern and the second coil pattern,
A conductive pattern for drawing is provided between the layers of the first coil pattern and the second coil pattern. That is, the substrate is formed as a multi-layer substrate having three or more conductive layers (usually four or more). The inner peripheral ends of the first coil pattern and the second coil pattern are electrically drawn out to the outside of the first coil pattern and the second coil pattern by using the conductive pattern for drawing.

A four-layer substrate having four layers of spiral coil patterns is disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-233996.

JP 2009-016504 A

However, when the substrate is formed into a multi-layer substrate having three or more conductive layers (usually four or more layers), there is a problem in that the substrate structure becomes complicated and the cost increases.

The present invention has been made in consideration of the above points, and provides a first coil pattern and a second coil pattern.
An object of the present invention is to provide a transformer capable of preventing the structure of a substrate having a coil pattern from becoming complicated.

A transformer according to the present invention includes a two-layer substrate having an insulating base material, a first conductive spiral coil pattern provided on a first surface of the base material, and a second conductive spiral coil pattern provided on a second surface of the base material, and a core that electromagnetically couples the first coil pattern and the second coil pattern, wherein a first wiring pattern is provided on the first surface of the base material and is disposed at a predetermined distance from the first coil pattern,
The inner end of the first coil pattern and one end of the first wiring pattern are electrically connected by a first jumper member, and a second wiring pattern is provided on the second surface of the substrate, the second wiring pattern being positioned a predetermined distance away from the second coil pattern, and the inner end of the second coil pattern and one end of the second wiring pattern are electrically connected by a second jumper member.

According to the transformer of the present invention, the end of the first coil pattern on the inner periphery side and one end of the first wiring pattern are electrically connected by a first jumper member. This allows the end of the first spiral coil pattern on the inner periphery side to be electrically drawn out by the first jumper member. Similarly, the end of the second coil pattern on the inner periphery side and one end of the second wiring pattern are electrically connected by a second jumper member. This allows the end of the second spiral coil pattern on the inner periphery side to be electrically drawn out by the second jumper member. As a result, it is not necessary to form the substrate into a multilayer substrate having three or more conductive layers (usually four or more layers), so that the structure of the substrate can be prevented from becoming complicated and the cost can be prevented from increasing.

In the above transformer, preferably, the first coil pattern has a first overlapping area overlapping with the core when viewed from the thickness direction of the two-layer board, and the second coil pattern has a second overlapping area overlapping with the core when viewed from the thickness direction, and at least the first overlapping area and the second overlapping area are provided in the same shape and at the same position when viewed from the thickness direction. When a current flows through the first coil pattern and the second coil pattern, the first coil pattern and the second coil pattern generate heat, which may adversely affect the characteristics of the transformer. Therefore, as described above, if at least the first overlapping area and the second overlapping area are provided in the same shape and at the same position when viewed from the thickness direction, the first overlapping area and the second overlapping area can be brought close to each other, so that the heat of the coil pattern that generates a large amount of heat among the first coil pattern and the second coil pattern can be dissipated (thermally conducted) to the coil pattern that generates a small amount of heat among the first coil pattern and the second coil pattern. Therefore, it is possible to prevent the temperature of the coil pattern that generates a large amount of heat among the first coil pattern and the second coil pattern from becoming too high, and therefore it is possible to prevent the characteristics of the transformer from deteriorating.

The above transformer preferably includes a metal housing including a flat base on which the core and the two-layer board are laminated, the first coil pattern and the second coil pattern are a primary coil and a secondary coil, the two-layer board is disposed so that the first surface faces the base, the first coil pattern includes a non-overlapping area that does not overlap with the core when viewed in the thickness direction of the two-layer board, a heat dissipation section for dissipating heat from the two-layer board is provided on the base so as to protrude from the base toward the two-layer board, and an insulating heat dissipation member is provided between the heat dissipation section and the non-overlapping area so as to be in close contact with the heat dissipation section and the non-overlapping area. With this configuration, the heat of the first coil pattern, which is the primary coil, can be efficiently dissipated (thermally conducted) to the heat dissipation section via the heat dissipation member. Therefore, when a circuit configuration is used in which a larger current flows through the primary coil than the secondary coil (the heat generation amount of the primary coil is larger than that of the secondary coil), the heat dissipation can be further improved. Furthermore, since the heat dissipation member is insulating, a metal can be used for the heat dissipation portion, and heat dissipation can be easily improved.

In the above transformer, preferably, the inner ends of the first coil pattern and the second coil pattern are arranged on one side of the core, the outer ends of the first coil pattern and the second coil pattern are arranged on the other side of the core, the one ends of the first wiring pattern and the second wiring pattern are arranged on one side of the core, and the other ends of the first wiring pattern and the second wiring pattern are arranged on the other side of the core.
With this configuration, the inner peripheral ends of the first coil pattern and the second coil pattern arranged on one side of the core can be easily electrically led out to the other side of the core.

The above transformer preferably includes a metal housing including a flat base on which the core and the two-layer substrate are laminated, the core includes a pair of cores arranged at a predetermined distance from each other when viewed in a thickness direction of the two-layer substrate, and the base is provided with a central heat dissipation portion arranged between the pair of cores so as to protrude from the base toward the two-layer substrate,
An insulating heat dissipation member is provided between the central heat dissipation section and the two-layer substrate so as to be in close contact with the central heat dissipation section and the two-layer substrate. Heat generated when a current flows through the first coil pattern and the second coil pattern is likely to be trapped in the center of the substrate. Therefore, as described above, if a central heat dissipation section disposed between a pair of cores is provided on a base, and a heat dissipation member is provided between the central heat dissipation section and the two-layer substrate so as to be in close contact with the central heat dissipation section and the two-layer substrate, the heat in the center of the two-layer substrate can be efficiently dissipated (thermally conducted) to the central heat dissipation section. In addition, since the heat dissipation member is insulating, a metal can be used for the central heat dissipation section, and heat dissipation can be easily improved.

According to the present invention, it is possible to provide a transformer capable of preventing the structure of a substrate having a first coil pattern and a second coil pattern from becoming complicated.

1 is a perspective view showing a structure of a transformer according to an embodiment of the present invention; 1 is an exploded perspective view showing a structure of a transformer according to an embodiment of the present invention. 1 is a perspective view showing a structure of a housing of a transformer according to an embodiment of the present invention; 2 is a cross-sectional view taken along line 100-100 in FIG. 1. 1 is a diagram showing a substrate of a transformer according to an embodiment of the present invention, viewed from a first surface side. 2 is a diagram showing a substrate of a transformer according to an embodiment of the present invention as viewed from a second surface side. FIG. 1. This is a cross-sectional view taken along line 150-150 in FIG. 2 is an enlarged cross-sectional view showing a structure around a first jumper pin and a second jumper pin of a transformer according to an embodiment of the present invention. FIG.

Hereinafter, the structure of a transformer 1 according to an embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the transformer 1 includes a metal housing 10, a heat dissipation sheet (heat dissipation member) 21, a lower core 22, a heat dissipation sheet (heat dissipation member) 23, a substrate (two-layer substrate) 30,
It is composed of a heat dissipation sheet (heat dissipation member) 24, spacers 25a and 25b, an upper core (core) 26, a heat dissipation sheet (heat dissipation member) 27, and a metal pressing plate 28.

The entire housing 10 is made of a metal having good thermal conductivity, such as copper or aluminum. As shown in Figs. 2 and 3, the housing 10 includes a flat base 11 on which the lower core 22, the substrate 30, the upper core 26, etc. are stacked, and is attached to a heat sink (not shown) using screw insertion holes 11a formed at the four corners of the base 11. As described later, the housing 10 dissipates (conducts) heat generated in the lower core 22, the substrate 30, and the upper core 26 to the heat sink (not shown) via the base 11. Note that a heat dissipation sheet or the like having good thermal conductivity is disposed between the base 11 and the heat sink (not shown).

A pair of sheet-mounting recesses 11b having a predetermined depth and in which a heat dissipation sheet 21 is disposed are formed in a predetermined region of the base 11. The pair of sheet-mounting recesses 11b are disposed at a predetermined interval from each other in the direction of the arrow AA'.

A central heat dissipation section 12 is formed between the pair of sheet placement recesses 11b of the base 11 so as to protrude upward (towards the substrate 30) from the upper surface of the base 11. The central heat dissipation section 12 is formed so as to extend in the direction of the arrow BB'. A screw hole 12a for fixing the substrate 30 is formed in the center of the central heat dissipation section 12.

The base 11 is provided with a first heat dissipation section 14a, a second heat dissipation section 14b, and a third heat dissipation section 14c, which are arranged to sandwich a pair of sheet placement recesses 11b in the direction of arrow AA'. The first heat dissipation section 14a, the second heat dissipation section 14b, and the third heat dissipation section 14c are formed to protrude upward from the upper surface of the base 11 and extend in the direction of arrow BB'. The central heat dissipation section 12, the first heat dissipation section 14a, the second heat dissipation section 14b, and the third heat dissipation section 14c are formed so that the heights of their upper surfaces are approximately the same.

The second heat dissipation section 14b is formed so as to be shorter in the direction of the arrow BB' than the central heat dissipation section 12, the first heat dissipation section 14a, and the third heat dissipation section 14c. The second heat dissipation section 14b is disposed in the direction of the arrow B' with respect to the center of the base 11 in the direction of the arrow BB'. For this reason,
A space S is formed in the portion of the second heat dissipation portion 14b in the direction of the arrow B. As shown in Fig. 4, the second heat dissipation portion 14b is disposed at a predetermined gap from the sheet-mounting recess 11b, and the first heat dissipation portion 14a is disposed at a predetermined gap from the second heat dissipation portion 14b. The third heat dissipation portion 14c is disposed at a predetermined gap from the sheet-mounting recess 11b. By blowing cooling air into these gaps, it is possible to improve the heat dissipation performance of the transformer 1.

3, the base 11 is provided with two pairs of walls 15 on either side of the pair of sheet placement recesses 11b in the direction of the arrow BB'. A pair of screw insertion holes 15a are provided at the upper end of each wall 15. The screw insertion holes 15a are formed in an elliptical shape that is slightly longer in the vertical direction so that the mounting height of the screws can be adjusted.

The base 11 has four corners, and the fixing portions 16 are provided adjacent to the screw insertion holes 11a. The fixing portions 16 are provided so as to protrude upward from the upper surface of the base 11, and are connected to the central heat dissipation portion 12, the first heat dissipation portion 14a, the second heat dissipation portion 14b, and the like.
It is formed so as to be slightly higher (for example, approximately the same height as the thickness of the heat dissipation sheet 23) than the upper surfaces of the heat dissipation portion 14b and the third heat dissipation portion 14c.

The heat dissipation sheet 21 is a thermally conductive sheet that fills gaps to transfer heat, and is also an electrically insulating sheet made of, for example, silicone or rubber that has elasticity. For example, the heat dissipation sheet 21 preferably has a thermal conductivity of 0.5 W/m·K or more. From the viewpoint of heat dissipation, a higher thermal conductivity is preferable, but the upper limit of the current manufacturing technology is about 50 W/m·K. The heat dissipation sheet 21 also preferably has an Asker C hardness of 50 or less. From the viewpoint of adhesion to uneven surfaces, a lower Asker C hardness is preferable, but the lower limit of the current manufacturing technology is about 1. The heat dissipation sheet 21 also preferably has a thermal conductivity of 0.5 kV/mm
It is preferable that the dielectric breakdown voltage is equal to or higher than 0.5 kV/mm. However, depending on the environment in which the transformer 1 of this embodiment is used, a dielectric breakdown voltage of less than 0.5 kV/mm (for example, 0.1 kV/mm) may be applicable. In addition, from the viewpoint of voltage resistance, a higher dielectric breakdown voltage is preferable, but the upper limit in current manufacturing technology is about 30 kV/mm. The heat dissipation sheet 21 may contain particles with good thermal conductivity, such as ceramic or filler, as necessary. The heat dissipation sheets 23, 24, and 27 are formed, for example, from a heat dissipation sheet made of the same material as the heat dissipation sheet 21.

2, the heat dissipation sheets 21 are formed to extend in the direction of the arrow BB', and are provided in a pair at a predetermined distance from each other in the direction of the arrow AA'. The pair of heat dissipation sheets 21 are respectively arranged in the pair of sheet-mounting recesses 11b. As will be described later, the heat dissipation sheet 21 is arranged between the upper surface of the sheet-mounting recess 11b and the lower surface of the lower core 22, so that the heat dissipation sheet 21 is tightly attached to the upper surface of the sheet-mounting recess 11b and the lower surface of the lower core 22 without any gaps. As a result, when the lower core 22 generates heat, the heat from the lower core 22 is transferred to the heat dissipation sheet 21.
The heat is dissipated (thermally conducted) to the base 11 of the housing 10 via the casing 10 .

There are four lower cores 22. The lower cores 22 are made of ferrite, a magnetic metal, a powder magnetic core, or the like.

The lower core 22 is a U-shaped core having convex portions 22b formed on both ends of an upper surface 22a in the direction of the arrow BB'.
It is formed so as to be substantially flush with the upper surfaces of the heat dissipation portion 14b and the third heat dissipation portion 14c.

A pair of lower cores 22 adjacent to each other in the direction of the arrow BB' constitute an E-shaped core.
The lower core 22 may be formed of an E-shaped core instead of a U-shaped core. That is, the E-shaped core may be formed of a lower core 22 consisting of one E-shaped core, instead of a pair of U-shaped cores. The E-shaped cores (the pair of lower cores 22) are provided in pairs at a predetermined interval from each other in the direction of arrow AA'. Each E-shaped core is formed to be approximately the same size and shape as the heat dissipation sheet 21. The entire lower surface of the E-shaped core is in close contact with the heat dissipation sheet 21.

The heat dissipation sheet 23 is formed so as to avoid (not overlap) the protruding portion 22b of the lower core 22.
b and a slit 23 a is formed at a position corresponding to the screw hole 12 a of the central heat dissipation portion 12 .

The heat dissipation sheet 23 includes a first region 23b arranged on the first heat dissipation section 14a and the second heat dissipation section 14b, a second region 23c arranged on the upper surface 22a of the E-shaped core (the pair of lower cores 22) in the direction of the arrow A, a third region 23d arranged on the central heat dissipation section 12, a fourth region 23e arranged on the upper surface 22a of the E-shaped core (the pair of lower cores 22) in the direction of the arrow A', and a fifth region 23f arranged on the third heat dissipation section 14c. The heat dissipation sheet 23 closely contacts the upper surfaces of the first heat dissipation section 14a, the second heat dissipation section 14b, the central heat dissipation section 12, and the third heat dissipation section 14c of the housing 10 without any gaps, and also closely contacts the upper surface 22a of the pair of E-shaped cores without any gaps. As a result, when the lower core 22 generates heat, the heat of the lower core 22 is transferred to the housing 10 through the heat dissipation sheet 23.
The heat is radiated (thermally conducted) to the first heat radiating portion 14a, the second heat radiating portion 14b, the central heat radiating portion 12, and the third heat radiating portion 14c.

Furthermore, the substrate 30 is placed on the heat dissipation sheet 23. The heat dissipation sheet 23 is tightly attached to a first conductive layer 32 (described later) of the substrate 30 without any gaps. As a result, when the substrate 30 generates heat, the heat of the substrate 30 is transferred through the heat dissipation sheet 23 to the first heat dissipation portion 14a, the second heat dissipation portion 14b,
The heat is dissipated (thermally conducted) to the central heat dissipation portion 12 and the third heat dissipation portion 14 c. When the temperature of the substrate 30 is higher than that of the lower core 22, the heat of the substrate 30 is also dissipated (thermally conducted) to the lower core 22 via the heat dissipation sheet 23, and when the temperature of the lower core 22 is higher than that of the substrate 30, the heat of the lower core 22 is also dissipated (thermally conducted) to the substrate 30 via the heat dissipation sheet 23.

As shown in FIGS. 5 and 6, the substrate 30 is made of an insulating base material 31 and a first surface 3 of the base material 31.
1a (lower surface in FIG. 2 ) of the substrate 31, and a second conductive layer 33 provided on a second surface 31b (upper surface in FIG. 2 ) of the substrate 31. As described later, the first conductive layer 32
The first conductive layer 32 includes a first spiral coil pattern 32a which serves as a primary coil, and the second conductive layer 33 includes
The substrate 30 includes a second coil pattern 33a having a spiral shape that serves as a secondary coil. The detailed structure of the substrate 30 will be described later.

As shown in Fig. 2, the heat dissipation sheets 24 are formed to extend in the direction of the arrow AA', and are provided in pairs at a predetermined interval from each other in the direction of the arrow BB'. The heat dissipation sheets 24 are disposed on the second conductive layer 33 of the substrate 30. As described later, the heat dissipation sheet 24 is disposed between the second conductive layer 33 of the substrate 30 and the lower surface of the upper core 26, so that the heat dissipation sheet 24 is in close contact with the second conductive layer 33 of the substrate 30 and the lower surface of the upper core 26. As a result, when the temperature of the substrate 30 is higher than that of the upper core 26, the heat of the substrate 30 is dissipated (thermally conducted) to the upper core 26 via the heat dissipation sheet 24, and when the temperature of the upper core 26 is higher than that of the substrate 30, the heat of the upper core 26 is also dissipated (thermally conducted) to the substrate 30 via the heat dissipation sheet 24.

As shown in FIGS. 2 and 7, the spacers 25a are formed to extend in the direction of the arrow AA', and are provided in pairs at a predetermined interval from each other in the direction of the arrow BB'.
The pair of spacers 25a are disposed on the convex portions 22b at both ends in the direction of the arrow BB' of the E-shaped core (the pair of lower cores 22). The spacers 25b are formed to extend in the direction of the arrow AA' and are provided in pairs at a predetermined interval from each other in the direction of the arrow AA'. The pair of spacers 25b are disposed on the central convex portion 22b in the direction of the arrow BB' of the E-shaped core (the pair of lower cores 22).

The pair of spacers 25a are disposed so as to sandwich the pair of heat dissipation sheets 24 in the direction of the arrow BB', and the pair of spacers 25b are disposed between the pair of heat dissipation sheets 24.

The spacers 25a and 25b are arranged in a state where the upper core 26 is disposed on the heat dissipation sheet 24.
This prevents the heat dissipation sheets 23 and 24 from being compressed too much in the thickness direction, and defines a predetermined distance between the lower surface of the upper core 26 and the upper surface 22a of the lower core 22. The material of the spacers 25a and 25b is not particularly limited, but an insulating resin substrate, for example, can be used.

The upper core 26 is a flat I-shaped core, and is made of ferrite, magnetic metal, powder magnetic core, etc., like the lower core 22. The upper core 26 is formed to extend in the direction of the arrow BB', and is provided in pair at a predetermined interval from each other in the direction of the arrow AA'. The upper core 26 is formed to have approximately the same size and shape as the E-shaped core when viewed in the thickness direction.

The upper core 26 and the E-shaped core (the pair of lower cores 22) form a core that electromagnetically couples the first coil pattern 32a and the second coil pattern 33a of the substrate 30. As a result, for example, when a current flows through the first coil pattern 32a of the substrate 30, a magnetic flux is generated in the magnetic path of the core (upper core 26 and E-shaped core). Then, a current flows through the second coil pattern 33a so as to cancel out the magnetic flux generated in the core. Note that the upper core 26 and the E-shaped core (
The pair of lower cores 22) may be disposed so as to be in contact with each other, or may be disposed at a predetermined distance from each other.

The heat dissipation sheet 27 is formed so as to extend in the direction of the arrow BB' and also in the direction of the arrow AA
The pair of heat dissipation sheets 27 are disposed on the pair of upper cores 26, respectively. The heat dissipation sheets 27 are disposed on the upper cores 26, respectively, when viewed from the thickness direction.
It is formed in approximately the same size and shape as 6.

As described below, the heat dissipation sheet 27 is disposed between the upper surface of the upper core 26 and the lower surface of the pressing plate 28, so that the heat dissipation sheet 27 is tightly attached to the upper surface of the upper core 26 and the lower surface of the pressing plate 28 without any gaps. As a result, when the upper core 26 generates heat, the heat of the upper core 26 is dissipated (thermally conducted) to the pressing plate 28 via the heat dissipation sheet 27.

The pressure plates 28 are made of metal such as copper or aluminum having good thermal conductivity. The pressure plates 28 are formed to extend in the direction of the arrow BB', and are provided in pairs at a predetermined interval in the direction of the arrow AA'. The pair of pressure plates 28 are respectively disposed on the pair of heat dissipation sheets 27. The pressure plates 28 are formed to be approximately the same size and shape as the heat dissipation sheets 27 when viewed in the thickness direction.

A pair of screw holes 28a are provided on each side surface of the pressing plate 28 in the direction of the arrow BB' so as to correspond to the screw insertion holes 15a of the housing 10. The pressing plate 28 is fixed to the wall 15 of the housing 10 while pressing the heat dissipation sheet 27.

Next, the detailed structure of the substrate 30 will be described.

As shown in FIGS. 5 and 6 , the substrate 30 includes a base material 31, a first conductive layer 32 provided on a first surface 31 a of the base material 31, a second conductive layer 33 provided on a second surface 31 b of the base material 31,
The substrate 30 is disposed so that the first surface 31 a faces the base 11 of the housing 10 (with the first surface 31 a facing downwards). For ease of understanding, the first conductive layer 32 is hatched in Fig. 5 and the second conductive layer 33 is hatched in Fig. 6.

The substrate 31 is made of an insulating material such as fluororesin or other resin, and is formed in a flat plate shape. The outer shape of the substrate 31 is formed in a substantially H-shape when viewed in the thickness direction, and wide portions 31c are formed at both ends of the substrate 31 in the direction of the arrow AA', the wide portions 31c being longer in the direction of the arrow BB' than the other portions. The wide portions 31c are disposed on the outer side of the pair of E-shaped cores in the direction of the arrow AA'.

At a predetermined position of the base material 31, an opening 31d is formed penetrating in the thickness direction. The opening 31d is formed to extend in the direction of the arrow AA', and a pair of openings 31d is provided at a predetermined interval from each other in the direction of the arrow AA'. The opening 31d is formed slightly larger than the central protrusion 22b of the E-shaped core in the direction of the arrow BB', and the substrate 30 is inserted into the heat dissipation sheet 23.
In this state, the central protrusion 22b of the E-core in the direction of the arrow BB' is inserted into the opening 31d.

Screw insertion holes 31e are formed at the four corners of the base material 31 so as to correspond to the fixing parts 16 of the housing 10, and a screw insertion hole 31f is formed at the center of the base material 31 so as to correspond to the screw hole 12a of the central heat dissipation part 12. The base material 31 is fixed to the fixing parts 16 of the housing 10 and the central heat dissipation part 12 using the screw insertion holes 31e and 31f.

The first conductive layer 32 is composed of a Cu layer formed on the first surface 31a of the base material 31 and an Au plating layer covering the surface of the Cu layer.
The Cu layer is formed by applying a Cu paste in a predetermined pattern on the first surface 31a of the base material 31 and curing the paste. The Cu layer may be formed by etching a copper foil that is attached to the entire surface of the first surface 31a of the base material 31 into a predetermined pattern.

5, the first conductive layer 32 includes a first spiral coil pattern 32a that serves as a primary coil, and a first wiring pattern 32b that is substantially linear and disposed at a predetermined distance from the first coil pattern 32a.
The amount of heat generated is greater than that of the coil pattern 33a.

The first coil pattern 32a is formed in a spiral shape around the pair of openings 31d. The first coil pattern 32a includes a portion 32c extending in parallel to the direction of the arrow AA′ and a portion 32b extending in parallel to the direction of the arrow BB.
The portion 32c is formed by connecting the portion 32c extending parallel to the direction of the arrow A and the portion 32d extending parallel to the direction of the arrow B, and here, the portion 32c is formed counterclockwise from the inner periphery side to the outer periphery side for about two and a half revolutions. The portion 32c is formed to have a line width about twice that of the portion 32d.

An end 32e on the inner periphery side of the first coil pattern 32a is disposed in the portion in the direction of the arrow A with respect to the pair of E-shaped cores, and an end 32f on the outer periphery side of the first coil pattern 32a is disposed in the portion in the direction of the arrow A' with respect to the pair of E-shaped cores.
An insulating resist layer 34 having an opening 34a is formed on end 32e on the inner periphery side of the substrate 30a. End 32f is connected to the substrate 30 by a through hole penetrating the substrate 30 in the thickness direction.
1 is connected to a primary electrode 33i on the second surface 31b of the first transformer 1.

One end 32g of the first wiring pattern 32b is disposed in the portion in the direction of the arrow A relative to the pair of E-shaped cores, and the other end 32h of the first wiring pattern 32b is disposed in the portion in the direction of the arrow A' relative to the pair of E-shaped cores. A resist layer 34 having an opening 34b is formed on one end 32g of the first wiring pattern 32b. The end 32h is formed so as to extend in the direction of the arrow B. The end 32h is connected to a primary electrode 33j on the second surface 31b of the base material 31 by a through hole penetrating the substrate 30 in the thickness direction.

In this embodiment, as shown in FIG. 5 and FIG. 8, a first jumper pin (
One end of the first jumper member 35 is soldered to the first wiring pattern 32b.
The first jumper pin 35 is connected to the end 32g of the first jumper pin 35 through the opening 34b of the resist layer 34.
That is, the other end of the first coil pattern 32a is soldered to the inner periphery of the end 32.
e is electrically connected to one end 32g of the first wiring pattern 32b by a first jumper pin 35 that straddles a part of the first coil pattern 32a.

As shown in FIG. 6, the second conductive layer 33 includes a spiral second coil pattern 33a which serves as a secondary coil, and a substantially linear second wiring pattern 33b which is arranged at a predetermined distance from the second coil pattern 33a.

The second coil pattern 33a is formed in a spiral shape around the pair of openings 31d. The second coil pattern 33a includes a portion 33c extending in parallel to the direction of the arrow AA′ and a portion 33b extending in parallel to the direction of the arrow BB.
The portion 33c is formed by connecting the portion 33c extending parallel to the direction of the arrow A and the portion 33d extending parallel to the direction of the arrow B, and here, the portion 33c is formed in a clockwise direction from the inner periphery side to the outer periphery side over about two and a half revolutions. The portion 33c is formed to have a line width about twice that of the portion 33d.

The inner end 33e of the second coil pattern 33a is disposed in the portion in the direction of the arrow A with respect to the pair of E-shaped cores, and the outer end 33f of the second coil pattern 33a is disposed in the portion in the direction of the arrow A' with respect to the pair of E-shaped cores.
An insulating resist layer 36 is formed over substantially the entire area of the second coil pattern 33c. An opening 36a is formed in the resist layer 36 above an end 33e on the inner periphery side of the second coil pattern 33a.

The end 33f is formed so as to extend in the direction of the arrow B. A secondary electrode 33k is formed on the end 33f. The secondary electrode 33k is electrically connected to the first surface 31a of the base material 31 by a through hole penetrating the substrate 30 in the thickness direction. A resist layer 36 is also formed on almost the entire area of the wide portion 31c in the direction of the arrow A'.
6, primary electrodes 33i and 33j, secondary electrode 33k, and secondary electrode 33l described later.
A circular opening is formed so that the

One end 33g of the second wiring pattern 33b is disposed in the portion in the direction of the arrow A relative to the pair of E-shaped cores, and the other end 33h of the second wiring pattern 33b is disposed in the portion in the direction of the arrow A' relative to the pair of E-shaped cores. An opening 36b is formed in the resist layer 36 on the one end 33g of the second wiring pattern 33b. A secondary electrode 33l is formed on the other end 33h. The secondary electrode 33l is electrically connected to the first surface 31a of the base material 31 by a through hole penetrating the substrate 30 in the thickness direction.

6 and 8, in this embodiment, one end of a second jumper pin (second jumper member) 37 is soldered to an end 33e on the inner periphery side of the second coil pattern 33a through an opening 36a in the resist layer 36. Also, the other end of the second jumper pin 37 is soldered to an end 33g of the second wiring pattern 33b through an opening 36b in the resist layer 36. That is, the end 33e on the inner periphery side of the second coil pattern 33a is soldered to an end 33g of the second wiring pattern 33b through an opening 36b in the resist layer 36.
The openings 36a and 36b of the resist layer 36 are electrically connected to one end 33g of the second wiring pattern 33b by a second jumper pin 37 that straddles a part of the second coil pattern 33a.
It is formed at the same position and of the same size as 4b.

5 and 6, in this embodiment, the first coil pattern 32a has a first overlap region R32 that overlaps with the cores (upper core 26 and lower core 22) when viewed in the thickness direction of the substrate 30, and the second coil pattern 33a has a second overlap region R33 that overlaps with the cores (upper core 26 and lower core 22) when viewed in the thickness direction of the substrate 30. At least the first overlap region R32 and the second overlap region R
The coils 33 are provided at the same position and shape as viewed in the thickness direction, that is, in plane symmetry with respect to the base material 31. In this embodiment, the coils 33 are provided in substantially the entire region of the first coil pattern 32a (region excluding the end portion 32f) and substantially the entire region of the second coil pattern 33a (region excluding the end portion 33f).
are provided in the same position and with the same shape (plane symmetrical) when viewed from the thickness direction.
Approximately the entire area of the wiring pattern 32b (area excluding the other end 32h) and the second wiring pattern 33b
The substantially entire region (excluding the other end 33h) is defined as the region having the same shape and the same position when viewed from the thickness direction.
The two sensors are arranged in a plane symmetrical manner.

In this embodiment, most of the non-overlapping area of the first coil pattern 32a that does not overlap with the core when viewed in the thickness direction (arranged on the wide portion 31c) is a non-resist area that is not covered with the resist layer 34.
The heat sink 14 is disposed so as to be in close contact with the first heat sink 14a, the second heat sink 14b and the third heat sink 14c of the housing 10 via the first region 23b and the fifth region 23f of the third heat sink 14.

In this embodiment, as described above, the inner peripheral end 32e of the first coil pattern 32a and one end 32g of the first wiring pattern 32b are electrically connected by the first jumper pin 35. As a result, the inner peripheral end 32e of the spiral first coil pattern 32a is
can be electrically drawn out by the first jumper pin 35. Similarly, the inner periphery end 33e of the second coil pattern 33a and one end 33g of the second wiring pattern 33b are electrically connected by the second jumper pin 37. This allows the inner periphery end 33e of the spiral second coil pattern 33a to be electrically drawn out by the second jumper pin 37. As a result, it is not necessary to form the substrate 30 as a multilayer substrate having three or more (usually, four or more) conductive layers, so that the structure of the substrate 30 can be prevented from becoming complicated and an increase in costs can be prevented.

Furthermore, since the first coil pattern 32a and the second coil pattern 33a are provided on the first surface 31a and the second surface 31b of the substrate 31, respectively, unlike a case in which the first coil pattern 32a and the second coil pattern 33a are provided on an inner layer of the substrate 31 (for example, a case in which the substrate 30 is a four-layer substrate and the first coil pattern 32a and the second coil pattern 33a are provided on the inner two layers), it is possible to prevent heat generated by the first coil pattern 32a and the second coil pattern 33a from being trapped inside the substrate 30. In other words, it is possible to prevent a decrease in the heat dissipation performance of the substrate 30.

As described above, at least the first overlap region R32 and the second overlap region R33 are provided in the same position and with the same shape as seen from the thickness direction. When a current flows through the first coil pattern 32a and the second coil pattern 33a, the first coil pattern 32a and the second coil pattern 33a generate heat, which may adversely affect the characteristics of the transformer 1. Therefore, by providing at least the first overlap region R32 and the second overlap region R33 in the same position and with the same shape as seen from the thickness direction as described above, the first overlap region R32 and the second overlap region R33 can be brought closer to each other, so that the heat of the first coil pattern 32a, which generates a large amount of heat, can be dissipated (heat conducted) to the second coil pattern 33a, which generates a small amount of heat. Therefore, it is possible to prevent the temperature of the first coil pattern 32a from becoming too high, and therefore it is possible to prevent the characteristics of the transformer 1 from deteriorating.

As described above, the first coil pattern 32a includes a non-overlapping region that does not overlap with the core when viewed in the thickness direction of the substrate 30 (disposed on the wide portion 31c), and between the non-overlapping region and the first heat dissipation portion 14a, the second heat dissipation portion 14b, and the third heat dissipation portion 14c,
The heat dissipation sheet 23 is provided so as to be in close contact with the non-overlapping region, the first heat dissipation portion 14 a, the second heat dissipation portion 14 b, and the third heat dissipation portion 14 c.
The heat of a can be efficiently dissipated (thermally conducted) to the housing 10 via the heat dissipation sheet 21 .
Therefore, when a circuit configuration is used in which a larger current flows through the primary coil than through the secondary coil (the amount of heat generated by the primary coil is larger than that of the secondary coil), the heat dissipation can be further improved. In addition, since the heat dissipation sheet 21 is insulating, metal can be used for the first heat dissipation portion 14a, the second heat dissipation portion 14b, and the third heat dissipation portion 14c, and the heat dissipation can be easily improved.

As described above, the inner peripheral ends 32e and 33e of the first coil pattern 32a and the second coil pattern 33a are disposed in the portion in the direction of the arrow A with respect to the cores (the lower core 22 and the upper core 26), and the outer peripheral ends 32f and 33f of the first coil pattern 32a and the second coil pattern 33a are disposed in the portion in the direction of the arrow A with respect to the cores (the lower core 22 and the upper core 26).
The first wiring pattern 32b and the second wiring pattern 33b are disposed in the direction of the arrow A' with respect to the cores (the lower core 22 and the upper core 26).
), and the other ends 32h and 33h of the first wiring pattern 32b and the second wiring pattern 33b are disposed in the direction of the arrow A with respect to the cores (the lower core 22 and the upper core 26).
As a result, the inner peripheral ends 32e and 33e of the first coil pattern 32a and the second coil pattern 33a, which are arranged in the direction of the arrow A with respect to the cores (the lower core 22 and the upper core 26), are
2 and upper core 26) in the direction of arrow A'.

Usually, heat generated when a current flows through the first coil pattern 32a and the second coil pattern 33a tends to be trapped in the center of the substrate 30. Therefore, as described above, by providing the central heat dissipation section 12 between the pair of E-shaped cores and providing the heat dissipation sheet 21 between the central heat dissipation section 12 and the substrate 30 so as to be in close contact with the central heat dissipation section 12 and the substrate 30, the heat in the center of the substrate 30 can be efficiently dissipated (thermally conducted) to the central heat dissipation section 12. In addition, since the heat dissipation sheet 21 is insulating, a metal can be used for the central heat dissipation section 12, and heat dissipation can be easily improved.

In addition, by using elastic heat dissipation sheets 21, 23, 24 and 27 as heat dissipation members, vibrations and impacts can be absorbed by heat dissipation sheets 21, 23, 24 and 27, thereby preventing damage to substrate 30 and cores (lower core 22 and upper core 26) due to vibrations and impacts.

It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope of the claims.

For example, in the above embodiment, the housing 10 and the pressing plate 28 are made of metal, but the present invention is not limited to this.
Alternatively, the heat dissipation sheet may be made of insulating ceramics, etc. In this case, a heat dissipation sheet that does not have insulating properties may also be used.

In the above embodiment, the heat dissipation sheet is used as the heat dissipation member, but the present invention is not limited to this. For example, grease containing metal, or thermoplastic resin or thermosetting resin having thermal conductivity can be used as the heat dissipation member.

In the above embodiment, an example has been shown in which only the first jumper pin 35 and the second jumper pin 37 are attached to the substrate 30, but the present invention is not limited to this. A capacitor, a resistor, etc. may also be attached to the substrate 30.

In the above embodiment, the first jumper pin 35 is attached to the first surface 31a of the substrate 30, and the second jumper pin 37 is attached to the second surface 31b of the substrate 30. However, the present invention is not limited to this. For example, a first jumper pin 37 may be provided in which the inner end 32e of the first coil pattern 32a and one end 32g of the first wiring pattern 32b are electrically connected to the second surface 31b by through holes, and the inner end 32e of the first coil pattern 32a and one end 32g of the first wiring pattern 32b are attached to the second surface 31b.
The second coil pattern 33 may be electrically connected to the first coil pattern 32 by a jumper pin 35.
The inner end 33e of the second coil pattern 33a and one end 33g of the second wiring pattern 33b may be electrically connected to the first surface 31a by through holes, and the inner end 33e of the second coil pattern 33a and one end 33g of the second wiring pattern 33b may be electrically connected by a second jumper pin 37 attached to the first surface 31a.

1: transformer, 10: housing, 11: base, 12: central heat dissipation section, 14a: first heat dissipation section (heat dissipation section), 14b: second heat dissipation section (heat dissipation section), 14c: third heat dissipation section (heat dissipation section), 21: heat dissipation sheet (heat dissipation member), 22: lower core (core), 26: upper core (core), 30: substrate (two-layer substrate), 31: base material, 31a: first surface, 31b: second surface, 32a: first coil pattern, 32b: first wiring pattern, 32e: inner peripheral end, 32f: outer peripheral end, 32g
: one end portion, 32h: other end portion, 33a: second coil pattern, 33b: second wiring pattern,
33e: inner peripheral end, 33f: outer peripheral end, 33g: one end, 33h: other end, 35
: first jumper pin (first jumper member), 37: second jumper pin (second jumper member), R32: first overlap region, R33: second overlap region

Claims (6)

a rectangular two-layer substrate having an insulating base material, a first conductive spiral coil pattern provided on a first surface of the base material, and a second conductive spiral coil pattern provided on a second surface of the base material;
a core that electromagnetically couples the first coil pattern and the second coil pattern;
a metal housing including a flat base on which the core and the two-layer substrate are laminated;
Equipped with
a first wiring pattern is provided on the first surface of the base material and is arranged at a predetermined distance from the first coil pattern;
an inner peripheral end of the first coil pattern and one end of the first wiring pattern are electrically connected by a first jumper member;
a second wiring pattern is provided on the second surface of the base material and is arranged at a predetermined distance from the second coil pattern;
an inner peripheral end of the second coil pattern and one end of the second wiring pattern are electrically connected by a second jumper member;
the first coil pattern and the second coil pattern are a primary coil and a secondary coil, respectively;
the two-layer substrate is disposed such that the first surface faces the base;
the first coil pattern includes a pair of non-overlapping regions that do not overlap with the core when viewed in a thickness direction of the two-layer substrate , on both sides of the core in a longitudinal direction of the two-layer substrate ,
the base is provided with heat dissipation parts for dissipating heat of the two-layer board at positions corresponding to each of the pair of non-overlapping regions so as to protrude from the base toward the two-layer board,
an insulating heat dissipation member is provided between the heat dissipation portion and the non-overlapping region so as to be in close contact with the heat dissipation portion and the non-overlapping region;
the first jumper member is provided in one of the pair of non-overlapping regions,
the heat dissipation portion provided at a position corresponding to the one of the non-overlapping regions includes a first heat dissipation portion formed along a short-side direction of the two-layer board, and a second heat dissipation portion formed adjacent to the first heat dissipation portion and closer to the core than the first heat dissipation portion so as to provide a space for disposing the first jumper member;
A transformer characterized in that the second heat dissipation portion is in close contact with the wiring portion on the inner periphery of the first coil pattern to which the first jumper member is connected, via the heat dissipation member . 2. The transformer according to claim 1, wherein a gap is formed between the first heat dissipation portion and the second heat dissipation portion. the core includes a pair of cores arranged at a predetermined interval from each other when viewed in a thickness direction of the two-layer substrate,
the base is provided with a central heat dissipation portion disposed between the pair of cores so as to protrude from the base toward the two-layer substrate,
2. The transformer according to claim 1, wherein an insulating heat dissipation member is provided between the central heat dissipation portion and the two-layer substrate so as to be in close contact with the central heat dissipation portion and the two-layer substrate. an opening is formed in the two-layer substrate, and the first coil pattern and the second coil pattern are formed in a spiral shape so as to go around the opening;
a partition portion is provided on the base material at a center of the opening portion along a short-side direction of the two-layer substrate so as to divide the opening portion into two portions;
screw insertion holes into which screws for fixing the substrate to the base are inserted are formed at four corners of the two-layer substrate and at a center of the partition portion in the short side direction;
The base is provided with fixing portions for fixing the two-layer board, the fixing portions being formed adjacent to the screw insertion holes formed at the four corners of the two-layer board, the fixing portions protruding from a surface of the base,
The central heat dissipation portion is formed with a screw hole for fixing the two-layer board so as to be adjacent to the screw insertion hole formed in the partition portion,
4. The transformer according to claim 3, wherein the two-layer board is fixed to each of the fixing portions and the central heat dissipation portion at four corners and partition portions of the two-layer board by screws inserted into the screw insertion holes. The base is provided with two pairs of wall portions on both sides along the longitudinal direction,
4. The transformer according to claim 3, wherein the pair of walls are spaced apart from each other along the longitudinal direction, sandwiching the central heat dissipation portion, when viewed from the short-side direction. the first coil pattern has a first overlap region that overlaps with the core when viewed in a thickness direction of the two-layer substrate,
the second coil pattern has a second overlap region that overlaps with the core when viewed in the thickness direction,
2. The transformer according to claim 1 , wherein at least the first overlap region and the second overlap region are provided in the same position and with the same shape when viewed in the thickness direction.

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