JP2020161725A - Transformer - Google Patents

Abstract

To provide a transformer capable of suppressing complication of a structure of a substrate having a first coil pattern and a second coil pattern.SOLUTION: A transformer includes a substrate 30 which has a base material 31, a first coil pattern 32a provided for a first surface 31a provided for the base material 31, and a second coil pattern provided on a second surface of the base material 31. The first surface 31a is provided with a first wiring pattern 32b, and an end part 32e on an inner peripheral side of the first coil pattern 32a and an end part 32b of a first wiring pattern 32b are electrically connected by a first jumper pin 35. The second surface is provided with a second wiring pattern, and an end part on an inner peripheral side of the second coil pattern and one end part of the second wiring pattern are electrically connected by a second jumper pin.SELECTED DRAWING: Figure 5

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

A four-layer substrate provided with four layers of spiral coil patterns is disclosed in, for example, Patent Document 1.

JP-A-2009-016504

However, if the substrate is formed into a multilayer substrate having three or more layers (usually four or more layers), there is a problem that the structure of the substrate becomes complicated and the cost increases.

The present invention has been made in view of these points, and it is an object of the present invention to provide a transformer capable of suppressing the structure of a substrate having a first coil pattern and a second coil pattern from becoming complicated. And.

The transformer according to the present invention has an insulating base material, a conductive spiral first coil pattern provided on the first surface of the base material, and a conductive spiral provided on the second surface of the base material. A two-layer substrate having the shape of the second coil pattern, and a core that electromagnetically couples the first coil pattern and the second coil pattern are provided, and the first surface of the base material has the first surface. A first wiring pattern is provided which is arranged at a predetermined distance from one coil pattern, and an end portion on the inner peripheral side of the first coil pattern and one end portion of the first wiring pattern are first. It is electrically connected by one jumper member, and the second surface of the base material is provided with a second wiring pattern that is arranged at a predetermined distance from the second coil pattern. The inner peripheral 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 inner peripheral end of the first coil pattern and one end of the first wiring pattern are electrically connected by a first jumper member. As a result, the end portion on the inner peripheral side of the spiral first coil pattern can be electrically pulled out by the first jumper member. Similarly, the inner peripheral end of the second coil pattern and one end of the second wiring pattern are electrically connected by a second jumper member. As a result, the end portion on the inner peripheral side of the spiral second coil pattern can be electrically pulled out by the second jumper member. As a result, since it is not necessary to form the substrate into a multilayer substrate having three or more layers (usually four or more layers), it is possible to suppress the structure of the substrate from becoming complicated and suppress the increase in cost. it can.

In the transformer, preferably, the first coil pattern has a first overlapping region that overlaps the core when viewed from the thickness direction of the two-layer substrate, and the second coil pattern is viewed from the thickness direction. It has a second overlap region that overlaps with the core, and at least the first overlap region and the second overlap region are provided at the same position with the same shape 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 overlap region and the second overlap region are provided at the same position with the same shape when viewed from the thickness direction, the first overlap region and the second overlap region can be obtained. Can be brought close to each other, so that the heat of the coil pattern that generates a large amount of heat in the first coil pattern and the second coil pattern is dissipated to the coil pattern that generates a small amount of heat in the first coil pattern and the second coil pattern. (Heat conduction) is possible. Therefore, it is possible to prevent the temperature of the coil pattern having a large amount of heat generation from the first coil pattern and the second coil pattern from becoming too high, and thus it is possible to suppress the deterioration of the transformer characteristics.

The transformer preferably includes a metal housing including a flat base on which the core and the two-layer substrate are laminated, and the first coil pattern and the second coil pattern are each primary coil. And the secondary coil, the two-layer substrate is arranged so that the first surface faces the base, and the first coil pattern is the core when viewed from the thickness direction of the two-layer substrate. The base includes a non-overlapping region that does not overlap with the base, and a heat radiating portion for radiating heat from the two-layer substrate is provided so as to project from the base toward the two-layer substrate. An insulating heat radiating member is provided between the heat radiating portion and the non-overlapping region so as to be in close contact with the radiating portion and the non-overlapping region. With this configuration, the heat of the first coil pattern, which is the primary coil, can be efficiently radiated (heat conduction) to the heat radiating portion via the heat radiating member. Therefore, when a circuit configuration is used in which a larger current than the secondary coil is passed through the primary coil (the amount of heat generated by the primary coil is larger than the amount of heat generated by the secondary coil), the heat dissipation can be further improved. it can. Further, since the heat radiating member is insulating, metal can be used for the heat radiating portion, and the heat radiating property can be easily improved.

In the transformer, preferably, the inner peripheral end portion of the first coil pattern and the second coil pattern is arranged on one side of the core, and the first coil pattern and the second coil pattern are described. The outer peripheral end of the second coil pattern is arranged on the other side of the core, and the first wiring pattern and the one end of the second wiring pattern are unilateral to the core. It is arranged on the side portion, and the other end portion of the first wiring pattern and the second wiring pattern is arranged on the other side portion with respect to the core. With this configuration, the inner peripheral end of the first coil pattern and the second coil pattern, which are arranged on one side of the core, can be easily electrified to the other side of the core. Can be pulled out.

The transformer preferably includes a metal housing including the core and a flat base on which the two-layer substrate is laminated, and the cores are predetermined to each other when viewed from the thickness direction of the two-layer substrate. The base includes a pair of cores arranged at intervals, and the base is provided with a central heat radiating portion arranged between the pair of cores so as to project from the base toward the two-layer substrate side. An insulating heat radiating member is provided between the central heat radiating portion and the two-layer substrate so as to be in close contact with the central radiating portion and the two-layer substrate. The heat generated when a current flows through the first coil pattern and the second coil pattern tends to be trapped in the central portion of the substrate. Therefore, as described above, a central heat radiating portion arranged between the pair of cores is provided on the base, and heat is radiated between the central heat radiating portion and the two-layer substrate so as to be in close contact with the central heat radiating portion and the two-layer substrate. If the member is provided, the heat in the central portion of the two-layer substrate can be efficiently dissipated (heat conduction) to the central heat dissipation portion. Further, since the heat radiating member is insulating, metal can be used for the central heat radiating portion, and the heat radiating property can be easily improved.

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

It is a perspective view which shows the structure of the transformer which concerns on one Embodiment of this invention. It is an exploded perspective view which shows the structure of the transformer which concerns on one Embodiment of this invention. It is a perspective view which shows the structure of the housing of the transformer which concerns on one Embodiment of this invention. It is sectional drawing which follows the line 100-100 of FIG. It is a figure which shows the substrate of the transformer which concerns on one Embodiment of this invention from the 1st surface side. It is a figure which shows the substrate of the transformer which concerns on one Embodiment of this invention from the 2nd surface side. It is sectional drawing along the line 150-150 of FIG. It is an enlarged sectional view which shows the structure around the 1st jumper pin and the 2nd jumper pin of the transformer which concerns on one Embodiment of this invention.

Hereinafter, the structure of the transformer 1 (transformer) according to the 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 (core) 22, a heat dissipation sheet (heat dissipation member) 23, and a substrate (two-layer substrate). It is composed of 30, 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 such as copper or aluminum having good thermal conductivity. As shown in FIGS. 2 and 3, the housing 10 includes a flat plate-shaped base 11 on which a lower core 22, a substrate 30, an upper core 26, and the like are laminated and arranged, and is formed at four corners of the base 11. It is attached to a heat sink (not shown) using the screw insertion holes 11a. As will be described later, the housing 10 dissipates (heat conducts) heat generated in the lower core 22, the substrate 30, and the upper core 26 to a heat sink (not shown) via the base 11. A heat radiating sheet or the like having good thermal conductivity is arranged between the base 11 and the heat sink (not shown).

A pair of sheet mounting recesses 11b having a predetermined depth and in which the heat radiating sheet 21 is arranged are formed in the predetermined area of the base 11. The pair of sheet mounting recesses 11b are arranged at predetermined intervals in the direction of arrow AA'.

A central heat radiating portion 12 is formed in a portion of the base 11 between the pair of seat mounting recesses 11b so as to project upward (toward the substrate 30) from the upper surface of the base 11. The central heat radiating portion 12 is formed so as to extend in the direction of arrow BB'. Further, a screw hole 12a for fixing the substrate 30 is formed in the center of the central heat radiating portion 12.

The base 11 is provided with a first heat radiating portion 14a, a second heat radiating portion 14b, and a third heat radiating portion 14c so as to sandwich the pair of sheet mounting recesses 11b in the direction of the arrow AA'. The first heat radiating portion 14a, the second heat radiating portion 14b, and the third heat radiating portion 14c are formed so as to project upward from the upper surface of the base 11 and extend in the direction of the arrow BB'. The central heat radiating unit 12, the first heat radiating unit 14a, the second heat radiating unit 14b, and the third heat radiating unit 14c are formed so that the heights of the upper surfaces thereof are substantially the same.

The second heat radiating unit 14b is formed so that the length in the arrow BB'direction is shorter than that of the central heat radiating unit 12, the first heat radiating unit 14a, and the third heat radiating unit 14c. Further, the second heat radiating portion 14b is arranged in the direction of the arrow B'with respect to the center of the base 11 in the direction of the arrow BB'. Therefore, a space S is formed in the portion of the second heat radiating portion 14b in the direction of the arrow B. Further, as shown in FIG. 4, the second heat radiating portion 14b is arranged with a predetermined gap from the sheet mounting recess 11b, and the first heat radiating portion 14a has a predetermined gap from the second heat radiating portion 14b. Are arranged apart from each other. Further, the third heat radiating portion 14c is arranged with a predetermined gap from the sheet mounting recess 11b. By blowing cooling air into these gaps, it is possible to improve the heat dissipation of the transformer 1.

As shown in FIG. 3, the base 11 is provided with two pairs of wall portions 15 so as to sandwich the pair of seat mounting 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 portion 15. The screw insertion hole 15a is formed in an oval shape slightly longer in the vertical direction so that the mounting height of the screw can be adjusted.

In the vicinity of the four corners of the base 11, fixing portions 16 made of bolts for fixing the substrate 30 are provided so as to be adjacent to the screw insertion holes 11a. The fixing portion 16 is provided so as to project upward from the upper surface of the base 11, and is slightly smaller than the upper surfaces of the central heat radiation portion 12, the first heat radiation portion 14a, the second heat radiation portion 14b, and the third heat radiation portion 14c. It is formed so as to be only (for example, substantially the same height as the thickness of the heat radiating sheet 23).

The heat radiating sheet 21 is a heat conductive sheet that fills a gap and transfers heat, and is an electrically insulating sheet made of, for example, silicone or rubber, which has elasticity. For example, the heat radiating sheet 21 preferably has a thermal conductivity of 0.5 W / m · K or more. The thermal conductivity is preferably higher from the viewpoint of heat dissipation, but in the current manufacturing technology, the upper limit is about 50 W / m · K. Further, the heat radiating sheet 21 preferably has an Asker C hardness of 50 or less. The Ascar C hardness is preferably lower from the viewpoint of adhesion to uneven surfaces, but in the current manufacturing technology, about 1 is the lower limit value. Further, the heat radiating sheet 21 preferably has a breakdown voltage of 0.5 kV / mm or more. However, depending on the usage environment of the transformer 1 of the present embodiment, it may be applicable even if it is less than 0.5 kV / mm (for example, 0.1 kV / mm). Further, the dielectric breakdown voltage is preferably higher from the viewpoint of withstand voltage, but in the current manufacturing technology, the upper limit is about 30 kV / mm. The heat radiating sheet 21 may contain particles having good thermal conductivity such as ceramics and fillers, if necessary. The heat radiating sheets 23, 24 and 27 are formed of, for example, a heat radiating sheet made of the same material as the heat radiating sheet 21.

As shown in FIG. 2, the heat radiating sheets 21 are formed so as to extend in the direction of arrow BB', and are provided in pairs in the direction of arrow AA'with a predetermined interval from each other. The pair of heat radiating sheets 21 are arranged in the pair of sheet mounting recesses 11b, respectively. As will be described later, the heat radiating 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 upper surface of the sheet mounting recess 11b and the lower surface of the lower core 22 are arranged. It adheres tightly to and. As a result, when the lower core 22 generates heat, the heat of the lower core 22 is dissipated (heat conduction) to the base 11 of the housing 10 via the heat radiating sheet 21.

Four lower cores 22 are provided. The lower core 22 is formed of ferrite, a magnetic metal, a dust core, or the like.

The lower core 22 is composed of a U-shaped core in which convex portions 22b are formed at both ends of the upper surface 22a in the direction of the arrow BB'. The upper surface 22a of the lower core 22 is formed so as to be substantially flush with the upper surfaces of the central heat radiating portion 12, the first heat radiating portion 14a, the second heat radiating portion 14b, and the third heat radiating portion 14c.

An E-shaped core is formed by a pair of lower cores 22 adjacent to each other in the direction of arrow BB'. The lower core 22 may be formed by an E-shaped core instead of a U-shaped core. That is, the E-shaped core may not be composed of the lower core 22 composed of a pair of U-shaped cores, but may be composed of the lower core composed of one E-shaped core. A pair of E-shaped cores (a pair of lower cores 22) are provided in the direction of arrow AA'with a predetermined distance from each other. Each E-shaped core is formed to have substantially the same size and shape as the heat radiating sheet 21. Then, the entire lower surface of the E-shaped core comes into close contact with the heat radiating sheet 21.

The heat radiating sheet 23 is formed so as to avoid (do not overlap) the convex portion 22b of the lower core 22. Further, a slit 23a is formed in the central portion of the heat radiating sheet 23 in the direction of the arrow BB'at a position corresponding to the convex portion 22b of the lower core 22 and the screw hole 12a of the central heat radiating portion 12.

The heat radiating sheet 23 is arranged on the first region 23b arranged on the first heat radiating portion 14a and the second radiating portion 14b, and on the upper surface 22a of the E-shaped core (pair of lower cores 22) in the arrow A direction. The second region 23c, the third region 23d arranged on the central heat radiating portion 12, and the fourth region 23e arranged on the upper surface 22a of the E-shaped core (pair of lower cores 22) in the direction of arrow A'. , A fifth region 23f arranged on the third heat radiating unit 14c, and the like. The heat radiating sheet 23 is in close contact with the upper surfaces of 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 of the housing 10 without a gap, and has a gap between the upper surfaces 22a of the pair of E-shaped cores. Adhere without. As a result, when the lower core 22 generates heat, the heat of the lower core 22 passes through the heat radiating sheet 23 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 of the housing 10. Heat is dissipated (heat conduction) to the portion 14c.

Further, the substrate 30 is arranged on the heat radiating sheet 23. The heat radiating sheet 23 is in close contact with the first conductive layer 32 described later of the substrate 30 without any gap. As a result, when the substrate 30 generates heat, the heat of the substrate 30 is dissipated to the first heat dissipation portion 14a, the second heat dissipation portion 14b, the central heat dissipation portion 12 and the third heat dissipation portion 14c of the housing 10 via the heat dissipation sheet 23. (Heat conduction). When the temperature of the substrate 30 is higher than the temperature of the lower core 22, the heat of the substrate 30 is radiated (heat conduction) to the lower core 22 via the heat radiating sheet 23, and the temperature of the lower core 22 is increased. When is higher than the temperature of the substrate 30, the heat of the lower core 22 is radiated (heat conduction) to the substrate 30 via the heat radiating sheet 23.

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

As shown in FIG. 2, the heat radiating sheets 24 are formed so as to extend in the direction of the arrow AA'and are provided in pairs in the direction of the arrow BB'with a predetermined interval from each other. The heat radiating sheet 24 is arranged on the second conductive layer 33 of the substrate 30. As will be described later, the heat radiating sheet 24 is arranged between the second conductive layer 33 of the substrate 30 and the lower surface of the upper core 26 so as to be placed on the second conductive layer 33 of the substrate 30 and the lower surface of the upper core 26. In close contact. As a result, when the temperature of the substrate 30 is higher than the temperature of the upper core 26, the heat of the substrate 30 is dissipated (heat conduction) to the upper core 26 via the heat radiating sheet 24, and the temperature of the upper core 26 becomes the temperature of the substrate 30. When the temperature is higher than the above temperature, the heat of the upper core 26 is radiated (heat conduction) to the substrate 30 via the heat radiating sheet 24.

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

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

The spacers 25a and 25b prevent the heat radiating sheets 23 and 24 from being over-compressed in the thickness direction in a state where the upper core 26 is arranged on the heat radiating sheet 24, and the lower surface of the upper core 26 and the upper surface 22a of the lower core 22. This is for defining the distance from and to a predetermined size. The materials of the spacers 25a and 25b are not particularly limited, but for example, an insulating resin substrate or the like can be used.

The upper core 26 is made of a flat plate-shaped I-shaped core, and is formed of a ferrite, a magnetic metal, a dust core, or the like, like the lower core 22. The upper cores 26 are formed so as to extend in the direction of arrow BB', and are provided in pairs in the direction of arrow AA'with a predetermined distance from each other. The upper core 26 is formed to have substantially the same size and shape as the E-shaped core when viewed from the thickness direction.

The upper core 26 and the E-shaped core (a 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 is passed through the first coil pattern 32a of the substrate 30, 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 the magnetic flux generated in the core. The upper core 26 and the E-shaped core (a pair of lower cores 22) may be arranged so as to be in contact with each other, or may be arranged at a predetermined distance from each other.

The heat radiating sheets 27 are formed so as to extend in the direction of arrow BB', and are provided in pairs in the direction of arrow AA'with a predetermined interval. The pair of heat radiating sheets 27 are respectively arranged on the pair of upper cores 26. The heat radiating sheet 27 is formed to have substantially the same size and shape as the upper core 26 when viewed from the thickness direction.

As will be described later, the heat radiating sheet 27 is arranged between the upper surface of the upper core 26 and the lower surface of the pressing plate 28 so that the upper surface of the upper core 26 and the lower surface of the pressing plate 28 are in close contact with each other without a gap. As a result, when the upper core 26 generates heat, the heat of the upper core 26 is dissipated (heat conduction) to the pressing plate 28 via the heat radiating sheet 27.

The presser plate 28 is made of a metal such as copper or aluminum having good thermal conductivity. The presser plates 28 are formed so as to extend in the direction of arrow BB', and are provided in pairs in the direction of arrow AA'with a predetermined interval. The pair of pressing plates 28 are arranged on the pair of heat radiating sheets 27, respectively. The presser plate 28 is formed to have substantially the same size and shape as the heat radiating sheet 27 when viewed from the thickness direction.

A pair of screw holes 28a are provided on each side surface of the presser 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 portion 15 of the housing 10 in a state where the heat radiating sheet 27 is pressed.

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

As shown in FIGS. 5 and 6, the substrate 30 has a base material 31, a first conductive layer 32 provided on the first surface 31a of the base material 31, and a second surface 31b provided on the second surface 31b of the base material 31. 2 Conductive layer 33 and. The substrate 30 is arranged so that the first surface 31a faces the base 11 of the housing 10 (the first surface 31a faces downward). In addition, in order to facilitate understanding, the first conductive layer 32 is hatched in FIG. 5, and the second conductive layer 33 is hatched in FIG.

The base material 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 base material 31 is formed in a substantially H shape when viewed from the thickness direction, and the length in the arrow BB'direction is longer at both ends of the base material 31 in the arrow AA'direction than the other parts. Part 31c is formed. The wide portion 31c is arranged outside in the direction of arrow AA'with respect to the pair of E-shaped cores.

An opening 31d penetrating in the thickness direction is formed at a predetermined position of the base material 31. The openings 31d are formed so as to extend in the direction of arrow AA', and are provided in pairs in the direction of arrow AA'with a predetermined distance from each other. The opening 31d is formed to be slightly larger than the central convex portion 22b in the direction of the arrow BB'of the E-shaped core, and the E-shaped core is formed in the opening 31d with the substrate 30 arranged on the heat dissipation sheet 23. The central convex portion 22b in the direction of the arrow BB'is inserted.

Screw insertion holes 31e are formed at the four corners of the base material 31 so as to correspond to the fixing portions 16 of the housing 10, and the screw holes 12a of the central heat dissipation portion 12 correspond to the center of the base material 31. The screw insertion hole 31f is formed as described above. The base material 31 is fixed to the fixing portion 16 and the central heat radiating portion 12 of the housing 10 by 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 to a predetermined pattern on the first surface 31a of the base material 31 and curing it. The Cu layer may be formed by etching a solid copper foil attached to the entire surface of the first surface 31a of the base material 31 into a predetermined pattern.

As shown in FIG. 5, the first conductive layer 32 has a spiral first coil pattern 32a as a primary coil and a substantially linear shape arranged at a predetermined distance from the first coil pattern 32a. The first wiring pattern 32b and the like are included. The first coil pattern 32a generates more heat than the second 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 is formed by connecting a portion 32c extending parallel to the arrow AA'direction and a portion 32d extending parallel to the arrow BB'direction, and here, from the inner peripheral side to the outer peripheral side. It is formed over about two and a half laps in the counterclockwise direction. The portion 32c is formed so as to have a line width approximately twice that of the portion 32d.

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

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

Here, in the present embodiment, as shown in FIGS. 5 and 8, the first jumper pin (the first jumper pin (the first jumper pin) is provided at the inner peripheral end 32e of the first coil pattern 32a via the opening 34a of the resist layer 34. One end of 1 jumper member) 35 is soldered. Further, the other end of the first jumper pin 35 is soldered to one end 32g of the first wiring pattern 32b via the opening 34b of the resist layer 34. That is, the end portion 32e on the inner peripheral side of the first coil pattern 32a and the one end portion 32g of the first wiring pattern 32b are electrically connected by a first jumper pin 35 straddling a part of the first coil pattern 32a. ing.

As shown in FIG. 6, the second conductive layer 33 has a spiral second coil pattern 33a as a secondary coil and a substantially linear shape arranged at a predetermined distance from the second coil pattern 33a. The second wiring pattern 33b and the like are included.

The second coil pattern 33a is formed in a spiral shape around the pair of openings 31d. The second coil pattern 33a is formed by connecting a portion 33c extending parallel to the arrow AA'direction and a portion 33d extending parallel to the arrow BB'direction, and here, from the inner peripheral side to the outer peripheral side. It is formed over about two and a half laps in the clockwise direction. The portion 33c is formed so as to have a line width approximately twice that of the portion 33d.

The inner peripheral end 33e of the second coil pattern 33a is arranged in the direction of the arrow A with respect to the pair of E-shaped cores, and the outer peripheral end 33f of the second coil pattern 33a is a pair. It is arranged in the direction of arrow A'with respect to the E-shaped core. An insulating resist layer 36 is formed in substantially the entire area of the wide portion 31c in the direction of arrow A. Then, an opening 36a is formed in the resist layer 36 on the end 33e on the inner peripheral side of the second coil pattern 33a.

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

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

Further, in the present embodiment, as shown in FIGS. 6 and 8, a second jumper pin (second jumper pin (second) is provided at the end 33e on the inner peripheral side of the second coil pattern 33a via the opening 36a of the resist layer 36. One end of the jumper member) 37 is soldered. Further, the other end of the second jumper pin 37 is soldered to one end 33g of the second wiring pattern 33b via the opening 36b of the resist layer 36. That is, the end 33e on the inner peripheral side of the second coil pattern 33a and the one end 33g of the second wiring pattern 33b are electrically connected by a second jumper pin 37 straddling a part of the second coil pattern 33a. ing. The openings 36a and 36b of the resist layer 36 are formed at the same positions and the same size as the openings 34a and 34b of the resist layer 34 when viewed from the thickness direction.

Further, in the present embodiment, as shown in FIGS. 5 and 6, the first coil pattern 32a overlaps with the cores (upper core 26 and lower core 22) when viewed from the thickness direction of the substrate 30. 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 from the thickness direction of the substrate 30. At least the first overlap region R32 and the second overlap region R33 are provided in the same shape and at the same position when viewed from the thickness direction, that is, plane-symmetrically with the base material 31 as the center. In the present embodiment, 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 viewed from the thickness direction. They are provided in the same shape and at the same position (plane symmetrically). Further, substantially the entire region of the first wiring pattern 32b (the region excluding the other end 32h) and substantially the entire region of the second wiring pattern 33b (the region excluding the other end 33h) have the same shape when viewed from the thickness direction. Are provided at the same position (symmetrically).

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

In the present embodiment, as described above, the inner peripheral end 32e of the first coil pattern 32a and the one end 32g of the first wiring pattern 32b are electrically connected by the first jumper pin 35. As a result, the end portion 32e on the inner peripheral side of the spiral first coil pattern 32a can be electrically pulled out by the first jumper pin 35. Similarly, the inner peripheral end 33e of the second coil pattern 33a and the one end 33g of the second wiring pattern 33b are electrically connected by a second jumper pin 37. As a result, the end 33e on the inner peripheral side of the spiral second coil pattern 33a can be electrically pulled out by the second jumper pin 37. As a result, it is not necessary to form the substrate 30 into a multilayer substrate having three or more layers (usually four or more layers), so that the structure of the substrate 30 is suppressed from becoming complicated and the cost increase is suppressed. be able to.

Further, 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 base material 31, respectively, the first coil pattern 32a and the second coil pattern 33a are used as the inner layer of the base material 31. Unlike the case where the substrate 30 is provided as a 4-layer substrate and the first coil pattern 32a and the second coil pattern 33a are provided on the inner two layers, heat is generated by the first coil pattern 32a and the second coil pattern 33a. It is possible to suppress heat from being trapped inside the substrate 30. That is, it is possible to suppress the decrease in heat dissipation of the substrate 30.

Further, as described above, at least the first overlap region R32 and the second overlap region R33 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 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, as described above, by providing at least the first overlap region R32 and the second overlap region R33 at the same position with the same shape when viewed from the thickness direction, the first overlap region R32 and the second overlap region R33 Can be brought close to each other, so that the heat of the first coil pattern 32a, which generates a large amount of heat, can be dissipated (heat conduction) 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 thus it is possible to prevent the characteristics of the transformer 1 from deteriorating.

Further, as described above, the first coil pattern 32a includes a non-overlapping region (arranged on the wide portion 31c) that does not overlap with the core when viewed from the thickness direction of the substrate 30, and is the first with the non-overlapping region. A heat-dissipating sheet is placed between the heat-dissipating portion 14a, the second heat-dissipating portion 14b, and the third heat-dissipating portion 14c so as to be in close contact with the non-overlapping region, the first heat-dissipating portion 14a, the second heat-dissipating portion 14b, and the third heat-dissipating portion 14c. 23 is provided. As a result, the heat of the first coil pattern 32a can be efficiently dissipated (heat conduction) to the housing 10 via the heat dissipation sheet 21. Therefore, when a circuit configuration is used in which a larger current than the secondary coil is passed through the primary coil (the amount of heat generated by the primary coil is larger than the amount of heat generated by the secondary coil), the heat dissipation can be further improved. it can. Further, since the heat radiating sheet 21 has an insulating property, metal can be used for the first heat radiating section 14a, the second heat radiating section 14b, and the third heat radiating section 14c, and the heat radiating property can be easily improved.

Further, as described above, the inner peripheral end portions 32e and 33e of the first coil pattern 32a and the second coil pattern 33a are located in the portion in the direction of arrow A with respect to the cores (lower core 22 and upper core 26). The first coil pattern 32a and the second coil pattern 33a are arranged so that the outer peripheral end portions 32f and 33f are arranged in the portion in the direction of arrow A'with respect to the cores (lower core 22 and upper core 26). The one ends 32g and 33g of the first wiring pattern 32b and the second wiring pattern 33b are arranged in the direction of the arrow A with respect to the cores (lower core 22 and upper core 26), and the first wiring The other ends 32h and 33h of the pattern 32b and the second wiring pattern 33b are arranged in the portion in the direction of the arrow A'with respect to the cores (lower core 22 and upper core 26). As a result, the inner peripheral end portions 32e and 33e of the first coil pattern 32a and the second coil pattern 33a, which are arranged in the portion in the direction of the arrow A with respect to the core (lower core 22 and upper core 26), are separated. It can be easily electrically pulled out to the portion in the direction of arrow A'with respect to the core (lower core 22 and upper core 26).

Normally, the heat generated when a current flows through the first coil pattern 32a and the second coil pattern 33a tends to be trapped in the central portion of the substrate 30. Therefore, as described above, the central heat radiating portion 12 is provided between the pair of E-shaped cores, and the heat radiating sheet 21 is provided between the central heat radiating portion 12 and the substrate 30 so as to be in close contact with the central heat radiating portion 12 and the substrate 30. By providing the heat, the heat in the central portion of the substrate 30 can be efficiently dissipated (heat conduction) to the central heat radiating portion 12. Further, since the heat radiating sheet 21 is insulating, metal can be used for the central heat radiating portion 12, and the heat radiating property can be easily improved.

Further, by using the heat-dissipating sheets 21, 23, 24 and 27 having elasticity as the heat-dissipating member, vibrations and shocks can be absorbed by the heat-dissipating sheets 21, 23, 24 and 27, so that the substrate 30 and the core (lower). It is possible to prevent the side core 22 and the upper core 26) from being damaged by vibration or impact.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not considered to be restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the above-described embodiment, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

For example, in the above embodiment, an example in which the housing 10 and the holding plate 28 are made of metal has been shown, but the present invention is not limited to this. For example, the housing 10 and the holding plate 28 may be made of an insulating ceramic or the like. In this case, it is also possible to use a heat radiating sheet having no insulating property.

Further, in the above embodiment, an example in which a heat radiating sheet is used as the heat radiating member has been shown, but the present invention is not limited to this. As the heat radiating member, for example, grease containing a metal, a thermoplastic resin having thermal conductivity, or a thermosetting resin can be used.

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

Further, in the above embodiment, an example in which the first jumper pin 35 is attached to the first surface 31a side of the substrate 30 and the second jumper pin 37 is attached to the second surface 31b side of the substrate 30 has been shown. Not limited to this. For example, the end 32e on the inner peripheral side of the first coil pattern 32a and the one end 32g of the first wiring pattern 32b are electrically connected to the second surface 31b side by through holes, respectively, and the inner circumference of the first coil pattern 32a is formed. The side end portion 32e and the one end portion 32g of the first wiring pattern 32b may be electrically connected by a first jumper pin 35 attached to the second surface 31b side. Similarly, the end 33e on the inner peripheral side of the second coil pattern 33a and the one end 33g of the second wiring pattern 33b are electrically connected to the first surface 31a side by through holes, respectively, and inside the second coil pattern 33a. The peripheral end 33e and the 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 part, 14a: First heat dissipation part (heat dissipation part), 14b: Second heat dissipation part (heat dissipation part), 14c: Third heat dissipation part (heat dissipation part) Part), 21: Heat dissipation sheet (heat dissipation member), 22: Lower core (core), 26: Upper core (core), 30: Substrate (two-layer substrate), 31: Substrate, 31a: First surface, 31b : 2nd surface, 32a: 1st coil pattern, 32b: 1st wiring pattern, 32e: inner peripheral side end, 32f: outer peripheral side end, 32g: one end, 32h: other end, 33a: first 2 coil pattern, 33b: 2nd wiring pattern, 33e: inner peripheral side end, 33f: outer peripheral side end, 33g: 1 end, 33h: other end, 35: 1st jumper pin (1st jumper member) ), 37: 2nd jumper pin (2nd jumper member), R32: 1st overlap area, R33: 2nd overlap area

Claims (5)

An insulating base material, a conductive spiral first coil pattern provided on the first surface of the base material, and a conductive spiral second coil pattern provided on the second surface of the base material. With a two-layer substrate having,
A core that electromagnetically couples the first coil pattern and the second coil pattern,
With
A first wiring pattern arranged at a predetermined distance from the first coil pattern is provided on the first surface of the base material.
The 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 so as to be arranged at a predetermined distance from the second coil pattern.
A transformer characterized in that an end portion on the inner peripheral side of the second coil pattern and one end portion of the second wiring pattern are electrically connected by a second jumper member. The first coil pattern has a first overlapping region that overlaps with the core when viewed from the thickness direction of the two-layer substrate.
The second coil pattern has a second overlap region that overlaps with the core when viewed from the thickness direction.
The transformer according to claim 1, wherein at least the first overlap region and the second overlap region are provided at the same position with the same shape when viewed from the thickness direction. A metal housing including a flat base on which the core and the two-layer substrate are laminated is provided.
The first coil pattern and the second coil pattern are a primary coil and a secondary coil, respectively.
The two-layer substrate is arranged so that the first surface faces the base.
The first coil pattern includes a non-overlapping region that does not overlap with the core when viewed from the thickness direction of the two-layer substrate.
The base is provided with a heat radiating portion for radiating heat from the two-layer substrate so as to project from the base toward the two-layer substrate.
According to claim 1 or 2, an insulating heat radiating member is provided between the heat radiating portion and the non-overlapping region so as to be in close contact with the heat radiating portion and the non-overlapping region. The transformer described. The end portion of the first coil pattern and the second coil pattern on the inner peripheral side is arranged on one side of the core.
The outer peripheral end of the first coil pattern and the second coil pattern is arranged on the other side of the core.
The first wiring pattern and the one end portion of the second wiring pattern are arranged on one side of the core.
The transformer according to any one of claims 1 to 3, wherein the other end of the first wiring pattern and the second wiring pattern is arranged on the other side of the core. .. A metal housing including a flat base on which the core and the two-layer substrate are laminated is provided.
The core includes a pair of cores arranged at predetermined intervals from each other when viewed from the thickness direction of the two-layer substrate.
The base is provided with a central heat radiating portion arranged between the pair of cores so as to project from the base toward the two-layer substrate side.
Claims 1 to 4, wherein an insulating heat radiating member is provided between the central heat radiating portion and the two-layer substrate so as to be in close contact with the central heat radiating portion and the two-layer substrate. The transformer according to any one item.

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