JP2012134291A - Electronic circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic circuit device having an electronic component in which eddy current loss can be reduced efficiently while reducing the thickness and the size.SOLUTION: The electronic circuit device is provided with an electronic component (a first transformer (3)) which has a core (33) where a first core (332C) and a magnetic gap (3G) are arranged in a first direction, a small number of turn winding (32) arranged around the first core and having a first clearance L1 from the peripheral surface of the first core in a second direction intersecting the first direction, and a large number of turn winding (31) arranged around a magnetic gap while being laminated on the small number of turn winding in the first direction and having a second clearance L2 larger than the first clearance L1 from the peripheral surface of the first core in the second direction.

Description

  The present invention relates to an electronic circuit device, and more particularly to an electronic circuit device on which an electronic component having a magnetic material is mounted.

  For example, a DC-DC converter is incorporated in a power supply unit of a general-purpose television. The DC-DC converter converts, for example, a DC voltage converted from a 100 V AC voltage for general home use into a DC voltage used for a control circuit unit, a drive circuit unit, and the like. The DC-DC converter finally generates a DC voltage of 12V or 24V.

  In developing general-purpose televisions such as liquid crystal televisions and plasma televisions that are becoming thinner and larger in screen, it is important to make power supply units thinner and smaller. Patent Document 1 below discloses a coil device that is optimal for reducing the thickness and size of a power supply unit. This coil device uses a laminated sheet coil. The laminated coil sheet of the coil device sequentially laminates a primary coil substrate, a secondary coil substrate, and a primary coil substrate. A coil sheet is provided on each of the primary coil substrate and the secondary coil substrate. In the core mounting hole of the laminated sheet coil, the protruding portion of the upper core portion is attached from the front surface side of the laminated sheet coil, the protruding portion of the lower core portion is attached from the back surface side, and there is a gap between both protruding portions. Is provided. In this coil device, the coil sheet (secondary coil) of the secondary coil substrate close to the position of the gap is separated from the gap, and the leakage magnetic flux from the gap passing through this sheet coil can be reduced. There is a feature that energy loss can be reduced.

  Further, Patent Document 2 below discloses an electromagnetic induction device such as an inductance, a transformer or the like with high accuracy of an inductance value, a transformation ratio, and a current transformation ratio. The electromagnetic induction device includes a magnetic core having a gap portion in a part of a magnetic path, and a winding wound around the magnetic core by skipping the gap portion.

Japanese Patent Laid-Open No. 9-162035 Japanese Unexamined Patent Publication No. 1-286408

  However, in the coil device disclosed in Patent Document 1 and the electromagnetic induction device disclosed in Patent Document 2, the following points have not been considered.

  First, in the coil device disclosed in Patent Document 1, each of laminated sheet coils is a primary coil (multiple winding: P), a secondary coil (small number winding: S), and a primary coil (multiple winding: P). These coil sheets are sequentially laminated, and the coil sheet closest to the gap is a secondary coil. Since the volume of the coil sheet that is the secondary coil is set larger than the volume of the coil sheet that is the primary coil, the coil sheet that is the secondary coil can easily pick up leakage magnetic flux from the gap. For this reason, it has been difficult to efficiently reduce eddy current loss.

  On the other hand, in the electromagnetic induction device disclosed in Patent Document 2, since the winding is wound around the magnetic core by skipping the gap portion, useless space is required around the gap portion, and the thickness and size can be reduced. It was difficult to realize.

  The present invention has been made to solve the above problems. Accordingly, the present invention is to provide an electronic circuit device including an electronic component capable of efficiently reducing eddy current loss while realizing a reduction in thickness and size.

  In order to solve the above problems, according to a first feature of an embodiment of the present invention, there is provided an electronic circuit device comprising: a magnetic body in which a magnetic core and a magnetic gap are arranged in a first direction; A minority winding disposed around the core having a first separation distance from the circumferential surface of the magnetic core in the second direction intersecting, and laminated in the first direction on the minority winding, and in the second direction And an electronic component having a plurality of windings disposed around the magnetic gap and having a second separation distance larger than the first separation distance from the circumferential surface of the magnetic core.

  In the electronic circuit device according to the first feature, the fourth separation distance is set between the magnetic gap and the minority winding and between the magnetic gap and the majority winding, and the fourth separation distance is the second separation distance. It is preferable that the distance is set.

  In the electronic circuit device according to the first feature, the minority winding is constituted by the first conductor disposed on the surface of the first insulating base, and the majority winding is the surface of the second insulating base. The electronic component is a sheet transformer in which each of the first insulating base, the first conductor, the second insulating base, and the second conductor is laminated. It is preferable that

  In the electronic circuit device according to the first feature, in the minority winding, the width dimension of the region having the first separation distance from at least the magnetic core of the first conductor is set smaller than the width dimension of the other region, In the multiple windings, it is preferable that the width dimension of the region having the second separation distance from at least the magnetic core of the second conductor is set smaller than the width dimension of the other regions.

  In the electronic circuit device according to the first feature, the width dimension of the region where the side surface of the first conductor is opposed to the magnetic core or the magnetic body in the minority winding is set smaller than the width dimension of the other regions. In the multiple windings, it is preferable that the width dimension of the region where the side surface of the second conductor and the magnetic gap, the magnetic core, or the magnetic body face each other is set smaller than the width dimension of the other regions.

  In the electronic circuit device according to the first feature, it is preferable that a heat radiator is mounted on the first conductor of the minority winding and the second conductor of the majority winding.

  According to a second feature of an embodiment of the present invention, in the electronic circuit device, a magnetic body in which the first magnetic core, the magnetic gap, and the second magnetic core are arranged in the first direction, and the first direction, A first minority winding disposed around the first magnetic core and having a first separation distance from the circumferential surface of the first magnetic core in the intersecting second direction; and the first minority winding in the first direction. A plurality of windings stacked around the magnetic gap and having a second spacing distance greater than the first spacing distance from the circumferential surface of the first magnetic core in the second direction, wherein the windings are stacked on the minority windings. In the first direction, a plurality of windings are interposed and stacked on the first minority winding, and in the second direction, the third separation distance is smaller than the second separation distance from the peripheral surface of the second magnetic core. And an electronic component having a second minority winding disposed around the second magnetic core.

  According to the present invention, it is an object of the present invention to provide an electronic circuit device including an electronic component that can efficiently reduce eddy current loss while realizing a reduction in thickness and size.

1 is a circuit system block diagram of an electronic circuit device according to Embodiment 1 of the present invention. It is the top view (top view) which removed the resin sealing body of the electronic circuit device which concerns on Example 1. FIG. It is the bottom view (bottom view) which removed the resin sealing body of the electronic circuit device shown in FIG. FIG. 4 is a side cross-sectional view of the electronic circuit device shown in FIGS. 2 and 3. FIG. 4 is an overall perspective view including a resin sealing body of the electronic circuit device shown in FIGS. 2 to 3. 1 is an exploded perspective view of a first transformer (electronic component) of an electronic circuit device according to Embodiment 1. FIG. It is principal part sectional drawing of the 1st trans | transformer shown in FIG. FIG. 8 is a plan view of a part of the minority winding of the first transformer shown in FIGS. 6 and 7 and an insulating substrate. FIG. 8 is a plan view of multiple windings and an insulating substrate of the first transformer shown in FIGS. 6 and 7. FIG. 8 is a plan view of another part of the minority winding of the first transformer shown in FIGS. 6 and 7 and an insulating substrate. FIG. 3 is an exploded plan view for explaining a lamination state and a connection state of a multiplicity winding and a small number winding of the first transformer according to the first embodiment. It is a figure which shows the relationship between the wiring width of the 1st trans | transformer which concerns on Example 1, and loss. It is a top view of a part of minority winding of a 1st transformer, and an insulating base material in an electronic circuit device concerning Example 2 of the present invention. It is principal part sectional drawing of a 1st trans | transformer in the electronic circuit apparatus which concerns on Example 3 of this invention. (A) is a top view of the 1st transformer in the electronic circuit device concerning Example 4 of the present invention, and (B) is a side view of the 1st transformer.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic and different from actual ones. In addition, there may be a case where the dimensional relationships and ratios are different between the drawings.

  Further, the following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention specifies the arrangement of each component as follows. It is not what you do. The technical idea of the present invention can be variously modified within the scope of the claims.

Example 1
Embodiment 1 of the present invention describes an example in which the present invention is applied to an electronic circuit device as a power supply module incorporated in a power supply unit. Here, the electronic circuit device is a DC-DC converter.

[Electronic circuit system block configuration of electronic circuit device]
As shown in FIG. 1, the electronic circuit device 1 according to the first embodiment is constructed by using a DC-DC converter as one power supply module. The electronic circuit device 1 includes a transistor unit 2, a first transformer (electronic component) 3 used as a main transformer, capacitors 41, 42 and 43 (electronic components), a diode (electronic component) 5, a control unit 6, and a drive. It includes at least a plurality of electronic components such as a second transformer (electronic component) 7 and a temperature detection unit 8 that are used as a power transformer. In the electronic circuit device 1, the input terminals Vin +, Vin-, the output terminals Vout +, Vout-, the DC voltage terminal DCIN, the switching signal terminal ON / OFF, the output voltage adjustment terminal TRM, the remote sensing terminals Vs +, Vs- are arranged. It is installed.

  The transistor section 2 includes a first insulated gate transistor (hereinafter simply referred to as an IGFET (Insulated Gate Field Effect Transistor)) 21, a second IGFET 22, and diodes 23 and 24. Here, IGFET is used in the meaning including both MOSFET (metal oxide semiconductor field effect transistor) and MISFET (metal insulated semiconductor field effect transistor). The transistor unit 2 is not limited to an IGFET as long as it has an equivalent function, and for example, an IGBT (insulated gate bipolar transistor), a bipolar transistor, or the like can be used.

  One end of the main electrode of the first IGFET 21 is connected to the input terminal Vin +, the other end of the main electrode is connected to one end of the main electrode of the second IGFET 22, and the gate electrode is connected to the second transformer 7. A diode 23 is provided in the reverse bias direction between one end and the other end of the main electrode of the first IGFET 21. The other end of the main electrode of the second IGFET 22 is connected to the input terminal Vin−, and the gate electrode is connected to the second transformer 7. A diode 24 is provided in the reverse bias direction between one end and the other end of the main electrode of the second IGFET 22. A capacitor 42 is inserted between the input terminals Vin + and Vin−.

  The first transformer (electronic circuit according to the first embodiment) 3 includes a multiple winding (P) 31 used as a primary coil, a small winding (S) 32 used as a secondary coil, and a core (magnetic). Body) 33. One end of the multiple winding 31 is connected to the output of the transistor unit 2, that is, the other end of the main electrode of the first IGFET 21 and one end of the main electrode of the second IGFET 22, and the other end is electrically connected in series with the capacitor 41. Connected to the input terminal Vin-. That is, the multiple winding 31 is a winding (coil) connected to the commercial power supply side. One end of the minority winding 32 is connected to the output terminal Vout + with the diode 5 electrically connected in series, and the other end is connected to the output terminal Vout−.

  Between the output terminals Vout + and Vout−, each of the capacitor 43 and the temperature detecting unit 8 is electrically connected in parallel. The temperature detection unit 8 detects the temperature of the electronic circuit device 1 and outputs the detection result to the control unit 6. In the control unit 6, when a preset temperature rise is detected based on the detection result from the temperature detection unit 8, the control for stopping the operation of the transistor unit 2 through the second transformer 7, that is, this Control for stopping the operation of the electronic circuit system can be performed.

  Although not illustrated, the control unit 6 includes at least a control IC and a photocoupler. The control unit 6 controls the operation of the DC-DC converter of the electronic circuit device 1 based on a switching signal input from the switching signal terminal ON / OFF.

[Operation of electronic circuit device]
In the electronic circuit device 1 according to the first embodiment shown in FIG. 1, first, a DC voltage before conversion is applied between the input terminals Vin + and Vin−, and further, a DC voltage, for example, 12V is supplied to the DC voltage terminal DCIN. A switching signal (activation signal) of the electronic circuit device 1 is given to the terminals ON / OFF. When the ON signal is given to the switching signal terminal ON / OFF, the control unit 6 performs the ON operation of the first IGFET 21 of the transistor unit 2 through the second transformer 7 and performs the OFF operation of the second IGFET 22. . When the ON operation of the first IGFET 21 is performed, a direct current flows from the transistor unit 2 (the other end of the main electrode of the first IGFET 21) to the multiple windings 31 of the first transformer 3. When a direct current flows through the majority winding 31, a direct current is generated in the minority winding 32 by electromagnetic induction. This DC voltage is output as a DC voltage after conversion between the output terminals Vout + and Vout−.

  In the electronic circuit device 1 according to the first embodiment, the DC voltage before conversion is, for example, 385V, and the DC voltage after conversion is, for example, 12V or 24V.

[Basic device structure of electronic circuit device (overall structure)]
The basic device cross-sectional structure of the electronic circuit device 1 according to the first embodiment is as shown in FIGS. The electronic circuit device 1 is disposed on a substrate (circuit board) 11 having a first surface 11A and a second surface 11B opposite to the first surface 11A, and from the first surface 11A to the second surface 11B. The first transformer (electronic component) 3 and the bottom surface of the first transformer 3 (the lower surface in FIG. 4 and the mounting surface side of the electronic circuit device 1) are arranged facing each other. A stress buffer 91 made of a plate-making material, and a resin sealing body 17 that covers at least the first transformer 3 side of the substrate 11, the first transformer 3, and the stress buffer 91 are provided.

  In the first embodiment, a magnetic material is used for the core 33 constituting the first transformer 3 of the electronic circuit device 1, and this magnetic material is a ferromagnetic material. The detailed structure of the first transformer 3 will be described later.

  In the first embodiment, the second transformer (electronic component) 7 has the same structure as the first transformer 3, but is set to a smaller size (smaller conversion efficiency) than the first transformer 3. Has been. Further, a stress buffer 91 is disposed on the bottom surface of the second transformer 7 so as to face each other, but the second transformer 7 and the stress buffer 91 are slightly separated from each other.

  Further, in the first embodiment, the first transformer 3 and the second transformer 7 are used in the electronic circuit device 1, but the electronic component constructed by the magnetic material is not limited to this. The circuit device 1 may be equipped with electronic components constructed of magnetic materials such as reactances and inductors.

  The stress buffer 91 has a function of reducing the stress exerted on the magnetic body such as the first transformer 3 by the thermal contraction of the resin sealing body 17 in the first embodiment, and further the heat generated from the magnetic body. It has a function of releasing (heat generated by the operation of the first transformer 3 and the second transformer 7) to the outside of the resin sealing body 17.

[Configuration of board (circuit board)]
As shown in FIGS. 2 to 4, the structure of the substrate 11 of the electronic circuit device 1 is not clearly shown, but the insulating base, the surface of the insulating base (the first surface 11A side), And a conductor disposed on at least one of the opposing back surfaces (second surface 11B side). Although the number of stacked layers is not particularly limited, in Example 1, the substrate 11 has a single-layer structure having one plate-like insulating base, and each of the first surface 11A and the second surface 11B. Conductors (terminals, wirings, etc.) are disposed on the surface. The conductors disposed on the first surface 11A and the second surface 11B are connection hole wiring (through-hole wiring or via wiring) disposed from the first surface 11A to the second surface 11B of the substrate 11. ). The substrate 11 may include a multilayer insulating substrate having two or more layers.

  The insulating base material of the board | substrate 11 is comprised by the glass epoxy resin board | substrate used frequently for the printed wiring board in Example 1. FIG. Although not necessarily limited to this value, the substrate 11 has a rectangular planar shape in which the long side is set to 60 mm-62 mm, for example, and the short side is set to 42 mm-44 mm, for example. The thickness of the substrate 11 shown in FIG. 4 is set to 0.8 mm to 1.6 mm, for example.

  The conductor of the board | substrate 11 is comprised in the material excellent in electroconductivity, such as copper (Cu), Cu alloy, and gold (Au), in Example 1. For example, when Cu is used, it is formed of a Cu foil attached by a lamination method or a press molding method or a composite film in which a Cu plating layer is laminated on the surface of the Cu foil by a plating method. In the case of a single layer Cu foil, the film thickness is set to 30 μm to 40 μm, for example. In the case of the composite film, the film thickness of the Cu foil is set to 15 μm to 20 μm, for example, and the Cu plating layer is set to 15 μm to 25 μm, for example.

[Configuration of electronic components]
As shown in FIGS. 2 and 4, on the first surface 11A of the substrate 11, as the electronic components, the transistor unit 2, the first transformer 3, the capacitors 42 and 43, and the diode 5 described in FIG. A control unit 6, a second transformer 7, a temperature detection unit 8, and the like are mounted. As shown in FIGS. 3 and 4, for example, a capacitor 41 or the like is mounted on the second surface 11 </ b> B of the substrate 11 as the electronic component described with reference to FIG. 1.

  As shown in FIGS. 1, 2, and 4, the transistor unit 2 includes a semiconductor device in which a semiconductor chip having a first IGFET 21 and a diode 23 is sealed with a resin sealing body, and similarly, a second IGFET 22 and a diode. And a semiconductor device in which a semiconductor chip having 24 is sealed with a resin sealing body, and is constructed by two semiconductor devices. The transistor portion 2 is disposed on the first surface 11A on the lower right side of the peripheral region in FIG.

  The capacitor 42 is configured, for example, by sealing a capacitor body with a resin sealing body. In one embodiment, a glass epoxy resin can be practically used for the resin sealing body. The number of capacitors 42 to be mounted is not limited by the target capacitance value, but four capacitors 42 are arranged on the first surface 11A of the substrate 11 on the lower right side of the peripheral region in FIG. . The capacitor 43 is configured, for example, by sealing a capacitor body with a resin sealing body. Similarly, the number of capacitors 43 to be mounted is not limited by the target capacitance value, but six capacitors 43 are arranged on the lower left side of the peripheral region in FIG. Yes.

  The capacitor 41 is configured by sealing a capacitor body with a resin sealing body, for example, in the same manner as the capacitors 42 and 43 described above. The number of capacitors 41 is not limited by the target capacitance value, but four capacitors 41 are arranged on the second surface 11B of the substrate 11 on the lower left side of the peripheral region in FIG. The capacitor 41 is disposed at a position facing the position where the capacitor 42 is disposed.

  The diode 5 is configured, for example, by sealing a diode body, specifically a diode chip (semiconductor element) with a resin sealing body. The number of diodes 5 mounted is not limited by the intended rectification characteristics, but one diode 5 is disposed on the upper left side of the peripheral region in FIG.

  The control unit 6 includes a semiconductor device (control IC) 61 in which a semiconductor chip having a circuit for controlling at least the transistor unit 2 such as a transistor, a logic circuit, a resistor, and a capacitor is sealed with a resin sealing body, and a photocoupler 62. And 63, and is constructed. The semiconductor device 61 of the control unit 6 is arranged on the first surface 11A of the substrate 11 on the upper right side of the peripheral region in FIG. Photocouplers 62 and 63 are disposed on the upper left side in FIG. 2 on first surface 11A of substrate 11.

  The temperature detection unit 8 is disposed on the first surface 11A of the substrate 11 on the upper left side of the peripheral region in FIG. 2 and between the diode 5 and the photocouplers 62 and 63. The temperature detector 8 is disposed at a position away from the region where the diode 5 is disposed, so that the temperature detector 8 itself is prevented from being damaged or malfunctioning due to heat.

[Configuration of first transformer and second transformer (electronic component)]
In the electronic circuit device 1 according to the first embodiment, the first transformer 3 and the second transformer 7 are constructed of a magnetic material, specifically, a ferromagnetic material. As shown in FIGS. 2 to 4, the first transformer 3 is inserted and disposed in the opening 15 in the central region of the first surface 11 </ b> A of the substrate 11. In the first embodiment, the opening 15 is configured as a through hole penetrating from the first surface 11A of the substrate 11 to the second surface 11B facing the substrate 11.

  As shown in FIGS. 6 to 11, in the first embodiment, the first transformer (electronic component) 3 has a sheet transformer structure. The first transformer 3 includes a large number of windings 31 (1) -31 (4), a first minority winding 32 (1), and a second minority winding 32 (2). 7, the transformer substrate 12 having a through hole 125 in the central portion, the front surface 12A of the transformer substrate 12 (upper surface in FIGS. 6 and 7), and the back surface 12B (in FIGS. The core 33 having the first magnetic core 332C, the second magnetic core 331C, and the magnetic gap 3G of the toroidal core is also provided in the central through hole 125 disposed along a part of the lower surface) and the side surface 12C. Yes. Here, the core 33 includes a first core (lower core) 331 and a second core (upper core) 332, and the first magnetic core 332C is integrally formed with the second core 332, and the second magnetic core is formed. 331 </ b> C is integrally formed with the first core 331.

  In the first transformer 3, the first magnetic core 332C, the magnetic gap 3G, and the second magnetic core 331C are sequentially arranged in the first direction (the direction opposite to the Z direction in FIGS. 6 and 7). And a first separation distance L1 from the circumferential surface of the first magnetic core 332C in a second direction (X direction and Y direction in FIGS. 6 and 7) intersecting the first direction. And the first minority winding 32 (1) disposed around the first magnetic core 332C and laminated in the first direction on the first minority winding 32 (1) in the second direction. , Multiple windings 31 (1) -31 (4) having a second separation distance L2 larger than the first separation distance L1 from the peripheral surface of the first magnetic core 332C and disposed around the magnetic gap 3G. And the first minority winding 3 with a large number of windings 31 (1) -31 (4) interposed in the first direction. (3), and has a third separation distance L3 smaller than the second separation distance L2 from the peripheral surface of the second magnetic core 331C in the second direction, and is disposed around the second magnetic core 331C. And a second minority winding 32 (2).

  The transformer substrate (simply referred to as “substrate” in some cases) 12 is a surface (surface on the surface 12A side of the transformer substrate 12 as shown in FIG. 7). .) And the first insulating base material 121 (1) having the back surface (the back surface on the front surface 12B side of the transformer substrate 12 and the same shall apply hereinafter in the description of the transformer substrate 12), and the surface and A first insulating substrate 121 (2) having a back surface, a second insulating substrate 122 (1), a first insulating substrate 121 (3), and a second insulating substrate 122 (2); The first insulating base 121 (4) and the first insulating base 121 (5) are sequentially stacked in the first direction. Although not necessarily limited to the number of stacked layers, in Example 1, the transformer substrate 12 includes five layers of first insulating base materials 121 (1) -121 (5) and two layers of second insulating materials. The base materials 122 (1) and 122 (2) are stacked, and a total of seven sheet-like insulating base materials are stacked.

  A first conductor 127 (1) is disposed on the surface of the first insulating base 121 (1). A third conductor 128 (1) is disposed on the surface of the first insulating base 121 (2). The back surface of the first insulating base material 121 (1) is disposed to face the surface of the first insulating base material 121 (2), and the back surface of the first insulating base material 121 (1) and the first insulating base material 121 (1). The surface of the substrate 121 (2) is bonded. The back surface of the first insulating substrate 121 (2) is bonded to the surface of the second insulating substrate 122 (1).

  A second conductor 126 (1) is disposed on the surface of the second insulating substrate 122 (1), and a second conductor 126 (2) is disposed on the back surface. A second conductor 126 (3) is disposed on the surface of the second insulating substrate 122 (2), and a second conductor 126 (4) is disposed on the back surface. The back surface of the second insulating base material 122 (1) is disposed so as to face the surface of the second insulating base material 122 (2), and the back surface of the second insulating base material 122 (1) is the first insulating material. The substrate is bonded to the surface of the second insulating substrate 122 (2) through the substrate 121 (3).

  A first conductor 127 (2) is disposed on the back surface of the first insulating base 121 (5). A third conductor 128 (2) is disposed on the back surface of the first insulating base 121 (4). The surface of the first insulating substrate 121 (5) is disposed facing the back surface of the first insulating substrate 121 (4), and the surface of the first insulating substrate 121 (5) and the first insulating substrate 121 (5). The back surface of the substrate 121 (4) is bonded. The surface of the first insulating substrate 121 (4) is bonded to the back surface of the second insulating substrate 122 (4).

  That is, the transformer substrate 12 has a first conductor 127 (1), a first insulating base 121 (1), and a third conductor 128 (from the front surface 12 A side to the front surface 12 B side as the back surface. 1), first insulating substrate 121 (2), second conductor 126 (1), second insulating substrate 122 (1), second conductor 126 (2), first insulating group Material 121 (3), second conductor 126 (3), second insulating base material 122 (2), second conductor 126 (4), first insulating base material 121 (4), third Each of the conductor 128 (2), the first insulating base 121 (5), and the first conductor 127 (2) is sequentially stacked, and the insulating base and the conductor are alternately stacked. It is.

  As shown in FIGS. 6, 7, 8, and 11, the first conductor 127 (1) is wound around and extends around the through hole 125 of the transformer substrate 12. A wire (secondary coil) 32 is formed. In the first conductor 127 (1), at least the width dimension W1 of the region having the first separation distance L1 from the first magnetic core 332C is set smaller than the width dimension W1h of the other regions. More specifically, the first conductor 127 (1) has a width dimension W1 of a region where the side surface thereof faces the first magnetic core 332C or the second core 332 facing the first magnetic core 332C. It is set to be smaller than the width dimension W1h of the region other than.

  The region of the width dimension W1 of the first conductor 127 (1) is a region in which a separation distance from the magnetic gap 3G and the second core 332 is secured, and from the magnetic gap 3G and the second core 332 and the like. Makes it difficult to pick up the leakage magnetic flux. On the other hand, the region of the width dimension W1h of the first conductor 127 (1) expands the conductor width by effectively using the dead space of the first insulating base 121 (1) to expand the arrangement area. This is the area. This region, particularly the region given the reference numeral 32H and hatched, emits heat generated as the wiring resistance value increases due to the reduction of a part of the first conductor 127 (1) to the width dimension W1. A radiator 32H is constructed.

  As shown in FIGS. 7, 10, and 11, the first conductor 127 (2) has a configuration similar to that of the first conductor 127 (1) and is centered on the through hole 125 of the transformer substrate 12. As shown in FIG. 2, the coil is wound around the periphery of the first conductor 127 (1) and connected in series to form a minority winding (secondary coil) 32. Basically, like the first conductor 127 (1) shown in FIG. 8, the first conductor 127 (2) is at least a third distance from the second magnetic core 331C as shown in FIG. The width dimension W3 of the area having the distance L3 is set smaller than the width dimension W3h of the other areas. More specifically, the first conductor 127 (2) has a width dimension W3 of a region where the side surface thereof faces the second magnetic core 331C or the first core 331 facing the second magnetic core 331C. It is set smaller than the width dimension W3h of the area other than.

  The region of the width dimension W3 of the first conductor 127 (2) is a region in which a separation distance from the magnetic gap 3G and the first core 331 is secured, and from the magnetic gap 3G and the first core 331 and the like. Makes it difficult to pick up the leakage magnetic flux. On the other hand, the area of the width dimension W3h of the first conductor 127 (2) extends the conductor width by effectively using the dead space of the first insulating base material 121 (5) to expand the arrangement area. This is the area. This region (hatched region) constitutes a heat radiating body 32H that releases heat generated with an increase in the wiring resistance value due to the reduction of a part of the first conductor 127 (2) to the width dimension W3.

  In other words, in the first embodiment, the minority winding 32 has a function of making it difficult to pick up the leakage magnetic flux, efficiently reducing the eddy current loss, and efficiently releasing the heat generated as its adverse effect. Further, in the first embodiment, the minority winding 32 and the heat radiating body 32H are integrally configured (attached) by the same first conductor 127 (1) or first conductor 127 (2). And it is comprised by the simple structure, utilizing effectively the dead space of the 1st insulating base material 121 (1) or 121 (5).

  As shown in FIGS. 7, 9, and 11, the second conductor 126 (1) disposed on the surface of the second insulating base material 122 (1) has a periphery around the through hole 125. A plurality of windings (primary coils) 31 are formed by spirally winding a plurality of turns. The first transformer 3 according to the first embodiment includes four layers of second conductors 126 (1) to 126 (4), and is disposed on the back surface of the second insulating base material 122 (1). Two conductors 126 (2), the second conductor 126 (3) disposed on the surface of the second insulating substrate 122 (2), and the back surface of the second insulating substrate 122 (2) Similarly, each of the second conductors 126 (4) disposed on the outer periphery of the second conductor 126 (4) extends in a spiral manner around the through-hole 125 to form a plurality of windings 31. Yes. Although not described in detail, the second conductors 126 (1) -126 (4) are each electrically connected in series through connection hole wiring.

  As shown in FIG. 9 in particular, the second conductor 126 (1) has a second separation distance L2 that is at least larger than the first separation distance L1 and the third separation distance L3 from the first magnetic core 332C. The width dimension W2 of the area is set smaller than the width dimension W2h of the other areas. More specifically, the second conductor 126 (1) has a width dimension W2 of a region where the side surface and the first magnetic core 332C or the second core 332 facing the first magnetic core 332C face each other. It is set smaller than the width dimension W2h of the other region.

  Similar to the minority winding 32, the region of the width dimension W2 of the second conductor 126 (1) is a region that secures a separation distance from the magnetic gap 3G and the second core 332, and the magnetic gap 3G. And leakage magnetic flux from the second core 332 and the like are difficult to pick up. On the other hand, the area of the width dimension W2h of the second conductor 126 (1) extends the conductor width by effectively using the dead space of the second insulating base material 122 (2) to expand the arrangement area. This is the area. In this region (hatched region), a heat radiating body 31H that releases heat generated with an increase in the wiring resistance value due to the reduction of a part of the second conductor 126 (1) to the width dimension W2 is constructed.

  As shown in FIG. 7, the first transformer 3 according to the first embodiment includes the first insulating base 121 (3) on the substantially same plane as the magnetic gap 3 </ b> G and along the periphery of the magnetic gap 3 </ b> G. The second insulating base material 122 (1) is disposed on the surface of the first insulating base material 121 (3), and the second insulating base material 121 (3) is disposed on the back surface of the second insulating base material 121 (3). An insulating substrate 122 (2) is provided. With this structure, each of the first conductors 126 (1) and 126 (2) is disposed around the first magnetic core 332 C of the second core 32, and the first core 31 Each of the first conductors 126 (3) and 126 (4) is disposed around the second magnetic core 331C.

  Therefore, the second conductor 126 (2) is basically different in basic plan shape as shown in FIG. 10 in order to be electrically connected in series to the first conductor 126 (1). Specifically, similarly to the second conductor 126 (1), a region having a width dimension W2 and a region having a width dimension W2h are provided, and a radiator 31H is provided. Each of the second conductors 126 (3) and 126 (4) has a slightly different planar shape, but basically has a width dimension W2 similar to that of the second conductor 126 (1). The area | region which has and the area | region which has the width dimension W2h are provided, and the heat radiator 31H is provided. In each of the second conductors 126 (3) and 126 (4), the reference position of the second separation dimension L 2 is the peripheral surface of the second magnetic core 331 C of the first core 311.

  The third conductor 128 (1) shown in FIG. 7 includes a second conductor 126 (1) that constructs the majority winding 31 and a first conductor 127 (1) that constructs the minority winding 32. It is disposed (sandwiched) between them and functions as a shield layer. Similarly, the third conductor 128 (2) is between the second conductor 126 (4) that constructs the majority winding 31 and the first conductor 127 (2) that constructs the minority winding 32. Is disposed (sandwiched) to function as a shield layer. A space between the third conductor 128 (1) and the peripheral surface of the first magnetic core 332C is set to a fifth separation distance L5 between the first separation distance L1 and the second separation distance L2. Yes. Similarly, between the third conductor 128 (2) and the peripheral surface of the second magnetic core 331C, the fifth separation distance L5 between the third separation distance L3 and the second separation distance L2 is set. Is set.

  In Example 1, the first conductors 127 (1), 127 (2), the second conductors 126 (1) -126 (4), and the third conductors 128 (1), 128 (2) The same conductive material is used for each. For example, a metal foil or metal film having excellent conductivity such as Cu, Cu alloy, or Au is used for these conductors. When, for example, a Cu foil is used for the first conductors 127 (1), 127 (2) and the second conductors 126 (1) -126 (4), the film thickness is set to 60 μm-80 μm, for example. ing. When, for example, Cu foil is used for the third conductors 128 (1) and 128 (2), the film thicknesses thereof are the first conductors 127 (1), 127 (2), and the second conductors 126. It is thinner than the film thickness of (1) -126 (4), and is set to 20 μm-40 μm, for example.

The first insulating base materials 121 (1) -121 (5) have at least an electrical insulating function and an adhesive function. In Example 1, the first insulating base materials 121 (1) -121 (5) were impregnated with, for example, a thermosetting resin adhesive that was not cured at the time of lamination and was cured after the lamination. Glass fiber cloth, so-called prepreg, is used. In the glass fiber cloth, for example, there are several single yarns having a diameter of 3 μm to 10 μm to which SiO ₂ is a main component and at least one of Al ₂ O ₃ , CaO, MgO, R ₂ O, B ₂ O _{3 and the} like is added. Ten to several hundreds are bundled and plain weave. For example, an epoxy resin is used as the thermosetting resin adhesive. The film thickness of the first insulating base 121 (1) -121 (5) is set to 180 μm-220 μm, for example.

  Similarly, the second insulating base materials 122 (1) and 122 (2) have at least an electrical insulating function and an adhesive function. The second insulating substrate 122 (1) has the second conductor 126 (1) on the front surface and the second conductor 126 (2) on the back surface, and is cured at this time. In the case of lamination, it is already cured. The second insulating substrate 122 (2) has the second conductor 126 (3) on the front surface and the second conductor 126 (4) on the back surface, and is cured at this time. In the case of lamination, it is already cured. For example, a glass fiber impregnated with a thermosetting resin adhesive in the second insulating base materials 122 (1) and 122 (2), as in the first insulating base materials 121 (1) to 121 (5). Cross is used. The film thickness of the second insulating base materials 122 (1) and 122 (2) is set to, for example, 50 μm-70 μm.

  Although not specifically described with reference numerals, electrical connection between the first conductors 127 (1) and 127 (2) and electrical connection between the second conductors 126 (1) -126 (4). The electrical connection between the third conductors 128 (1) and 128 (2) includes the first insulating base 121 (1) -121 (5) and the second insulating base 122 (1). , 122 (2), through connection hole wiring (through-hole wiring or via wiring) embedded in the connection holes. This connection layout is as shown in FIG. For the connection hole wiring, a metal material such as Cu, Cu alloy, Au, etc., which is excellent in electrical conductivity and easy to manufacture in the semiconductor manufacturing process, is used.

  Here, in the first embodiment, the width dimension W1 of the first conductor 127 (1) and the width dimension W3 of the first conductor 127 (2) constituting the minority winding 32 are set to the same dimension. For example, it is set to 4.9 mm-5.1 mm. Further, the width dimension W1h of the first conductor 127 (1) and the width dimension W3h of the first conductor 127 (2) are set to the same dimension, for example, 5.5 mm to 7.0 mm. ing. The radiator 32H is an area obtained by effectively subtracting the width dimension W1 from the width dimension W1h of the first conductor 127 (1). The radiator 32H is an area obtained by effectively subtracting the width dimension W1 from the width dimension W1h of the first conductor 127 (1).

  In the first transformer 3 according to the first embodiment, the first conductors 127 (1) and 127 (2) that construct the minority winding 32 have a copper loss when Cu is used as shown in FIG. Is set to width dimensions W1 and W2. Here, the copper loss is electric energy (loss) lost due to electric resistance (winding resistance). The lost electrical energy becomes Joule heat. In FIG. 12, the horizontal axis represents the wiring width of the first conductor 127, and the vertical axis represents the loss. The DC resistance loss of the first conductor 127 decreases as the wiring width increases, whereas the AC resistance loss increases as the wiring width increases. The width dimension W1 of the first conductor 127 (1) and the width dimension W3 of the first conductor 127 (2) are set within a range in which the DC resistance loss and the AC resistance loss (copper loss) are minimized. Yes.

  On the other hand, each of the width dimensions W2 of the second conductors 126 (1) -126 (4) constituting the multiple windings 31 is set to the same dimension, for example, 0.8 mm to 0.9 mm. . In addition, each of the width dimensions W2h of the second conductors 126 (1) to 126 (4) is set to the same dimension, for example, 1.0 mm to 3.0 mm. The radiator 31H is an area obtained by effectively subtracting the width dimension W2 from the width dimension W2h of the second conductors 126 (1) -126 (4).

  Similar to the width dimension W1 of the first conductor 127 (1) and the width dimension W3 of the first conductor 127 (2), the width dimension W2 of the second conductors 126 (1) -126 (4) is 12 is set within a range in which the copper loss shown in FIG. 12 is minimized.

  Further, as shown in FIG. 7, in the first transformer 3, the first conductive is formed between the magnetic gap 3 </ b> G and the end of the first conductor 127 (1) of the minority winding 32 on the magnetic gap 3 </ b> G side. Between the end of the body 127 (2) on the magnetic gap 3G side and between the magnetic gap 3G and the end of the multiple conductors 31 on the magnetic gap 3G side of the second conductors 126 (1)-(4). Are set to the fourth separation distance L4. The reference position C1 of the fourth separation distance L4 is on the extension around the first magnetic core 332C and the second magnetic core 331C and in the middle of the first direction of the magnetic gap 3G. In the first embodiment, the fourth separation distance L4 is set to be the same as the second separation distance L2, and as a result, a concentric circle (for convenience) with the reference position C1 as the center and the fourth separation distance L4 as the radius. The boundary region in which the leakage magnetic flux has an influence is indicated by a broken line.) The first conductor 127 (1), the second conductor 126 (1) -126 (4), the first conductor on the upper side or the outer side thereof. The ends of the respective conductors 127 (2) on the magnetic gap 3G side are disposed. Here, the end portions of the third conductors 128 (1) and 128 (2) on the magnetic gap 3G side are similarly arranged concentrically (or outside). By securing the fourth separation distance L4 from the magnetic gap 3G and positioning the respective end portions of the minority winding 32 and the majority winding 31, the leakage magnetic flux from the magnetic gap 3G is reduced to the minority winding 32, the majority winding. Each of the lines 31 is difficult to pick up. In other words, since the influence of the leakage magnetic flux from the magnetic gap 3G is large in the concentric circles, the minority winding 32, the majority winding 31 and the like are arranged on or outside the concentric circle where the influence of the leakage magnetic flux is small. Yes.

  Similarly, in the first transformer 3, the first conductor 127 (1) of the minority winding 32 is similarly formed from the reference position C2 facing the magnetic gap 3G of the core (magnetic body) 33 in the second direction. ) Of the first conductor 127 (2) opposite to the magnetic gap 3G, the end of the first conductor 127 (2) opposite to the magnetic gap 3G, and the second conductor 126 (1)-( The ends on the side opposite to the magnetic gap 3G of 4) are set to the fourth separation distance L4. In the first embodiment, the reference position C2 is arranged on the inner wall surface disposed along the side surface 12C of the transformer substrate 12 of the first core 31 and along the side surface 12C of the transformer substrate 12 of the second core 32. This is a position on the inner wall surface where the first core 31 and the second core 32 are overlapped. Accordingly, the first conductor 127 (1) and the second conductors 126 (1) -126 (4) are arranged concentrically with the reference position C2 as the center and the fourth separation distance L4 as the radius or on the outer side thereof. The ends of the first conductors 127 (2) opposite to the magnetic gaps 3G are disposed. The ends of the third conductors 128 (1) and 128 (2) opposite to the magnetic gap 3G are similarly arranged concentrically. Positioning of the ends of the minority winding 32 and the majority winding 31 on the opposite side to the magnetic gap 3G by securing a fourth separation distance L4 from the connecting portion between the first core 31 and the second core 32. By performing the above, it becomes difficult for each of the minority winding 32 and the majority winding 31 to pick up the leakage magnetic flux from the connecting portion.

The core 33 shown in FIG. 6 is a ferromagnetic body formed of, for example, a ferrite magnetic material obtained by sintering a metal oxide as a ceramic. As the metal oxide, for example, iron oxide (Fe ₂ O ₂ ) as a main component and a mixture of metal compounds such as manganese (Mn), magnesium (Mg), nickel (Ni), zinc (Zn), etc. are practical. Can be used for Alternatively, the core 33 may be formed of an amorphous magnetic material. The core 33 integrally constitutes and protrudes the second magnetic core 331C, protrudes along both side surfaces 12C of the transformer substrate 12 around the second magnetic core 331C, and is disposed on the back surface 12B side of the transformer substrate 12. The formed first core (lower core material) 331 and the first magnetic core 332C are integrally formed and protruded, and protrude along the both side surfaces 12C of the transformer substrate 12 around the first magnetic core 332C. And a second core (upper core material) 332 disposed on the surface 12A side of the transformer substrate 12. The second magnetic core 331C of the first core 331 and the first magnetic core 332C of the second core 332 are magnetically connected via a magnetic gap 3G. Here, both sides of the first core 331 and both sides of the second core 332 are in direct contact and magnetically connected.

  Since the cross-sectional shape of the first core 331 is E-shaped and the cross-sectional shape of the second core 332 is E-shaped, the core 33 has an EE-type core shape. The core 33 may have an I-shaped core shape with a cross-sectional shape of one of the first core 331 and the second core 332 being an I-shaped shape. In this case, since the magnetic core does not exist on the I-shaped core side, a part of the first conductor 127 of the minority winding 32 is omitted on the side where the magnetic core does not exist. For example, in the first transformer 3, when the first core 331 is I-shaped and the second magnetic core 331C is omitted, the first conductor 127 (2) disposed around the first core 331 is omitted. The The first conductor 127 (1) that constructs the minority winding 32 is disposed around the first magnetic core 332C of the second core 332, and the first magnetic core 332C of the second core 332 and the first magnetic core 332C Second conductors 126 (1) to 126 (4) for constructing multiple windings 31 are disposed around the magnetic gap 3 G between the first core 331 and the first core 331.

  Although a detailed description of the structure is omitted, the second transformer 7 has a sheet transformer structure similar to the structure of the first transformer 3 in which the induced electromotive force and the overall size are set smaller than those of the first transformer 3. It is comprised by. Further, as shown in FIGS. 2 to 4, the second transformer 7 is inserted into the opening 16 provided in the substrate 11 in the same manner as the mounting method of the first transformer 3 to the substrate 11. Has been implemented.

[Structure and properties of curable stress relieving material]
As shown in FIGS. 2 to 4, in the electronic circuit device 1 according to the first embodiment, around the side surface of the core 33 of the first transformer 3, that is, along two long sides and two short sides of the transformer substrate 12. At least the curable stress relieving material 35 is disposed on only the four side surfaces corresponding to the four side surfaces 12C and parallel to the four side surfaces 12C. Here, as shown in FIG. 4, the curable stress relaxation material 35 is not disposed on the upper surface 3 </ b> A and the lower surface 3 </ b> B of the core 33. The film thickness of the curable stress relaxation material 35 is set to be thinner as the distance from the side surface of the core 33 increases. The film thickness of the curable stress relaxation material 35 is substantially zero at a position (terminal) farthest from the side surface of the core 33. The curable stress relaxation material 35 disposed on the side surface of the core 33 of the first transformer 3 contributes to a reduction in stress exerted on the core 33 of the first transformer 3 of the resin sealing body 17.

In Example 1, for the curable stress relieving material 35, for example, a thermosetting adhesive liquid silicone rubber (thermosetting silicone resin) having white semi-fluidity is used. This heat-curable adhesive liquid silicone rubber has white semi-fluidity before curing, and has a viscosity of about 3.5 Pa · s-4.5 Pa · s at a temperature of 23 ° C., for example. The heat-curable adhesive liquid silicone rubber is applied by using a coating technique, a potting technique, etc., and then cured by heat treatment at 150 ° C. for 1 hour, for example. After curing, the heat curable adhesive liquid silicone rubber changes to a white rubber shape and has a hardness (type A) of, for example, 20-22, for example, 2.0 × 10 ^{−4 /} ° C.-2.2. It has a linear expansion coefficient of × 10 ^-4 / K.

  The curable stress relaxation material 35 is not limited to a thermosetting silicone resin. Any material that reduces the stress generated by the shrinkage of the resin sealing body 17 on the core 33 of the first transformer 3 may be an ultraviolet curable silicone resin (rubber), a room temperature curable silicone resin (rubber), or a thermosetting type. Any one of an ultraviolet curable epoxy resin and a room temperature curable epoxy resin can be used as the curable stress relaxation material 35. For example, a gel-type resin that is not curable flows out in the manufacturing process of the resin sealing body 17 using the transfer mold method, and it is difficult to reliably attach the gel-like resin to the side surface of the core 33.

[Lead structure]
As shown in FIGS. 2 to 5, leads (external terminals) 180 to 189 are arranged on one side surface (the lower side surface in FIGS. 2 and 3, the left side surface in FIG. 5) along the long side of the substrate 11. Leads 190 to 193 are arranged on the other side surface (the upper side surface in FIGS. 2 and 3 and the right side surface in FIG. 5) opposite to the one side surface. In these leads 180-193, the part inside the resin sealing body 17 is an inner part, and the part protruding outside the resin sealing body 17 is an outer part.

  The lead 180 is used as a DC voltage terminal DCIN. The lead 181 is used as a switching signal terminal ON / OFF. The lead 182 is used as the input terminal Vin +. The lead 183 is used as the input terminal Vin−. The lead 184 is used as the output terminal Vout−. The lead 185 is used as a negative remote sensing terminal Vs−. The lead 186 is an empty terminal NC. The lead 187 is used as an output voltage adjustment terminal TRM. The lead 188 is used as a positive remote sensing terminal Vs +. The lead 189 is used as the output terminal Vout−. The lead 186 used as the empty terminal NC has a function as a heat dissipation path in the first embodiment.

  Leads 190-193 are empty terminals NC. The leads 190-193 used as the empty terminals NC similarly have a function as a heat dissipation path.

  The leads 180-193 are made of, for example, Cu or Cu alloy having excellent electrical conductivity. This conductive material has low thermal resistance and excellent thermal conductivity. The thickness of the leads 180-193 is set to 0.3 mm-0.5 mm, for example.

  The leads 180-193 are not labeled, but are electrically and mechanically connected to terminals arranged on the substrate 11 through an adhesive layer. For this adhesive layer, it is possible to use, for example, solder, paste or the like having a low thermal resistance and excellent thermal conductivity. For example, Sn-Ag-Cu solder can be used practically as the solder. Further, for example, an Ag paste used as a conductive paste can be used practically.

[Structure of stress buffer]
As shown in FIG. 2 to FIG. 5, the stress buffer 91 has the first core 331 of the core 33 of the first transformer 3 with the adhesive layer 4 interposed on the surface 91 </ b> A (upper surface in FIG. 4). The lower surface 3B is bonded and attached to the first transformer 3. The stress buffer 91 is given to the core (magnetic body) 33 of the first transformer 3 along with the temperature contraction immediately after the resin sealing body 17 of the electronic circuit device 1 is molded by using, for example, a transfer molding method in the manufacturing process. It has a function of reducing stress by the rigidity of the stress buffer 91. That is, the stress buffer 91 has a function of repelling the compressive stress accompanying the thermal contraction of the resin sealing body 17, and effectively reduces the stress applied to the core 33. The stress buffer 91 is given to the core 33 accompanying the thermal expansion and thermal contraction of the resin sealing body 17 when it is generated by the temperature cycle of the temperature increase and the temperature decrease in actual operation after being completed as a product of the electronic circuit device 1. Has the function of reducing stress.

  In order to reduce the stress applied to the core 33 as much as possible and to reduce the thickness and size of the electronic circuit device 1, the stress buffer 91 has a size of the surface 91A and the size of the lower surface 3B of the core 33 facing the surface 91A. Is set as large as possible. Since the ratio of the stress buffer body 91 to the ratio of the resin sealing body 17 increases as the size of the stress buffer body 91 increases, the stress applied to the core 33 by the stress buffer body 91 can be reliably reduced. In other words, since the ratio of the resin sealing body 17 is reduced, the stress generation factor itself can be reduced. Further, the stress buffer 91 can improve the mechanical strength of the resin sealing body 17 that is particularly thinned.

The stress buffer 91 is made of a metal plate material, and this metal plate material has a moderate rigidity higher than that of the resin sealing body 17 and is much more thermally conductive than the resin sealing body 17. It is preferable to use, for example, a Cu (linear expansion coefficient: 1.7 × 10 ⁻⁶ ) plate or a Cu alloy plate that is excellent and close to the linear expansion coefficient of the core 33. This Cu plate or Cu alloy plate can be used as it is (in a pure state), but a plating film such as a Ni film may be formed on the surface.

  As shown in FIG. 4, the adhesive layer 4 has a function of electrically insulating the first transformer 3 and the stress buffer 91 in addition to a function of mechanically mounting the first transformer 3 and the stress buffer 91. In the first embodiment, for example, a prepreg in which a glass fiber cloth is impregnated with a thermosetting adhesive is used for the adhesive layer 4. In addition, it replaces with the prepreg which impregnated the glass fiber cloth with the thermosetting adhesive, and the glass fiber cloth which apply | coated the thermosetting adhesive to both surfaces can be used for the contact bonding layer 4, for example.

[Structure of resin encapsulant]
As shown in FIGS. 2 to 5, in the electronic circuit device 1 according to the first embodiment, the substrate 11 on which a plurality of electronic components are mounted is hermetically sealed by the resin sealing body 17 as described above. The resin sealing body 17 is formed by a transfer mold method. The electronic circuit device 1 according to the first embodiment is obtained by molding a DC-DC converter as one component. For example, an ortho-cresol novolac epoxy resin containing a release agent is used for the resin sealing body 17.

[Characteristics of electronic circuit device]
The electronic circuit device 1 according to the first embodiment configured as described above includes a minority winding 32 (first conductor 127 (1)), a majority winding 31 (126 (1) -126 (4)), a minority winding. It has a sheet transformer structure in which windings 32 (127 (2)) are sequentially stacked, and a small number of windings 31 are disposed around the magnetic gap 3G of the core 33, and a second spacing is provided with respect to the magnetic gap 3G. A first transformer (electronic component) 3 is provided in which a small number of windings 31 are separated by securing a distance L2 (or a fourth separation distance L4). The first transformer 3 employs a sheet transformer structure, and a large number of windings 31 are arranged around the magnetic gap 3G. Therefore, the first transformer 3 can be reduced in thickness and size. Further, in the first transformer 3, a large number of windings 31 having a small overall volume are arranged around the magnetic gap 3 G instead of a small number of windings 32 having a large overall volume. Since the distance to the line 31 is increased, the leakage magnetic flux picked up by the multiple windings 31 from the magnetic gap 3G can be reduced, and the eddy current loss can be reduced efficiently. As a result, the electronic circuit device 1 on which the first transformer 3 is mounted can be reduced in thickness and size, and eddy current loss can be efficiently reduced. The same effect can be obtained with the second transformer (electronic component) 7.

  Furthermore, in the electronic circuit device 1, since the first transformer 3 includes the radiator 32H in the minority winding 32 and the radiator 31H in the majority winding 31, the eddy current loss can be further reduced. it can. In the heat radiating body 32H, the dead space of the first insulating base materials 121 (1) and 121 (5) is effectively used, and the width dimension W1h obtained by expanding the wiring width of the first conductor 127 (1). This can be realized by a simple structure in which the wiring width of the first conductor 127 (2) is set to the expanded width dimension W3h. In the radiator 31H, the dead space of the second insulating base materials 122 (1) and 122 (2) is effectively used, and the wiring width of the second conductors 126 (1) to 126 (4) is expanded. This can be realized by a simple structure set to the width dimension W2h.

(Example 2)
In the second embodiment of the present invention, in the first transformer 3 (or the second transformer 7) of the electronic circuit device 1 according to the first embodiment, it is difficult to pick up the leakage magnetic flux from the magnetic gap 3G, and the wiring of the windings An example will be described in which the width is secured to reduce the generation of heat associated with the increase in resistance value, thereby reliably reducing eddy current loss.

[Configuration of first transformer (electronic component)]
As shown in FIG. 13, in the first transformer 3 of the electronic circuit device 1 according to the second embodiment, the first conductor 127 (1) that constructs a part of the minority winding 32 has the side surface and the first conductor 3. A portion having a width dimension W11 and a portion having a width dimension W1h larger than the width dimension W11 in a region where the magnetic core 332C or the second core 332 facing the first magnetic core 332C is opposed to the first core 332C. The conductor 127 (1) is repeatedly arranged in the extending direction. That is, a part of the first conductor 127 (1) has an extension of the first conductor 127 (1) when viewed from the first direction (Z direction of the coordinate axes shown in FIGS. 6 and 7). It has a zigzag planar shape that undulates alternately on the right and left sides in the direction of the movement.

  Here, the width dimension W11 is further outside the boundary (shown using a broken line for convenience) where the influence of the magnetic flux 3G and the leakage magnetic flux from the core 33 occurs, and the circumferential surface of the first magnetic core 332C. Or the wiring width of the first conductor 127 (1) that exceeds the first separation distance L1 from the inner wall surface of the second core 32. That is, the width dimension W11 is smaller than the width dimension W1 of the first conductor 127 (1) according to the first embodiment. The width dimension W1h is the same as the width dimension W1h of the first conductor 127 (1) according to Example 1 described above.

  In the first transformer 3 configured as described above, a sufficient distance from the magnetic gap 3G and the core 33 is secured in the portion of the width dimension W11 of the first conductor 127 (1) to further pick up the leakage magnetic flux. The wiring width can be increased in the portion of the width dimension W1h of the first conductor 127 (1) to reduce the wiring resistance and reduce the generation of heat, thereby reliably reducing the eddy current loss. it can.

  Here, in the first transformer 3, the first conductor 127 (1) that constructs a part of the minority winding 32 has been described, but the first conductor that constructs the other part of the minority winding 32. A similar configuration is adopted for the conductor 127 (2) and the second conductors 126 (1) to 126 (4) that construct the multiple windings 31. Further, the structure of the first transformer 3 may be adopted in the second transformer 7.

[Characteristics of electronic circuit device]
In the electronic circuit device 1 according to the second embodiment, the same effects as those obtained by the electronic circuit device 1 according to the first embodiment can be obtained.

Example 3
A third embodiment of the present invention describes a modification of the first transformer 3 and the like in the electronic circuit device 1 according to the second embodiment.

[Configuration of first transformer (electronic component)]
As illustrated in FIG. 14, the first transformer 3 of the electronic circuit device 1 according to the third embodiment includes the second conductors 126 (1) and 126 (3) that construct the multiple windings 31 on the magnetic gap 3 G side. Is set to be smaller than the second separation distance L2 (or the fourth separation distance L4) and close to the magnetic gap 3G side, and the magnetic gap 3G of the second conductors 126 (1) and 126 (3) is set. The end on the opposite side is set to be larger than the second separation distance L2, and is separated from the inner wall of the core 33. Further, the first transformer 3 is configured such that the end of the second conductors 126 (2) and 126 (4) constituting the multiple winding 31 on the magnetic gap 3G side is connected to the second separation distance L2 (or the fourth separation distance L2). The distance from the magnetic gap 3G is set larger than the separation distance L4), and the end of the second conductors 126 (2) and 126 (4) opposite to the magnetic gap 3G is set to be larger than the second separation distance L2. It is set small and close to the inner wall side of the core 33.

  In other words, the first transformer 3 brings the second conductor 126 (1) constituting the multi-winding 31 close to the magnetic gap 3G (second magnetic core 332C) side, and the second transformer 126 under the second conductor 126 (1). The conductor 126 (2) is brought close to the inner wall surface of the core 33 (second core 332) opposite to the magnetic gap 3G, and the second conductor 126 (3) under the conductor 126 (2) is again connected to the magnetic gap 3G (first gap). The second conductor 126 (4) underneath is close to the inner wall surface opposite to the magnetic gap 3G of the core 33 (first core 331). The second conductors 126 (1) -126 (4) have the first direction (the direction opposite to the Z axis) when viewed from the second direction (the Y direction of the coordinate axes shown in FIGS. 6 and 7). ) In a direction intersecting on the same plane as the second direction (X direction).

  In the first transformer 3 configured as described above, the distance from the magnetic gap 3G or the core 33 at one end of the second conductors 126 (1) to 126 (4) is set to the second distance. Since it can be set larger than L2, it is difficult to pick up the leakage magnetic flux in this portion, and eddy current loss can be surely reduced.

  In the first transformer 3, the second conductors 126 (1) and 126 (2) are shifted in the same direction, and the second conductors 126 (3) and 126 (4) are the same in a different direction. It may be shifted in the direction. The first transformer 3 shifts the second conductors 126 (1) and 126 (4) in the same direction, and the second conductors 126 (2) and 126 (3) are the same in different directions. It may be shifted in the direction. Further, the structure of the first transformer 3 may be adopted in the second transformer 7.

Example 4
Example 4 of this invention demonstrates the example which improved the thermal radiation characteristic in the electronic circuit device 1 which concerns on either of Example 1 thru | or Example 3. FIG.

[Configuration of first transformer (electronic component)]
As shown in FIGS. 15A and 15B, the first transformer 3 of the electronic circuit device 1 according to the fourth embodiment extends to the first insulating base 121 (1) outside the core 33. A heat radiating body 32H is disposed on the surface of the first conductor 127 (1), and the first conductor 127 (2) extends outside the core 33 and extends to the first insulating base 121 (2). A heat radiator 32H is disposed on the surface. For example, a Cu plate (Cu prism) or a Cu alloy plate (Cu alloy prism) excellent in thermal conductivity can be used for the radiator 32H. Here, the planar shape of the radiator 32H is a square shape, but may be any of a circular shape, an elliptical shape, a triangular shape, and a polygonal shape having five or more corners. The radiator 32H is thermally and mechanically connected to the surfaces of the first conductors 127 (1) and 127 (2) using, for example, an adhesive having excellent thermal conductivity. For example, solder is used as the adhesive.

  The heat radiator 32H according to the fourth embodiment is formed of a material different from each of the first conductors 127 (1) and 127 (2), but has a three-dimensional shape. A large contact area can be secured. That is, since the thermal resistance value from the heat radiating body 32H to the resin sealing body 17 can be reduced, the heat radiating effect can be enhanced, and the eddy current loss can be further reliably reduced.

(Other embodiments)
As mentioned above, although this invention was described by Example 1 and Example 2, the description and drawing which make a part of this indication do not limit this invention. The present invention can be applied to various alternative embodiments, examples, and operational technologies.

  For example, the present invention is not limited to a DC-DC converter as the electronic circuit device 1, but a power factor correction (PFC: Power Factor Correction) for constructing a DC-DC converter and a power supply module therewith in the preceding stage. The circuit may be the electronic circuit device 1. In addition, the present invention can be widely applied to an electronic circuit device including an electronic component manufactured using a magnetic material.

  The present invention is widely applicable to an electronic circuit device including an electronic component that can efficiently reduce eddy current loss while realizing a reduction in thickness and size.

DESCRIPTION OF SYMBOLS 1 ... Electronic circuit apparatus 11 ... Board | substrate 12 ... Transformer board 121 ... 1st insulation base material 122 ... 2nd insulation base material 126 ... 2nd conductor 127 ... 1st conductor 128 ... 3rd conductor 17 ... Resin encapsulant 180-193, 1800-1808, 1900-1903 ... Lead 2 ... Transistor part 21 ... First IGFET
22 ... Second IGFET
3 ... 1st transformer 3G ... Magnetic gap 33 ... Core 31H, 32H ... Radiator 331 ... 1st core 331C ... 2nd magnetic core 332 ... 2nd core 332C ... 1st magnetic core 41-43 ... Capacitor 5 ... Diode 6 ... Control unit 7 ... Second transformer 8 ... Temperature detection unit 91 ... Stress buffer

Claims (7)

A magnetic body in which a magnetic core and a magnetic gap are arranged in a first direction;
A minority winding disposed around the magnetic core and having a first separation distance from a circumferential surface of the magnetic core in a second direction intersecting the first direction;
It is stacked on the minority winding in the first direction, and has a second separation distance larger than the first separation distance from the circumferential surface of the magnetic core in the second direction, and is arranged around the magnetic gap. With many windings installed,
An electronic circuit device comprising an electronic component having   A fourth separation distance is set between the magnetic gap and the minority winding and between the magnetic gap and the majority winding, and the fourth separation distance is set to the second separation distance. The electronic circuit device according to claim 1, wherein:   The minority winding is constituted by a first conductor disposed on the surface of the first insulating substrate, and the majority winding is a second conductor disposed on the surface of the second insulating substrate. It is composed of a conductor, and the electronic component is a sheet transformer in which each of the first insulating base material, the first conductor, the second insulating base material, and the second conductor is laminated. The electronic circuit device according to claim 1 or 2, characterized in that   In the minority winding, the width dimension of the region having the first separation distance from the magnetic core of the first conductor is set smaller than the width dimension of the other region, and the second winding in the majority winding. 4. The electronic circuit device according to claim 3, wherein the width dimension of the region having the second separation distance from the magnetic core of the conductor is set smaller than the width dimension of the other region.   In the minority winding, the width dimension of the region where the side surface of the first conductor and the magnetic core or the magnetic body face each other is set smaller than the width dimension of the other region, The width dimension of a region where the side surface of the second conductor and the magnetic gap, the magnetic core, or the magnetic body face each other is set smaller than the width dimension of the other region. 3. The electronic circuit device according to 3.   6. The electron according to claim 3, wherein a heat radiator is mounted on the first conductor of the minority winding and the second conductor of the majority winding. Circuit device. A magnetic body in which each of the first magnetic core, the magnetic gap, and the second magnetic core is arranged in the first direction;
A first minority winding disposed around the first magnetic core and having a first separation distance from a circumferential surface of the first magnetic core in a second direction intersecting the first direction;
The first minority winding is stacked in the first direction, and has a second separation distance larger than the first separation distance from the peripheral surface of the first magnetic core in the second direction. Multiple windings arranged around the magnetic gap;
The first direction is stacked on the first minority winding with the majority winding interposed therebetween, and the second direction is smaller than the second separation distance from the peripheral surface of the second magnetic core in the second direction. A second minority winding having a separation distance of 3 and disposed around the second magnetic core;
An electronic circuit device comprising an electronic component having