JP6084148B2 - Coil integrated printed circuit board, magnetic device - Google Patents

Description

  The present invention relates to a coil-integrated printed board in which a coil pattern is formed in a plurality of layers, and a magnetic device such as a choke coil or a transformer provided with the coil-integrated printed board.

  For example, there is a switching power supply device such as a DC-DC converter (DC-DC converter) that converts a high-voltage direct current into a alternating current after switching to a low-voltage direct current. The switching power supply device uses a magnetic device such as a choke coil or a transformer.

  For example, Patent Documents 1 to 7 disclose a substrate provided with a coil pattern that constitutes a coil winding and a magnetic device including the substrate.

  In patent documents 1-5, the core which consists of a magnetic body has penetrated the board | substrate. The substrate is made of an insulator and has a plurality of layers. A coil pattern is formed on each layer so as to be wound around the core. Coil patterns of different layers are connected by through holes or the like. The coil pattern and the through hole are made of a conductor such as copper. The winding shape of the coil pattern and the connection state by the through hole are also disclosed in Patent Document 8. Further, Patent Document 9 discloses a technique for filling the inside of the through hole with solder in order to reduce the electrical resistance in the through hole portion.

  In Patent Document 6, the substrate is composed of a pair of insulating layers and a magnetic layer sandwiched between the insulating layers. A coil pattern made of a conductor is formed on the magnetic layer. The coil pattern is wound a plurality of times in the plate surface direction and the thickness direction of the substrate. In Patent Document 7, coil patterns are formed on a plurality of layers of a multilayer substrate. The coil patterns of different layers or the coil pattern and the wiring circuit are connected by a through hole or a heat radiating member. The heat radiating member is made of a through hole or a copper pin.

  When a current flows through the coil pattern, heat is generated from the coil pattern, and the temperature of the substrate increases. As a heat dissipation measure for the substrate, in Patent Document 1, the coil pattern is spread over almost the entire area of each layer of the substrate. Moreover, the heat | fever of a coil pattern is led outside by the terminal which penetrates a board | substrate. Furthermore, a radiator is attached to the end of the substrate.

  In Patent Document 3, a part of the coil pattern on each layer of the substrate is widened to provide a heat radiation pattern portion. Further, the lower substrate is protruded from the upper substrate, and a heat radiation pattern portion is provided on the protruding portion so as to directly touch the outside air. Furthermore, the position of the heat radiation pattern portion provided in each layer in the surface direction is varied.

  In Patent Document 6, a heat-transfer through conductor that penetrates the magnetic layer and the lower insulating layer is provided inside the coil pattern, and a heat-dissipating conductor layer connected to the heat-transfer through conductor is provided on the lower surface of the substrate. ing. The through conductor for heat transfer and the conductive layer for heat dissipation are not connected to the coil pattern.

  In Patent Document 7, a cooling unit is provided below the substrate via a thermally conductive insulating sheet, and a heat radiating member is provided so as to penetrate the substrate or be buried in the substrate. One end of the heat dissipating member is in contact with the cooling part via a heat conductive insulating sheet, and the other end is connected to a coil pattern or a wiring circuit.

JP 2008-205350 A Japanese Unexamined Patent Publication No. 7-38262 Japanese Patent Laid-Open No. 7-86755 Reissue WO2010 / 026690 JP-A-8-69935 JP 2008-177516 A JP 2010-109309 A JP 2002-280230 A JP 2002-111159 A

  For example, in a substrate integrated with a coil for a magnetic device used in a DC-DC converter through which a large current flows, a large current flows through the coil pattern and the amount of heat generated in the coil pattern increases. Further, as the number of layers of the substrate on which the coil pattern is provided is increased, the heat generated in the coil pattern is accumulated and the temperature of the substrate is likely to rise. When the temperature of the substrate rises, there is a risk that the characteristics of the magnetic device will vary and the performance will deteriorate. In addition, when an electronic component such as another IC chip is mounted on the same substrate, there is a risk of malfunction or destruction of the electronic component. Furthermore, if there is a portion with a large electrical resistance in the current path of the coil pattern, the current flow may be hindered and the predetermined performance of the coil may not be achieved.

  An object of the present invention is to provide a coil-integrated printed circuit board and a magnetic device that can easily dissipate heat generated from a coil pattern without hindering the current flow of the coil pattern.

  The coil-integrated printed circuit board according to the present invention includes a coil pattern formed in a plurality of layers, an electrical interlayer connection means for electrically connecting coil patterns in different layers, and a coil pattern in a specific layer. And thermal interlayer connection means for thermally connecting to the outer surface layer. Then, an extended region in which a part of the coil pattern is extended in the width direction is provided at a position deviating from the current path of the coil pattern in the specific layer, and other regions are provided corresponding to the coil pattern in the specific layer. A heat radiation pattern is provided on the outer surface layer, and the expansion region of the corresponding coil pattern and the heat radiation pattern are thermally connected by the thermal interlayer connection means.

  A magnetic device according to the present invention includes the above-described coil-integrated printed board and a core made of a magnetic material and penetrating the coil-integrated printed board, and is wound around the core so as to be wound around the core. Coil patterns are formed on a plurality of layers of the substrate.

  According to the above configuration, the expansion region of the coil pattern provided at a position deviated from the current path of the coil pattern of the specific layer and the corresponding heat radiation pattern provided on the other outer surface layer are heated by the thermal interlayer connection means. Connected. For this reason, heat generated from the coil pattern of a specific layer is transmitted to the heat radiation pattern on the other outer surface layer by the thermal interlayer connection means without disturbing the current flow of the coil pattern, so that the heat can be easily radiated to the outside. Can do.

  According to the present invention, in the coil-integrated printed board, the extended area of the corresponding coil pattern and the heat radiation pattern are provided to face each other, the thermal interlayer connection means includes a metal pin, and the corresponding coil pattern The coil-integrated printed board may be penetrated so as to pass through the extended region and the heat radiation pattern.

  In the present invention, in the above-described coil-integrated printed board, the electrical interlayer connecting means may be a through hole, and may penetrate the coil-integrated printed board on the current path of the coil pattern to be connected. .

  According to the present invention, in the coil-integrated printed circuit board, the electrical interlayer connection means includes a through hole group in which a plurality of through holes are gathered at a predetermined interval, and the through hole group is a coil pattern in a different layer. A plurality may be provided according to the number of connections between them.

  In the present invention, in the coil-integrated printed board, the through hole may be filled with a conductive member.

  In the present invention, the coil-integrated printed board includes a front-side outer surface layer, a back-side outer surface layer, and at least one inner layer provided between each of these layers, and each layer is provided with a coil pattern, and the front-side outer surface layer and the inner layer An extended region of each coil pattern is provided at a position deviating from the current path of each coil pattern, and a heat radiation pattern is provided on the back outer surface layer corresponding to each coil pattern in the front outer surface layer and the inner layer. Good. Further, the thermal interlayer connection means passes through the coil-integrated printed board so as to pass through the extended region of the coil pattern of the front outer layer and the heat dissipation pattern corresponding to the coil pattern, and the corresponding outer layer of the front outer layer. The coil-integrated printed circuit board passes through the first thermal interlayer connection means for thermally connecting the coil pattern and the heat dissipation pattern, the extended region of the inner coil pattern, and the heat dissipation pattern corresponding to the coil pattern. And a second thermal interlayer connecting means for thermally connecting the corresponding inner layer coil pattern and heat radiation pattern.

  In the present invention, in the coil-integrated printed board, the number of second thermal interlayer connection means may be larger than the number of first thermal interlayer connection means.

  Further, in the present invention, in the coil-integrated printed board, the first thermal interlayer connection means and the second thermal interlayer connection means are formed of columnar bodies, and from the diameter of the first thermal interlayer connection means, The diameter of the second thermal interlayer connecting means may be increased.

  Furthermore, in the present invention, in the magnetic device, a heat radiator may be provided on the other outer surface layer side of the coil-integrated printed board.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the coil integrated printed circuit board and magnetic device which can make it easy to radiate the heat | fever from a coil pattern, without disturbing the flow of the current of a coil pattern.

It is a block diagram of a switching power supply device. 1 is an exploded perspective view of a magnetic device according to a first embodiment of the present invention. It is a top view of each layer of the coil integrated type printed circuit board of FIG. It is sectional drawing of the magnetic device of FIG. It is sectional drawing of the magnetic device of FIG. It is a top view of each layer of a coil integrated type printed circuit board of a magnetic device by a 2nd embodiment of the present invention. It is sectional drawing of the magnetic device of FIG. It is a top view of each layer of a coil integrated type printed circuit board of a magnetic device by a 3rd embodiment of the present invention. It is sectional drawing of the magnetic device of FIG. It is a disassembled perspective view of the magnetic device by 4th Embodiment of this invention. FIG. 10 is a plan view of each layer of the coil-integrated printed board of FIG. 9. It is sectional drawing of the magnetic device of FIG. It is sectional drawing of the magnetic device of FIG. It is sectional drawing of the magnetic device of FIG. It is sectional drawing of the magnetic device of FIG. It is a top view of each layer of a coil integrated type printed circuit board of a magnetic device by a 5th embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a configuration diagram of the switching power supply apparatus 100. The switching power supply device 100 is a DC-DC converter for an electric vehicle (or a hybrid car), which switches a high-voltage direct current to an alternating current and then converts it to a low-voltage direct current. This will be described in detail below.

  A high voltage battery 50 is connected to the input terminals T <b> 1 and T <b> 2 of the switching power supply device 100. The voltage of the high voltage battery 50 is, for example, DC 220V to DC 400V. The DC voltage Vi of the high-voltage battery 50 input to the input terminals T1 and T2 is applied to the switching circuit 52 after noise is removed by the filter circuit 51.

  The switching circuit 52 is formed of a known circuit having, for example, an FET (Field Effect Transistor). In the switching circuit 52, the FET is turned on / off based on a PWM (Pulse Width Modulation) signal from the PWM drive unit 58, and a switching operation is performed on the DC voltage. As a result, the DC voltage is converted into a high-frequency pulse voltage.

  The pulse voltage is given to the rectifier circuit 54 via the transformer 53. The rectifier circuit 54 rectifies the pulse voltage by a pair of diodes D1 and D2. The voltage rectified by the rectifier circuit 54 is input to the smoothing circuit 55. The smoothing circuit 55 smoothes the rectified voltage by the filtering action of the choke coil L and the capacitor C, and outputs the smoothed voltage to the output terminals T3 and T4 as a low DC voltage. With this DC voltage, the low voltage battery 60 connected to the output terminals T3 and T4 is charged to, for example, DC12V. The DC voltage of the low-voltage battery 60 is supplied to various on-vehicle electrical components (not shown).

  The output voltage Vo of the smoothing circuit 55 is detected by the output voltage detection circuit 59 and then output to the PWM drive unit 58. The PWM drive unit 58 calculates the duty ratio of the PWM signal based on the output voltage Vo, generates a PWM signal corresponding to the duty ratio, and outputs the PWM signal to the gate of the FET of the switching circuit 52. As a result, feedback control is performed to keep the output voltage constant.

  The control unit 57 controls the operation of the PWM drive unit 58. A power source 56 is connected to the output side of the filter circuit 51. The power supply 56 steps down the voltage of the high voltage battery 50 and supplies a power supply voltage (for example, DC 12 V) to the control unit 57.

  In the switching power supply device 100 described above, magnetic devices 1, 1 ′, 1 ″, 21 and 31 described later are used as the choke coil L of the smoothing circuit 55. A large current of, for example, DC 150A flows through the choke coil L. At both ends of the choke coil L, terminals 6i and 6o for power input / output are provided.

  Next, the structure of the magnetic device 1 according to the first embodiment and the coil-integrated printed circuit board 3 (hereinafter simply referred to as “substrate 3”) included in the magnetic device 1 will be described with reference to FIGS. While explaining.

  2 is an exploded perspective view of the magnetic device 1 (the same applies to magnetic devices 1 ′, 1 ″, and 31 described later). FIG. 3 is a plan view of each layer of the substrate 3. FIG. It is sectional drawing of the device 1, (a) has shown XX section of Drawing 3, and (b) has shown YY section of Drawing 3. Drawing 4-2 is a sectional view of magnetic device 1. FIG. 3 shows a U-U cross section of FIG.

  As shown in FIG. 2 and FIG. 4-1 (a), the cores 2a and 2b are composed of a pair of an upper core 2a having an E-shaped cross section and a lower core 2b having an I-shaped cross section. ing. The cores 2a and 2b are made of a magnetic material such as ferrite or amorphous metal.

  The upper core 2a has three convex portions 2m, 2L, and 2r so as to protrude downward. The left and right protrusions 2L and 2r have a larger amount of protrusion than the center protrusion 2m.

  As shown in FIG. 4A, the lower ends of the left and right convex portions 2L, 2r of the upper core 2a are brought into close contact with the upper surface of the lower core 2b, and the cores 2a, 2b are combined. In this state, a gap of a predetermined size is provided on the upper surface of the convex portion 2m of the upper core 2a and the upper surface of the lower core 2b in order to improve the DC superimposition characteristics. Thereby, even when a large current is passed through the magnetic device 1 (choke coil L), a predetermined inductance can be realized (the same applies to magnetic devices 1 ′, 1 ″, 21 and 31 described later). 2b is fixed by fixing means, such as a screw and a metal fitting (not shown).

  The lower core 2 b is fitted into a recess 10 k (FIG. 2) provided on the upper side of the heat sink 10. A fin 10 f is provided on the lower side of the heat sink 10. The heat sink 10 is made of metal and is an example of the “heat radiator” of the present invention.

  The board | substrate 3 is comprised from the thick copper foil board | substrate with which the pattern was formed in each layer of the thin-plate-shaped base material which consists of an insulator with thick copper foil (conductor). In the present embodiment, no other electronic components or circuits are provided on the substrate 3, but when the magnetic device 1 is actually used in the switching power supply apparatus 100 of FIG. 1, the magnetic device 1 is formed on the same substrate larger than the substrate 3. In addition, other electronic components and circuits are provided for the switching power supply apparatus 100 (the same applies to magnetic devices 1 ′, 1 ″, 21, and 31 described later).

  A front-side outer surface layer L1 as shown in FIG. 3A is provided on the surface of the substrate 3 (the upper surface in FIGS. 2, 4-1, and 4-2). On the back surface of the substrate 3 (the lower surface in FIGS. 2, 4-1, and 4-2), a back-side outer surface layer L3 as shown in FIG. 3C is provided. As shown in FIGS. 4A and 4B, an inner layer L2 as shown in FIG. 3B is provided between the outer surface layers L1 and L3. That is, the substrate 3 has three layers L1, L2, and L3, that is, two outer surface layers L1 and L3 and one inner layer L2.

  The substrate 3 is provided with a plurality of through holes 3m, 3L, 3r, and 3a. Among them, as shown in FIGS. 2 to 4A, the convex portions 2m, 2L, and 2r of the core 2a are inserted into the large-diameter through holes 3m, 3L, and 3r, respectively. That is, the convex portions 2m, 2L, and 2r of the core 2a penetrate through the layers L1 to L3 of the substrate 3.

  As shown in FIGS. 2 and 4-1 (b), each screw 11 is inserted into the plurality of small diameter through holes 3a. The back surface (back side outer surface layer L3) of the substrate 3 is opposed to the upper surface (the surface opposite to the fin 10f) of the heat sink 10. Then, the screws 11 are passed through the through holes 3 a from the surface (front side outer surface layer L 1) side of the substrate 3 and screwed into the screw holes 10 a of the heat sink 10. As a result, as shown in FIGS. 4A and 4B, the heat sink 10 is fixed to the back side outer surface layer L3 side of the substrate 3 in the proximity state.

  An insulating sheet 12 having heat conductivity is sandwiched between the substrate 3 and the heat sink 10. Since the insulating sheet 12 has flexibility, it is in close contact with the substrate 3 and the heat sink 10 without a gap.

As shown in FIG. 3, the substrate 3 has through holes 8a and 8d, through hole groups 9a to 9d, pads 8b and 8c, terminals 6i and 6o, patterns 4a to 4f, 5a _{1 to} 5a ₉ , 5b _{1 to} 5b. ₉ and conductors such as pins 7a to 7f are provided. Through-holes 8a, 8d and the through hole group 9a~9d connects different layers L1, L2, L3 open a pattern _4a-4f, the _{5a 7 ~5a 9, 5b 7 ~5b} 9 together.

Specifically, each through hole 8a penetrates the substrate 3, and connects the patterns 4a, 4b of the front side outer surface layer L1 to the other layers L2, L3. Each through-hole 8d penetrates the substrate 3 as shown in FIG. 4-1, and connects the front side outer surface layer L1 and the other layers L2, L3, and the patterns 4a, 4b of the front side outer surface layer L1. The patterns 5a ₉ and 5b ₉ of the back side outer surface layer L3 are connected, and the patterns 4c and 4d of the inner layer L2 and the patterns 5a ₇ , 5a ₈ , 5b ₇ and 5b ₈ of the back side outer surface layer L3 are connected.

  Each through-hole group 9a, 9b, 9c, 9d has a smaller diameter than the through-holes 8a, 8d, and a plurality of through-holes penetrating the substrate 3 are gathered at a predetermined interval as shown in FIG. (The cross sections of the through-hole groups 9c and 9d are not shown). As shown in FIG. 3, the through-hole groups 9a and 9d connect the patterns 4a and 4b of the front outer surface layer L1 and the patterns 4c and 4d of the inner layer L2. The through-hole groups 9b and 9c connect the patterns 4c and 4d of the inner layer L2 and the pattern 4e of the back outer surface layer L3.

  Of the pair of large-diameter through holes 8a, a power input terminal 6i is embedded in one, and a power output terminal 6o is embedded in the other. Terminals 6i and 6o are made of copper pins. Pads 8b made of copper foil are provided around the terminals 6i and 6o of the front side outer surface layer L1 and the back side outer surface layer L3. Copper plating is applied to the surfaces of the terminals 6i and 6o and the pad 8b. The lower ends of the terminals 6i and 6o are in contact with the insulating sheet 12 (not shown).

Coil patterns _{4 a to 4} e and heat radiation patterns 5 a _{1 to} 5 a ₉ and 5 b _{1 to} 5 b ₉ are provided on each layer L 1, L 2, L 3 of the substrate 3. Each pattern _{4a~4e, 5a 1 ~5a 9, 5b} 1 ~5b 9 is made of a copper foil. Each pattern _4a of the front outer surface layer L1, _4b, on the surface of _{5a 1 ~5a 4, 5b 1 ~5b} 4, insulating treatment is applied. The width, thickness and cross-sectional area of the coil patterns 4a to 4e can suppress the amount of heat generated in the coil patterns 4a to 4e to some extent even when a predetermined large current (for example, DC150A) is passed while achieving the predetermined performance of the coil. And it is set so that heat can be radiated from the surfaces of the coil patterns 4a to 4e.

  As shown in FIG. 3A, in the front side outer surface layer L1, the coil pattern 4a is wound once in four directions around the convex portion 2L. The coil pattern 4b is wound once in four directions around the convex portion 2r.

  As shown in FIG. 3B, in the inner layer L2, the coil pattern 4c is wound once in four directions around the convex portion 2L. The coil pattern 4d is wound once in the four directions around the convex portion 2r.

  As shown in FIG. 3C, in the back side outer surface layer L3, the coil pattern 4e is wound once in the four directions around the convex portion 2L and then once in the three directions around the convex portion 2m. Furthermore, it is wound once in four directions around the convex portion 2r.

  One end of the coil pattern 4a and one end of the coil pattern 4c are electrically connected (can be conducted) by the through-hole group 9a. The through-hole group 9a is provided on the current path (portion drawn by the width W1) of the coil patterns 4a and 4c, and penetrates the substrate 3. The other end of the coil pattern 4c and one end of the coil pattern 4e are electrically connected by a through hole group 9c. The through-hole group 9c is provided on the current path (portion drawn by the width W1) of the coil patterns 4c and 4e and penetrates the substrate 3. The other end of the coil pattern 4e and one end of the coil pattern 4d are electrically connected by a through hole group 9b. The through-hole group 9b is provided on the current path (portion routed with the width W1) of the coil patterns 4e and 4d and penetrates the substrate 3. The other end of the coil pattern 4d and one end of the coil pattern 4b are electrically connected by a through hole group 9d. The through-hole group 9d is provided on the current path (portion drawn with the width W1) of the coil patterns 4d and 4b and penetrates the substrate 3. As described above, a plurality (four) of through-hole groups 9a to 9d are provided according to the number of connections between the coil patterns 4a to 4e in the different layers L1 to L3.

  The surface of each small-diameter through-hole constituting the through-hole groups 9a to 9d is plated with copper, and the inside of the through-hole is filled with copper or the like. The through-hole groups 9a to 9d are examples of the “electrical interlayer connection means” in the present invention.

  Small patterns 4f are provided around the through-hole groups 9b and 9c of the front-side outer surface layer L1 and around the through-hole groups 9a and 9d of the back-side outer surface layer L3 in order to facilitate the formation of each through-hole. . Each through-hole group 9a-9d and the small pattern 4f are connected. The small pattern 4f is made of copper foil. The surface of the small pattern 4f of the front side outer surface layer L1 is subjected to insulation processing.

  The other end of the coil pattern 4a is electrically connected to the terminal 6i through the pad 8b. The other end of the coil pattern 4b is electrically connected to the terminal 6o via the pad 8b.

  With the above configuration, the coil patterns 4a to 4e of the substrate 3 are wound on the front side outer surface layer L1 from the terminal 6i that is the starting point around the convex portion 2L, and then through the through hole group 9a. Connected to the inner layer L2. Next, the coil patterns 4a to 4e are the inner layer L2, and after the second time is wound around the convex portion 2L, the coil patterns 4a to 4e are connected to the back-side outer surface layer L3 via the through-hole group 9c.

  Next, the coil patterns 4a to 4e are the back side outer surface layer L3, the third time is wound around the convex portion 2L, and the fourth time is wound around the convex portion 2r via the periphery of the convex portion 2m. Thereafter, it is connected to the inner layer L2 via the through-hole group 9b. Next, the coil patterns 4a to 4e are the inner layer L2, and after the fifth time is wound around the convex portion 2r, the coil patterns 4a to 4e are connected to the front-side outer surface layer L1 via the through-hole group 9d. And the coil patterns 4a-4e are front side outer surface layer L1, and after the 6th time is wound around the convex part 2r, they are connected to the terminal 6o which is an end point.

  As described above, the current flowing through the magnetic device 1 is also the terminal 6i, the coil pattern 4a, the through hole group 9a, the coil pattern 4c, the through hole group 9c, the coil pattern 4e, the through hole group 9b, the coil pattern 4d, and the through hole group. 9d, coil pattern 4b, and terminal 6o flow in this order.

The heat radiation patterns 5a _{1 to} 5a ₉ and 5b _{1 to} 5b ₉ are formed separately from the patterns 4a to 4e and 4f in the empty areas around the coil patterns 4a to 4e and the small patterns 4f of the layers L1 to L3. ing. Further, the heat radiation patterns 5a _{1 to} 5a ₉ and 5b _{1 to} 5b ₉ are separated from each other and are electrically insulated. In other words, the heat radiation pattern _{5a 1 ~5a 9, 5b 1 ~5b} 9 , the coil patterns 4 a to 4 e, making it separate from the small pattern 4f and other heat radiation pattern _{5a 1 ~5a 9, 5b 1 ~5b} 9 , Electrically insulated.

Against heat radiation pattern _{5a 1 ~5a 9, 5b 1 ~5b} 9, pad 8b, terminal 6i, 6o, the through-hole 3a, and the screw 11 are insulated. Since the head portion 11a having a larger diameter than the shaft portion 11b of the screw 11 is disposed on the surface side of the substrate 3, from the insulating region (region having no conductor) R2 around the through hole 3a of the inner layer L2 and the back outer surface layer L3, The insulating region R1 around the through hole 3a of the front side outer surface layer L1 is wider (see FIG. 3).

  Heat radiation pins 7a to 7f are embedded in the plurality of large-diameter through holes 8d, respectively. The heat radiation pins 7a to 7f are formed of metal pins formed in a columnar shape with a conductor such as copper. Pads 8c made of copper foil are provided around the heat radiation pins 7a to 7f of the front side outer surface layer L1 and the back side outer surface layer L3. Copper plating is applied to the surfaces of the heat radiation pins 7a to 7f and the pad 8c. The lower ends of the heat radiation pins 7a to 7f are in contact with the insulating sheet 12 (see FIG. 4B). The heat radiation pins 7a to 7e, the peripheral pads 8c, and the through holes 8d are examples of the “thermal interlayer connection means” in the present invention.

As shown in FIG. 3 (a), the front outer surface layer L1, a position off the current path of the coil pattern 4a, extended area 4t ₁ is provided with the extended portion of the coil pattern 4a in the width direction . In other words, extended area 4t ₁ and coil pattern 4a is integral. For extended area 4t ₁ coil pattern 4a, the pad 8c and the through-holes 8d of the ambient and the heat dissipation pins 7a is connected to a thermal (heat enable conduction). Further, at a position deviated from the current path of the coil pattern 4b, extended area 4t ₂ is provided with the extended portion of the coil pattern 4b in the width direction. In other words, extended area 4t ₂ and coil pattern 4b is integral. For extended area 4t ₂ coil patterns 4b, pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7b are thermally connected. Other radiation fins 7c~7f and these peripheral pads 8c and the through-hole 8d is the heat radiation pattern _{5a 1 ~5a 4, 5b 1 ~5b} 4, coil patterns 4a, 4b, and the small pattern 4f, electrical Is insulated. Further, with respect to the heat radiation pattern _{5a 1 ~5a 4, 5b 1 ~5b} 4, coil patterns 4a, 4b and the small pattern 4f are electrically insulated.

As shown in FIG. 3 (b), in the inner layer L2, expansion regions 4t ₃ and 4t ₄ obtained by extending a part of the coil pattern 4c in the width direction are provided at positions outside the current path of the coil pattern 4c. Yes. That is, the coil pattern 4c and the extended regions 4t ₃ and 4t ₄ are integrated. The heat dissipation pins 7c and 7e and the surrounding through holes 8d are thermally connected to the extended regions 4t ₃ and 4t _{4 of the} coil pattern 4c, respectively. In addition, extended regions 4t ₅ and 4t ₆ are provided in which portions of the coil pattern 4d are expanded in the width direction at positions outside the current path of the coil pattern 4d. That is, the coil pattern 4d and the extended regions 4t ₅ and 4t ₆ are integrated. The expansion pins 4d ₅ and 4t _{6 of the} coil pattern 4d are thermally connected to the heat dissipation pins 7d and 7f and the surrounding through holes 8d, respectively. Other heat dissipating pins 7a, 7b and these around the through-hole 8d is the heat radiation pattern _{5a 5, 5a 6, 5b 5} , 5b 6 and the coil pattern 4c, against 4d, it is electrically insulated. The coil patterns 4c and 4d are electrically insulated from the heat radiation patterns 5a ₅ , 5a ₆ , 5b ₅ and 5b ₆ .

The extended regions 4t _{1 to} 4t ₆ of the coil patterns 4a to 4d are arranged in the layers L1 and L2 so as not to overlap in the plate thickness direction of the substrate 3, respectively. The width W2 of the portion extended area _4t 1 _{~4t 6} of the coil pattern 4 a to 4 d is provided, W3, W4 are larger than the width W1 of the current path of each coil pattern 4 a to 4 d (W1 <W2, W3 , W4). The area of the expansion region _4t 1 _{~4t 6} is larger than the cross-sectional area perpendicular to the axis of the heat radiating fin 7a to 7f.

As shown in FIG. 3 (c), the back side outer surface layer L3 is provided with a heat radiation pattern 5a ₉ corresponding to the coil pattern 4a of the front side outer surface layer L1, and the heat radiation pattern 5b ₉ corresponding to the coil pattern 4b. Is provided. Further, heat radiation patterns 5a ₇ and 5a ₈ are provided corresponding to the coil pattern 4c of the inner layer L2, and heat radiation patterns 5b ₇ and 5b ₈ are provided corresponding to the coil pattern 4d. Extended area _4t 1 of corresponding coil pattern _{4a~4d, 4t 2, 4t 3,} 4t 4, 4t 5, 4t 6 and the radiating pattern _{5a 9, 5b 9, 5a 7} , 5a 8, 5b 7, 5b part of ₈ Are opposed to each other in the thickness direction of the substrate 3.

Further, the back side outer surface layer L3, pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7c is thermally connected to the heat radiation pattern 5a _7. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7e is thermally connected to the heat radiation pattern 5a _8. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7a is thermally connected to the heat radiation pattern 5a _9.

Further, the back side outer surface layer L3, pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7d are thermally connected to the heat radiation pattern 5b _7. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7f is thermally connected to the heat radiation pattern 5b _8. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7b is thermally connected to the heat radiation pattern 5b _9.

Further, the back side outer surface layer L3, with respect to the heat radiation pattern _{5a 7 ~5a 9, 5b 7 ~5b} 9, the coil pattern 4e and small patterns 4f are electrically insulated. Further, the coil pattern 4e and the small pattern 4f are electrically insulated from the heat radiation pins 7a to 7f, the pad 8c, and the through hole 8d.

With the above structure, through hole 8d of the ambient and the heat dissipation pins 7a, like passing through the heat radiation pattern 5a ₉ of the extended area 4t ₁ and the back side outer surface layer L3 of the coil pattern 4a of the front outer surface layer L1, through the substrate 3 ing. Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 7a, and the extended area 4t ₁ coil pattern 4a and the heat radiation pattern 5a ₉ is thermally connected. The through-holes 8d of the ambient and the heat dissipation pins 7b, like passing through the heat radiation pattern 5b ₉ of the extension region 4t ₂ and the back outer surface layer L3 of the coil pattern 4b of the front outer surface layer L1, penetrates the substrate 3 . Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 7b, the extended area 4t ₂ coil pattern 4b and the heat radiation pattern 5b ₉ is thermally connected. The radiating pins 7a and 7b, their surrounding pads 8c, and the through holes 8d are examples of the “first thermal interlayer connecting means” in the present invention.

The heat dissipation pins 7c and 7e and the surrounding through holes 8d pass through the expansion regions 4t ₃ and 4t ₄ of the coil pattern 4c of the inner layer L2 and the heat dissipation patterns 5a ₇ and 5a _{8 of the} back outer surface layer L3 so as to pass through the substrate 3 It penetrates. Therefore, the expansion regions 4t ₃ and 4t ₄ of the coil pattern 4c and the heat radiation patterns 5a ₇ and 5a ₈ are thermally connected by the heat radiation pins 7c and 7e, the surrounding through holes 8d, and the pads 8c. Further, the heat dissipation pins 7d, 7f and a through hole 8d in these surroundings, as passing through the heat radiation pattern _5b 7, 5b ₈ of the extended area _4t 5, 4t ₆ and the back side outer surface layer L3 of the coil pattern 4d of the inner layer L2, It penetrates the substrate 3. Therefore, the expansion regions 4t ₅ and 4t ₆ of the coil pattern 4d and the heat radiation patterns 5b ₇ and 5b ₈ are thermally connected by the heat radiation pins 7d and 7f, the surrounding through holes 8d, and the pads 8c. The heat radiation pins 7c to 7f, the peripheral pads 8c, and the through holes 8d are examples of the “second thermal interlayer connection means” in the present invention.

The coil patterns 4a and 4b of the front side outer surface layer L1 are thermally connected to the heat radiation patterns 5a ₉ and 5b ₉ of the corresponding back side outer surface layer L3 at one place respectively. On the other hand, the coil patterns 4c and 4d of the inner layer L2 are thermally connected to the heat radiation patterns 5a ₇ , 5a ₈ , 5b ₇ and 5b ₈ of the corresponding back side outer surface layer L3 at two locations, respectively.

The volume of each heat radiation pin 7a to 7f, the volume of each pad 8c, and the volume of each through hole 8d are the same. For this reason, the inner layer L2 is determined based on the total volume of the plurality of (two places) first thermal interlayer connecting means for connecting the coil patterns 4a and 4b of the front outer layer L1 and the heat radiation patterns 5a ₉ and 5b ₉ of the rear outer layer L3. of the coil pattern 4c, the direction of total volume of the second thermal interlayer connecting means of a plurality (four points) that connects the heat radiation pattern _{5a 7, 5a 8, 5b 7} , 5b 8 of 4d and the back outer surface layer L3, larger It has become. The former first thermal interlayer connection means is the radiating pins 7a, 7b and their surrounding pads 8c and the through holes 8d, and the latter second thermal interlayer connection means is the radiating pins 7c-7e. These are the surrounding pad 8c and the through hole 8d.

  Since a large current flows through the coil patterns 4a to 4e, the coil patterns 4a to 4e serve as heat generation sources, and the temperature of the substrate 3 rises.

In front outer surface layer L1, the heat of the substrate 3 is diffused to the heat radiation pattern _{5a 1 ~5a 4, 5b 1 ~5b} 4 , patterns _4a, 4b, _4f, conductors such as _{5a 1 ~5a 4, 5b 1 ~5b} 4 The heat is dissipated on the surface. The heat of the substrate 3 is radiated by the heat sink 10 through the insulating sheet 12 through the conductors penetrating the substrate 3 such as the radiation pins 7a to 7f, the through holes 8d and 8a, and the through hole groups 9a to 9d. . The through hole groups 9a to 9d function as thermal vias.

In particular, heat generated in the coil patterns 4a and 4b on the front side outer surface layer L1 is diffused to the heat radiation patterns 5a ₉ and 5b ₉ on the back side outer surface layer L3 through the extended regions 4t ₁ and 4t ₂ and the heat radiation pins 7a and 7b. Then, heat is dissipated by the heat sink 10 through the insulating sheet 12 from the surfaces of the heat radiation patterns 5a ₉ and 5b ₉ and the lower surfaces of the heat radiation pins 7a and 7b.

In the inner layer L2, the heat of the substrate 3 is diffused to the heat radiation pattern _{5a 5, 5a 6, 5b 5} , 5b 6, through the substrate 3 such as a heat radiating fin 7a~7f and through holes 8d and through hole group 9a~9d Heat is radiated by the heat sink 10 through the insulating sheet 12 through the conductor. In particular, the coil pattern 4c, the heat generated in 4d, extended area _{4t 3,} 4t _4, the heat radiation pattern _5a 7 of 4t 5, 4t ₆ and the heat-radiating fin 7c~7f back outer surface layer L3 along the _like, 5a 8, 5b _7, is diffused to 5b _8, it is radiated by the heat sink 10 from the lower surface of the heat radiation pattern _{5a 7,} 5a _8, 5b 7, the surface of 5b ₈ and the heat-radiating fin 7c~7f via the insulating sheet 12.

In the back outer surface layer L3, the heat of the substrate 3, the heat radiation pattern _5a 7 is diffused into _{~5a 9,} 5b 7 _{~5b 9,} pattern _{4e, 4f,} the surface of the conductor such as _{5a 7 ~5a 9, 5b 7 ~5b} 9 Then, heat is radiated from the heat sink 10 through the insulating sheet 12. In particular, the heat generated in the coil pattern 4e is radiated from the surface of the coil pattern 4e by the heat sink 10 via the insulating sheet 12.

According to the first embodiment, the extended regions 4t _{1 to} 4t ₆ of the coil patterns 4a to 4d are provided at positions deviated from the current paths of the coil patterns 4a to 4d of the front outer surface layer L1 and the inner layer L2 of the substrate 3. Yes. Further, in correspondence with the coil patterns 4a to 4d, the heat radiation patterns 5a _{7 to} 5a ₉ and 5b _{7 to} 5b ₉ are provided on the back side outer surface layer L3. Then, the expansion regions 4t _{1 to} 4t _{6 of} the corresponding coil patterns 4a to 4d and the heat radiation patterns 5a _{7 to} 5a ₉ and 5b _{7 to} 5b ₉ are connected to the thermal interlayer such as the heat radiation pins 7a to 7f penetrating the substrate 3. Thermally connected by means.

For this reason, the heat generation from the coil patterns 4a to 4d of the front side outer surface layer L1 and the inner layer L2 is prevented from disturbing the current flow of the coil patterns 4a to 4e, and the heat radiation pattern 5a ₇ of the back side outer surface layer L3 by the thermal interlayer connection means. You can tell ~5a _{9, 5b} 7 ~5b _9. Then, heat and convey the surface of the heat radiation pattern _{5a 7 ~5a 9, 5b 7 ~5b} 9 to the heat sink 10 may be easier to heat radiation from the heat sink 10 to the outside. Further, since the current flow of the coil patterns 4a to 4e is not hindered, it is possible to achieve a predetermined performance of the coil.

In addition, the coil patterns 4a to 4e of the different layers L1 to L3 are electrically connected to each other through the through-hole groups 9a to 9d, and the corresponding coil patterns 4a to 4d and the heat radiation patterns 5a _{7 to} 5a ₉ , 5b _{7 to} 5b ₉ are connected. The heat dissipation pins 7a to 7f are connected thermally. Further, the back outer surface layer L3, and the coil pattern 4e radiating pattern _{5a 7 ~5a 9, 5b 7 ~5b} 9 separately, are electrically insulated. For this reason, in coil pattern 4a-4e, an electric current path and a thermal radiation path | route can be divided reliably, and an electricity supply performance and a thermal radiation performance can be improved.

Further, the heat radiation pattern _5a 7 _{to 5 A} 9 of the heat generated by the coil patterns 4a~4d in front exterior layer L1 and the inner layer L2 of the substrate 3, heat radiating fins 7a~7f and back outer surface layer _L3, 5b 7 ~5b ₉ It is possible to efficiently dissipate heat by transmitting to the heat sink 10 through different heat dissipation paths.

Further, the expansion regions 4t _{1 to} 4t _{6 of} the corresponding coil patterns 4a to 4d and the heat radiation patterns 5a _{7 to} 5a ₉ and 5b _{7 to} 5b ₉ are provided on the substrate 3 so as to face each other, and the heat radiation pins pass through these. 7 a to 7 f and through holes 8 d are penetrated through the substrate 3. For this reason, the radiation pins 7a to 7f and the through holes 8d can be easily provided in the substrate 3, and the manufacture of the substrate 3 can be facilitated.

  Further, the through-hole groups 9a to 9d are provided so as to penetrate the substrate 3 on the current paths of the coil patterns 4a to 4e to be connected. Further, conductive members such as copper are filled in the small diameter through holes constituting the through hole groups 9a to 9d. For this reason, the electrical conductivity of the through-hole groups 9a to 9d is improved, and the reliability of the electrical connection between the coil patterns 4a to 4e is increased, and the through-hole groups 9a to 9d can be easily provided on the substrate 3. 3 can be made easy.

Further, the coil patterns 4c and 4d of the inner layer L2 and the back side are determined from the number of first thermal interlayer connection means for connecting the coil patterns 4a and 4b of the front outer layer L1 and the heat radiation patterns 5a ₉ and 5b ₉ of the back outer layer L3. The number of second thermal interlayer connecting means for connecting the heat radiation patterns 5a ₇ , 5a ₈ , 5b ₇ , 5b ₈ of the outer surface layer L3 is larger. Accordingly, the heat radiation volume from the coil patterns 4a and 4b of the front outer layer L1 to the heat radiation patterns 5a ₉ and 5b ₉ of the rear outer layer L3 from the coil patterns 4c and 4d of the inner layer L2 to the heat radiation pattern 5a of the rear outer layer L3. _{7, 5a} 8, 5b _7, towards the heat transfer capacity is increased to 5b _8. For this reason, the heat generated in the coil patterns 4c and 4d of the inner layer L2 that does not touch the outside air can be more easily transferred to the back side outer surface layer L3 than the heat generated in the coil patterns 4a and 4b of the front side outer surface layer L1. Then, the heat generated in the inner layer L2 can be radiated from the backside outer surface layer L3 to the outside via the heat sink 10 so that the substrate 3 is not easily trapped.

  Next, the structure of the magnetic device 1 ′ according to the second embodiment and the coil-integrated printed circuit board 3 ′ (hereinafter simply referred to as “substrate 3 ′”) included in the magnetic device 1 ′ is shown in FIGS. The description will be given with reference.

FIG. 5 is a plan view of each layer of the substrate 3 ′. 6A and 6B are cross-sectional views of the magnetic device 1 ′, in which FIG. 6A shows the Z ₁ -Z ₁ cross section of FIG. 5, and FIG. 6B shows the Z ₂ -Z ₂ cross section of FIG.

  The substrate 3 ′ is provided with a front-side outer surface layer L1 ′ as shown in FIG. 5A on the front surface (upper surface in FIG. 6), and as shown in FIG. 5B on the back surface (lower surface in FIG. 6). It is composed of a two-layer thick copper foil substrate provided with a back-side outer surface layer L2 ′.

  As shown in FIG. 6 (a), the convex portions 2m, 2L, and 2r of the upper core 2a are inserted into the through holes 3m, 3L, and 3r of the substrate 3 ′, so that the layers L1 ′ and L2 ′ are formed. It penetrates. A heat sink 10 is fixed by screws 11 in the proximity state on the backside outer surface layer L2 'side of the substrate 3'. An insulating sheet 12 is sandwiched between the substrate 3 ′ and the heat sink 10.

As shown in FIG. 5, through-holes 8a and 8d, through-hole groups 9a 'and 9b', pads 8b and 8c, terminals 6i and 6o, patterns 4a 'to 4c', 5L _{1 to} 5L ₇ are provided on the substrate 3 '. Conductors such as 5r _{1 to} 5r ₇ and pins 7a ′ to 7f ′ are provided. Through-holes 8a, 8d and the through hole group 9a ', 9b' are different layers L1 ', L2' pattern 4a'~4c in _{', 5L 5 ~5L 7, 5r} 5 ~5r 7 connected to each other.

Specifically, the through hole 8a penetrates the substrate 3 ′ and connects the patterns 4a ′ and 4b ′ of the front outer layer L1 ′ and the rear outer layer L2 ′. The through hole 8d passes through the substrate 3 ′ as shown in FIG. 6A, and connects the front side outer surface layer L1 ′ and the back side outer surface layer L2 ′, or the patterns 4a ′, 4b of the front side outer surface layer L1 ′. 'and back outer surface layer L2' or to connect the pattern _{5L 5 ~5L 7, 5r 5 ~5r} 7 of.

  Each through-hole group 9a ′, 9b ′ has a smaller diameter than the through-holes 8a, 8d, and a plurality of through-holes penetrating the substrate 3 ′ are gathered at a predetermined interval as shown in FIG. 6B. Yes. As shown in FIG. 5, the through hole group 9a 'connects the pattern 4a' of the front outer surface layer L1 'and the pattern 4c' of the back outer surface layer L2 '. The through hole group 9 b ′ connects the pattern 4 b ′ of the front side outer surface layer L <b> 1 ′ and the pattern 4 c ′ of the back side outer surface layer L <b> 2 ′.

Coil patterns 4a ′ to 4c ′ and heat radiation patterns 5L _{1 to} 5L ₇ and 5r _{1 to} 5r ₇ are formed on the respective layers L1 ′ and L2 ′. These patterns 4a ′ to 4c ′, 5L _{1 to} 5L ₇ , and 5r _{1 to} 5r ₇ are made of copper foil, and the surface is subjected to insulation processing. The layout of each layer L1 ′, L2 ′ is plane symmetric. The coil patterns 4a ′ to 4c ′ have the width, thickness, and cross-sectional area of the coil patterns 4a ′ to 4c ′ even when a predetermined large current (for example, DC150A) is applied while achieving the predetermined performance of the coil. Is set to be able to radiate heat from the surfaces of the coil patterns 4a ′ to 4c ′.

  As shown in FIG. 5A, in the front side outer surface layer L1 ', the coil pattern 4a' is wound twice in the four directions around the convex portion 2L. The coil pattern 4b 'is wound twice in the four directions around the convex portion 2r.

  As shown in FIG. 5B, in the back side outer surface layer L2 ′, the coil pattern 4c ′ is wound once in the four directions around the convex portion 2L and then passed through the three directions around the convex portion 2m. It is wound once in four directions around the convex part 2r.

  One end of the coil pattern 4a 'and one end of the coil pattern 4c' are electrically connected by a through hole group 9a '. The through hole group 9a 'is provided on the current path (portion routed by the width W5) of the coil patterns 4a' and 4c 'and penetrates the substrate 3'. The other end of the coil pattern 4c 'and one end of the coil pattern 4b' are electrically connected by a through hole group 9b '. The through hole group 9b 'is provided on the current path (portion routed by the width W5) of the coil patterns 4c' and 4b 'and penetrates the substrate 3'. Thus, a plurality (two) of through-hole groups 9a 'and 9b' are provided according to the number of connections between the coil patterns 4a 'to 4c' in the different layers L1 'and L2'.

  Copper plating is applied to the surface of each small-diameter through hole constituting each of the through-hole groups 9a 'and 9b', and the inside of each through-hole is filled with copper or the like. The through-hole groups 9a 'and 9b' are examples of the "electrical interlayer connection means" in the present invention.

  The other end of the coil pattern 4a 'is electrically connected to the terminal 6i through the pad 8b and the through hole 8a. The other end of the coil pattern 4b 'is electrically connected to the terminal 6o through the pad 8b and the through hole 8a.

  That is, the coil patterns 4a ′ to 4c ′ of the substrate 3 ′ are the outer surface layer L1 ′, and after the first and second windings are wound around the convex portion 2L from the starting terminal 6i, the through hole group 9a. It is connected to the backside outer surface layer L2 'via'.

Next, the coil patterns 4a ′ to 4c ′ are the back side outer surface layer L2 ′, and the third time is wound around the convex portion 2L, and the fourth time around the convex portion 2r via the periphery of the convex portion 2m. After being wound, through the through-hole group 9b ′, the front outer surface layer L1 ′
Connected to. And coil pattern 4a '-4c' is front side outer surface layer L1 ', and after the 5th time and the 6th time are wound around the convex part 2r, it is connected to the terminal 6o which is an end point.

  The current flowing through the magnetic device 1 ′ also flows in the order of the terminal 6i, the coil pattern 4a ′, the through hole group 9a ′, the coil pattern 4c ′, the through hole group 9b ′, the coil pattern 4b ′, and the terminal 6o as described above. .

The heat radiation patterns 5L _{1 to} 5L ₇ and 5r _{1 to} 5r ₇ are formed separately from the patterns 4a ′ to 4c ′ in empty areas around the coil patterns 4a ′ to 4c ′ of the respective layers L1 ′ and L2 ′. ing. Further, the heat radiation patterns 5L _{1 to} 5L ₇ and 5r _{1 to} 5r ₇ are separate from each other and are electrically insulated. In other words, the heat radiation pattern _{5L 1 ~5L 7, 5r 1 ~5r} 7 is it the coil pattern 4A'～4c 'and other heat radiation pattern _{5L 1 ~5L 7, 5r 1 ~5r} 7 separately, electrical Is electrically insulated. Against heat radiation pattern _{5L 1 ~5L 7, 5r 1 ~5r} 7, pad 8b, terminal 6i, 6o, the through-hole 3a, and the screw 11 are insulated.

  Heat dissipation pins 7a 'to 7f' are embedded in the plurality of large-diameter through holes 8d. The heat radiating pins 7a 'to 7f' are formed of metal pins formed in a columnar shape with a conductor such as copper. Pads 8c made of copper foil are provided around the heat dissipation pins 7a 'to 7f' of the layers L1 'and L2'. Copper plating is applied to the surfaces of the heat radiation pins 7a 'to 7f' and the pad 8c. The lower ends of the heat radiation pins 7a 'to 7f' are in contact with the insulating sheet 12 (see FIG. 6A). The radiating pins 7a 'to 7f', the pads 8c around these pins, and the through holes 8d are examples of the "thermal interlayer connecting means" of the present invention.

As shown in FIG. 5A, in the front side outer surface layer L1 ′, extended regions 4s _{1 to} 4s in which a part of the coil pattern 4a ′ is extended in the width direction at a position deviated from the current path of the coil pattern 4a ′. ₃ is provided. The coil pattern 4a ′ and the extended regions 4s _{1 to} 4s ₃ are integrated. In addition, extended regions 4s _{4 to} 4s ₆ are provided by extending a part of the coil pattern 4b ′ in the width direction at positions outside the current path of the coil pattern 4b ′. The coil pattern 4b ′ and the extended regions 4s _{4 to} 4s ₆ are integrated. The expansion regions 4s _{1 to} 4s ₃ of the coil pattern 4a ′ are thermally connected to the radiating pins 7a ′, 7c ′, and 7e ′, the pads 8c around them, and the through holes 8d, respectively. The expansion regions 4s _{4 to} 4s ₆ of the coil pattern 4b ′ include heat radiation pins 7b ′, 7d ′, and 7f ′.
These peripheral pads 8c and through holes 8d are thermally connected to each other. The coil patterns 4a ′ and 4b ′, the heat radiation pins 7a ′ to 7f ′, the pads 8c, and the through holes 8d are electrically insulated from the heat radiation patterns 5L _{1 to} 5L ₄ and 5r _{1 to} 5r ₄ .

The widths W6, W7, W8 of the portions where the extended regions 4s _{1 to} 4s _{6 of the} coil patterns 4a ′, 4b ′ are provided are larger than the width W5 of the current path of each coil pattern 4a ′, 4b ′ (W5). <W6, W7, W8). The area of the expansion region _4s 1 _{~4s 6} is larger than the cross-sectional area perpendicular to the axis of the heat radiating fin 7a'~7f '.

As shown in FIG. 5B, the back side outer surface layer L2 ′ is provided with heat radiation patterns 5L _{5 to} 5L ₇ corresponding to the coil pattern 4a ′ of the front side outer surface layer L1 ′, and is made to correspond to the coil pattern 4b ′. In addition, the heat radiation patterns 5r _{5 to} 5r ₇ are provided. Corresponding coil patterns 4a ′, 4b ′ of extended regions 4s ₁ , 4s ₂ , 4s ₃ , 4s ₄ , 4s ₅ , 4s ₆ and heat radiation patterns 5L ₇ , 5L ₅ , 5L ₆ , 5r ₇ , 5r ₅ , 5r ₆ Some of them face each other in the thickness direction of the substrate 3 ′.

Further, 'in, heat radiating fins 7c' back outer surface layer L2 pads 8c and the through-holes 8d of the surrounding and is thermally connected to the heat radiation pattern 5L _5. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7e 'is thermally connected to the heat radiation pattern 5L _6. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7a 'is thermally connected to the heat radiation pattern 5L _7.

Further, 'the heat dissipation pins 7d' back outer surface layer L2 pads 8c and the through-holes 8d of the surrounding and is thermally connected to the heat radiation pattern 5r _5. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7f 'is thermally connected to the heat radiation pattern 5r _6. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 7b 'are thermally connected to the heat radiation pattern 5r _7.

Further, in the back side outer surface layer L2 ′, the coil pattern 4c ′ is electrically insulated from the heat radiation patterns 5L _{5 to} 5L ₇ and 5r _{5 to} 5r ₇ . The coil pattern 4c ′ is electrically insulated from the heat radiation pins 7a ′ to 7f ′, the pad 8c, and the through hole 8d.

With the above configuration, the radiating pins 7c ′, 7e ′, 7a ′ and the surrounding through holes 8d are provided in the extended regions 4s ₂ , 4s ₃ , 4s ₁ and the back side outer surface layer L2 of the coil pattern 4a ′ of the front side outer surface layer L1 ′. The substrate 3 ′ is penetrated so as to pass through the heat radiation patterns 5L ₅ , 5L ₆ , and 5L ₇ . Therefore, the expansion regions 4s ₂ , 4s ₃ , 4s ₁ and the heat radiation patterns 5L ₅ , 5L ₆ , 5L _{7 of} 4a ′ are formed by the heat radiation pins 7c ′, 7e ′, 7a ′, the through holes 8d and the pads 8c around them. And are thermally connected.

Further, the heat dissipation pins 7d ', 7f', 7b 'and the through-holes 8d of the surrounding, the front outer surface layer L1' coil pattern 4b 'of the extended region _{4s 5, 4s 6, 4s 4} and the back outer surface layer L2' of The substrate 3 is penetrated so as to pass through the heat radiation patterns 5r ₅ , 5r ₆ , 5r ₇ . Therefore, the expansion regions 4s ₅ , 4s ₆ , 4s ₄ and the heat radiation pattern heat radiation patterns 5r ₅ , 5r of the coil pattern 4b ′ are formed by the heat radiation pins 7d ′, 7f ′, 7b ′ and the surrounding through holes 8d and the pads 8c. ₆ , 5r ₇ are thermally connected.

Furthermore, 'coil patterns 4a' of the front outer surface layer L1, 4b 'is at three places respectively, the corresponding rear outer surface layer L2' is connected to the heat radiation pattern _{5L 5 ~5L 7, 5r 5 ~5r} 7 of.

Since a large current flows through the coil patterns 4a ′ to 4c ′, the coil patterns 4a ′ to 4c ′ serve as heat generation sources, and the temperature of the substrate 3 ′ increases. ', The substrate 3' front outer surface layer L1 heat is diffused to the heat radiation pattern _{5L 1 ~5L 4, 5r 1 ~5r} 4, pattern _{4a ', 4b', 5L 1} ~5L 4, 5r 1 ~5r 4 etc. Heat is dissipated on the surface of the conductor. Further, the heat of the substrate 3 ′ travels through conductors penetrating the substrate 3 ′ such as the heat radiation pins 7 a ′ to 7 f ′, the through holes 8 d and 8 a, and the through hole groups 9 a ′ and 9 b ′, via the insulating sheet 12. Heat is radiated by the heat sink 10. Through-hole groups 9a ′ and 9b ′ function as thermal vias.

The portions where the widths of the coil patterns 4a ′ and 4b ′ are narrower have higher heat generation than the others. The heat generated in the coil patterns 4a ′ and 4b ′ is transmitted through the extended regions 4s _{1 to} 4s ₆ and the heat dissipation pins 7a ′ to 7f ′ and the heat dissipation patterns 5L _{1 to} 5L ₄ , 5r _{1 to} 5r of the back outer surface layer L2 ′. ₄ and is radiated by the heat sink 10 through the insulating sheet 12 from the surface of the heat radiation patterns 5L _{1 to} 5L ₄ , 5r _{1 to} 5r ₄ and the lower surface of the heat radiation pins 7a ′ to 7f ′.

', The substrate 3' backside exterior layer L2 heat is diffused to the heat radiation pattern _{5L 5 ~5L 7, 5r 5 ~5r} 7 , pattern 4c _', the conductors such as _{5L 5 ~5L 7, 5r 5 ~5r} 7 Heat is radiated from the surface by the heat sink 10 via the insulating sheet 12. In particular, the heat generated in the coil pattern 4c ′ is radiated from the surface of the coil pattern 4c ′ by the heat sink 10 via the insulating sheet 12.

According to the second embodiment, the extended regions 4s _{1 to} 4s _{6 of the} coil patterns 4a ′ and 4b ′ are located at positions away from the current paths of the coil patterns 4a ′ and 4b ′ of the front side outer surface layer L1 ′ of the substrate 3 ′. Is provided. Further, in correspondence with the coil patterns 4a ′ and 4b ′, the heat radiation patterns 5L _{5 to} 5L ₇ and 5r _{5 to} 5r ₇ are provided on the back outer surface layer L2 ′. The corresponding coil patterns 4a ', 4b' of the extended region _4s 1 _{~4s 6} of a radiator pattern _{5L 5 ~5L 7, 5r 5 ~5r} 7, such as 'radiation fins 7a'~7f penetrating the' substrate 3 These are thermally connected by thermal interlayer connection means.

Therefore, heat from the coil patterns 4a ′ and 4b ′ of the front outer layer L1 ′ is radiated from the back outer layer L2 ′ by the thermal interlayer connection means without disturbing the current flow of the coil patterns 4a ′ to 4c ′. The patterns 5L _{5 to} 5L ₇ and 5r _{5 to} 5r ₇ can be transmitted. Then, heat and convey the heat radiation pattern _{5L 5 ~5L 7, 5r 5 ~5r} 7 heat sink 10 from the surface of the can be easier to heat radiation from the heat sink 10 to the outside. Further, since the current flow of the coil patterns 4a ′ to 4c ′ is not hindered, it is possible to achieve a predetermined performance of the coil.

In addition, the coil patterns 4a ′ to 4c ′ of the different layers L1 ′ and L2 ′ are electrically connected to each other through the through-hole groups 9a ′ and 9b ′, and the corresponding coil patterns 4a ′ to 4c ′ and the heat radiation patterns 5L _{5 to} 5L. ₇ , 5r _{5 to} 5r ₇ are thermally connected by heat radiation pins 7a ′ to 7f ′ or the like. Further, the coil pattern 4c ′ and the heat radiation patterns 5L _{5 to} 5L ₇ and 5r _{5 to} 5r ₇ are separated and electrically insulated by the back side outer surface layer L2 ′. For this reason, the current path and the heat dissipation path of the coil patterns 4a ′ to 4c ′ can be surely divided to improve the energization performance and the heat dissipation performance.

Further, the extension regions 4s _{1 to} 4s _{6 of} the corresponding coil patterns 4a ′ and 4b ′ and the heat radiation patterns 5L _{5 to} 5L ₇ and 5r _{5 to} 5r ₇ are provided on the substrate 3 ′ so as to face each other and pass through them. In addition, heat radiation pins 7a 'to 7f' and through holes 8d are passed through the substrate 3 '. For this reason, the heat radiation pins 7a ′ to 7f ′ and the through holes 8d are easily provided in the substrate 3 ′, and the manufacture of the substrate 3 ′ can be facilitated.

  Furthermore, through-hole groups 9a 'and 9b' are provided so as to penetrate the substrate 3 'on the current path of the coil patterns 4a' to 4c 'to be connected. In addition, conductive members such as copper are filled in the small diameter through holes constituting the through hole groups 9a 'and 9b'. Therefore, the through hole groups 9a ′ and 9b ′ are improved in electrical conductivity and the electrical connection reliability between the coil patterns 4a ′ to 4c ′ is improved, and the through hole groups 9a ′ and 9b ′ are formed on the substrate 3 ′. The substrate 3 ′ can be easily manufactured.

  Next, the structure of the magnetic device 1 ″ according to the third embodiment and the coil-integrated printed board 3 ″ (hereinafter simply referred to as “substrate 3 ″”) included in the magnetic device 1 ″ is shown in FIGS. The description will be given with reference.

FIG. 7 is a plan view of each layer of the substrate 3 ″. FIG. 8 is a cross-sectional view of the magnetic device 1 ″, in which FIG. 7A shows the V ₁ -V ₁ cross section of FIG. FIG. 8 shows a V ₂ -V ₂ cross section of FIG. 7.

  The substrate 3 ″ has a front side outer surface layer L1 ″ as shown in FIG. 7A on the front surface (upper surface in FIG. 8), and a rear surface (lower surface in FIG. 8) as shown in FIG. 7B. It is composed of a two-layer thick copper foil substrate provided with a back side outer surface layer L2 ″.

  As shown in FIG. 8 (a), the convex portions 2m, 2L, and 2r of the upper core 2a are inserted into the through holes 3m, 3L, and 3r of the substrate 3 ″, thereby forming the layers L1 ″ and L2 ″. The heat sink 10 is fixed to the back side outer surface layer L2 ″ side of the substrate 3 ″ by screws 11 (FIG. 7). The insulating sheet 12 is interposed between the substrate 3 ″ and the heat sink 10. Is sandwiched.

As shown in FIG. 7, the substrate 3 ″ has through holes 8a and 8d, through hole groups 9a ″ and 9b ″, pads 8b and 8c, terminals 6i and 6o, patterns 4a ″ to 4c ″, 4u, 5s ₀ to 5s ₆ , and conductors such as pins 7a ″ to 7f ″ are provided. The through holes 8a and 8d and the through hole groups 9a ″ and 9b ″ have patterns 4a ″ to 4c ″ in different layers L1 ″ and L2 ″, 5s ₁ ~5s to connect the ₆ each other.

Specifically, the through hole 8a penetrates the substrate 3 ″ and connects the patterns 4a ″, 4b ″ of the front side outer surface layer L1 ″ and the back side outer surface layer L2 ″. The through hole 8d is shown in FIG. As shown, the substrate 3 ″ passes through and connects the front outer layer L1 ″ and the rear outer layer L2 ″, or the patterns 4a ″, 4b ″ of the front outer layer L1 ″ and the pattern 5s ₁ of the rear outer layer L2 ″. ~ 5s ₆ and so on.

  Each through hole group 9a ″, 9b ″ has a smaller diameter than the through holes 8a, 8d, and a plurality of through holes penetrating the substrate 3 ″ are gathered at a predetermined interval as shown in FIG. 8B. 7, the through-hole group 9a ″ connects the pattern 4a ″ of the front outer surface layer L1 ″ and the pattern 4c ″ of the back outer surface layer L2 ″. The through hole group 9b ″ connects the pattern 4b ″ of the front outer layer L1 ″ and the pattern 4c ″ of the rear outer layer L2 ″.

Coil patterns 4a ″ to 4c ″ and heat radiation patterns 5s _{0 to} 5s ₆ and 4u are formed on the respective layers L1 ″ and L2 ″. These patterns 4a ″ to 4c ″, 4u, 5s _{0 to} 5s ₆ are made of copper foil, and the surface is subjected to insulation processing. The layout of each layer L1 ″, L2 ″ is plane symmetric. The width, thickness, and cross-sectional area of the coil patterns 4a "-4c" achieve the predetermined performance of the coil, and the amount of heat generated in the coil patterns 4a "-4c" even when a predetermined large current (for example, DC150A) is passed. Is set to be able to radiate heat from the surface of the coil patterns 4a "to 4c".

  As shown in FIG. 7A, in the front side outer surface layer L1 ″, the coil pattern 4a ″ is wound once in the four directions around the convex portion 2L. The coil pattern 4b ″ is wound once in four directions around the convex portion 2r.

  As shown in FIG. 7B, in the back side outer surface layer L2 ″, the coil pattern 4c ″ is wound once in the four directions around the convex portion 2L and then passed through the three directions around the convex portion 2m. It is wound once in four directions around the convex part 2r.

  One end of the coil pattern 4a "and one end of the coil pattern 4c" are electrically connected by a through-hole group 9a ". The through-hole group 9a" has a current path (width Wa) of the coil patterns 4a "and 4c". The other end of the coil pattern 4c ″ and one end of the coil pattern 4b ″ are electrically connected by a through hole group 9b ″. Yes. The through hole group 9b ″ is provided on the current path (portion drawn by the width Wa) of the coil patterns 4c ″ and 4b ″ and penetrates the substrate 3 ″. Thus, a plurality (two) of through-hole groups 9a "and 9b" are provided according to the number of connections between the coil patterns 4a "to 4c" in different layers L1 "and L2".

  Copper plating is applied to the surface of each small-diameter through-hole constituting each of the through-hole groups 9a ″ and 9b ″, and the inside of each through-hole is filled with copper or the like. The through-hole groups 9a "and 9b" are examples of the "electrical interlayer connection means" in the present invention.

  The other end of the coil pattern 4a ″ is electrically connected to the terminal 6i via the pad 8b and the through hole 8a. The other end of the coil pattern 4b ″ is connected to the terminal via the pad 8b and the through hole 8a. 6o is electrically connected.

  In other words, the coil patterns 4a ″ to 4c ″ of the substrate 3 ″ are front-side outer surface layer L1 ″, and the first time is wound around the convex portion 2L from the terminal 6i that is the starting point, and then passes through the through-hole group 9a ′. Then, it is connected to the back side outer surface layer L2 ″.

  Next, the coil patterns 4a ″ to 4c ″ are the back side outer surface layer L2 ″, and the second time is wound around the convex portion 2L, and the third time around the convex portion 2r via the periphery of the convex portion 2m. After being wound, the coil patterns 4a "to 4c" are connected to the outer surface layer L1 "via the through-hole group 9b". After the second turn, the terminal 6o that is the end point is connected.

  The current flowing through the magnetic device 1 ″ also flows in the order of the terminal 6i, the coil pattern 4a ″, the through hole group 9a ″, the coil pattern 4c ″, the through hole group 9b ″, the coil pattern 4b ″, and the terminal 6o as described above. .

As shown in FIG. 7A, in the empty area around the coil patterns 4a ″ and 4b ″ on the front surface layer L1 ″, a plurality of heat radiation patterns 5s ₀ are provided separately from the coil patterns 4a ″ and 4b ″. The heat radiation patterns 5s ₀ are separated from each other and are electrically insulated from each other, with respect to the heat radiation pattern 5s ₀ , the pads 8b, the terminals 6i and 6o, and the through holes 3a. And the screw 11 are insulated.

As shown in FIG. 7 (b), heat radiation patterns 5s _{1 to} 5s ₆ are formed separately from the coil pattern 4c ″ in an empty area around the coil pattern 4c ″ of the backside outer surface layer L2 ″. The heat radiation patterns 5s _{1 to} 5s ₆ and 4u are separated from each other and are electrically insulated from the pads 8b, the terminals 6i and 6o, and the through holes 3a with respect to the heat radiation patterns 5s _{1 to} 5s ₆ . , And the screw 11 are electrically insulated.

  Heat dissipation pins 7a "to 7f" are embedded in the plurality of large-diameter through holes 8d, respectively. The radiating pins 7a "to 7f" are made of metal pins formed in a columnar shape with a conductor such as copper. A pad 8c made of copper foil is provided around the heat radiation pins 7a "to 7f" of the respective layers L1 "and L2". Copper plating is applied to the surfaces of the heat dissipation pins 7a "to 7f" and the pad 8c. The lower ends of the radiating pins 7a ″ to 7f ″ are in contact with the heat sink 10 via the insulating sheet 12 (see FIG. 8A). The radiating pins 7a "to 7f", their surrounding pads 8c, and the through holes 8d are examples of the "thermal interlayer connecting means" of the present invention.

As shown in FIG. 7A, in the front-side outer surface layer L1 ″, extended regions 4u _{1 to} 4u in which a part of the coil pattern 4a ″ is extended in the width direction at a position deviated from the current path of the coil pattern 4a ″. _The coil pattern 4a ″ and the extended regions 4u _{1 to} 4u ₃ are integrated. In addition, extended regions 4u _{4 to} 4u ₆ are provided in which a part of the coil pattern 4b ″ is extended in the width direction at a position outside the current path of the coil pattern 4b ″. The coil pattern 4b ″ and the extended regions 4u _{4 to} 4u ₆ are integrated. The extended regions 4u _{1 to} 4u ₃ of the coil pattern 4a ″ include the heat radiation pins 7a ″, 7c ″, and 7e ″ and the surroundings thereof. The pad 8c and the through hole 8d are thermally connected to each other. The expansion regions 4u _{4 to} 4u ₆ of the coil pattern 4b ″ are provided with heat radiation pins 7b ″, 7d ″, 7f ″ and their surrounding pads 8c and through-hole 8d are thermally connected. relative to the heat radiation pattern 5s _0, the coil pattern 4a ", 4b", the heat dissipation pins 7a "~7f", pads 8c, and the through-hole 8d are electrically insulated Has been.

The widths Wb, Wc, Wd of the portions where the expanded regions 4u _{1 to} 4u _{6 of the} coil patterns 4a ″, 4b ″ are provided are larger than the width Wa of the current path of each coil pattern 4a ″, 4b ″ (Wa <Wb, Wc, Wd). Further, the area of each expansion region 4u _{1 to} 4u ₆ is the heat dissipation pin 7a ″ to 7f.
It is larger than the cross-sectional area perpendicular to the axis "".

As shown in FIG. 7B, the back side outer surface layer L2 ″ is provided with heat radiation patterns 5s _{1 to} 5s ₃ corresponding to the coil pattern 4a ″ of the front side outer surface layer L1 ″, and is made to correspond to the coil pattern 4b ″. Te, it is provided the heat radiation pattern _5s 4 _{~5s 6.} Corresponding coil patterns 4a ″, 4b ″ of extended regions 4u ₁ , 4u ₂ , 4u ₃ , 4u ₄ , 4u ₅ , 4u ₆ and heat radiation patterns 5s ₃ , 5s ₁ , 5s ₂ , 5s ₆ , 5s ₄ , 5s ₅ Each part is opposed to the thickness direction of the substrate 3 ″. In the backside outer surface layer L2 ″, the heat radiation patterns 5s ₃ , 5s ₁ , 5s ₂ , 5s ₆ , 5s ₄ , 5s ₅ are separated from each other. And electrically insulated.

Moreover, "in, heat radiating fins 7c" backside exterior layer L2 pads 8c and the through-holes 8d of the surrounding and is thermally connected to the heat radiation pattern 5s _1. The radiating pin 7e "and the surrounding pad 8c and the through hole 8d are thermally connected to the radiating pattern 5s _{2. The} radiating pin 7a" and the surrounding pad 8c and the through hole 8d are connected to the radiating pattern 5s ₃ . Thermally connected.

Moreover, "in the heat dissipation pins 7d" backside exterior layer L2 pads 8c and the through-holes 8d of the surrounding and is thermally connected to the heat radiation pattern 5s _4. The radiating pin 7f ″ and the surrounding pad 8c and the through hole 8d are thermally connected to the radiating pattern 5s _{5. The} radiating pin 7b ″ and the surrounding pad 8c and the through hole 8d are connected to the radiating pattern 5s ₆ . Thermally connected.

Furthermore, in the back side outer surface layer L2 ″, the coil pattern 4c ″ is electrically insulated from the heat radiation patterns 5s _{1 to} 5s ₆ . In addition, the coil pattern 4c ″ is insulated from the heat radiation pins 7a ″ to 7f ″, the pad 8c, and the through hole 8d. Further, the coil pattern 4c is removed from the current path of the coil pattern 4c ″. The extended regions 4u _{7 to} 4u ₉ and 4u ₀ are formed by extending a part of “in the width direction. The coil pattern 4c” and the extended regions 4u _{7 to} 4u ₉ and 4u ₀ are integrated.

With the above configuration, the radiating pins 7c ″, 7e ″, 7a ″ and the surrounding through-holes 8d are formed in the extended regions 4u ₂ , 4u ₃ , 4u ₁ and the back side outer surface layer L2 of the coil pattern 4a ″ of the front side outer surface layer L1 ″. The substrate 3 passes through the heat radiation pattern 5s ₁ , 5s ₂ , 5s ₃ . Therefore, the expansion regions 4u ₂ , 4u ₃ , 4u ₁ and the heat radiation patterns 5s ₁ , 5s ₂ , the coil pattern 4a ″ are formed by the heat radiation pins 7c ″, 7e ″, 7a ″ and the surrounding through holes 8d and the pads 8c. 5s ₃ is thermally connected.

Further, the heat dissipation pins 7d ", 7f ', 7b' and the through-holes 8d of the surrounding, the front outer surface layer L1" coil pattern 4b for "extended area _{4u 5, 4u 6, 4u 4} and the back outer surface layer L2" of The substrate 3 is penetrated so as to pass through the heat radiation patterns 5s ₄ , 5s ₅ , 5s ₆ . Therefore, the expansion regions 4u ₅ , 4u ₆ , 4u ₄ and the heat radiation patterns 5s ₄ , 5s ₅ , the coil pattern 4b ″ are formed by the heat radiation pins 7d ″, 7f ″, 7b ″ and the surrounding through holes 8d and the pads 8c. 5s ₆ is thermally connected.

As shown in FIG. 7, the coil pattern 4 a ″, 4 b ″ of the front side outer surface layer L 1 ″ is obtained from the area of the coil pattern 4 c ″ of the back side outer surface layer L 2 ″ (including the areas of the extended regions 4 u _{7 to 4} u ₉ , 4 u ₀ ). And the total area of the heat radiation patterns 5s _{1 to} 5s ₆ of the back side outer surface layer L2 ″ corresponding thereto is larger. Further, the total area of the heat radiation patterns 5s _{1 to} 5s ₆ is larger than the total area of the expansion regions 4u _{7 to} 4u ₉ and 4u ₀ .

Since a large current flows through the coil patterns 4a ″ to 4c ″, the coil patterns 4a ″ to 4c ″ serve as heat sources, and the temperature of the substrate 3 ″ rises. In the front outer layer L1 ″, the heat of the substrate 3 ″ Is diffused to the heat radiation pattern 5s ₀ and is radiated on the surface of the conductor such as the patterns 4a ″, 4b ″, 5s _{0. The} heat of the substrate 3 ″ is also radiated from the heat radiation pins 7a ″ to 7f ″ and the through holes 8d, 8a and through-hole groups 9a ", 9b" and other conductors that pass through the substrate 3 ", and are radiated by the heat sink 10 through the insulating sheet 12. In particular, heat generated by the coil patterns 4a", 4b " is extended region _4u 1 _{~4u 6} and the heat-radiating fin 7a along the like "~7f" is diffused to the heat radiation pattern _5s 1 _{~5s 6} backside exterior layer L2 ", the surface and heat-radiating fin of the heat radiation pattern _5s 1 _{~5s 6} 7a "-7 Is radiated by the heat sink 10 from the lower surface of the "through the insulating sheet 12.

"In the substrate 3" backside exterior layer L2 heat is diffused to the heat radiation pattern _5s 1 _{~5s 6,} pattern 4c ', _4u, the heat sink 10 via the insulating sheet 12 from the surface of the conductor, such as 5s 1 ~5s ₆ in the heat radiation. in particular, the coil pattern 4c "heat generated in is diffused in the extended area _4u 7 _~4u 9, _{4u 0,} the coil pattern 4c" insulated from and extended area _4u 7 surface _~4u 9, 4u ₀ Heat is radiated from the heat sink 10 via the sheet 12.

According to the third embodiment, the coil patterns 4a "and 4b" of the front outer layer L1 "of the substrate 3"
The extended regions 4u _{1 to} 4u ₆ of the coil patterns 4a ″ and 4b ″ are provided at positions deviating from the current path. Further, heat radiation patterns 5s _{1 to} 5s ₆ are provided on the back side outer surface layer L2 ″ in correspondence with the coil patterns 4a ″ and 4b ″. Then, the expansion regions 4u _{1 to} 4u of the corresponding coil patterns 4a ″ and 4b ″. ₆ and the heat radiation patterns 5s _{1 to} 5s ₆ are thermally connected by thermal interlayer connection means such as heat radiation pins 7a ″ to 7f ″ penetrating the substrate 3 ″.

Therefore, heat from the coil patterns 4a ″ and 4b ″ of the front side outer surface layer L1 ″ is radiated from the back side outer surface layer L2 ″ by the thermal interlayer connection means without disturbing the current flow of the coil patterns 4a ″ to 4c ″. The pattern 5s _{1 to} 5s ₆ can be transmitted. Then, the heat and transferred from the surface of the heat radiation pattern _5s 1 _{~5s 6} to the heat sink 10 may be easier to heat radiation from the heat sink 10 to the outside. In addition, since the current flow of the coil patterns 4a "to 4c" is not hindered, it is possible to achieve a predetermined performance of the coil.

Furthermore, different layers L1 ", L2" coil patterns 4a "~4c" between the through-hole group 9a ", 9b" electrically connected with the corresponding coil pattern 4a "~4c" and the heat dissipation pattern _5s 1 _{~5s 6} are thermally connected by radiating pins 7a "to 7f" and the like. Further, the coil pattern 4c ″ and the heat radiation patterns 5s _{1 to} 5s ₆ are separated and electrically insulated by the back side outer surface layer L2 ″. For this reason, the current path and the heat dissipation path of the coil patterns 4a "to 4c" can be reliably separated to improve the energization performance and the heat dissipation performance.

Further, the expansion regions 4u _{1 to} 4u _{6 of} the corresponding coil patterns 4a ″ and 4b ″ and the heat radiation patterns 5s _{1 to} 5s ₆ are provided on the substrate 3 ′ so as to face each other, and the heat radiation pins 7a ″ to pass through these. 7f ″ and the through hole 8d are penetrated through the substrate 3 ″. For this reason, the heat radiation pins 7a ″ to 7f ″ and the through hole 8d can be easily provided in the substrate 3 ″, thereby facilitating the manufacture of the substrate 3 ′. it can.

  Further, through-hole groups 9a "and 9b" are provided so as to penetrate the substrate 3 "on the current path of the coil patterns 4a" to 4c "to be connected. The through-hole groups 9a" and 9b "are configured. Each through hole having a small diameter is filled with a conductive member such as copper. For this reason, the electric conductivity of the coil patterns 4a "to 4c" is improved by improving the conductivity of the through hole groups 9a "and 9b". While improving the connection reliability, the through-hole groups 9a ″ and 9b ″ can be easily provided on the substrate 3 ″, and the manufacture of the substrate 3 ″ can be facilitated.

  Next, the structure of the magnetic device 21 according to the fourth embodiment and the coil-integrated printed board 23 (hereinafter simply referred to as “substrate 23”) included in the magnetic device 21 will be described with reference to FIGS. To do.

FIG. 9 is an exploded perspective view of the magnetic device 21. FIG. 10 is a plan view of each layer of the substrate 23 of the magnetic device 21. 11 to 14 are cross-sectional views of the magnetic device 21, FIG. 11 shows a cross section A ₁ -A ₁ of FIG. 10, FIG. 12 shows a cross section A ₂ -A _{2 of} FIG. It shows the _a 3 -A ₃ the cross-section of FIG. 10, FIG. 14 shows the cross section B-B in FIG. 10.

  As shown in FIG. 9, the magnetic device 21 includes a pair of upper and lower cores 2 a and 2 b, a substrate 23, and a heat sink 10.

The board | substrate 23 is comprised from the thick copper foil board | substrate of 3 layers. On the surface of the substrate 23 (upper surface in FIGS. 11 to 13), it is provided the front side outer surface layer La ₁ as shown in FIG. 10 (a), on the back surface (lower surface in FIGS. 11 to 13) is 10 ( A back side outer surface layer La ₃ as shown in c) is provided. One inner layer La ₂ as shown in FIG. 10B is provided between the front side outer surface layer La ₁ and the back side outer surface layer La ₃ .

  The substrate 23 is provided with a plurality of openings 23m, 23L, and 23r. The opening 23m is formed of a large-diameter circular through hole, and the openings 23L and 23r are formed of notches. As shown in FIGS. 9, 10, and 12, the central protrusion 2m of the upper core 2a is inserted into one opening 23m at the center, and the openings 23L and 23r on the left and right are The left and right convex portions 2L and 2r of the core 2a are respectively inserted.

  As shown in FIG. 12, the cores 2a and 2b are combined by bringing the upper surface of the lower core 2b into close contact with the lower ends of the left and right convex portions 2L and 2r of the upper core 2a. The lower core 2 b is fitted into a recess 10 k provided on the upper side of the heat sink 10.

As shown in FIG. 9, the substrate 23 is provided with two small-diameter and circular through holes 23a. As shown in FIG. 13, the screw 11 is inserted into each through hole 23a. The back surface of the substrate 23 is opposed to the upper surface of the heat sink 10. Then, the two screws 11 are passed through the through holes 23 a from the surface side of the substrate 23 and screwed into the screw holes 10 a of the heat sink 10. Thus, as shown in FIGS. 11 to 14, the back outer surface layer La ₃ side to the heat sink 10 of the substrate 23 are fixed in a close state. Between the board | substrate 23 and the heat sink 10, the insulating sheet 12 which has heat conductivity is inserted | pinched.

As shown in FIG. 10, the substrate 23 has through holes 8a and 8d, through hole groups 29a and 29b, pads 8b and 8c, terminals 6i and 6o, patterns 24a to 24d, 25s _{0 to} 25s ₉ , and pins 27a to 27a. A conductor such as 27d is provided. The through holes 8a and 8d, the through hole groups 29a and 29b, the terminals 6i and 6o, and the pins 27a to 27d are provided so as to penetrate the substrate 23 (see FIGS. 11, 13, and 14).

Terminals 6i and 6o are embedded in the pair of through holes 8a, respectively. The outer surface layer _La 1, terminal 6i of La _3, around the 6o, pad 8b of the through hole 8a is provided. The lower ends of the terminals 6i and 6o are in contact with the insulating sheet 12 (not shown).

  The through-hole groups 29a and 29b are smaller in diameter than the through-holes 8a and 8d, and a plurality of through-holes penetrating the substrate 23 are gathered at a predetermined interval as shown in FIG.

Coil patterns 24 a to 24 c and heat radiation patterns 25 s _{0 to} 25 s ₉ are provided on each layer La _{1 to} La ₃ of the substrate 23. Each pattern _24a~24c, 25s 0 ~25s ₉ is made of a copper foil. Each pattern _24a of the front outer surface layer La _1, on the surface of the 25s 0 ~25s _2, insulation processing is given. The width, thickness, and cross-sectional area of the coil patterns 24a to 24c can suppress the amount of heat generated in the coil patterns 24a to 24c to some extent even when a predetermined large current (for example, DC150A) is passed while achieving the predetermined performance of the coil. And it is set so that heat can be radiated from the surfaces of the coil patterns 24a to 24c.

As shown in FIG. 10, the coil patterns 24 a to 24 c are wound twice around the center convex portion 2 m by the layers La _{1 to} La ₃ . One end of the front outer surface layer La ₁ of the coil pattern 24a, and one end of the coil pattern 24b of the inner layer La _2, are electrically connected by the through-hole group 29a. The through-hole group 29a is provided on the current path (portion routed by the width W1 ′) of the coil patterns 24a and 24b and penetrates the substrate 23. The other end of the coil pattern 24b of the inner layer La _2, and one end of the coil pattern 24c of the rear side outer surface layer La _3, are electrically connected by the through-hole group 29b. The through hole group 29 c is provided on the current path (portion routed by the width W 1 ′) of the coil patterns 24 b and 24 c and penetrates the substrate 23.

That is, the through-hole groups 29a and 29b connect the coil patterns 24a to 24c in different layers La _{1 to} La ₃ to each other, and a plurality (two) of the through hole groups 29a and 29b are provided according to the number of connections. The surface of each small-diameter through-hole constituting each of the through-hole groups 29a and 29b is plated with copper, and the inside of each through-hole is filled with copper or the like. The through hole groups 29a and 29b are an example of the “electrical interlayer connection means” in the present invention.

And surrounding the through-hole group 29b of the front outer surface layer La _1, the periphery of the through hole group 29a of the rear outer surface layer La _3, the small pattern 24d are respectively provided. Each through-hole group 29a, 29b and the small pattern 24d are connected. The small pattern 24d is made of copper foil. On the surface of the front outer surface layer La ₁ small pattern 24d, insulating treatment is applied.

As shown in FIG. 10 (a), the other end of the front outer surface layer La ₁ coil pattern 24a is connected to the terminal 6o electrically through the pad 8b and the through-hole 8a. As shown in FIG. 10 (c), the other end of the coil pattern 24c of the rear side outer surface layer La ₃ is connected to terminals 6i and electrically through a pad 8b and the through-hole 8a.

With the above configuration, the coil patterns 24a to 24c of the substrate 23 are formed on the backside outer surface layer La ₃ after the first and second windings around the convex portion 2m from the starting terminal 6i, and the through hole group 29b is formed. through, it is connected to the inner layer La _2. Next, the coil pattern 24a~24c is the inner layer La _2, after the third and the fourth is wound around the convex portion 2m, via the through-hole group 29a, are connected to the front side outer surface layer La ₁ . The coil pattern 24a~24c is a front outer surface layer La _1, after the fifth and sixth on the periphery of the convex portion 2m is wound, are connected to the terminal 6o is the end point.

  As described above, the current flowing in the magnetic device 21 is also input from the terminal 6i and flows in the order of the coil pattern 24c, the through hole group 29b, the coil pattern 24b, the through hole group 29a, and the coil pattern 24a, and then the terminal 6o. Is output from.

As shown in FIG. 10, the heat radiation patterns 25s _{0 to} 25s ₉ are formed separately from the patterns 24a to 24d in the empty areas around the coil patterns 24a to 24c and the small patterns 24d of the layers La _{1 to} La _3. Has been. Further, the heat radiation patterns 25s _{0 to} 25s ₉ are separate from each other. That is, in each of the layers La _{1 to} La ₃ , the heat radiation patterns 25s _{0 to} 25s ₉ are electrically insulated from each other and to the coil patterns 24a to 24c in the same layer. Further, with respect to the heat radiation pattern _25s 0 _{~25s 9,} pad 8b, terminal 6i, 6o, through-holes 23a, and the screw 11 is electrically insulated.

Heat dissipation pins 27a to 27d are embedded in the plurality of large-diameter through holes 8d, respectively. The radiating pins 27a to 27d are made of metal pins formed in a columnar shape with a conductor such as copper. Around the heat radiating fin 27a~27d of the front outer surface layer La ₁ and the back outer surface layer La _3, pad 8c made of copper foil is provided. Copper plating is applied to the surfaces of the heat radiation pins 27a to 27d and the pad 8c. The lower ends of the heat radiation pins 27a to 27d are in contact with the insulating sheet 12 (see FIGS. 11 and 13). The heat radiation pins 27a to 27d, their surrounding pads 8c, and the through holes 8d are examples of the “thermal interlayer connection means” of the present invention.

As shown in FIG. 10 (a), the front outer surface layer La _1, at a position deviated from the current path of the coil pattern 24a, extension regions _24t that extend partially in the width direction of the coil patterns 24a 0, _24t 1, 24t ₂ is provided. That is, the coil pattern 24a and the extended regions 24t ₀ , 24t ₁ , 24t ₂ are integrated. The heat dissipation pins 27a and 27c, the pads 8c around them, and the through holes 8d are thermally connected to the extended regions 24t ₀ and 24t _{1 of the} coil pattern 24a, respectively. The other heat radiation pins 27b and 27d and their surrounding pads 8c and through-holes 8d are thermally connected to the heat radiation patterns 25s ₁ and 25s ₂ , respectively, but the coil pattern 24a, the extended regions 24t ₀ and 24t ₁ , 24t ₂ , the heat radiation pattern 25s ₀ , and the small pattern 24d are electrically insulated.

Further, the heat radiation patterns 25s ₁ and 25s ₂ of the front outer layer La ₁ are provided so as to correspond to the coil pattern 24b of the inner layer La ₂ . In the vicinity of the extension region 24t ₂ of the heat radiation pattern 25s ₁ and the coil pattern 24a, these relative so as to be electrically insulated, are provided radiating pattern 25s _0. Against heat radiation pattern _25s 0 _{~25s 2,} the coil patterns 24a are electrically insulated. Through-holes 8a and pad 8b of the surrounding terminal 6i is electrically insulated from the extension area 24t ₀ in the neighborhood. Through-holes 8a and pad 8b of the surrounding terminal 6o is connected is expanded region 24t ₂ electrically in the vicinity, and is electrically insulated from the heat radiation pattern 25s _0.

As shown in FIG. 10B, the inner layer La ₂ is provided with extended regions 24t ₃ and 24t _{4 in} which a part of the coil pattern 24b is expanded in the width direction at a position outside the current path of the coil pattern 24b. ing. That is, the coil pattern 24b and the extended regions 24t ₃ and 24t ₄ are integrated. The heat dissipation pins 27b and 27d, the pads 8c around them, and the through holes 8d are thermally connected to the extended regions 24t ₃ and 24t _{4 of the} coil pattern 24b, respectively. The other radiating pins 27a and 27c and their surrounding pads 8c and through-holes 8d are thermally connected to the radiating patterns 25s ₃ and 25s ₄ respectively, but the coil patterns 24b and the extended regions 24t ₃ and 24t ₄ are connected to each other. On the other hand, it is electrically insulated.

Further, in the inner layer La _2, with respect to the heat radiation pattern _25s 3, 25s _4, the coil pattern 24b are electrically insulated. Through hole 8a of the peripheral and terminal 6i it is electrically insulated from the heat radiation pattern 25s _3. Through hole 8a of the peripheral and terminal 6o it is electrically insulated from the extended area 24t _3.

As shown in FIG. 10C, the back side outer surface layer La ₃ is provided with heat radiation patterns 25s ₅ and 25s ₆ corresponding to the coil pattern 24a of the front side outer surface layer La ₁ . Further, heat radiation patterns 25s ₇ and 25s ₈ are provided corresponding to the coil pattern 24b of the inner layer La ₂ . The extended regions 24t ₀ , 24t ₁ , 24t ₃ , 24t _{4 of the} corresponding coil patterns 24a, 24b and the heat radiation patterns 25s ₁ , 25s ₂ , 25s ₅ , 25s ₆ , 25s ₇ , 25s ₈ are part of the substrate 23. It faces in the thickness direction.

Further, the back side outer surface layer La _3, pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 27a is thermally connected to the heat radiation pattern 25s _5. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 27c are thermally connected to the heat radiation pattern 25s _6. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 27b are thermally connected to the heat radiation pattern 25s _7. Pads 8c and the through-holes 8d of the ambient and the heat dissipation pins 27d are thermally connected to the heat radiation pattern 25s _8.

Further, in the back side outer surface layer La ₃ , extended regions 24 t ₅ and 24 t ₆ are provided in which a part of the coil pattern 24 c is extended in the width direction at a position outside the current path of the coil pattern 24 c. That is, the coil pattern 24c and the extended regions 24t ₅ and 24t ₆ are integrated. For extended region 24t ₅ of the coil pattern 24c, terminal 6i and these peripheral through-holes 8a and pads 8b are electrically connected. Through-holes 8a and pad 8b of the surrounding terminal 6o is electrically connected to the heat radiation pattern 25s _9, it is electrically insulated from the extension area 24t _6. Against the coil pattern 24c extended region _24t 5, _{24t 6,} the heat radiation pattern _25s 5 _{~25s 8} is electrically insulated.

The extended regions 24t ₀ , 24t ₁ , 24t ₃ , 24t ₄ of the coil patterns 24a, 24b of the front side outer surface layer La ₁ and the inner layer La ₂ are layered on the layers La ₁ , La ₂ so as not to overlap in the plate thickness direction of the substrate 23. Each is arranged. Also, the widths W2 ′, W3 ′, W4 ′, and W5 ′ of the portions where the extended regions 24t ₀ , 24t ₁ , 24t ₃ , and 24t _{4 of} the coil patterns 24a and 24b are provided are the current paths of the coil patterns 24a and 24b. It is larger than the width W1 ′ (W1 ′ <W2 ′, W3 ′, W4 ′, W5 ′). The area of the expansion region _24t 0 _{~24t 6} of the coil pattern 24a~24c is larger than the cross-sectional area perpendicular to the axis of the heat radiating fin 27a-27d.

With the above structure, through hole 8d of the ambient and the heat dissipation pins 27a are heat radiation pattern of extended regions 24t ₀ of the front outer surface layer La ₁ of the coil pattern 24a, the heat radiation pattern 25s ₃ of the inner layer La _2, and back outer surface layer La ₃ 25s ₅ passes through the substrate 23. Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 27a, and the extended region 24t ₀ of the coil pattern 24a and the heat radiation pattern _25s 3, 25s ₅ are thermally connected. The through-holes 8d of the ambient and the heat dissipation pins 27b are radiating pattern 25s ₁ of the front outer surface layer La _1, extended area 24t ₃ of the coil pattern 24b of the inner layer La _2, and the heat radiation pattern 25s ₇ of the back outer surface layer La ₃ It penetrates the substrate 23 so as to pass. Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 27b, and the extended region 24t ₃ of the coil pattern 24b and the heat radiation pattern _25s 1, 25s ₇ are thermally connected. The radiating pins 27a and 27b, their surrounding pads 8c, and the through holes 8d are examples of the “first thermal interlayer connecting means” in the present invention.

Through holes 8d of the ambient and the heat dissipation pins 27c, like through the heat radiation pattern 25s ₆ of the front outer surface layer coil pattern 24a extended region 24t ₁ of the La _1, the heat radiation pattern 25s ₄ of the inner layer La _2, and back outer surface layer La ₃ Further, the substrate 23 is penetrated. Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 27c, and the extended region 24t ₁ of the coil pattern 24a and the heat radiation pattern _25s 4, 25s ₆ are thermally connected. The through-holes 8d of the ambient and the heat dissipation pins 27d are radiating pattern 25s ₂ of the front outer surface layer La _1, the coil pattern 24b extended region 24t ₄ of the inner layer La _2, and the heat radiation pattern 25s ₈ backside exterior layer La ₃ It penetrates the substrate 23 so as to pass. Therefore, the through hole 8d and the pad 8c of the ambient and the heat dissipation pins 27d, and the extended region 24t ₄ of the coil pattern 24b and the heat radiation pattern _25s 2, 25s ₈ are thermally connected. The radiating pins 27c and 27d, the pads 8c around them, and the through holes 8d are examples of the “second thermal interlayer connecting means” in the present invention.

Front outer surface layer La ₁ and the inner layer La ₂ coil patterns 24a, 24b is a two respectively, are in corresponding thermally and the heat radiation pattern _25s 5 _{~25s 8} backside exterior layer La ₃ connections.

  Since a large current flows through the coil patterns 24a to 24c, the coil patterns 24a to 24c serve as heat generation sources, and the temperature of the substrate 23 rises.

In front outer surface layer La _1, heat of the substrate 23, for example, be diffused into the conductor, such as expanded region _24t 0 _{~24t 2} and heat radiation pattern _25s 0 _{~25s 2,} is radiated from the surface of the conductor. Further, the heat of the substrate 23 is transmitted through a conductor penetrating the substrate 23 such as the heat radiation pins 27a to 27d, the terminals 6i and 6o, the through holes 8d and 8a, and the through hole groups 29a and 29b, and is transmitted through the insulating sheet 12. The heat sink 10 radiates heat. The through hole groups 29a and 29b also function as thermal vias.

In particular, heat generated by the coil patterns 24a of the front outer surface layer La ₁ is liable to be diffused in the extended region _24t 0 _{~24t 2,} is radiated from the surface of the coil patterns 24a and _24t 0 _{~24t 2.} Further, heat generated in the coil pattern 24a is heat-radiating fin 27a from the extended region _24t 0 _{~24t 2,} 27c, down along pin 6o, and these around the through-hole 8d, the 8a, another layer _La 2, La ₃ The heat dissipation patterns 25s _{3 to} 25s ₆ and 25s ₉ are diffused. Then, the diffused heat is transferred from the heat radiation pattern 25s ₅ , 25s ₆ , 25s ₉ surface of the back side outer surface layer La ₃ , the lower surfaces of the heat radiation pins 27a and 27c, and the lower surface of the terminal 6o via the insulating sheet 12 to the heat sink 10. The heat sink 10 dissipates heat.

In the inner layer La _2, heat of the substrate 23, for example, are spread to a conductor such as a diffusion region _24t 3, 24t ₄ and the heat radiation pattern _25s 3, 25s _4, heat radiating fins 27a~27d and terminals 6i, 6o and the through hole 8d, 8a, through-hole groups 29a, 29b and the like that pass through the conductors penetrating the substrate 23, the extended regions 24t _{0 to} 24t ₂ , 24t ₅ , 24t ₆ and the heat radiation pattern 25s _{0 of} the front side outer surface layer La ₁ and the back side outer surface layer La _3. It is diffused to ˜25s ₂ , 25s _{5 to} 25s ₉ . Then, the diffused heat expansion region _24t 5 such or is radiated from the extended region _24t 0 _{~24t 2} and heat radiation pattern _25s 0 _{~25s 2} of the surface of the front outer surface layer La _1, the back side outer surface layer La _3, 24t ₆ and the heat radiation patterns 25 s _{5 to} 25 s ₉ are transmitted to the heat sink 10 via the insulating sheet 12 and are radiated by the heat sink 10.

In particular, heat generated in the coil pattern 24b of the inner layer La ₂ is liable to be diffused in the diffusion region _24t 3, 24t _4, heat radiating fins 27b from the diffusion region _24t 3, 24t _4, 27d and those around the through-hole 8d Then, the heat dissipation patterns 25s ₁ , 25s ₂ , 25s ₇ and 25s ₈ of the other layers La ₁ and La ₃ are diffused. The diffused heat is radiated from the surfaces of the heat radiation patterns 25s ₁ and 25s ₂ of the front side outer surface layer La ₁ , or the surfaces of the heat radiation patterns 25s ₇ and 25s ₈ of the back side outer surface layer La ₃ and the heat radiation pins 27b and 27d. The heat is transmitted to the heat sink 10 through the insulating sheet 12 from the lower surface of the heat and is radiated by the heat sink 10.

In the back side outer surface layer La ₃ , the heat of the substrate 23 is diffused to conductors such as diffusion regions 24 t ₅ and 24 t ₆ and heat radiation patterns 25 s _{5 to} 25 s _9, and is transmitted from the conductors to the heat sink 10 via the insulating sheet 12. The heat sink 10 radiates heat. Further, the heat of the substrate 23 is transmitted through a conductor penetrating the substrate 23 such as the heat radiation pins 27a to 27d, the terminals 6i and 6o, the through holes 8d and 8a, and the through hole groups 9a and 9b, and the front side outer surface layer La _1. The diffusion regions 24t _{0 to} 24t ₂ and the heat radiation patterns 25s _{0 to} 25s ₂ are diffused and radiated from the surfaces of these conductors.

In particular, heat generated in the coil pattern 24c of the rear side outer surface layer La ₃ is liable to be diffused in the diffusion region _24t 5, 24t _6, through the surface and the diffusion region _24t 5, the insulating sheet 12 from the surface of 24t ₆ of the coil pattern 24c The heat is transmitted to the heat sink 10 and is radiated by the heat sink 10. Further, heat generated in the coil pattern 24c is along the terminal 6i and its surrounding through hole 8a, and is radiated from such surfaces of and which around the pad 8b of the terminal 6i of the front outer surface layer La _1.

According to the fourth embodiment, the expansion regions 24t ₀ , 24t ₁ , 24t ₁ , 24t ₁ , 24t ₁ , 24b of the coil patterns 24a, 24b are located at positions deviated from the current paths of the coil patterns 24a, 24b of the front side outer surface layer La ₁ and the inner layer La ₂ of the substrate 23. 24t ₃ and 24t ₄ are provided. Further, heat radiation patterns 25s _{5 to} 25s ₈ are provided on the back outer surface layer La ₃ in correspondence with the coil patterns 24a and 24b. The corresponding coil patterns 24a, 24b and the extension region _{24t 0, 24t 1, 24t 3} , 24t 4 and the heat radiation pattern _25s 5 _{~25s 8} of thermal interlayer connection, such as heat radiating fin 27a~27d through the substrate 23 Thermally connected by means.

Therefore, without interrupting the flow of current in the coil patterns 24a-24c, the front outer surface layer La ₁ and the inner layer La ₂ coil pattern 24a, the heat generated from 24b, by thermally interconnecting means backside exterior layer La ₃ radiator it is possible to convey to the pattern _25s 5 _{~25s 8.} Then, the heat and transferred from the surface of the heat radiation pattern _25s 5 _{~25s 8} to the heat sink 10 may be easier to heat radiation from the heat sink 10 to the outside. Further, since the current flow of the coil patterns 24a to 24c is not hindered, it is possible to achieve a predetermined performance of the coil.

Further, the coil patterns 24a to 24c of the different layers La ₁ , La ₂ and La ₃ are electrically connected through the through-hole groups 29a and 29b, and the corresponding coil patterns 24a and 24b and the heat radiation patterns 25s _{5 to} 25s ₈ are radiated. The pins 27a to 27d are thermally connected. Further, behind the outer surface layer La ₃ by the coil pattern 24c and the heat dissipation pattern _25s 5 _{~25s 8} separately, it is electrically insulating. For this reason, the current path and the heat radiation path of the coil patterns 24a to 24c can be reliably separated, and the energization performance and the heat radiation performance can be enhanced.

Further, each coil patterns 24a in the front outer surface layer La ₁ and the inner layer La ₂ of the substrate 23, the heat generated in 24b, different heat dissipation pattern _25s 5 _{~25s 8} heat radiating fin 27a~27d and back outer surface layer La ₃ It can be transmitted to the heat sink 10 through the heat dissipation path to efficiently dissipate heat.

Further, the expansion regions 24t ₀ , 24t ₁ , 24t ₃ , 24t ₄ and the heat radiation patterns 25s _{5 to} 25s _{8 of} the corresponding coil patterns 24a, 24b are provided on the substrate 23 so as to face each other, and the heat radiation pins pass through these. 27 a to 27 d and through holes 8 d are passed through the substrate 23. For this reason, the heat radiation pins 27a to 27d and the through holes 8d can be easily provided in the substrate 23, and the manufacture of the substrate 23 can be facilitated.

  Further, the through-hole groups 29a and 29b are provided so as to penetrate the substrate 23 on the current paths of the coil patterns 24a to 24c to be connected. In addition, conductive members such as copper are filled in the small diameter through holes constituting the through hole groups 29a and 29b. For this reason, the electrical conductivity of the through hole groups 29a and 29b is improved, and the reliability of electrical connection between the coil patterns 24a to 24c is increased, and the through hole groups 29a and 29b are easily provided on the substrate 23. 23 can be easily manufactured.

In the present invention, various embodiments other than those described above can be adopted. For example, in the above embodiment, all the layers L1 to L3, L1 ′, L2 ′, L1 ″, L2 ″, La ₁ , La ₂ , La ₃ of the substrates 3, 3 ′, 3 ″, 23 are arranged on the coil pattern 4 a. -4e, 4a 'to 4c', 4a "to 4c", 24a to 24c are shown as examples, but the present invention is not limited to this example. In a substrate having a plurality of layers, a heat dissipation pattern is formed. A coil pattern may be formed on the provided outer surface layer and at least one other layer.

Further, in the above embodiment, the coil patterns 4a to 4e on the substrates 3, 3 ′, 3 ″, 23 are wound around the three convex portions 2m, 2L, 2r or the central convex portion 2m of the core 2a. Although examples in which 4a ′ to 4c ′, 4a ″ to 4c ″ and 24a to 24c are formed are shown, the present invention is not limited to this. The coil pattern is wound around at least one convex portion of the core. It only has to be done.

In the first embodiment shown in FIG. 3 and the like, thermally to the radiation pattern _{5a 7 ~5a 9, 5b 7 ~5b} 9 of the coil pattern 4a~4d of the front outer surface layer L1 and the inner layer L2 backside exterior layer L3 Although the example which made the diameter of thermal interlayer connection means, such as the thermal radiation pin 7a-7f connected, the same was shown, this invention is not limited only to this. In addition to this, thermal interlayer connection means such as heat radiation pins 37a to 37f, such as a coil-integrated printed board 33 (hereinafter simply referred to as "substrate 33") of the magnetic device 31 of the fifth embodiment shown in FIG. You may vary the diameter of.

  In the substrate 33 shown in FIG. 15, heat radiation pins 37 a to 37 f are embedded in the through holes 8 d and 8 d ′. The radiating pins 37a to 37f are made of metal pins formed in a columnar shape with a conductor such as copper. The diameters of the heat radiation pins 37c, 37d, 37e, and 37f and the surrounding through holes 8d and the pads 8c are larger than the diameters of the heat radiation pins 37a and 37b and the surrounding through holes 8d 'and the pads 8c'. It has become. The radiating pins 37a to 37f and the surrounding through holes 8d 'and 8d and the pads 8c' and 8c are examples of the "thermal interlayer connecting means" of the present invention.

The heat dissipation pins 37a and 37b, the surrounding through holes 8d ′ and the pads 8c ′ are formed by the expansion regions 4t ₁ and 4t ₂ of the coil patterns 4a and 4b of the front side outer surface layer L1, and the heat dissipation patterns 5a ₉ and 5b of the back side outer surface layer L3. ₉ are thermally connected to each other. The heat radiation pins 37a and 37b, the surrounding through holes 8d ′ and the pads 8c ′ are examples of the “first thermal interlayer connection means” in the present invention.

Radiation fins 37c, 37d, 37e, through holes 8d and the pad 8c and surrounding these 37f are radiating pattern _5a 7 of the coil pattern 4c, 4d extend region _4t 3 _{~4t 6} and the back outer surface layer L3 of the inner layer L2, 5a ₈ , 5b ₇ and 5b ₈ are thermally connected to each other. The radiating pins 37c, 37d, 37e, and 37f, and the surrounding through holes 8d and the pads 8c are examples of the “second thermal interlayer connecting means” in the present invention.

That is, the coil pattern 4c of the inner layer L2 is determined from the diameter of the first thermal interlayer connecting means which is a columnar body that connects the coil patterns 4a and 4b of the front outer layer L1 and the heat radiation patterns 5a ₉ and 5b ₉ of the rear outer layer L3. The diameter of the second thermal interlayer connecting means which is a columnar body connecting the heat radiation patterns 5a ₇ , 5a ₈ , 5b ₇ , 5b ₈ of 4d and the backside outer surface layer L3 is larger.

Accordingly, the heat radiation volume from the coil patterns 4a and 4b of the front outer layer L1 to the heat radiation patterns 5a ₉ and 5b ₉ of the rear outer layer L3 from the coil patterns 4c and 4d of the inner layer L2 to the heat radiation pattern 5a of the rear outer layer L3. _{7, 5a} 8, 5b _7, towards the heat transfer capacity is increased to 5b _8. For this reason, the heat generated in the coil patterns 4c and 4d of the inner layer L2 that does not touch the outside air can be more easily transferred to the back side outer surface layer L3 than the heat generated in the coil patterns 4a and 4b of the front side outer surface layer L1. Then, the heat generated in the inner layer L2 can be dissipated from the backside outer surface layer L3 to the outside via the heat sink 10 so that the substrate 33 is hardly trapped.

  Moreover, although the example which connected the coil pattern and heat dissipation pattern which correspond to a different layer with the heat dissipation pin, the pad, and the through hole was shown in the above embodiment, this invention is not limited only to this. In addition to this, for example, the corresponding coil patterns and heat radiation patterns of different layers may be connected by at least one thermal interlayer connecting means such as terminals, pins, and through holes.

  Moreover, although the example which connected the coil patterns of a different layer by the through hole group was shown in the above embodiment, this invention is not limited only to this. In addition to this, coil patterns of different layers may be connected to each other by other electrical interlayer connection means such as terminals, pins, and a single through hole.

  Moreover, although the example which used the heat sink 10 was shown as a heat radiator in the above embodiment, this invention is not limited only to this, Other air-cooled type or water-cooled type heat radiators, or refrigerant | coolants You may use the radiator etc. which used. Moreover, you may use not only a metal radiator but the radiator formed with resin with high heat conductivity. In this case, it is not necessary to provide the insulating sheet 12 between the radiator and the substrate, and the insulating sheet 12 can be omitted. Furthermore, a radiator may be provided on each of the outer surface layers of the substrate, or the radiator may be omitted.

  Moreover, although the example using the thick copper foil board | substrate was shown as a coil integrated type printed circuit board in the above embodiment, this invention is not limited only to this. Other substrates such as a printed circuit board or a metal substrate on which a copper foil having a normal thickness is formed may be used. In the case of a metal substrate, an insulator may be provided between the base material and each pattern. The present invention can also be applied to a multilayer substrate provided with a plurality of inner layers.

  Moreover, although the example which combined the I-shaped lower core 2b with the E-shaped upper core 2a was shown in the above embodiment, this invention is applicable also to the magnetic device which combined two E-shaped cores. it can.

  Furthermore, in the above embodiment, the example which applied this invention to the magnetic device 1, 1 ', 1 ", 21, 31 used as the choke coil L of the smoothing circuit 55 in the switching power supply device 100 for vehicles is given. However, the present invention can also be applied to a magnetic device used as the transformer 53 (FIG. 1), and a magnetism used in, for example, a switching power supply for electronic equipment other than a vehicle. The present invention can also be applied to devices.

1, 1 ′, 1 ″, 21, 31 Magnetic device 2a Upper core 2b Lower core 3, 3 ′, 3 ″, 23, 33 Coil-integrated printed circuit boards 4a to 4e, 4a ′ to 4c ′, 4a ″ to 4c ″ , 24a-24c coil pattern _{4t 1 ~4t 6, 4s 1 ~4s} 6, 4u 1 ~4u 6, 24t 0, 24t 1, 24t 3, 24t 4 extension region _{5a 7 ~5a 9, 5b 7 ~5b} 9, 5L _{5 to} 5L ₇ , 5r _{5 to} 5r ₇ , 5s _{1 to} 5s ₆ , 25s _{5 to} 25s ₈ heat radiation pattern 7a to 7f, 7a 'to 7f', 7a "to 7f", 27a to 27d, 37a to 37f heat radiation pin 8d , 8d 'through holes 8c, 8c' pads 9a~9d, 9a ', 9b', 9a ", 9b", 29a, 29b through hole group 10 heatsink L1, L1 ', L1 ", La 1 front outer surface layer L , La ₂ inner layer L3, L2 ', L2 ", La 3 back outer surface layer

Claims (10)

A coil pattern formed in a plurality of layers;
Electrical interlayer connection means for electrically connecting the coil patterns in different layers;
In a coil-integrated printed board comprising: a thermal interlayer connection means for thermally connecting the coil pattern in a specific layer to another outer surface layer;
An extended region in which a part of the coil pattern is extended in the width direction is provided at a position deviated from the current path of the coil pattern in the specific layer,
In correspondence with the coil pattern in the specific layer, a heat dissipation pattern is provided on the other outer surface layer,
A coil-integrated printed circuit board, wherein the corresponding extended region of the coil pattern and the heat radiation pattern are thermally connected by the thermal interlayer connection means. In the coil integrated type printed circuit board according to claim 1,
The corresponding extended area of the coil pattern and the heat dissipation pattern are provided to face each other,
The thermal interlayer connection means includes a metal pin, and penetrates the coil-integrated printed board so as to pass through the corresponding extended area of the coil pattern and the heat dissipation pattern. Body type printed circuit board. The coil-integrated printed circuit board according to claim 1 or 2,
The coil-integrated printed circuit board, wherein the electrical interlayer connecting means includes a through hole, is provided on a current path of the coil pattern to be connected, and penetrates the coil-integrated printed circuit board. In the coil integrated type printed circuit board according to any one of claims 1 to 3,
The electrical interlayer connection means comprises a through hole group in which a plurality of through holes are gathered at a predetermined interval.
A plurality of the through-hole groups are provided in accordance with the number of connection between the coil patterns in the different layers. In the coil integrated type printed circuit board according to claim 3 or 4,
A coil-integrated printed board, wherein the through hole is filled with a conductive member. The coil-integrated printed circuit board according to any one of claims 1 to 5,
A front-side outer surface layer, a back-side outer surface layer, and at least one inner layer provided between each of these layers;
Providing each coil with the coil pattern;
The extended areas of the coil patterns are respectively provided at positions outside the current paths of the coil patterns in the front outer surface layer and the inner layer,
Corresponding to each coil pattern in the front outer surface layer and the inner layer, the heat radiation pattern is provided in the back outer surface layer,
The thermal interlayer connection means includes:
The coil pattern and the heat radiation pattern of the corresponding front outer surface layer penetrate through the coil integrated printed board so as to pass through the extended region of the coil pattern of the front outer surface layer and the heat radiation pattern corresponding to the coil pattern. First thermal interlayer connection means for thermally connecting
The coil pattern and the heat radiation pattern corresponding to the inner layer are thermally passed through the coil-integrated printed circuit board so as to pass through the extended region of the coil pattern of the inner layer and the heat radiation pattern corresponding to the coil pattern. A coil-integrated printed circuit board comprising: a second thermal interlayer connection means for connection. The coil-integrated printed board according to claim 6,
A coil-integrated printed circuit board, wherein the number of the second thermal interlayer connection means is greater than the number of the first thermal interlayer connection means. In the coil integrated type printed circuit board according to claim 6 or 7,
The first thermal interlayer connection means and the second thermal interlayer connection means are formed of columnar bodies,
A coil-integrated printed circuit board, wherein the diameter of the second thermal interlayer connection means is larger than the diameter of the first thermal interlayer connection means. A coil-integrated printed circuit board according to any one of claims 1 to 8,
A core made of a magnetic material and penetrating the coil-integrated printed board,
A magnetic device, wherein a coil pattern is formed on a plurality of layers of the coil-integrated printed circuit board so as to be wound around the core. The magnetic device according to claim 9, wherein
A magnetic device, wherein a radiator is provided on the other outer surface layer side of the coil-integrated printed board having a heat radiation pattern.

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