JP2016197952A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic apparatus which can efficiently radiate heat generated by a coil of a magnetic device and an electronic component, and which can also enable downsizing.SOLUTION: An electronic apparatus 100 comprises: a transformer 2 in which coils 22a and 22b are wound around a columnar part 21c located at the center between cores 21a and 21b each having an E-shaped cross section; an FET 3 which is a heat-generating electronic component; a base 1 made of a heat radiation material; and a wiring board 5 which connects a terminal of the coil 22a to a terminal 3t of the FET 3. A projection 1b projecting upward is provided at an end of an upper face 1a of the base 1. The transformer 2 is mounted on the upper face 1a of the base 1 such that the radial direction of the coils 22a and 22b is parallel to the upper face 1a of the base 1, and that edge faces 21f and 21g, of the cores 21a and 21b, opposite to the coils 22a and 22b come closer to an inner face 1c of the projection 1b. The FET 3 is mounted on an outer face 1d, of the projection 1b, opposite to the cores 21a and 21b.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a heat dissipation structure for an electronic device including electronic components that generate heat, such as a coil and a switching element.

  For example, electronic devices such as DC-DC converters use many electronic components that generate heat, such as choke coils, transformers, switching elements, and diodes. When the temperature rises due to such heat generation of the electronic component, various techniques for radiating the heat generated in the electronic component have been proposed to adversely affect a malfunction or failure.

  For example, in Patent Documents 1 to 4, a switching element is mounted on a side surface of a radiator that is perpendicular to a wiring board, and heat generated by the switching element is radiated by the radiator. In Patent Document 1, a magnetic device such as a transformer or a choke coil is mounted on the upper surface of a radiator (base plate), and heat generated by the magnetic device is radiated by the radiator. Further, in Patent Document 5, a transformer and a choke coil are mounted on the upper surface of the radiator through separate heat transfer plates, so that heat generated by the transformer and the choke coil can be easily transmitted to the radiator.

  Moreover, in patent document 6, the transistor arrangement | positioning part which protrudes upwards is provided in the upper surface of the heat radiating body (heat sink) which is the foundation of an electronic device. A transistor is mounted on the inclined surface of the transistor arrangement portion, and heat generated by the transistor is radiated by the heat radiating body. Further, relays are arranged at intervals on the opposite side of the inclined surface of the transistor arrangement portion.

JP 2000-14149 A JP 2004-198078 A JP 2007-221057 A JP 2011-60567 A JP 2010-232391 A JP 2004-1621 A

  Magnetic devices such as choke coils and transformers have coils that generate heat when energized. In particular, in a magnetic device used in a DC-DC converter, a large current flows through the coil and the amount of heat generated by the coil increases. For this reason, if a coil and other electronic components that generate heat are arranged in the proximity state as in, for example, Patent Documents 1 and 2, the temperature of these and surrounding components becomes high and it is difficult to dissipate heat. Further, if the interval between the coil and other electronic components that generate heat is widened, heat becomes difficult to collect, but the electronic device becomes large.

  The subject of this invention is providing the electronic device which can thermally radiate the heat | fever which generate | occur | produced with the coil and electronic component of the magnetic device efficiently, and can implement | achieve size reduction.

  An electronic apparatus according to the present invention includes a magnetic device in which a coil is wound around a pillar portion at the center of an E-shaped core, a heat generating electronic component, a pedestal formed of a heat dissipation material, a coil terminal, and an electronic device. And a wiring board for connecting the terminal of the component. A protruding portion that protrudes upward is provided at the end of the upper surface of the pedestal. The magnetic device is mounted on the upper surface of the pedestal so that the radial direction of the coil is parallel to the upper surface of the pedestal and the end surface opposite to the coil of the core is close to one side surface of the protrusion. Furthermore, an electronic component is mounted on the other side surface opposite to the core of the protruding portion.

  According to the above, the magnetic device is mounted on the upper surface of the pedestal having heat dissipation, the core of the magnetic device is brought close to one side surface of the projecting portion provided at the end of the pedestal, and on the side surface opposite to the projecting portion, It is equipped with electronic parts that generate heat. For this reason, the heat generated in the coil of the magnetic device can be transmitted to the pedestal directly below and efficiently radiated downward to the pedestal. In addition, the heat transmitted from the coil to the core and the heat generated in the electronic component can be transmitted from the projecting portion to the pedestal and efficiently radiated downward to the pedestal. In addition, it is possible to reduce the size of the electronic device in the lateral direction by arranging the core of the magnetic device and the electronic component in an approaching state so that the protruding portion is interposed therebetween. Furthermore, when the diameter dimension is larger than the height dimension of the electronic component, the electronic component can be further reduced in the lateral direction by mounting the electronic component vertically on the side surface of the protruding portion.

  Further, according to the present invention, in the electronic device, a protruding portion is provided at each of both opposing ends of the upper surface of the pedestal so as to contact the opposite end surfaces of the core, and the other of the protruding portions on the opposite side of the core. The electronic parts may be mounted so as to lean on the side surfaces.

  In the present invention, in the electronic device, the other side surface opposite to the core of the protruding portion may be inclined so as to face obliquely upward, and an electronic component may be mounted on the inclined surface.

  According to the present invention, in the electronic device, a first heat radiating member is interposed between the core and the pedestal, a second heat radiating member is interposed between the core and the protruding portion, and the electronic component is interposed between the protruding portion. A third heat radiating member may be interposed.

  According to the present invention, in the electronic apparatus, the wiring board includes a first wiring board mounted on the upper surface of the pedestal on the side of the magnetic device having no protrusion and a second wiring board disposed above the magnetic device. The terminal of the coil may be connected to the first wiring board or the second wiring board, and the terminal of the electronic component may be connected to the second wiring board.

  According to the present invention, the electronic device further includes a base formed of a heat dissipation material and fixed to the upper portion of the protruding portion, the second wiring board is mounted on the upper surface of the base, and the magnetic device is mounted by the base and the pedestal. It may be held.

  Furthermore, in the present invention, in the electronic device, a fourth heat radiating member may be interposed between the base and the core.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the electronic device which can thermally radiate the heat | fever generate | occur | produced with the coil and electronic component of a magnetic device efficiently, and can implement | achieve size reduction.

It is the figure which showed the electric constitution of the electronic device by embodiment of this invention. It is a disassembled perspective view of the same electronic device. It is a perspective view which shows the state which assembled some electronic devices of FIG. It is a top view which shows the state which assembled some electronic devices of FIG. It is a perspective view which shows the state which assembled the electronic device of FIG. It is a top view which shows the state which assembled the electronic device of FIG. It is XX sectional drawing of FIG. FIG. 3 is an enlarged perspective view of the transformer of FIG. 2. It is an expansion perspective view of the base of FIG.

  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 diagram illustrating an electrical configuration of an electronic device 100 according to an embodiment of the present invention. The electronic device 100 is a DC-DC converter for an electric vehicle (or a hybrid car), for example. The electronic device 100 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 electronic 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 includes a known circuit having a plurality of FETs (Field Effect Transistors) 3 and a reactor (not shown), for example. In the switching circuit 52, each FET 3 is turned on / off based on a PWM (Pulse Width Modulation) signal from the PWM drive unit 58 to perform a switching operation 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 2.

  Terminals 24 a and 24 b of the primary side coil 22 a of the transformer 2 are connected to the output side of the switching circuit 52. Terminals 22c, 22d, and 22e of the secondary coil 22b of the transformer 2 are connected to the input side of the rectifier circuit 54.

  The rectifier circuit 54 includes a known circuit having a plurality of diodes (not shown), and rectifies the pulse voltage using these diodes. The voltage rectified by the rectifier circuit 54 is input to the smoothing circuit 55.

  The smoothing circuit 55 is a known circuit having a reactor and a capacitor (both not shown). The smoothing circuit 55 smoothes the rectified voltage by the filter action of the reactor and the capacitor, 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 it to the gate of each FET 3 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.

  Next, the structure of the electronic device 100 will be described with reference to FIGS.

  FIG. 2 is an exploded perspective view of the electronic device 100. FIG. 3 is a perspective view showing a state in which a part of the electronic device 100 is assembled. FIG. 4 is a plan view showing a state in which a part of the electronic device 100 is assembled. FIG. 5 is a perspective view showing a state in which the electronic device 100 is assembled. FIG. 6 is a plan view showing a state in which the electronic device 100 is assembled. 7 is a cross-sectional view taken along the line XX in FIG. FIG. 8 is an enlarged perspective view of the transformer 2 of FIG. FIG. 9 is an enlarged perspective view of the pedestal 1 of FIG.

  As shown in FIG. 2, the electronic device 100 includes a pedestal 1, a transformer 2, an FET 3, a base 4, wiring boards 5, 6 and 9, and a heat dissipation sheet 7.

  Among them, the pedestal 1 and the base 4 are formed of a heat dissipation material such as aluminum die casting. The pedestal 1 is formed in a rectangular shape when viewed from above. The base 4 is also formed in a rectangular shape when viewed from above. The size of the base 4 is about half the size of the base 1. The base 1 and the base 4 function as a heat sink.

  In FIG. 2, projecting portions 1 b projecting upward in a trapezoidal shape are provided at both ends in the short direction of the upper surface 1 a in the left portion of the base 1. As shown in FIGS. 7 and 9, the opposing inner surface 1 c of each protrusion 1 b is perpendicular to the upper surface 1 a of the pedestal 1. The opposite outer surface 1d of each protrusion 1b is inclined so as to face diagonally upward.

  As shown in FIG. 1, the transformer 2 is provided between the switching circuit 52 and the rectifier circuit 54 and insulates them. As shown in FIGS. 7 and 8, the transformer 2 includes a core 21, a coil 22, a substrate 23, terminals 24a and 24b, and the like. The transformer 2 is an example of the “magnetic device” in the present invention.

  As shown in FIG. 7, the core 21 includes an upper core 21a and a lower core 21b each having an E-shaped cross section. Specifically, the upper core 21a and the lower core 21b are combined so that the three column portions 21c, 21d, and 21e of the upper core 21a and the three column portions 21c, 21d, and 21e of the lower core 21b face each other. 21 is configured. The upper core 21a and the lower core 21b are made of a magnetic material such as ferrite or amorphous metal.

  The coil 22 is wound around the central column 21c so as to pass between the column 21c at the center of the core 21 and the columns 21d and 21e at both ends. The coil 22 includes a primary coil 22 a mounted on the lower surface of the substrate 23 and a secondary coil 22 b mounted on the upper surface of the substrate 23. Each coil 22a, 22b consists of conductors, such as a copper pattern and a copper plate. The central column portion 21 c of the core 21 passes through the substrate 23.

  As shown in FIG. 4, terminals 22 c, 22 d, and 22 e protrude from one side of the core 21 in the short direction. The terminal 22c is a center tap of the transformer 2 (see FIG. 1). Terminals 22d and 22e are input / output terminals of the secondary coil 22b.

  Terminals 24a and 24b are mounted on the end of the substrate 23 opposite to the terminals 22c, 22d and 22e so as to protrude upward. The terminals 24a and 24b are electrically connected to the primary coil 22a via the substrate 23. The terminals 24a and 24b are input / output terminals of the primary coil 22a.

  As shown in FIGS. 3, 4, and 7, the transformer 2 is disposed between the two protrusions 1 b on the upper surface 1 a of the pedestal 1 so that the radial direction of the coil 22 is parallel to the upper surface 1 a of the pedestal 1. It is installed. In this mounted state, as shown in FIG. 7, the end surfaces 21f and 21g on the opposite side of the coil 22 of the core 21 are close to the inner side surface 1c of each protruding portion 1b.

  In FIG. 7, the heat radiating member 11 is interposed between the end surfaces 21f and 21g of the core 21 and the inner side surface 1c of each protruding portion 1b without any gap. The heat radiating member 11 has insulating properties, and is made of, for example, a heat radiating adhesive, a potting resin, or a heat radiating sheet. The material of the heat dissipation sheet is made of, for example, silicon rubber, elastomer, or resin. Thereby, the core 21 and the protrusion part 1b are thermally connected through the heat radiating member 11. FIG. Further, when a heat radiation adhesive or potting resin is used as the heat radiation member 11, the core 21 and the protruding portion 1 b are fixed via the heat radiation member 11. The heat dissipation member 11 is an example of the “second heat dissipation member” in the present invention.

  With the transformer 2 mounted on the pedestal 1, the lower surface of the lower core 21 b is close to the upper surface 1 a of the pedestal 1. A heat dissipation member 12 is interposed between the lower surface of the lower core 21b and the upper surface 1a of the pedestal 1. The heat radiating member 12 has insulating properties and is made of heat radiating grease or heat radiating adhesive. Thereby, the lower core 21b and the base 1 are thermally connected. Further, when a heat radiation adhesive is used as the heat radiation member 12, the lower core 21 b and the base 1 are fixed via the heat radiation member 12. The heat dissipation member 12 is an example of the “first heat dissipation member” in the present invention.

  As shown in FIG. 3, the heights of the terminals 24a and 24b of the primary coil 22a of the transformer 2 when the upper surface 1a of the base 1 is used as a reference are higher than the heights of the protruding portions 1b. The heights of the terminals 22c, 22d, and 22e of the secondary coil 22b of the transformer 2 are lower than the heights of the protruding portions 1b. The terminals 22c, 22d, and 22e protrude to the side of each protrusion 1b.

  Four FETs 3 are provided as shown in FIG. 2 and the like, and are included in the switching circuit 52 (FIG. 1) described above. Each FET 3 is an example of the “electronic component” in the present invention.

  As shown in FIGS. 3, 4, and 7, the FETs 3 are mounted so as to lean against each other on the inclined outer surface 1 d opposite to the core 21 of each projecting portion 1 b of the base 1. Between the outer surface 1d and the FET 3, a heat dissipation sheet 7 having insulating properties is sandwiched. The material of the heat radiating sheet 7 is made of, for example, silicon rubber, elastomer, or resin.

  The outer side surface 1d, the heat radiation sheet 7, and the FET 3 are fixed to each other, for example, by interposing a heat radiation adhesive therebetween. Instead of this, for example, two fixing members (not shown) having elasticity are attached from the outside (on the outer surface 1d side) to each protrusion 1b, and the body (package portion) of each FET 3 is attached by each fixing member. The outer surface 1d, the heat dissipation sheet 7, and the FET 3 may be fixed by pressing against the outer surface 1d.

  In a state where each FET 3 is attached to the outer surface 1d as described above, the terminal 3t of each FET 3 protrudes upward from the protruding portion 1b. Further, the FET 3 is inclined with respect to the upper surface 1a of the base 1. For this reason, the height of the FET 3 is suppressed to be lower than that in the vertical posture. Further, the FET 3 and the protruding portion 1 b are thermally connected via the heat dissipation sheet 7. The heat dissipation sheet 7 is an example of the “third heat dissipation member” in the present invention.

  As shown in FIG. 7, the base 4 is fixed to the upper part of each protrusion 1b with a screw (not shown). A heat radiating member 14 is interposed at a contact portion between the upper surface of each protruding portion 1 b and the base 4. The heat radiating member 14 has insulating properties and is made of heat radiating grease or heat radiating adhesive. Thereby, the upper surface of the protrusion part 1b and the base 4 are thermally connected. When a heat radiation adhesive is used as the heat radiation member 14, the upper surface of the protruding portion 1 b and the base 4 are fixed via the heat radiation member 14.

  The heat radiating member 15 is interposed between the lower surface of the base 4 and the upper surface of the upper core 21a without a gap. The heat radiating member 15 is made of the same material as the heat radiating member 11 described above. Thereby, the base 4 and the upper core 21a are thermally connected via the heat dissipation member 15. When a heat radiation adhesive or potting resin is used as the heat radiation member 15, the base 4 and the upper core 21 a are fixed via the heat radiation member 15. Thus, the transformer 2 is disposed between the base 4 and the pedestal 1 and is held by the base 4 and the pedestal 1. The heat dissipation member 15 is an example of the “fourth heat dissipation member” in the present invention.

  A wiring board 5 is mounted on the upper surface of the base 4. The base 4 and the wiring board 5 are fixed by screws (not shown). That is, the wiring board 5 is disposed above the transformer 2. The wiring board 5 is made of, for example, a glass epoxy board.

  As shown in FIG. 5, the wiring board 5 is formed with a through hole 5a that penetrates the terminal 3t of each FET 3 and a through hole 5b that penetrates the tips of the terminals 24a and 24b. A land (not shown) is formed around each of the through holes 5a and 5b. Those lands and the terminals 3t, 24a, and 24b are soldered. Thereby, the terminal 3 t of the FET 3 and the terminals 24 a and 24 b of the primary side coil 22 a of the transformer 2 are electrically connected to the wiring board 5. The wiring board 5 is an example of the “second wiring board” in the present invention.

  Moreover, the reactor of the switching circuit 52 shown in FIG. 1, the control part 57, the PWM drive part 58, etc. are mounted on the wiring board 5 (illustration omitted). As shown in FIG. 5, the wiring board 9 (illustrated by a two-dot chain line) is mounted on the upper part of the columnar table 4d provided at each corner of the base 4 (see also FIG. 7). A filter circuit 51 shown in FIG. 1 is mounted on the wiring board 9 (not shown). In FIG. 6, illustration of the wiring board 9 is omitted.

  As shown in FIG. 4, the wiring board 6 is mounted on the upper surface 1a of the base 1 on the side of the transformer 2 where the projecting portion 1b does not exist. The base 1 and the wiring board 6 are fixed by screws (not shown). Wiring substrate 6 is made of, for example, an aluminum substrate.

  A land 6a is formed on the wiring board 6 as shown in FIG. 2, and two bus bars 6b are mounted thereon. As shown in FIG. 4, the terminal 22c of the transformer 2 is soldered to the land 6a. A through hole 22h is formed in the terminals 22d and 22e of the secondary coil 22b of the transformer 2. The end of each bus bar 6b passes through the through hole 22h and is soldered to the terminals 22d and 22e, respectively (FIG. 3). Thereby, the terminals 22 c, 22 d, and 22 e of the transformer 2 are electrically connected to the wiring board 6. The wiring board 6 is an example of the “first wiring board” in the present invention.

  Further, the rectifier circuit 54 shown in FIG. 1 and the like are mounted on the wiring board 6 (not shown). The smoothing circuit 55 shown in FIG. 1 is mounted on the end of the upper surface 1a of the base 1 opposite to the transformer 2 in FIG. 4 (not shown). The output voltage detection circuit 59, the power source 56, and the terminals T1 to T4 illustrated in FIG. 1 are provided on the pedestal 1.

  During the operation of the electronic device 100, each FET 3 generates heat by performing a switching operation. The coil 22 of the transformer 2 generates heat when a large current flows.

  As shown in FIG. 7, the heat generated in the primary coil 22a below the substrate 23 of the transformer 2 is transmitted to the pedestal 1 through the lower core 21b and the heat radiating member 12 below, and the pedestal 1 Heat is dissipated downward and to the side. Heat generated by the secondary coil 22b above the substrate 23 of the transformer 2 is transmitted to the base 4 via the upper core 21a and the heat radiating member 15 located above, and is radiated to the upper side and the side of the base 4. . Further, the heat generated in each coil 22a, 22b is also transmitted to the protruding portion 1b of the pedestal 1 through the column portions 21d, 21e of the core 21 on the side and the heat radiating member 11, and below and on the side of the pedestal 1. Heat is dissipated.

  The heat generated in each FET 3 is transmitted to the projecting portion 1b of the pedestal 1 through the heat radiating sheet 7, and is radiated to the lower side or the side of the pedestal 1.

  According to the above embodiment, the transformer 2 is mounted on the upper surface 1a of the pedestal 1 having heat dissipation. And the protrusion part 1b is provided in the both ends of the base 1 in the both sides of the transformer 2, and the core 21 of the transformer 2 is made to adjoin to the inner surface 1c of each protrusion part 1b. In addition, a plurality of FETs 3 are mounted on the outer surface 1d opposite to the core 21 of each protruding portion 1b. For this reason, the heat generated in the coil 22 of the transformer 2 can be transmitted to the pedestal 1 directly below and efficiently radiated downward to the pedestal 1. Further, the heat transmitted from the coil 22 to the core 21 and the heat generated by the plurality of FETs 3 can be transmitted from the respective projecting portions 1b to the pedestal 1 and efficiently radiated downward to the pedestal 1.

  Moreover, in the said embodiment, the core 21 and FET3 of the transformer 2 are arrange | positioned in the approaching state so that the protrusion part 1b may interpose. The FET 3 having a larger diameter dimension (package part width) than a height dimension (package part thickness) is mounted so as to lean against the outer surface 1d of the protrusion 1b. For this reason, it is possible to reduce the size of the electronic device 100 in the lateral direction, particularly in the lateral direction of the base 1.

  Moreover, in the said embodiment, the outer surface 1d of the protrusion part 1b is inclined upwards, and FET3 is mounted in this inclined surface 1d. For this reason, the height of the FET 3 with respect to the upper surface 1a of the pedestal 1 is reduced according to the height of the coil 22 and the core 21 of the transformer 2, and the electronic device 100 can be downsized in the height direction. can do. Moreover, since the path | route which the heat | fever of the transformer 2 or FET3 is transmitted to the lower surface of the base 1 which is a cooling surface through the protrusion part 1b becomes short, this heat can be thermally radiated still more efficiently.

  Moreover, in the said embodiment, since the thermal radiation member 12 is interposed between the lower core 21b and the upper surface 1a of the base 1, it is easy to transmit the heat | fever transmitted from the coil 22 to the lower core 21b to the base 1 directly under. Thus, heat can be radiated from the pedestal 1 more efficiently. Moreover, since the heat radiating member 11 is interposed between the cores 21a and 21b and the inner surface 1c of the protrusion 1b, the heat transferred from the coil 22 to the cores 21a and 21b is easily transferred to the protrusion 1b. Heat can be radiated from the pedestal 1 more efficiently. Furthermore, since the heat radiating sheet 7 is interposed between the FET 3 and the outer surface 1d of the protruding portion 1b, the heat generated in the FET 3 can be easily transferred to the protruding portion 1b and radiated from the pedestal 1 more efficiently. Can do.

  In the above embodiment, since the terminals 24a and 24b of the primary coil 22a of the transformer 2 and the terminal 3t of the FET 3 protrude upward, each terminal 24a is provided on the wiring board 5 mounted above the transformer 2. , 24b, 3t can be easily electrically connected. Further, since the terminals 22d, 22e, and 22c of the secondary side coil 22b of the transformer 2 are pulled out to the side in the short direction of the core 21 of the transformer 2 where the projecting portion 1b does not exist, Each terminal 22d, 22e, 22c can be easily electrically connected to the wiring board 6 mounted on the upper surface 1a. Further, the circuit arrangement is easily performed such that the switching circuit 52 on the primary side of the transformer 2 is mounted on the wiring board 5 and the rectifier circuit 54 on the secondary side of the transformer 2 is mounted on the wiring board 6. The electronic device 100 can be downsized.

  Moreover, in the said embodiment, the base 4 which has heat dissipation is fixed to the upper part of the protrusion part 1b of the base 1, the wiring board 5 is mounted in the upper surface of the base 4, and the base 2 and the base 1 of the transformer 2 from the upper and lower sides. The core 21 is held. For this reason, the heat generated in the coil 22 of the transformer 2 can be easily transferred to the upper and lower bases 4 and the pedestal 1 via the core 21 and can be efficiently radiated from these. Further, the base 4 can suppress the heat generated in the coil 22 from being transmitted to the wiring board 5.

  Further, in the above embodiment, since the heat radiating member 15 is interposed between the base 4 and the upper core 21a, the heat transferred from the coil 22 to the upper core 21a can be easily transferred to the base 4, Heat can be radiated more efficiently.

  In the present invention, various embodiments other than those described above can be adopted. For example, in the above embodiment, the example in which the projecting portions 1b are provided at both ends of the base 1 on both sides in the longitudinal direction of the core 21 of the transformer 2 has been shown, but the present invention is not limited to this. Absent. What is necessary is just to provide a protrusion part in the edge part of the base in the at least one side of the longitudinal direction of a core. Then, the end face of the core may be brought close to one side surface of the protruding portion, and an electronic component that generates heat such as an FET may be mounted on the other side surface.

  Moreover, although the example which mounted the transformer 2 in the upper surface 1a of the base 1 was shown in the above embodiment, this invention is not limited only to this. In addition to this, other magnetic devices such as a choke coil constituting a reactor of the switching circuit 52 or the smoothing circuit 55 may be mounted on the upper surface of the pedestal. Then, a protrusion is provided on the pedestal so as to be close to the end surface of the core of the magnetic device, and a heat generating electronic component such as an FET or a diode is mounted on the side surface opposite to the core of the protrusion. Also good.

  Moreover, although the example using the transformer 2 which has the core 21 which combined two E-shaped cores 21a and 21b was shown in the above embodiment, this invention is not limited only to this. Other than this, for example, the present invention can be applied to a magnetic device such as a transformer or a choke coil having a core obtained by combining an E-shaped core and an I-shaped core.

  Furthermore, in the above embodiment, although the example which applied this invention to the heat dissipation structure of the transformer 2 of the electronic device 100 which comprises the DC-DC converter for vehicles, and FET3 of the switching circuit 52 was given, The present invention can also be applied to a heat dissipation structure of a magnetic device and an electronic component that generate heat.

1 pedestal 1a upper surface of pedestal 1b protruding portion 1c inner side surface (one side surface) of protruding portion
1d Inclined outer surface of the protrusion (the other side surface)
2 transformer (magnetic device)
3 FET (electronic parts)
Terminal of 3t FET 4 Base 5 Wiring board (second wiring board)
6 Wiring board (first wiring board)
7 Heat dissipation sheet (third heat dissipation member)
11 Heat dissipation member (second heat dissipation member)
12 Heat dissipation member (first heat dissipation member)
15 Heat dissipation member (4th heat dissipation member)
21 core 21a upper core 21b lower core 21c pillar part 21f, 21g core end face 22 coil 22a primary coil 22b secondary coil 22c, 22d, 22e secondary coil terminals 24a, 24b primary Side coil terminal 100 Electronic equipment

Claims (7)

A magnetic device in which a coil is wound around a pillar portion at the center of an E-shaped core;
Electronic components that generate heat,
A pedestal made of heat dissipation material;
In an electronic device comprising a wiring board for connecting the terminal of the coil and the terminal of the electronic component,
Providing a protruding portion that protrudes upward at the end of the upper surface of the pedestal,
The magnetic device is mounted on the upper surface of the pedestal such that the radial direction of the coil is parallel to the upper surface of the pedestal and the end surface of the core opposite to the coil is close to one side surface of the protrusion. ,
The electronic device is characterized in that the electronic component is mounted on the other side surface of the protruding portion opposite to the core. The electronic device according to claim 1,
The protrusions are respectively provided at opposite ends of the upper surface of the pedestal so as to be in contact with both ends of the core opposite to the coils.
An electronic device, wherein the electronic component is mounted on the other side surface opposite to the core of each of the protrusions so as to lean on the electronic component. The electronic device according to claim 1 or 2,
An electronic apparatus, wherein the other side surface of the protruding portion opposite to the core is inclined so as to face obliquely upward, and the electronic component is mounted on the inclined surface. The electronic device according to any one of claims 1 to 3,
A first heat radiating member is interposed between the core and the pedestal,
A second heat dissipating member is interposed between the core and the protrusion,
An electronic apparatus, wherein a third heat dissipation member is interposed between the electronic component and the protrusion. The electronic device according to any one of claims 1 to 4,
The wiring board is
A first wiring board mounted on the upper surface of the pedestal, on the side of the magnetic device where the protrusion does not exist;
A second wiring board disposed above the magnetic device,
Connecting the terminal of the coil to the first wiring board or the second wiring board;
An electronic apparatus, wherein a terminal of the electronic component is connected to the second wiring board. The electronic device according to claim 5,
A base formed of a heat dissipating material and fixed to the upper portion of the protrusion;
Mounting the second wiring board on the upper surface of the base;
An electronic apparatus, wherein the magnetic device is held by the base and the pedestal. The electronic device according to claim 6,
An electronic apparatus, wherein a fourth heat radiating member is interposed between the base and the core.

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