JP6265459B2 - Electronic component mounting structure - Google Patents

Description

  The present invention relates to a mounting structure in consideration of heat dissipation of an electronic component having a lead terminal.

  2. Description of the Related Art Conventionally, there is a switching power supply device that converts a high voltage direct current to a low voltage direct current after switching to an alternating current. A large number of electronic components are used in this switching power supply device. Among them, in a magnetic device such as a transformer through which a large current flows, a large amount of heat is generated. Therefore, measures for heat radiation are taken so as not to deteriorate the performance.

  For example, in Patent Document 1 and Patent Document 2, a heat dissipating sheet is provided on the upper surface of the core of the transformer, and a bent portion is provided on the ceiling portion or both mounting arm portions of a metal reverse-concave mounting member. And the ceiling part of an attachment member is made to contact a heat-dissipating sheet, and the attachment part in the front-end | tip of both attachment arm parts is screwed to the attachment stand provided on the heat sink.

  In Patent Document 3, a semiconductor element is mounted on a substrate, and the peripheral portion of the upper surface of the semiconductor element and the substrate are connected by a lead frame. And the heat sink is made to contact the center part of the upper surface of a semiconductor element, and the upper surface of a lead frame via a heat dissipation connecting member.

  Moreover, in patent document 4, a terminal part is protruded from the annular part of the flat coil of a transformer, and the foot part for heat radiation is protruded from the side facing the terminal part across the hole inside the annular part. The terminal portion is bent sideways or downward and is connected to other electronic components. The heat radiation foot is screwed to the base plate on which the heat radiator is mounted via an insulating sheet.

  Further, in Patent Document 5, a connection terminal and a mounting terminal are provided integrally with a conductive terminal of a secondary coil of a transformer, and the outside of the mounting terminal is covered with a synthetic resin insulating coating. The two connection terminals provided are bent toward the same side and are connected to other electronic components. In order to release the heat generated by the transformer to the case, the mounting terminals are screwed onto the case.

JP 2009-206308 A JP 2009-212356 A JP 2012-253118 A JP 2004-303823 A JP 2001-85240 A

  For example, when downsizing of a switching power supply device is required, it is attempted to mount a plurality of electronic components used in the device at high density. At that time, an electronic component having a large outer shape such as a transformer is difficult to arrange, which hinders high-density mounting. Further, when electronic components are mounted at a high density, heat generated in the electronic components is likely to be trapped.

  The subject of this invention is providing the mounting structure of the electronic component which makes it easy to dissipate the heat which generate | occur | produces in an electronic component, and can make arrangement | positioning of an electronic component easy.

In the present invention, in an electronic component mounting structure in which an electronic component having a lead terminal and a substrate having a connection terminal are arranged on a heat radiator, the electronic component is composed of a magnetic device having a coil portion. The first lead terminal extends from the lower end of the coil part, and the second lead terminal extends from the upper end of the coil part. The connection terminal includes a first connection terminal provided corresponding to the first lead terminal and a second connection terminal provided corresponding to the second lead terminal. The root portion of the first lead terminal is positioned at the same height as the upper surface of the heat sink, and the intermediate portion of the first lead terminal extends horizontally from the root portion of the first lead terminal, It is bent in an L shape within a parallel plane and is in contact with the upper surface of the heat radiating body via an insulating sheet having heat conductivity. The tip of the first lead terminal is fixed to the first connection terminal. The root portion of the second lead terminal is located above the root portion of the first lead terminal, and the middle portion of the second lead terminal is longer than the middle portion of the first lead terminal, and from the root portion of the second lead terminal. Bends to the rear side bent downward, and is bent in an L shape in the same direction as the first lead terminal in the plane outside the intermediate portion of the first lead terminal, Contact is made through an insulating sheet. The tip of the second lead terminal is fixed to the second connection terminal.

If it does in this way, the contact area of the L-shaped intermediate part of each lead terminal and a heat sink via an insulating sheet can be enlarged. For this reason, the heat generated in the electronic component can be released from each lead terminal to the heat radiating body via the insulating sheet, and can be easily radiated. Moreover, each lead terminal and a heat radiator can also be insulated. Further, the space occupied by the lead terminals of the electronic component can be reduced, and the electronic component can be easily arranged.

  Further, in the present invention, in the electronic component mounting structure described above, when the heat dissipating body is rectangular, an L-shaped intermediate portion of the lead terminal may be disposed at the corner of the heat dissipating body.

Further, in the present invention, in the mounting structure of the electronic component, the electronic component of the first and second lead terminals from one of the left and right sides of the main body is protruded, the other lead terminal from the other of the right and left sides protrude Also good.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the mounting structure of the electronic component which makes it easy to radiate the heat which generate | occur | produces in an electronic component, and can make arrangement | positioning of an electronic component easy.

It is a block diagram of a switching power supply device. It is the figure which showed the mounting structure of the transformer by embodiment of this invention. It is a perspective view of the mounting structure of the transformer of FIG. It is AA sectional drawing of FIG. It is the B section enlarged view of FIG. FIG. 3 is a perspective view of the heat sink of FIG. 2. FIG. 3 is a perspective view of the transformer of FIG. 2.

  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 (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 applied to the rectifier circuit 54 via the transformer 1. 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, two input lead terminals Ta and Tb are provided on the primary side of the transformer 1, and two output lead terminals Td and Te and one intermediate are provided on the secondary side. Lead terminals Tc are provided.

The transformer 1 is an example of the “electronic component” and “magnetic device” of the present invention.
Hereinafter, the mounting structure of the transformer 1 will be described in detail with reference to FIGS.

  FIG. 2 is a diagram showing a mounting structure of the transformer 1, and the structure is viewed from above. FIG. 3 is a perspective view of the mounting structure of the transformer 1. 4 is a cross-sectional view taken along line AA in FIG. FIG. 5 is an enlarged view of a portion B in FIG. FIG. 6 is a perspective view of the heat sink 2. FIG. 7 is a perspective view of the transformer 1.

  The heat sink 2 shown in FIGS. 2-6 is metal, and comprises the lower case of the switching power supply device 100 (FIG. 1). On the heat sink 2, as shown in FIGS. 2 and 3, a transformer 1 and a substrate 3 are arranged.

  The substrate 3 is fixed on the heat sink 2 by screws 11. An insulating sheet 8d (shown in FIG. 4) having heat conductivity is interposed between the substrate 3 and the heat sink 2. Each part of the switching power supply device 100 shown in FIG. 1 is mounted on the substrate 3 (other than the transformer 1 and the terminals T1 to T3 are not shown).

  By covering an upper case (not shown) on the heat sink 2 and fixing with a screw or the like, each part of the switching power supply device 100 is housed. As shown in FIGS. 3 to 5, a plurality of fins 2 f are provided below the heat sink 2. The heat sink 2 dissipates heat generated in each part of the switching power supply device 100. The heat sink 2 is an example of the “heat radiator” in the present invention.

  As shown in FIGS. 2 and 3, the main body 1a of the transformer 1 is fixed on the heat sink 2 by fixing members 4a, 4b, and 4c. The fixing members 4a, 4b, 4c are made of metal.

  As shown in FIG. 4, the core 9 of the transformer 1 is composed of two pairs of an E-shaped upper core 9 a and a lower core 9 b. The core 9 is made of a magnetic material such as ferrite or amorphous metal.

  The lower core 9 b is fitted in a recess 2 k provided in the heat sink 2. Between the lower core 9b and the heat sink 2, an insulating sheet 8a having heat conductivity is interposed.

  The primary coil part 10 and the secondary coil part 20 of the transformer 1 are provided so as to be wound around the shaft core part 9 m at the center of the core 9.

  As shown in FIGS. 2 to 4 and 7, input lead terminals Ta and Tb project leftward from the left side surface 1 </ b> L of the main body 1 a of the transformer 1. The lead terminal Ta extends from the upper end of the primary coil portion 10, and the lead terminal Tb extends from the lower end of the primary coil portion 10. The lead terminals Ta and Tb are made of a conductor.

  As shown in FIG. 4, the lead terminal Tb extends horizontally from the base portion Tbr to the intermediate portion Tbm. The tip end portion Tbf of the lead terminal Tb is bent upward and is fixed to a connection terminal 6b provided on the substrate 3 with screws 5b as shown in FIGS.

  The root portion Tar of the lead terminal Ta is located above the root portion Tbr of the lead terminal Tb (FIG. 4). The intermediate portion Tam of the lead terminal Ta is bent downward from the root portion Tar and then extends leftward. The tip portion Taf of the lead terminal Ta is bent upward and is fixed to a connection terminal 6a provided on the substrate 3 by screws 5a as shown in FIGS.

  The lead terminals Ta and Tb are connected to the switching circuit 52 (FIG. 1) via connection terminals 6a and 6b and wiring (not shown) formed on the substrate 3.

  As shown in FIG. 4, a protrusion 2t is provided on the heat sink 2 so as to come into contact with the intermediate portions Tam and Tbm of the lead terminals Ta and Tb (see also FIG. 6). The protrusion 2 t is a conductor formed integrally with the heat sink 2. An insulating sheet 8c having heat conductivity is interposed between the protruding portion 2t and the intermediate portions Tam and Tbm of the lead terminals Ta and Tb. That is, the intermediate portions Tam and Tbm of the lead terminals Ta and Tb are in contact with the protruding portion 2t through the insulating sheet 8c.

  As shown in FIGS. 2 to 4 and 7, lead terminals Tc to Te project rightward from the right side surface 1 r of the main body 1 a of the transformer 1. The lead terminal Tc extends from the middle of the secondary coil portion 20. One lead terminal Td for output extends from the upper end of the secondary coil part 20, and the other lead terminal Te extends from the lower end of the secondary coil part 20. The lead terminals Tc to Te are made of a conductor. The lead terminal Te is an example of the “first lead terminal” in the present invention, and the lead terminal Td is an example of the “second lead terminal” in the present invention.

  As shown in FIGS. 3 and 5, the tip end portion Tcf of the lead terminal Tc is fixed to a convex portion 2s provided on the heat sink 2 by a screw 5c. The convex portion 2 s is a conductor formed integrally with the heat sink 2. The heat sink 2 is connected to the body ground of the electric vehicle. For this reason, the lead terminal Tc is connected to the body ground via the heat sink 2.

  As shown in FIG. 3, the root portion Ter of the lead terminal Te is located at substantially the same height as the upper surface 2 u of the heat sink 2. The intermediate portion Tem of the lead terminal Te extends horizontally from the root portion Ter, and is then bent into an L shape in a plane parallel to the upper surface 2u of the heat sink 2 (see also FIG. 7). The intermediate part Tem of the lead terminal Te is in contact with the upper surface 2u of the heat sink 2 via the insulating sheet 8b. The insulating sheet 8b has heat conductivity.

The tip portion Tef of the lead terminal Te is bent upward from the intermediate portion Tem, and is fixed to a connection terminal 6e provided on the substrate 3 with screws 5e as shown in FIGS. The connection terminal 6e is an example of the “first connection terminal” in the present invention.

  The root portion Tdr of the lead terminal Td is located above the root portion Ter of the lead terminal Te. The intermediate portion Tdm of the lead terminal Td is bent downward from the root portion Tdr and then extends rightward (see also FIG. 7). Further, the intermediate portion Tdm of the lead terminal Td is bent in an L shape toward the same direction on the outer side with respect to the intermediate portion Tem of the lead terminal Te, and as shown in FIGS. It contacts with the insulating sheet 8b.

The tip end portion Tdf of the lead terminal Td is bent upward from the intermediate portion Tdm, and is fixed to the connection terminal 6d provided on the substrate 3 by screws 5d. The connection terminal 6d is an example of the “second connection terminal” in the present invention.

The lead terminals Td and Te are respectively connected to the diodes D1 and D2 (FIG. 1) of the rectifier circuit 54 through the connection terminals 6d and 6e provided correspondingly and the wiring (not shown) formed on the substrate 3, respectively. It is connected.

  As shown in FIGS. 2, 3, and 6, the heat sink 2 is formed in a rectangular shape when viewed from above. Among the four corners 2a to 2d provided in the heat sink 2, one corner 2d at the lower right in FIG. 2 is provided with L-shaped intermediate portions Tdm and Tem of lead terminals Td and Te of the transformer 1, and leads. A tip end portion Tcf of the terminal Tc is disposed. The main body 1a of the transformer 1 and the lead terminals Ta and Tb are arranged at portions other than the corners 2a to 2d of the heat sink 2.

  When current flows through the coil portions 10 and 20 of the main body 1a of the transformer 1, the coil portions 10 and 20 generate heat. For example, when this heat is transmitted to the core 9, the heat is transmitted from the core 9 to the fixing members 4 a to 4 c and the insulating sheet 8 a and is radiated by the heat sink 2.

  Heat generated in the coil portions 10 and 20 of the main body 1a is easily transmitted to the lead terminals Ta to Te which are conductors. The heat transmitted from the primary coil portion 10 to the lead terminals Ta and Tb is transferred from the intermediate portions Tam and Tbm of each terminal to the insulating sheet 8c and radiated by the heat sink 2. The heat transferred from the secondary coil portion 20 to the lead terminal Tc is radiated by the heat sink 2 through the insulating sheet 8b from the tip portion Tcf of the terminal. The heat transferred from the secondary coil portion 20 to the lead terminals Td and Te is radiated from the heat sink 2 through the insulating sheet 8b from the L-shaped intermediate portions Tdm and Tem of the respective terminals.

  According to the above embodiment, the intermediate portions Tdm, Tem of the lead terminals Td, Te of the transformer 1 are bent in an L shape in a plane parallel to the upper surface 2 u of the heat sink 2. For this reason, the contact area between the intermediate portions Tdm and Tem of the lead terminals Td and Te and the upper surface 2u of the heat sink 2 via the insulating sheet 8b can be increased. Therefore, the heat generated in the transformer 1 can be released from the lead terminals Td and Te to the heat sink 2 via the insulating sheet 8b, and can be easily radiated.

  Further, the lead terminals Td, Te and the heat sink 2 can be insulated by the insulating sheet 8b. Further, the space occupied by the lead terminals Td and Te of the transformer 1 can be reduced, and the arrangement of the transformer 1 on the heat sink 2 can be facilitated.

  Of the lead terminals Ta to Te protruding from the left and right side surfaces 1L and 1r of the main body 1a of the transformer 1, the output lead terminals Td and Te intermediate portions Tdm and Tem protruding from the right side surface 1r are L-shaped in the same direction. Is bent. For this reason, the intermediate portions Tdm and Tem of the lead terminals Td and Te can be easily arranged at the corner 2d of the heat sink 2. Further, the main body 1a of the transformer 1 and the lead terminals Ta and Tb can be easily disposed at a place other than the corners 2a to 2d of the heat sink 2.

  Further, since the transformer 1 is disposed in the vicinity of the corner 2 d of the heat sink 2, the substrate 3 can be disposed in the remaining wide space of the heat sink 2. Then, other electronic components (diodes D1 and D2 of the switching circuit 52 and rectifier circuit 54 in FIG. 1) to which the lead terminals Ta, Tb, Td, and Te are connected can be freely arranged on the substrate 3. it can.

  Further, by disposing the main body 1a of the transformer 1 at a place other than the corners 2a to 2d of the heat sink 2, heat generated in the main body 1a is transferred from the lead terminals Ta to Te to the heat sink 2 via the insulating sheets 8b and 8c. Disperse widely and can dissipate heat evenly.

  In addition, although it is difficult to arrange electronic components at the corners 2a to 2d of the heat sink 2, the corners 2d of the transformer 1 can be arranged at the corner 2d of the heat sink 2 by arranging the intermediate portions Tdm and Tem of the transformer 1 at the corner 2d. 2d can be effectively used as a heat dissipation path.

  Further, the intermediate portion Tem of the lead terminal Te protruding from the low position of the main body 1a of the transformer 1 is bent inside the intermediate portion Tdm of the lead terminal Td protruding from the high position of the main body 1a and bent in an L shape in the same direction. Yes. For this reason, the space occupied by these lead terminals Td and Te can be made smaller, and the arrangement on the heat sink 2 can be facilitated.

In addition, since the shorter lead terminal Te is in contact with the heat sink 2 via the insulating sheet 8b immediately after protruding from the main body 1a, the heat generated in the main body 1a can be quickly dissipated. Further, in the longer lead terminal Td, the length of the intermediate portion Tdm is also long and the contact area with the heat sink 2 via the insulating sheet 8b is large, so that the heat generated in the main body 1a of the transformer 1 is transmitted to the heat sink 2. Heat dissipation can be facilitated.

  In the present invention, various embodiments other than those described above can be adopted. For example, in the above embodiment, although the example using the heat sink 2 was shown as a heat radiator, this invention is not limited only to this. In addition to this, other heat radiators such as an air-cooled or water-cooled radiator, a radiator using a refrigerant, or a metal body having heat dissipation may be used.

  Moreover, although the example which applied this invention to the lead terminals Td and Te for output in the transformer 1 of the switching power supply device 100 for vehicles was given in the above embodiment, other lead terminals Ta, Tb, and Tc were given. In contrast, the present invention can be applied. Further, the present invention can also be applied to the choke coil L (FIG. 1) of the smoothing circuit 55 of the switching power supply apparatus 100. Furthermore, the present invention can also be applied to magnetic devices other than vehicles, for example, used in switching power supply devices for electronic equipment, and other electronic components.

DESCRIPTION OF SYMBOLS 1 Transformer 1a Main body 1L Left side 1r Right side 2 Heat sink 2d Corner 2u Upper surface 3 Substrate
6d, 6e Connection terminal 8b Insulating sheet 20 Secondary coil part Ta, Tb, Td, Te Lead terminal Tdf, Tef Tip part Tdm, Tem Intermediate part Tdr, Ter Root part

Claims (4)

In an electronic component mounting structure in which an electronic component having a lead terminal and a substrate having a connection terminal are arranged on a heat sink,
The electronic component comprises a magnetic device having a coil portion,
The lead terminal comprises a first lead terminal extending from the lower end of the coil portion and a second lead terminal extending from the upper end of the coil portion,
The connection terminal comprises a first connection terminal provided corresponding to the first lead terminal, and a second connection terminal provided corresponding to the second lead terminal,
The root portion of the first lead terminal is located at the same height as the upper surface of the heat radiating body,
The intermediate portion of the first lead terminal extends horizontally from the base portion of the first lead terminal, and is then bent into an L shape in a plane parallel to the upper surface of the heat radiating body to be transmitted to the upper surface of the heat radiating body. Contact through a thermal insulating sheet,
The tip of the first lead terminal is fixed to the first connection terminal,
A root portion of the second lead terminal is located above a root portion of the first lead terminal;
The intermediate portion of the second lead terminal is longer than the intermediate portion of the first lead terminal, extends from the root portion of the second lead terminal to the rear side bent downward, and further, the first lead terminal. Outside of the intermediate portion, is bent in an L shape in the same direction as the first lead terminal in the plane, and is in contact with the upper surface of the radiator via the insulating sheet ,
The electronic component mounting structure , wherein a tip end portion of the second lead terminal is fixed to the second connection terminal . The electronic component mounting structure according to claim 1,
The first lead terminal is shorter than the second lead terminal, and is in contact with the radiator via the insulating sheet immediately after protruding from the main body of the electronic component,
The second lead terminal is longer than the first lead terminal and has an area in contact with the heat radiating body through the insulating sheet, and the first lead terminal is in contact with the heat radiating body through the insulating sheet. A mounting structure of an electronic component characterized by being larger than the area. In the electronic component mounting structure according to claim 1 or 2 ,
The radiator is rectangular,
An electronic component mounting structure, wherein an L-shaped intermediate portion of the first and second lead terminals is disposed at a corner portion of the radiator. In the mounting structure of the electronic component according to any one of claims 1 to 3 ,
The first and second lead terminals protrude from one of the left and right side surfaces of the main body of the electronic component,
An electronic component mounting structure, wherein another lead terminal protrudes from the other of the left and right side surfaces.

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