JP2015082960A - Dc-dc converter device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC-DC converter device capable of inhibiting local temperature rise.SOLUTION: A DC-DC converter device includes: a case; a first substrate housed in the case and including a power circuit; and a coil including a body part and a pair of lead terminals, the coil where the lead terminals are connected with the power circuit. A soaking plate for diffusing heat generated in the coil is connected to a surface of the body part of the coil, which is opposite to a surface facing the first substrate, in a heat conductive manner through a heat transfer sheet.

Description

  The present invention relates to a DC-DC converter device.

  2. Description of the Related Art Conventionally, as a device that performs energization or disconnection of an in-vehicle electrical component, a device in which a circuit structure including a circuit board on which various electronic components are mounted is accommodated in a case is known.

  As such a device, for example, a DC-DC converter device that converts an input DC voltage to a predetermined level of DC voltage and outputs the same is proposed. In such an apparatus, many electronic components mounted on a circuit board are small and have an excellent function. However, since these electronic components generate a relatively large amount of heat, heat generated from the electronic components is contained in the case. If this happens, the inside of the case becomes hot, and the performance of the electronic components housed in the case may be reduced.

  Therefore, various structures for radiating heat generated from circuit boards and electronic components have been proposed. For example, Patent Document 1 discloses a DC-DC converter device having a configuration in which a heat dissipation member is provided on a bus bar mold substrate.

JP 2013-99062 A

  However, as electronic components become smaller and the heat dissipation area becomes smaller, the electronic components themselves tend to be hotter than before, and there is a problem that the temperature locally increases in the apparatus. In particular, among the electronic components, the coil itself can flow a large current because of its high heat resistance. However, when the coil is downsized and locally heated, the surrounding electronic components and circuits are heated thermally. There is a risk of adverse effects. For this reason, after all, there is a problem that a small coil cannot be used for a circuit through which a large current flows.

  The present invention has been completed based on the above situation, and an object of the present invention is to provide a DC-DC converter device capable of suppressing a local temperature rise.

  The DC-DC converter device of the present invention includes a case, a first substrate that is housed in the case and includes a power circuit, a main body portion, and a pair of lead terminals, and the lead terminals are connected to the power circuit. And a soaking plate that dissipates heat generated in the coil is thermally connected to the main body of the coil on the surface opposite to the first substrate. However, it has characteristics.

  According to the above-described present invention, the heat generated from the coil is transferred from the main body portion to the heat equalizing plate and dispersed, so that it is possible to prevent the inside of the DC-DC converter device from being locally heated.

  The present invention may have the following configuration.

  It is good also as a structure which distributes a heat-transfer sheet | seat between a main-body part and a soaking | uniform-heating board. By interposing a soft heat transfer sheet between the main body and the heat equalizing plate, the heat generated from the coil is more easily transferred to the heat equalizing plate, and the heat dispersion effect is improved.

  The soaking plate may be made of aluminum or an aluminum alloy and anodized. The amount of heat released by radiation can be improved by anodizing.

  You may make it provide a reinforcement rib in the edge part of a soaking | uniform-heating board. The shape of the heat equalizing plate is stabilized by the reinforcing rib, and can be arranged in the case with high accuracy and can be reliably brought into contact with the coil.

  It is good also as a structure which arrange | positions a 2nd board | substrate in parallel with a 1st board | substrate on the surface side in which the coil of the 1st board | substrate was provided, and arrange | positions a soaking | uniform-heating board between a coil and a 2nd board | substrate. With such a configuration, it is possible to suppress the temperature of the second substrate from being locally increased due to the heat generated from the coil.

  As a configuration in which a connection through hole is provided in the first substrate, a plurality of bus bars are provided on the surface opposite to the surface on which the coil of the first substrate is provided, and the lead terminal is connected to the bus bar exposed through the connection through hole. Also good. By configuring the power circuit with a plurality of bus bars, a large current can flow through the power circuit.

  It is good also as a structure which provides the through-hole for heat radiation in the area | region of the 1st board | substrate corresponding to the main-body part of a coil. With such a configuration, the heat generated from the coil is transmitted to the region corresponding to the main body portion of the bus bar through the heat radiating through hole, so that the heat can be efficiently radiated by the bus bar.

  Moreover, it is good also as a structure which distributes a heat-transfer sheet | seat between the main-body part of a coil, and the bus bar exposed by the through-hole for heat radiation. With such a configuration, the heat generated from the coil is more easily transmitted to the bus bar, and the heat dissipation effect is improved.

  Furthermore, it is good also as a structure which provides a heat sink on the opposite side to the surface in which the coil of a 1st board | substrate is provided. With such a configuration, a DC-DC converter device having a high heat dissipation effect can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the DC-DC converter apparatus which can suppress a local temperature rise can be obtained.

The exploded perspective view of the DC-DC converter device of one embodiment Plan view of DC-DC converter device Front view of DC-DC converter device Right side view of the DC-DC converter device AA sectional view of FIG. BB sectional view of FIG. Plan view of a state in which the power circuit board is housed in the frame A plan view of a state in which the power circuit board and the heat equalizing plate are accommodated in the frame Plan view of soaking plate Front view of soaking plate Right side view of soaking plate Expanded cross-sectional view of the main part of the connection part between the coil and the heat equalizing plate The top view which shows the positional relationship of a bus-bar and a coil

  A DC-DC converter device 10 according to an embodiment will be described with reference to FIGS. 1 to 13. The device 10 of the present embodiment is a DC-DC converter device 10 mounted on a vehicle (not shown) or the like. In the following description, the upper side in FIG. 3 is the upper side, the lower side is the lower side, the right side is the right, and the left side is the left.

  As shown in FIG. 1, the DC-DC converter device 10 of the present embodiment includes a circuit configuration body 30 including a power circuit board 31 and a control circuit board 35, a heat equalizing plate 36, and heat generated in the circuit configuration body 30. A heat sink 40 for radiating heat, a shield cover 45, and a case 11 for housing them.

(Case 11)
The case 11 is made of a synthetic resin or the like, and includes an upper cover 12, a frame 20, and an under cover 25 as shown in FIG.

  The frame 20 is a frame having a substantially rectangular shape, and is formed in a size that can accommodate the circuit component 30 (see FIG. 7). Further, on the left side in FIG. 2, a support wall 21 having a substantially U-shaped cross section for supporting the three external connection terminals 33 </ b> F led out from the circuit structure 30 from the lower side is extended.

  The upper cover 12 has a shallow dish shape that is assembled so as to cover the upper portion of the frame 20. More specifically, the upper cover 12 includes a rectangular top plate portion 13 and four side wall portions 14 extending downward from four sides of the top plate portion 13. An insertion hole 16 for inserting a breathable waterproof valve 15 capable of adjusting the internal pressure of the case is provided at the center of the top plate portion 13. Further, from all the side wall portions 14, locking pieces 17 that are locked to locking protrusions 22 provided on the outer peripheral wall of the frame 20 are extended downward two by two.

  The under cover 25 is a plate-like member, and two opposing sides on the short side of the rectangular bottom wall portion 26 are vertically bent upward to form a vertical portion 27. These vertical portions 27 are screwed to side surfaces 42 of a heat sink 40 described later. The bottom wall portion 26 is provided with a plurality of recesses 28 intermittently along the long side direction. The under cover 25 functions as a rectifying plate for air flowing between the fins 41 of the heat sink 40 described later.

(Circuit structure 30)
The circuit configuration body 30 includes a plurality of power circuit boards 31 (an example of a first board), a control circuit board 35 (an example of a second board), and a plurality of circuits that are mounted on the surface side of the power circuit board 31 (upper side in FIG. 1). The electronic component 32 and a plurality of bus bars 33 (an example of a power circuit) arranged and bonded to the back surface side (lower side in FIG. 1) of the power circuit board 31 are provided.

  The power circuit board 31 has a rectangular shape that can be accommodated in the frame 20. A conductive path (not shown) is formed on the front surface by a printed wiring technique, and a plurality of bus bars 33 are arranged in a predetermined pattern on the back surface. Measured and bonded (see FIG. 13). Further, as shown in FIG. 7, a plurality of through holes 34 (an example of connection through holes and heat dissipation through holes) are provided at appropriate positions on the power circuit board 31. These through holes 34 are for mounting the electronic component 32 on the bus bar 33, and the electronic component 32 is connected to the surface of the bus bar 33 exposed from the through hole 34 by a known method such as soldering. Yes.

  The control circuit board 35 is a plate-like member having a substantially L shape as shown in FIG. 1, is arranged substantially in parallel with the power circuit board 31, and is connected to the power circuit board 31 by the relay terminal 43. .

  The circuit configuration body 30 of the present embodiment is a DC-DC converter. The DC-DC converter is a circuit that converts a direct-current voltage into a different direct-current voltage, and is provided to supply power to various vehicle loads in, for example, environment-friendly vehicles such as HEV vehicles and EV vehicles.

  A well-known circuit configuration can be used for the DC-DC converter, and the electronic component 32 configuring the DC-DC converter includes, for example, a switching element such as a resistor, a coil 320, a capacitor, and a MOSFET. Each of these electronic components 32 is a surface mount type, and is connected to the bus bar 33 exposed in the through hole 34 of the power circuit board 31 by a method such as soldering as described above.

(Soaking plate 36)
In a partial region between the power circuit board 31 and the control circuit board 35, a heat equalizing plate 36 is disposed in parallel with the power circuit board 31 and the control circuit board 35. The soaking plate 36 is made of, for example, aluminum or aluminum alloy having excellent thermal conductivity, and an alumite treatment is applied to the surface thereof.

  As shown in FIGS. 9 to 11, the heat equalizing plate 36 is a substantially rectangular flat plate-like member, and the reinforcing rib 36A is perpendicular to the plate surface in a partial region along the lower left corner of FIG. Standing up and formed. Further, one end side of the reinforcing rib 36A is bent to form a protruding portion 36D protruding in the lateral direction (lower side in FIG. 9) from the plate surface.

  A fixing hole 36B for fixing is provided at a position corresponding to a hole provided in the frame 20 and the heat sink 40 in the edge portion of the heat equalizing plate 36, and is fixed to the frame 20 or the heat sink 40 by screwing. It is fixed (see FIG. 8). One of the plurality of fixing holes 36B is provided in a fixing piece 36C extending in the horizontal direction from the edge of the protrusion 36D of the reinforcing rib 36A, and is set to be fixed to the frame 20. ing. The fixed piece 36C is flush with the plate surface of the heat equalizing plate 36.

  The heat equalizing plate 36 prevents the circuit component 30 from becoming locally hot due to the heat generated from the electronic component 32 mounted on the power circuit board 31.

(Heat sink 40)
A heat sink 40 is disposed below the circuit structure 30. The heat sink 40 is also a heat radiating member made of a metal material having excellent thermal conductivity such as aluminum or aluminum alloy, and has a function of radiating heat generated in the circuit component 30. The upper surface of the heat sink 40 has a flat plate shape, and a plurality of fins 41 extending downward are formed on the lower surface. Further, the opposing side surface 42 on the short side is plate-like and is integrated with the vertical portion 27 of the under cover 25 by screws (not shown).

  Note that the lower surface of the circuit component 30 (the lower surface of the bus bar 33) and the upper surface of the heat sink 40 are bonded to each other by an insulating heat conductive adhesive 38 (see FIG. 12).

(Shield cover 45)
The upper side of the circuit structure 30 is covered with a shield cover 45. The shield cover 45 is made of, for example, galvanized steel (made of metal), and is formed in a substantially rectangular shallow dish shape that is slightly smaller than the upper cover 12. A concave portion 47 is formed in the central portion of the top plate portion 46 so as not to interfere with the breathable waterproof valve 15 attached to the upper cover 12 so that the unit is lowered. Further, three of the four side wall portions 48 are provided with a fixed piece 49 having an L-shaped cross section facing downward, and the tip 49A is fixed to the vicinity of the edge of the heat sink 40 by screwing. Yes.

  In the present embodiment, among the electronic components 32 mounted on the power circuit board 31, the heat equalizing plate 36 is set so as to be in heat transfer contact with the upper surface of the coil 320. The coil 320 of the present embodiment is a surface mount type coil (SMD coil), and has a rectangular parallelepiped main body 321 whose upper surface is flat, and the edges of two opposing sides of the bottom surface of the main body 321. A pair of lead terminals 322 are exposed in the periphery of the part (see FIG. 12).

  As described above, a through hole 34 for mounting the electronic component 32 on the bus bar 33 is provided at a position where the electronic component 32 is mounted on the power circuit board 31. Of these through holes 34, the coil through hole 34A (an example of the connection through hole and the heat radiating through hole) where the coil 320 is mounted is longer than the main body 321 of the coil 320 as shown in FIG. The bus bar 33 is exposed from the coil through hole 34A.

  As shown in FIG. 8, the heat equalizing plate 36 in the present embodiment is about half the area of the power circuit board 31, and is a position covering the three coils 320 mounted on the power circuit board 31, that is, It is arranged on the right side in FIG. The heat equalizing plate 36 is screwed to the frame 20 or the heat sink 40 by inserting a screw through a fixing hole 36B provided at the edge thereof.

  As shown in FIG. 12, an insulating heat transfer sheet 39 is disposed between the main body 321 of the coil 320 and the soaking plate 36. That is, the main body portion 321 of the coil 320 and the heat equalizing plate 36 are in close contact via the soft heat transfer sheet 39 and are in a heat transfer connection state. Further, an insulating heat transfer sheet 37 is also disposed between the main body 321 of the coil 320 and the bus bar 33 facing the body 321, and is in a heat transfer connection state.

(Operation and effect of this embodiment)
According to the circuit configuration body 30 of the present embodiment, the heat generated in the coil 320 can be quickly transferred to the heat equalizing plate 36 disposed on the upper surface of the main body 321 of the coil 320 via the heat transfer sheet 39 and can be dispersed. Therefore, the peak temperature due to the heat generated by the coil 320 can be lowered, and the circuit structure 30 can be prevented from becoming locally hot.

  Moreover, since the soaking plate 36 is anodized, it has excellent heat dissipation due to radiation and high soaking capability.

  In addition, the heat equalizing plate 36 is provided with the reinforcing ribs 36A and the fixing holes 36B are provided in the fixing pieces 36C provided in the protrusions 36D of the reinforcing ribs 36A. The heat sink 40 can be fixed. That is, the heat equalizing plate 36 can be reliably connected to the coil 320 in a heat transfer manner.

  In addition, since the soaking plate 36 is disposed between the coil 320 and the control circuit board 35, the control circuit board 35 can be prevented from being locally heated by the heat generated from the coil 320. .

  Further, a through hole 34A is provided at a position facing the main body 321 in the power circuit board 31, and a heat transfer sheet 37 is disposed between the main body 321 and the bus bar 33 exposed from the through hole 34A. Therefore, heat can be efficiently radiated from the lower side of the main body 321 using the bus bar 33.

  Moreover, since the heat sink 40 is provided on the lower side of the power circuit board 31 (bus bar 33), the heat in the case 11 can be radiated.

  According to such a DC-DC converter device 10 of the present embodiment, the peak temperature due to the heat generation of the coil 320 can be lowered, and the local temperature rise can be suppressed.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  (1) In the above embodiment, the heat transfer sheet 39 is disposed between the main body portion 321 of the coil 320 and the heat equalizing plate 36. For example, as a structure in which rubber, an adhesive, an adhesive, or the like is disposed. Also good.

  (2) The soaking plate 36 may be disposed so as to have a gap between the coil 320 and the coil 320.

  (3) In the above embodiment, the lead terminal 322 is connected to the bus bar 33 exposed by the through hole 34A provided in the power circuit board 31, and the heat generated from the coil 320 is generated by arranging the heat transfer sheet 37. However, the connecting through hole and the heat radiating through hole may be provided separately. Alternatively, the through holes for heat dissipation may be omitted.

  (4) The heat transfer sheet 39 between the main body 321 of the coil 320 and the heat equalizing plate 36 is not necessarily provided. Further, the heat transfer sheet 37 between the main body 321 of the coil 320 and the bus bar 33 is not necessarily provided.

  (5) In the above embodiment, the embedded coil 320 that exposes the lead terminal 322 of the coil 320 on the lower surface of the main body 321 is used, but the L-shaped lead terminal 322 is protruded from the lower surface of the main body 321. A coil can also be used.

  (6) In the above embodiment, the configuration in which the coil 320 is mounted on the bus bar 33 (power circuit) provided on the opposite surface of the power circuit board 31 has been described. However, the power provided on the same surface side as the coil 320 is illustrated. The present invention can also be applied to a configuration mounted on a circuit.

  (7) The constituent material of the soaking plate 36 is not limited to aluminum or aluminum alloy. Further, the alumite treatment is not necessarily performed.

  (8) In the soaking plate 36, the reinforcing rib 36A is not necessarily provided.

  (9) The heat sink 40 is not necessarily provided.

DESCRIPTION OF SYMBOLS 10 ... DC-DC converter apparatus 11 ... Case 12 ... Upper case 20 ... Frame 25 ... Under case 30 ... Circuit structure 31 ... Power circuit board (1st board)
32 ... Electronic components 33 ... Bus bar (power circuit)
34 ... through hole (through hole for connection and through hole for heat dissipation)
35 ... Control circuit board (second board)
36 ... Soaking plate 39 ... Heat transfer sheet 40 ... Heat sink (heat sink)
45 ... Shield 320 ... Coil 321 ... Main body 322 ... Lead terminal

Claims (9)

Case and
A first substrate housed in the case and provided with a power circuit;
A main body part and a pair of lead terminals, the lead terminal comprising a coil connected to the power circuit,
A DC-DC converter characterized in that a heat equalizing plate that dissipates heat generated in the coil is connected to the main body of the coil on a surface opposite to the first substrate in a heat transfer manner. apparatus. The DC-DC converter device according to claim 1, wherein a heat transfer sheet is disposed between the main body portion and the heat equalizing plate. 3. The DC-DC converter device according to claim 1, wherein the soaking plate is made of aluminum or an aluminum alloy, and is subjected to alumite treatment. 4. The DC-DC converter device according to any one of claims 1 to 3, wherein a reinforcing rib is provided at an edge portion of the soaking plate. A second substrate is disposed in parallel to the first substrate on the surface side of the first substrate on which the coil is provided, and the soaking plate is disposed between the coil and the second substrate. 5. The DC-DC converter device according to claim 1, wherein the DC-DC converter device is provided. The first substrate has a through-hole for connection;
A plurality of bus bars are provided on the surface of the first substrate opposite to the surface on which the coil is provided,
The DC-DC converter device according to any one of claims 1 to 5, wherein the lead terminal is connected to the bus bar exposed through the connection through hole. The DC-DC converter device according to claim 6, wherein a heat radiating through hole is provided in a region of the first substrate corresponding to the main body portion of the coil. The DC-DC converter device according to claim 7, wherein a heat transfer sheet is disposed between the main body portion of the coil and the bus bar exposed by the heat radiating through hole. The DC-DC converter device according to any one of claims 1 to 8, wherein a heat radiating plate is provided on a side opposite to a surface of the first substrate on which the coil is provided.

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