JP6436052B2 - Insulated power converter - Google Patents

Description

  The present invention relates to an insulated power converter.

  Various electronic components constituting the insulated power converter are mounted on a common substrate (for example, Patent Document 1).

JP-A-3-135370

  Use of the same conductive material pattern on the primary side and the secondary side of the transformer leads to an increase in size. That is, in Patent Document 1, the voltage on the primary side of the transformer is different from the voltage on the secondary side, but the primary side pattern of the transformer and the secondary side pattern of the transformer are configured on the basis of the lower voltage. Yes. Therefore, a thick conductive material is used not only in a portion having a large current capacity but also in a portion having a small current capacity, resulting in an increase in size.

  The objective of this invention is providing the power converter device which can suppress an enlargement.

  In the first aspect of the present invention, the substrate, the input terminal provided on the substrate, the output terminal provided on the substrate, and the number of turns of the primary side winding and the primary side winding are different. A transformer provided on the substrate; a first pattern provided between the input terminal and the primary winding; and the output terminal and the secondary winding. An insulation type power conversion device having a second pattern provided between the first side of the transformer and the secondary side of the transformer, the one of the patterns on the lower voltage side. The part is made of a metal plate, the other part of the pattern is made of a metal foil having a smaller cross-sectional area than the metal plate, and the metal plate is mounted with solder on the pattern of the substrate. The gist.

  According to the first aspect of the present invention, a part of the pattern on the lower voltage side of the primary side of the transformer and the secondary side of the transformer is constituted by the metal plate, and the metal plate is mounted on the substrate. . Moreover, the other part of the pattern is comprised with the metal foil whose cross-sectional area is smaller than a metal plate. Therefore, compared to the case where the transformer primary side pattern and the transformer secondary side pattern are configured on the basis of the lower voltage and a metal plate is also used in a portion with a small current capacity, in the present invention, the transformer Since a part of the pattern on the lower side of the primary side and the secondary side of the transformer is made of a metal plate and the other part is made of a metal foil, an increase in size can be suppressed.

  As described in claim 2, in the insulated power converter according to claim 1, the primary side winding is mounted on the substrate by solder, and the secondary side winding is soldered on the substrate. It is preferable that a metal plate constituting the winding is mounted around a through hole that is mounted and through which the core of the transformer is inserted.

  According to the present invention, an increase in size can be suppressed.

The top view which shows the insulation type DC-DC converter in embodiment. The perspective view of an insulation type DC-DC converter. The circuit diagram which shows the electrical constitution of an insulation type DC-DC converter. The exploded perspective view of an insulation type DC-DC converter. The perspective view of an insulation type DC-DC converter. The perspective view of an insulation type DC-DC converter. The perspective view of an insulation type DC-DC converter. The perspective view of an insulation type DC-DC converter. The top view of a board | substrate. The bottom view of a board | substrate. The partial cross section figure of a board | substrate. (A), (b) is a partial cross section figure of an insulation type DC-DC converter. (A) is a top view which shows a trans | transformer part, (b) is sectional drawing in the AA of (a). (A) is a top view which shows a trans | transformer part, (b) is sectional drawing in the AA of (a).

Hereinafter, an embodiment embodied in an insulated DC-DC converter will be described with reference to the drawings.
As shown in FIG. 3, an insulated DC-DC converter 10 as an insulated power converter is a forward DC-DC converter, and includes a transformer 11. The transformer 11 includes a primary winding 11a and a secondary winding 11b. The insulated DC-DC converter 10 is for an automobile and is mounted on a vehicle. The insulated DC-DC converter 10 steps down the input voltage on the primary side of the transformer 11 and outputs it to the secondary side of the transformer 11. For example, input 300 volts, step down to 12 volts and output. The transformer 11 provided on the substrate 40 to be described later includes a primary side winding and a secondary side winding having a number of turns different from the number of turns of the primary side winding.

  15A flows as the primary current I1 in the primary winding 11a of the transformer 11, and 80A flows as the secondary current I2 in the secondary winding 11b. That is, when the voltage on the primary side of the transformer 11 is larger than the voltage on the secondary side of the transformer 11, the current flowing on the secondary side of the transformer 11 is larger than the current flowing on the primary side of the transformer 11.

  One terminal of the primary winding 11 a is connected to the input terminal, and the input terminal is connected to the positive terminal of the battery 12. The other terminal of the primary winding 11 a is grounded via the primary side switching element 14. A power MOSFET is used as the primary side switching element 14.

  A positive electrode of the smoothing capacitor 13 is connected between the input terminal and the primary winding 11a of the transformer 11, and a negative electrode of the smoothing capacitor 13 is grounded. An electrolytic capacitor is used as the smoothing capacitor 13. The primary side voltage of the transformer 11 is smoothed by the smoothing capacitor 13.

  A rectifier circuit composed of diodes 16 and 17 is connected to the secondary winding 11 b of the transformer 11. The diode 16 has an anode connected to the ground on the secondary side of the transformer 11 and a cathode connected to one end of the secondary winding 11 b of the transformer 11. The diode 17 has an anode connected to the anode of the diode 16 and a cathode connected to the other end of the secondary winding 11 b of the transformer 11.

  Further, a capacitor 19 is connected to the diode 17 in parallel. Coils 18 a and 18 b connected in series are provided between the secondary winding 11 b of the transformer 11 and the capacitor 19. A capacitor 21 is connected to the capacitor 19 in parallel. A coil 20 is provided between the capacitor 19 and the capacitor 21.

  A control IC 15 is connected to the gate terminal of the primary side switching element 14. A pulse signal is output from the control IC 15 to the gate terminal of the primary side switching element 14, and the primary side switching element 14 is switched by this pulse signal. When the primary side switching element 14 is on, energy is supplied from the primary side power source to the secondary side. When the primary side switching element 14 is off, the energy stored in the coils 18a, 18b, 20 is released to the output. Specifically, a DC voltage is supplied to the primary winding 11 a of the transformer 11 through the smoothing capacitor 13, and the primary side switching element 14 is on / off controlled by the control IC 15, and the primary side switching element 14 in this on / off operation is controlled. During the ON period, a primary current flows through the primary winding 11a, and a secondary current flows due to the electromotive force of the transformer 11. When the primary side switching element 14 is off, the current of the coils 18a, 18b, 20 flows to the output via the diode D17 by the counter electromotive force of the coils 18a, 18b, 20.

  A detection circuit 22 is connected to the control IC 15, and the output voltage Vout is detected by the detection circuit 22. The measurement result of the output voltage Vout by the detection circuit 22 is sent to the control IC 15. The control IC 15 controls the duty of the primary side switching element 14 so that the output voltage Vout becomes a desired constant value using the measurement result of the output voltage Vout by the detection circuit 22 as a feedback signal.

As described above, the primary side switching element 14 and the rectifier elements (diodes 16 and 17) generate heat due to the switching loss and conduction loss as the isolated DC-DC converter 10 is driven.
Hereinafter, a specific structure will be described.

FIG. 1 is a plan view of the insulated DC-DC converter 10, FIG. 2 is a perspective view of the insulated DC-DC converter 10, and FIG. 4 is an exploded perspective view of the insulated DC-DC converter 10.
As shown in FIG. 4, the insulated DC-DC converter 10 includes an aluminum case 30 as a heat dissipation member, a substrate 40, a pair of upper and lower cores 60, a pair of upper and lower cores 70, a pair of upper and lower cores 80, Is provided. The substrate 40 is provided with input terminals 100 and 101 and an output terminal 102. The insulated DC-DC converter 10 includes a first pattern provided between the input terminals 100 and 101 and the primary winding of the transformer, and an output terminal 102 and the secondary winding of the transformer. And a second pattern provided. As shown in FIG. 11, the substrate 40 has a patterned metal foil 121 formed on the upper surface of the insulating core member 120 and a patterned metal foil 122 formed on the lower surface of the core member 120. ing.

  As shown in FIG. 4, the core 60 includes a lower core 61 and an upper core 62. The lower core 61 is an I-type core, and the lower core 61 has a plate shape extending in the horizontal direction. The upper core 62 is an E-shaped core, and the upper core 62 has a rectangular plate shape, and protrudes from a central portion of a main body portion 62a extending in the horizontal direction and one surface (lower surface) of the main body portion 62a. The center magnetic leg 62b and the both side magnetic legs 62c and 62d projecting from the end of one surface (lower surface) of the main body 62a. The central magnetic leg 62b has a cylindrical shape.

  Similarly, the core 70 includes a lower core 71 and an upper core 72. The lower core 71 is an I-type core, and the lower core 71 has a plate shape extending in the horizontal direction. The upper core 72 is an E-type core, and the upper core 72 has a rectangular plate shape, and protrudes from a central portion of a main body portion 72a extending in the horizontal direction and one surface (lower surface) of the main body portion 72a. It consists of a central magnetic leg 72b and both side magnetic legs 72c and 72d protruding from the end of one surface (lower surface) of the main body 72a. The central magnetic leg 72b and the both-side magnetic legs 72c and 72d have a prismatic shape.

  The core 80 includes a lower core 81 and an upper core 82. The lower core 81 is an I-type core, and the lower core 81 has a plate shape extending in the horizontal direction. The upper core 82 is a U-shaped core. The upper core 82 has a rectangular plate shape, and protrudes from a main body 82a extending in the horizontal direction and an end of one surface (lower surface) of the main body 82a. It consists of both-side magnetic legs 82b and 82c. Both side magnetic legs 82b and 82c have a prismatic shape.

  The lower cores 61, 71, 81 are disposed on the aluminum case 30, the substrate 40 is disposed thereon, and the upper cores 62, 72, 82 are disposed thereon. Here, the upper surface of the lower core 61 and the central magnetic leg 62b of the upper core 62 are butted together, and the upper surface of the lower core 61 and both side magnetic legs 62c and 62d of the upper core 62 are butted. Similarly, the upper surface of the lower core 71 and the central magnetic leg 72b of the upper core 72 are abutted, and the upper surface of the lower core 71 and both side magnetic legs 72c and 72d of the upper core 72 are abutted. Further, the upper surface of the lower core 81 and both side magnetic legs 82b and 82c of the upper core 82 are brought into contact with each other.

  As shown in FIG. 8, an aluminum case 30 as a heat radiating base member has a square plate-like main body 31, and on its upper surface, protrusions 32a, 32b, 32c, 32d for positioning the core 60 are provided. And the protrusions 32e, 32f, 32g, and 32h for positioning the cores 70 and 80 are formed. Then, the lower core 61 is positioned on the aluminum case 30 as shown in FIG. 7 by the protrusions 32a, 32b, 32c, and 32d. Further, the lower core 71 and the lower core 81 are positioned on the aluminum case 30 as shown in FIG. 7 by the protrusions 32e, 32f, 32g, and 32h in FIG.

  Further, as shown in FIG. 8, on the upper surface of the main body 31 of the aluminum case 30, projections 33a, 33b, 33c for mounting power elements are formed. The upper surfaces of the protrusions 33a, 33b, and 33c are flattened. As shown in FIG. 6, a power element 37 is disposed on the upper surface of the protrusion 33a via a metal plate 56 (see FIG. 12) as shown in FIG. The power element 37 corresponds to the diodes 16 and 17 in FIG. As shown in FIG. 6, the power element 38 is disposed on the upper surface of the protrusion 33 b of FIG. 8 via a metal plate 57 (see FIG. 12), as shown in FIG. 6, via a heat radiation sheet 36 b (see FIG. 7). The power element 38 corresponds to the primary side switching element 14 of FIG. As shown in FIG. 6, a power element 39 on the substrate 40 is disposed on the upper surface of the protrusion 33c of FIG. 8 via a heat dissipation sheet 36c (see FIG. 7).

  As shown in FIG. 8, a plurality of substrate mounting protrusions 34 are provided on the upper surface of the main body 31 of the aluminum case 30. Then, the substrate 40 is placed on each substrate placement protrusion 34 as shown in FIG. As shown in FIGS. 2 and 4, the board 40 is fixed to the aluminum case 30 by screwing the screws Sc <b> 4 into the board mounting protrusions 34.

As shown in FIG. 8, screw fastening protrusions 35 a and 35 b are formed on both ends of the protrusion 33 a on the upper surface of the main body 31 of the aluminum case 30.
As shown in FIG. 8, bracket fastening protrusions 35 c, 35 d, and 35 e are formed on the upper surface of the body portion 31 of the aluminum case 30.

  As shown in FIGS. 2 and 4, the core 60 is provided with a bracket 90 that is a metal presser plate on the upper surface, and a screw Sc1 that penetrates one end of the bracket 90 is screwed into the bracket fastening projection 35 c of the aluminum case 30. As a result, the core 60 is pressed and supported by the aluminum case 30 by the other end of the bracket 90.

  Similarly, a bracket 91 which is a metal presser plate is disposed on the upper surface of the core 70, and a screw Sc2 penetrating one end of the bracket 91 is screwed into the bracket fastening protrusion 35 d of the aluminum case 30, so that The core 70 is pressed and supported by the aluminum case 30 by the end side.

  The core 80 is provided with a bracket 92 which is a metal presser plate on the upper surface, and the other end of the bracket 92 is screwed into the bracket fastening protrusion 35e of the aluminum case 30 by screwing a screw Sc3 penetrating one end of the bracket 92. The core 80 is pressed and supported by the aluminum case 30 by the side.

FIG. 9 shows the upper surface of the substrate 40 and FIG. 10 shows the lower surface of the substrate 40.
As shown in FIG. 9, a winding portion 41 as a primary pattern of the transformer 11 is mounted on the upper surface of the substrate 40. That is, the primary winding 11a of FIG. The winding part 41 is formed by forming a metal wire having a circular cross section into a spiral shape. The surface of the wire is covered with a resin insulating material. Both ends of the winding portion 41 constituting the primary winding penetrate the substrate 40 and extend to the lower surface of the substrate 40. A circular through hole 42 is formed at the center of the winding portion 41 in the portion where the winding portion 41 is disposed on the substrate 40. That is, the winding part 41 is extended (mounted) around the through hole 42. In addition, a through hole 43 and a notch 44 are formed on both sides of the winding part 41 in the arrangement part of the winding part 41 in the substrate 40. The central magnetic leg 62b of the upper core (E-type core) 62 of the core 60 is inserted into the through hole 42. Further, both side magnetic legs 62 c and 62 d of the upper core 62 are inserted into the through hole 43 and the notch 44.

  As shown in FIG. 10, a first metal plate 45 as a pattern on the secondary side of the transformer is mounted on the lower surface of the substrate 40. That is, the secondary winding 11b of FIG. 3 is configured by the pattern of the first metal plate 45. The first metal plate 45 is a copper plate formed into a “Ω” shape by press working. One end and the other end of the first metal plate 45 penetrate the substrate 40 and extend to the upper surface of the substrate 40. The first metal plate 45 extends around the through hole 42. That is, the first metal plate 45 is extended (mounted) around the through hole 42.

  As shown in FIG. 9, on the upper surface of the substrate 40, the second metal plate 46 constituting the conductor portion of the coil 18a is mounted. That is, the coil 18a of FIG. 3 is configured by the pattern of the second metal plate 46. The second metal plate 46 is a copper plate formed into a quadrangular ring shape by pressing. One end and the other end of the second metal plate 46 penetrate the substrate 40 and extend to the lower surface of the substrate 40. A rectangular through-hole 47 is formed at the center of the substrate 40 where the second metal plate 46 is disposed. In addition, rectangular through holes 48 and 49 are formed on both sides of the substrate 40 where the second metal plate 46 is disposed. The central magnetic leg 72b of the upper core (E-type core) 72 of the core 70 is inserted into the through hole 47. In addition, both side magnetic legs 72c and 72d of the upper core 72 are inserted into the through holes 48 and 49.

  As shown in FIG. 10, a third metal plate 50 that constitutes the conductor portions of the coils 18 b and 20 is mounted on the lower surface of the substrate 40. That is, the coils 18b and 20 in FIG. 3 are constituted by the pattern of the third metal plate 50. The third metal plate 50 is a copper plate formed into a desired shape by pressing. Ends C, D, and E of the third metal plate 50 penetrate the substrate 40 and extend to the upper surface of the substrate 40. The third metal plate 50 extends around the through hole 47 and between the through holes 52 and 53 described later.

10, the coil 18a of FIG. 3 is connected to the end C, the capacitor 19 of FIG. 3 is connected to the end D of FIG. 10, and the capacitor 21 of FIG. 3 is connected to the end E of FIG.
As shown in FIG. 10, a control IC 51 as a control element is mounted on the substrate 40 on the lower surface of the substrate 40. The control IC 51 has a resin portion 51a, and a lead 51b is projected from the side surface.

  9 and 10, rectangular through holes 52 and 53 are formed in the substrate 40. A third metal plate 50 extends between the through holes 52 and 53 in the substrate 40. Both side magnetic legs 82 b and 82 c of the upper core (U-shaped core) 82 of the core 80 are inserted into the through holes 52 and 53.

  As shown in FIGS. 9 and 10, a rectangular through hole 54 is formed in the substrate 40. As shown in FIG. 12A, a strip-shaped fourth metal plate 56 is mounted at the formation position of the through hole 54 on the lower surface of the substrate 40 so as to overlap the opening of the through hole 54. Specifically, both ends of the fourth metal plate 56 are fixed to the lower surface of the substrate 40 by soldering. The fourth metal plate 56 is made of a copper plate. A convex portion 56 a is formed on the fourth metal plate 56, and the convex portion 56 a is disposed in the through hole 54. That is, the fourth metal plate 56 is bent at the through hole 54, extends from the lower surface opening to the upper surface opening, and is flush with the upper surface of the substrate at the upper surface opening. A power element (secondary diode of the transformer) 37 is bonded (mounted) to the substrate 40 at the same level. The power element 37 has a resin portion 37a, a lower surface electrode 37b is formed on the lower surface, and leads 37c as electrodes protrude from the side surface as shown in FIG. The lower surface electrode 37 b of the power element 37 is joined (mounted) to the fourth metal plate 56. Leads 37 c of the power element 37 are bonded (mounted) to the metal foil 121 a on the upper surface of the substrate 40 on the upper surface of the substrate 40.

The fourth metal plate 56 forms a line connecting the common anode of the two diodes 16 and 17 of FIG. 3 and the ground.
By making the upper surface of the convex portion 56a of the fourth metal plate 56 and the upper surface of the substrate 40 flush with each other, the metal foil 121a on the upper surface of the substrate 40 and the lead 37c of the power element (diodes 16 and 17 on the secondary side of the transformer). It is easy to connect with.

Similarly, as shown in FIGS. 9 and 10, a rectangular through hole 55 is formed in the substrate 40. And it is the heat dissipation structure of the power element similar to what was demonstrated using FIG.
That is, as shown in FIG. 12A, a band-shaped fifth metal plate 57 is mounted on the bottom surface of the substrate 40 so as to overlap the opening of the through hole 55. . Specifically, both ends of the fifth metal plate 57 are fixed to the lower surface of the substrate 40 by soldering. The fifth metal plate 57 is made of a copper plate. A convex portion 57 a is formed on the fifth metal plate 57, and the convex portion 57 a is disposed in the through hole 55. That is, the fifth metal plate 57 is bent at the through hole 55, extends from the lower surface opening to the upper surface opening, and is flush with the upper surface of the substrate at the upper surface opening. A power element (power MOSFET) 38 is bonded (mounted) to the substrate 40 at the same level.

  As shown in FIG. 12 (a), the power element 38 has a resin portion 38a, a lower surface electrode 38b is formed on the lower surface, and a lead 38c as an electrode from the side surface as shown in FIG. 12 (b). Projected. The lower electrode 38 b of the power element 38 is joined (mounted) to the fifth metal plate 57. On the upper surface of the substrate 40, the lead 38c of the power element 38 is joined (mounted) to the metal foil 121a on the upper surface of the substrate 40.

  As shown in FIGS. 12A and 12B, the protrusion 33 a formed on the upper surface of the main body 31 of the aluminum case 30 extends toward the through hole 54 of the substrate 40. A heat radiating sheet 36 a is interposed between the flat upper surface of the protrusion 33 a and the fourth metal plate 56. Thereby, the 4th metal plate 56 and the aluminum case 30 are thermally connected. That is, the power element 37 is thermally coupled to the aluminum case 30 via the fourth metal plate 56 and the heat dissipation sheet 36a. As a result, heat generated in the power element 37 is radiated to the aluminum case 30 via the fourth metal plate 56 and the heat radiating sheet 36a. At this time, the heat generated in the power element 37 is easily released without passing through the resin. Further, when a diode is disposed on the lower surface of the substrate 40, heat is radiated through the mold resin, and the heat dissipation is poor, but in this embodiment, the power element (diode) 37 is excellent in heat dissipation.

  Similarly, the protrusion 33 b formed on the upper surface of the main body 31 of the aluminum case 30 extends toward the through hole 55 of the substrate 40. A heat dissipation sheet 36b is interposed between the flat upper surface of the protrusion 33b and the fifth metal plate 57. Thereby, the 5th metal plate 57 and the aluminum case 30 are thermally connected. That is, the power element 38 is thermally coupled to the aluminum case 30 via the fifth metal plate 57 and the heat dissipation sheet 36b. As a result, the heat generated in the power element 38 is radiated to the aluminum case 30 via the fifth metal plate 57 and the heat radiating sheet 36b. Therefore, the heat dissipation of the power element 38 is excellent.

  In the present embodiment, a part of the pattern on the secondary side having the lower voltage among the primary side of the transformer 11 and the secondary side of the transformer 11 is configured by the metal plates 45, 46, and 50. The other part of the pattern is made up of metal foils 121 and 122 having a smaller cross-sectional area than the metal plates 45, 46 and 50. Specifically, the portion through which a large current flows is mainly composed of metal plates (45, 46, 50), and the portion through which a large current does not flow is mainly composed of metal foils (121, 122). Thus, the metal plates 45, 46, and 50, which are thick copper plates, are used only at necessary portions, and the size is reduced.

  As described above, the insulated DC-DC converter 10 is provided between the substrate 40, the input terminals 100 and 101, the output terminal 102, the transformer 11, the input terminals 100 and 101, and the primary winding. A pattern having a first pattern and a second pattern provided between the output terminal 102 and the secondary winding. A part of the pattern on the lower side of the primary side of the transformer 11 and the secondary side of the transformer 11 is constituted by the metal plates 46 and 50, and the other part of the pattern has a smaller sectional area than the metal plates 46 and 50. It consists of metal foils 121 and 122, and the metal plates 46 and 50 are mounted on the pattern of the substrate 40 with solder. The primary side winding (winding portion 41) is mounted on one surface of the substrate 40 with solder, and the secondary side winding (metal plate 45) is mounted on the other surface of the substrate 40 with solder, A metal plate 45 constituting the secondary winding is mounted around the through hole 42 through which the core 60 of the transformer is inserted.

Next, the assembly process will be described.
An aluminum case 30 is prepared as shown in FIG. Then, as shown in FIG. 7, the lower cores 61, 71, 81 are fitted into the aluminum case 30. Moreover, heat dissipation sheets 36a, 36b, and 36c are mounted.

  Further, as shown in FIG. 6, a substrate 40 is mounted on the aluminum case 30. Then, as shown in FIG. 5, the upper cores 62, 72, and 82 are mounted. Then, the screw Sc4 passes through the substrate 40 and is screwed into the aluminum case 30 to fix the substrate 40 to the aluminum case 30.

  Further, brackets 90, 91, 92, which are metal pressing plates, are arranged on the upper cores 62, 72, 82, and screws Sc1, Sc2, Sc3 are screwed into the aluminum case 30, and the cores are formed by the brackets 90, 91, 92. Hold 60, 70, 80 and fix.

Next, the operation will be described.
1, 2, and 4, the winding portion 41 that constitutes the primary winding of the transformer and the first that constitutes the secondary winding in accordance with the switching operation of the power element 38 (corresponding to the primary side switching element 14 in FIG. 3). A current flows through the metal plate 45. Heat generated in the power element 37 (corresponding to the diodes 16 and 17) and the power element 38 (corresponding to the primary side switching element 14) is transferred to the aluminum case 30 via the metal plates 56 and 57, and is released from the aluminum case 30 to the atmosphere. It is.

  Further, in contrast to the case where a pattern made of a metal plate is used at a location where 80 A does not flow on the secondary winding side of the transformer. Since 80 A does not always flow on the secondary winding side of the transformer, in this embodiment, a metal plate is used only at a necessary portion, thereby saving space.

  In other words, high-density mounting can be achieved by patterning a portion where a large current does not flow with a metal foil that can be arranged at high density without using a metal plate. Further, the metal plates 45, 46, and 50 are soldered and electrically connected to the substrate 40 with respect to the portion where a large current flows. In this way, the size can be reduced.

  The heat of the power elements 37 and 38 is radiated to the aluminum case 30 through the metal plates 56 and 57 and the heat radiating sheets 36a and 36b. Therefore, since the insulating substrate which is a member with inferior thermal conductivity is not interposed, high heat dissipation is achieved. As a result, it is possible to construct an integrated structure substrate that also has high heat dissipation of the power element.

According to the above embodiment, the following effects can be obtained.
(1) The configuration of the insulated DC-DC converter 10 as an insulated power converter includes a substrate 40, input terminals 100 and 101 provided on the substrate 40, and an output terminal 102 provided on the substrate 40. Insulated DC-DC converter 10 includes a primary winding and a secondary winding having a number of turns different from that of the primary winding, and includes transformer 11 provided on substrate 40. The insulated DC-DC converter 10 includes a first pattern provided between the input terminals 100 and 101 and the primary winding, and a second pattern provided between the output terminal 102 and the secondary winding. And a pattern having the following pattern. A part of the pattern on the lower side of the primary side of the transformer 11 and the secondary side of the transformer 11 is constituted by the metal plates 46 and 50, and the other part of the pattern has a smaller sectional area than the metal plates 46 and 50. It consists of metal foils 121 and 122, and the metal plates 46 and 50 are mounted on the pattern of the substrate 40 with solder. Therefore, compared to the case where the primary side pattern of the transformer and the secondary side pattern of the transformer are configured on the basis of the lower voltage and a metal plate is also used in a portion with a small current capacity, in this embodiment, the transformer is Part of the pattern on the lower side of the primary side and the secondary side of the transformer is composed of metal plates 45, 46, and 50, and the other part is composed of metal foils 121 and 122. Can be suppressed.

  (2) The molded primary winding (winding portion 41) is mounted on the substrate 40 with solder, and the molded secondary winding (metal plate 45) is mounted on the substrate 40 with solder. For this reason, the metal plate 45 constituting the winding around the through hole 42 through which the core 60 of the transformer is inserted can be mounted with solder simultaneously with other mounting components.

(3) The substrate 40 is provided with a through-hole 42 through which the core 60 penetrates, and the first metal plate 45 is mounted around the through-hole 42, so that the rigidity of the substrate 40 can be suppressed from decreasing.
The embodiment is not limited to the above, and may be embodied as follows, for example.

  In FIG. 14, the thickness of the metal plate 45b as the secondary winding is t2, and the width is W2. On the other hand, as shown in FIG. 13, the thickness of the metal plate 45a as the secondary winding is t1, which is thicker than t2, and is W1, whose width is narrower than W2. In this way, the windings may be made smaller as shown in FIG. 13 than in FIG. In other words, by reducing the width W1 by increasing the thickness t1 of the metal plates (45a, 45b), the winding frame can be reduced and the size can be reduced. That is, it is possible to reduce the size of the upper core 62 by narrowing the space for the metal plate pattern and reducing the winding frame.

-For example, a low ON resistance MOS is used as a power element, which is preferable in terms of reducing loss.
In addition to the power MOSFET, for example, an IGBT or the like may be used as the primary side switching element.

-You may comprise the metal plates 45, 46, 50 with metal plates other than a copper plate.
-Heat radiation grease may be used instead of the heat radiation sheets 36a and 36b.
-The converter may be a boost type. That is, the input voltage on the primary side of the transformer may be boosted and output to the secondary side of the transformer. In this case, a part of the pattern on the primary side of the transformer and the secondary side of the transformer, which has the lower voltage, is formed of a metal plate, and the other part of the pattern is a metal foil having a smaller cross-sectional area than the metal plate. It is comprised and the metal plate is mounted with respect to the board | substrate.

  -It is not restricted to an insulation type DC-DC converter, You may apply to another insulation type power converter device.

  DESCRIPTION OF SYMBOLS 10 ... Insulation type DC-DC converter, 11 ... Transformer, 40 ... Board | substrate, 41 ... Winding part, 45 ... 1st metal plate, 46 ... 2nd metal plate, 50 ... 3rd metal plate, 100 ... Input terminal, 101 ... input terminal, 102 ... output terminal, 121 ... metal foil, 122 ... metal foil.

Claims (2)

A substrate,
An input terminal provided on the substrate;
An output terminal provided on the substrate;
A primary side winding and a secondary side winding having a number of turns different from the number of turns of the primary side winding, and a transformer provided on the substrate;
A pattern having a first pattern provided between the input terminal and the primary winding, and a second pattern provided between the output terminal and the secondary winding;
An insulated power converter having
A part of the pattern on the lower side of the primary side of the transformer and the secondary side of the transformer is made of a metal plate, and the other part of the pattern is a metal foil having a smaller cross-sectional area than the metal plate. An insulated power conversion device comprising: the metal plate mounted on the pattern of the substrate with solder.   The primary winding is mounted on the substrate with solder, the secondary winding is mounted on the substrate with solder, and the winding is configured around a through-hole through which the transformer core is inserted. The insulated power converter according to claim 1, wherein a metal plate is mounted.

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