JP2016039697A - Power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power unit capable of sufficiently preventing performance reduction of a filter circuit.SOLUTION: The power unit includes a base plate 2, a plurality of electronic components 3, a wiring layer 4a, an inductor 12, a capacitor 3, a shield layer 4b, a shield plate 7 and connection parts 8. A main circuit 10 is formed from the plurality of electronic components 3. A filter circuit 11 is formed from the inductor 12 and the capacitor 3. The shield layer 4b is provided at a position where the wiring layer 4a is covered in a thickness direction of the base plate 2, at least between the main circuit 10 and the filter circuit 11. The shield layer 4b and the shield plate 7 shield radiation noise H that is generated from the electronic components 3. The connection parts 8 electrically connect the shield layer 4b and the base plate 2. A loop L in which a current flows is formed from the shield layer 4b, the plurality of connection parts 8 and the base plate 2. The wiring layer 4a is arranged inside of the loop L.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply device including a filter circuit.

  As a power supply device such as a DC-DC converter, a main circuit composed of electronic components such as a transformer and a diode, a wiring unit connected to the electronic component and forming a current path between the main circuit and an external device, and the wiring unit And a filter circuit provided in the above are known.

  The filter circuit includes an inductor and a capacitor provided in the wiring part. When the main circuit is operated, a conduction noise current is generated and flows through the wiring portion. Therefore, the conduction noise current is removed by the filter circuit. This prevents a large conduction noise current from being transmitted to the external device.

  When the main circuit is operated, radiation noise is generated in addition to the conduction noise current. It is known that when this radiation noise is linked to the filter circuit, a conduction noise current is newly generated in the filter circuit, and the ability of the filter circuit to remove the conduction noise current is reduced. Therefore, a power supply device has been developed in which a shield plate that shields radiation noise is provided between the main circuit and the filter circuit (see Patent Document 1 below).

  When the shield plate is provided, radiation noise generated from the main circuit is hardly transmitted to the filter circuit. For this reason, it is possible to suppress a problem that a conduction noise current is newly generated from the filter circuit.

JP 2013-27077 A

  However, it cannot be said that the power supply device can sufficiently suppress the performance degradation of the filter circuit. That is, in the above power supply device, a portion of the wiring portion that is located on the main circuit side of the shield plate is greatly exposed, and radiation noise is linked to the exposed portion, and a conduction noise current is newly generated. May end up. For this reason, the conduction noise current transmitted to the filter circuit increases, and the conduction noise current may not be sufficiently removed by the filter circuit.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a power supply device that can sufficiently suppress the performance degradation of the filter circuit.

One aspect of the present invention is a metal base plate connected to the ground;
A plurality of electronic components fixed to the base plate and constituting a main circuit;
A wiring layer provided on the base plate in an insulated state, connected to the electronic component, and forming a current path between the main circuit and an external device;
An inductor and a capacitor provided in the wiring layer and constituting a filter circuit;
A shielding layer for shielding the radiation noise generated from the electronic component, provided at a position covering the wiring layer from the side opposite to the side on which the base plate is disposed;
A shield plate provided between the filter circuit and the main circuit, protruding from the shielding layer in the thickness direction of the base plate, and shielding the radiation noise;
A plurality of connecting portions for electrically connecting the shielding layer and the base plate;
The shielding layer covers at least a portion of the wiring layer located on the main circuit side from the shielding plate,
A first insulating layer is interposed between the wiring layer and the base plate, a second insulating layer is interposed between the wiring layer and the shielding layer, and the first insulating layer, the wiring layer, and the second The insulating layer and the shielding layer are stacked in the thickness direction,
In the power supply device, a loop through which a current flows is formed by the shielding layer, the plurality of connection portions, and the base plate, and the wiring layer penetrates the inside of the loop.

  In the power supply device, a portion of the wiring layer located on the main circuit side with respect to the shield plate is covered with the shielding layer. Therefore, it is possible to suppress the radiation noise from interlinking with the part by the shielding layer, and it is possible to suppress a problem that a conduction noise current is newly generated from the part. Therefore, the amount of conduction noise current transmitted to the filter circuit can be reduced, and the performance degradation of the filter circuit can be suppressed.

  Further, in the power supply device, the shield plate is provided between the main circuit and the filter circuit. Therefore, the radiation noise generated from the electronic component and transmitted to the filter circuit can be shielded by the shield plate. Therefore, it is possible to suppress a problem that a conduction noise current is newly generated due to radiation noise interlinking with an inductor or a capacitor constituting the filter circuit. For this reason, it is possible to suppress the performance degradation of the filter circuit.

  Further, in the power supply device, the loop through which current flows is formed around the wiring layer. Therefore, when an AC magnetic field, which is a kind of radiation noise, is transmitted to the filter circuit side through the periphery of the wiring layer, an eddy current can be generated in the loop, and this eddy current can cancel the AC magnetic field. Can be generated. Therefore, the filter circuit is not easily affected by the alternating magnetic field.

  As described above, according to the present invention, it is possible to provide a power supply device that can sufficiently suppress the performance degradation of the filter circuit.

FIG. 4 is a cross-sectional view of the power supply device according to the first embodiment, which is a cross-sectional view taken along the line II in FIG. 3. II-II sectional drawing of FIG. FIG. 3 is a view taken in the direction of arrow III in FIG. 1. IV-IV sectional drawing of FIG. VV sectional drawing of FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. The figure following FIG. The figure following FIG. The figure following FIG. 1 is a circuit diagram of a power supply device according to Embodiment 1. FIG. Sectional drawing of the power supply device in Example 2. FIG. FIG. 14 is a cross-sectional view of the power supply device according to the third embodiment, which is a cross-sectional view taken along the line XII-XII in FIG. 13. XIII-XIII sectional drawing of FIG. FIG. 16 is a cross-sectional view of the power supply device according to the fourth embodiment, which is a cross-sectional view taken along the line XIV-XIV in FIG. 15. XV-XV sectional drawing of FIG.

  The power supply device can be an in-vehicle power supply device to be mounted on a vehicle such as a hybrid vehicle or an electric vehicle.

Example 1
Examples of the power supply apparatus will be described with reference to FIGS. As shown in FIGS. 1 to 3, the power supply device 1 of this example includes a base plate 2, a plurality of electronic components 3, a wiring layer 4 a, an inductor 12, a capacitor 3, a shielding layer 4 b, and a shielding plate 7. And a plurality of connecting portions 8.

  The base plate 2 is made of metal and connected to the ground. The electronic component 3 is fixed to the base plate 2. A plurality of electronic components 3 constitute a main circuit 10 (see FIG. 10). The wiring layer 4 a is provided on the base plate 2 while being insulated from the base plate 2. The wiring layer 4a is connected to the electronic component 3 and forms a current path between the main circuit 10 and an external device (low voltage DC power supply 89: see FIG. 10).

The inductor 12 and the capacitor 13 are provided in the wiring layer 4a. The inductor 12 and the capacitor 13 constitute a filter circuit 11. The shielding layer 4b is provided at a position covering the wiring layer 4a from the side opposite to the side on which the base plate 2 is provided. The shielding layer 4 b shields radiation noise H generated from the electronic component 3.
The shield plate 7 is provided between the filter circuit 11 and the main circuit 10, and protrudes from the shielding layer 4b in the thickness direction (Z direction) of the base plate 2. The shield plate 7 shields the radiation noise H.
Each of the connection portions 8 electrically connects the shielding layer 4 b and the base plate 2.

The shielding layer 4b covers at least a portion 400 of the wiring layer 4a located on the main circuit 10 side with respect to the shielding plate 7.
A first insulating layer 5 a is interposed between the wiring layer 4 a and the base plate 2. The second insulating layer 5b is interposed between the wiring layer 4a and the shielding layer 4b. The first insulating layer 5a, the wiring layer 4a, the second insulating layer 5b, and the shielding layer 4b are stacked in the Z direction to constitute a stacked substrate 6.
The shielding layer 4b, the plurality of connecting portions 8, and the base plate 2 form a loop L through which a current flows. The wiring layer 4a penetrates the inside of the loop L.

  The power supply device 1 of this example is a vehicle-mounted power supply device mounted on a vehicle such as a hybrid vehicle or an electric vehicle.

  The power supply device 1 of this example is a DC-DC converter for charging the low-voltage DC power supply 89 by stepping down the voltage of the high-voltage DC power supply 88 as shown in FIG. The power supply device 1 of this example includes an input capacitor 3a, a MOS module 3b, a transformer 3c, a diode module 3d, a choke coil 3e, and a smoothing capacitor 3f as electronic components 3.

  A plurality of MOSFETs 30 are sealed in the MOS module 3b. By turning on and off the MOSFET 30, the DC voltage of the high-voltage DC power supply 88 is converted into an AC voltage, and this AC voltage is applied to the primary coil 31 of the transformer 3c. Then, the AC voltage output from the secondary coil 32 of the transformer 3c is rectified by the diode module 3d and smoothed using the choke coil 3e and the smoothing capacitor 3f.

  The conduction noise current included in the smoothed output current is removed by the filter circuit 11. The low voltage DC power supply 89 is charged using the output current that has passed through the filter circuit 11.

  On the other hand, in this example, as shown in FIGS. 1 to 3, the laminated substrate 6 is fixed to the base plate 2 using bolts 81. With this bolt 81, the shielding layer 4b and the base plate 2 are electrically connected. That is, the bolt 81 of this example has two functions, that is, a function of fixing the laminated substrate 6 to the base plate 2 and a function of electrically connecting the shielding layer 4 b and the base plate 2.

  As described above, the multilayer substrate 6 is formed by laminating the first insulating layer 5a, the wiring layer 4a, the second insulating layer 5b, and the shielding layer 4b in the Z direction. The laminated substrate 6 of this example is a so-called thick copper substrate capable of flowing a large current through the wiring layer 4a.

  As shown in FIG. 2, in the width direction (Y direction) of the wiring layer 4a, intermediate ground layers 42 (42a, 42b) are formed at positions sandwiching the wiring layer 4a. The intermediate ground layer 42 is formed of a metal plate having the same thickness as the wiring layer 4a. The intermediate ground layer 42 is electrically connected to the base plate 2, that is, the ground by bolts 81.

  A gap S is formed between the intermediate ground layer 42 and the wiring layer 4a. When the power supply device 1 is operated, an AC magnetic field, which is a kind of the radiation noise H, may be transmitted to the filter circuit 11 (see FIGS. 1 and 3) through the gap S and the insulating layers 5 (5a and 5b). is there. However, since the loop L is formed in this example, an eddy current I flows through the loop L when an AC magnetic field passes. Therefore, the eddy current I generates a magnetic field that cancels the alternating magnetic field, and the filter circuit 11 is not greatly affected by the alternating magnetic field.

  As shown in FIGS. 1 and 4, an inductor through-hole 61 is formed in the first insulating layer 5a, the second insulating layer 5b, and the shielding layer 4b. A magnetic core 121 is disposed in the inductor through hole 61. The magnetic core 121 is provided so as to surround the wiring layer 4a. As a result, the part surrounded by the magnetic core 121 in the wiring layer 4 a is the inductor 12.

  As shown in FIGS. 1 and 5, a capacitor through-hole 62 is formed in the second insulating layer 5b and the shielding layer 4b. The capacitor 13 is disposed in the capacitor through hole 62. Of the two electrodes 131 and 132 of the capacitor, one electrode 131 is connected to the wiring layer 4a, and the other electrode 132 is connected to the shielding layer 4b. The shielding layer 4 b is connected to the base plate 2, that is, the ground via the connection portion 8. Therefore, the other electrode 132 of the capacitor 13 is electrically connected to the ground via the shielding layer 4b.

  As shown in FIGS. 1 and 3, the second insulating layer 5 b and the shielding layer 4 b are formed with a notch 63. The output terminal 41 which is a part of the wiring layer 4a is exposed from the notch 63. The output terminal 41 is electrically connected to an external device (low voltage DC power supply 89: see FIG. 10).

  As described above, the shield plate 7 is attached to the shielding layer 4b. The shield plate 7 of this example is a separate member from the shielding layer 4b as shown in FIG. The shield plate 7 is connected to the shielding layer 4b by soldering or welding.

  Next, the manufacturing method of the power supply device 1 of this example is demonstrated. To manufacture the power supply device 1, as shown in FIG. 6, first, the first insulating layer 5 a in which the inductor through hole 61 is formed is prepared. As shown in FIG. 7, the wiring layer 4a and the intermediate ground layer 42 are disposed on the first insulating layer 5a. The wiring layer 4a and the intermediate ground layer 42 can be formed by, for example, pressing a metal plate.

  Next, as shown in FIG. 8, the second insulating layer 5b is disposed on the wiring layer 4a and the intermediate ground layer 42, and the shielding layer 4b is further disposed. The second insulating layer 5b and the shielding layer 4b are formed with an inductor through hole 61, a capacitor through hole 62, and a notch 63, respectively.

  Thereafter, the first insulating layer 5a, the wiring layer 4a, the intermediate ground layer 42, the second insulating layer 5b, and the shielding layer 4b are compressed in the Z direction to integrate them. Thereby, the laminated substrate 6 is formed.

  Next, as shown in FIG. 9, bolt insertion holes 810 for inserting the bolts 81 are formed in the laminated substrate 6. Further, the shield plate 7 is connected to the shielding layer 4a.

  Thereafter, the laminated substrate 6 is fixed to the base plate 2 (see FIG. 1) using the bolts 81. A plurality of electronic components 3 are arranged on the base plate 2 to form the main circuit 10, and the electronic components 3 are connected to the wiring layer 4a. The power supply device 1 of this example is manufactured by performing the above steps.

  The effect of this example will be described. As shown in FIGS. 1 and 3, in this example, a portion 400 of the wiring layer 4a that is located closer to the main circuit 10 than the shield plate 7 is covered with the shielding layer 4b. Therefore, it is possible to suppress the radiation noise H from interlinking with the part 400 by the shielding layer 4b, and it is possible to suppress a problem that a conduction noise current is newly generated from the part 400. Therefore, the amount of conduction noise current transmitted to the filter circuit 11 can be reduced, and the performance degradation of the filter circuit 11 can be suppressed.

  In this example, a shield plate 7 is provided between the main circuit 10 and the filter circuit 11. Therefore, the radiation noise H generated from the electronic component 3 and transmitted to the filter circuit 11 can be shielded by the shield plate 7. Therefore, it is possible to suppress the problem that radiation noise is linked to the inductor 12 and the capacitor 13 constituting the filter circuit 11 and a conduction noise current is newly generated. As a result, the performance degradation of the filter circuit 11 can be suppressed.

  Further, as shown in FIG. 2, in this example, a loop L through which a current flows is formed around the wiring layer 4a. Therefore, when an AC magnetic field, which is a kind of the radiation noise H, is transmitted to the filter circuit 11 side through the periphery of the wiring layer 4a, an eddy current I can be generated in the loop L. A magnetic field that cancels the alternating magnetic field can be generated. Therefore, the filter circuit 11 is not easily affected by the AC magnetic field.

  In this example, the first insulating layer 5a, the wiring layer 4a, the second insulating layer 5b, and the shielding layer 4b are laminated. Therefore, the layers 5a, 4a, 5b, 4b can be brought into close contact with each other, and the shielding layer 4b can be disposed at a position close to the base plate 2. Therefore, the area of the loop L can be reduced. Therefore, the amount of radiation noise H passing through the loop L can be reduced, and the influence of the radiation noise H on the filter circuit 11 can be further reduced.

  In this example, the first insulating layer 5 a, the wiring layer 4 a, the second insulating layer 5 b, and the shielding layer 4 b are laminated to form one laminated substrate 6. Therefore, these layers 5a, 4a, 5b, and 4b can be made into one part, and the structure of the power supply device 1 can be simplified.

  As shown in FIGS. 1 and 3, in this example, a portion 400 of the wiring layer 4a located on the main circuit 10 side of the shield plate 7 is covered with the shielding layer 4b, and the shielding plate 7 of the wiring layer 4a. Further, the part located on the filter circuit 11 side (filter side part 401) is also covered with the shielding layer 4b. Therefore, even when radiation noise H leaks from the shield plate 7 or the like, the radiation noise H can be prevented from interlinking with the filter side portion 401. Therefore, it is possible to effectively suppress the generation of a conduction noise current from the filter side portion 401.

  As described above, according to this example, it is possible to provide a power supply device that can sufficiently suppress the performance degradation of the filter circuit.

  In this example, the filter circuit 11 is provided on the output side as shown in FIG. 10, but the present invention is not limited to this, and the filter circuit 11 may be provided on the input side.

  In this example, the MOS module 3b including a plurality of MOSFETs 30 is used, but the present invention is not limited to this. That is, a so-called discrete component in which each MOSFET 30 is individually incorporated may be used. The same applies to the diode module 3d.

(Example 2)
In the following embodiments, the same reference numerals used in the drawings among the reference symbols used in the drawings represent the same components as those in the first embodiment unless otherwise specified.

  In this example, the structure of the shield plate 7 is changed. As shown in FIG. 11, in this example, the shield plate 7 and the shielding layer 4b are formed by one member. That is, the shield plate 7 is formed by bending a part of the shield layer 4b instead of making the shield plate 7 a separate member from the shield layer 4b.

If it is made like this example, since it becomes unnecessary to make the shield board 7 into a member different from the shielding layer 4b, the number of parts can be reduced. Therefore, the manufacturing cost of the power supply device 1 can be reduced.
In addition, the configuration and operational effects are the same as those of the first embodiment.

(Example 3)
In this example, the structure of the connecting portion 8 is changed. As shown in FIGS. 12 and 13, in this example, the connection portion 8 constituting the loop L is a contact via 80.
In this example, a metal plate connection layer 4 c connected to the base plate 2 is interposed between the first insulating layer 5 a and the base plate 2. The plate connection layer 4c, the first insulating layer 5a, the wiring 4a and the intermediate ground layer 42, the second insulating layer 5b, and the covering layer 4b are laminated to constitute the laminated substrate 6.

  In this example, as shown in FIG. 13, the contact via 80 is formed in the multilayer substrate 6. The contact via 80 passes through the second insulating layer 5b, the intermediate ground layer 42, and the first insulating layer 5a. The contact layer 80 connects the shielding layer 4b to the plate connection layer 4c. The shielding layer 4b is electrically connected to the base plate 2 through the contact via 80 and the plate connection layer 4c. The shielding layer 4b, the two contact vias 80, the plate connection layer 4c, and the base plate 2 form a loop L through which current flows.

  With the above configuration, the number of bolts 81 can be reduced as compared with the first embodiment. Therefore, it is possible to complete the work of fixing the laminated substrate 6 to the base plate 2 in a short time.

Moreover, when using the bolt 81 as the connection part 8, in order to suppress that the head of the bolt 81 interferes with the shield board 7, it is necessary to provide the bolt 81 in the position away from the shield board 7 (FIG. 1). However, in the case of the contact via 80, there is no such restriction. Therefore, for example, as in this example, the contact via 80 can be formed at a position overlapping the shield plate 7 when viewed from the Z direction.
In addition, the configuration and operational effects are the same as those of the first embodiment.

Example 4
In this example, as shown in FIGS. 14 and 15, a metal cover 14 is provided on the base plate 2. In the cover 14, a plurality of electronic components, the multilayer substrate 6, the shield plate 7, the inductor 12, and the capacitor 13 are arranged. The side surface 71 of the shield plate 7 is in contact with the inner surface 141 of the cover 14. Thus, no gap is formed between the shield plate 7 and the cover 14.

If it does in this way, it can control by cover 14 that radiated magnetic field H generated from electronic part 3 is transmitted to an external device. Moreover, since the radiation magnetic field H can be confined by the cover 14 and the shield plate 7, the amount of the radiation magnetic field H transmitted to the filter circuit 11 can be further reduced. Therefore, it is possible to more effectively suppress the performance degradation of the filter circuit 11.
In addition, the configuration and operational effects are the same as those of the first embodiment.

DESCRIPTION OF SYMBOLS 1 Power supply device 10 Main circuit 11 Filter circuit 12 Inductor 13 Capacitor 2 Base plate 3 Electronic component 4a Wiring layer 4b Shielding layer 5a First insulating layer 5b Second insulating layer 6 Multilayer substrate 7 Shield plate 8 Connection part L Loop

Claims (4)

A metal base plate (2) connected to the ground;
A plurality of electronic components (3) fixed to the base plate (2) and constituting a main circuit (10);
A wiring provided on the base plate (2) in an insulated state from the base plate (2), connected to the electronic component (3), and forming a current path between the main circuit (10) and an external device. Layer (4a);
An inductor (12) and a capacitor (13) provided in the wiring layer (4a) and constituting the filter circuit (11);
A shielding layer (4b) which is provided at a position covering the wiring layer (4a) from the side opposite to the side on which the base plate (2) is disposed, and shields radiation noise generated from the electronic component (3);
A shield plate (7) provided between the filter circuit (11) and the main circuit (10) and protruding from the shielding layer (4b) in the thickness direction of the base plate (2) to shield the radiation noise. When,
A plurality of connecting portions (8) for electrically connecting the shielding layer (4b) and the base plate (2);
The shielding layer (4b) covers at least a portion (400) located on the main circuit (10) side of the shielding plate (7) in the wiring layer (4a),
A first insulating layer (5a) is interposed between the wiring layer (4a) and the base plate (2), and a second insulating layer (5b) is interposed between the wiring layer (4a) and the shielding layer (4b). ), The first insulating layer (5a), the wiring layer (4a), the second insulating layer (5b), and the shielding layer (4b) are stacked in the thickness direction,
A loop (L) through which a current flows is formed by the shielding layer (4b), the plurality of connection portions (8), and the base plate (2). The wiring layer (4a) The power supply device (1) characterized by having penetrated.   The power supply device (1) according to claim 1, wherein the shield plate (7) and the shielding layer (4b) are formed of one member.   A metal plate connection layer (4c) connected to the base plate (2) is interposed between the first insulating layer (5a) and the base plate (2), and the plurality of connection portions ( 8), at least a part of the connecting portion (8) penetrates the first insulating layer (5a) and the second insulating layer (5b), and the shielding layer (4b) and the plate connecting layer (4c). The power supply device (1) according to claim 1 or 2, comprising contact vias (80) that electrically connect each other to each other.   A metal cover (14) is attached to the base plate (2), and within the cover (14), the plurality of electronic components (3), the laminated substrate (6), the shield plate (7), and the above The inductor (12) and the capacitor (13) are arranged, and the side surface (71) of the shield plate (7) and the inner surface (141) of the cover (14) are in contact with each other. The power supply device (1) according to any one of claims 1 to 3.

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