Power converter

Abstract

To provide a power conversion device with improved heat dissipation while satisfying both high current capability and lower inductance of a circuit board.SOLUTION: A power conversion device includes a plurality of circuit bodies, a wiring board, and a smoothing capacitor. The wiring board includes a plurality of lamination wiring parts to which the plurality of circuit bodies and the plurality of smoothing capacitors are connected, and an inter-layer wiring part formed between the respective lamination wiring parts. In the lamination wiring part, a positive electrode wiring and a negative electrode wiring are laminated in a mutually overlapping manner, and in the inter-layer wiring part, a plurality of positive electrode wirings and a plurality of negative electrode wirings are laminated in a mutually separated manner on the plane of the wiring board. The inter-layer wiring part includes a via penetrating in a thickness direction of the wiring board.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The present invention relates to a power conversion device.

Background Art

[0002] An inverter used in an automobile needs to meet the requirements of improving productivity and reducing inductance while corresponding to the performance of a hybrid vehicle or an electric vehicle by constructing a main circuit using a printed circuit board for passing an energization current.

[0003] In Patent Document 1 below, a configuration is disclosed in which a positive electrode wiring and a negative electrode conductor connecting each power module and each capacitor are laminated to reduce inductance.

Prior Art Document

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, the positive electrode wiring and the negative electrode wiring are laminated in all regions and each wiring is mixed. However, in such a configuration, when a heat dissipation via is provided, the number of disconnection points of each wiring increases and the cross-sectional area decreases, resulting in a problem that the electrical resistance increases. As a result, it becomes difficult to reduce the wiring temperature and improvement of the cooling performance is required. In view of this, an object of the present invention is to provide a power conversion device that improves heat dissipation while achieving both high current and low inductance of a substrate.

Means for Solving the Problems

[0006] The power converter comprises a plurality of circuit bodies, each having a plurality of power semiconductor elements; a wiring board electrically connected to the circuit bodies, on which a plurality of positive and negative electrode wirings are stacked in the thickness direction; and a plurality of smoothing capacitors provided corresponding to each of the plurality of circuit bodies. The wiring board has a plurality of stacked wiring sections to which the plurality of circuit bodies and the plurality of smoothing capacitors are connected, and interphase wiring sections formed between the plurality of stacked wiring sections. In the stacked wiring sections, the positive and negative electrode wirings are stacked overlapping each other; in the interphase wiring sections, the plurality of positive and negative electrode wirings are stacked separately in the plane of the wiring board; and the interphase wiring sections have vias penetrating in the thickness direction of the wiring board. Furthermore, the stacked wiring section does not have vias. . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a power conversion device that achieves both high current capacity and low inductance of the substrate while improving heat dissipation. [Brief explanation of the drawing]

[0008] [Figure 1] Electrical circuit diagram showing multiple circuit components in a power converter. [Figure 2] Overall diagram of the circuit board of a power conversion device according to the first embodiment of the present invention. [Figure 3] This figure shows the arrangement area of ​​the laminated wiring section, inter-phase wiring section, and main circuit terminal according to the first embodiment of the present invention. [Figure 4] This is a cross-section of line A-A' in Figure 2, showing the laminated wiring section. [Figure 5] This is a cross-section of line B-B' in Figure 2, showing the interphase wiring section. [Figure 6] Modified version of Figure 4 (First modified version) [Figure 7] Figure 5 shows a cross-sectional view of the stacked wiring section with a cooler placed inside. [Figure 8] Cross-sectional perspective view showing the relationship between the multilayer wiring section and the interphase wiring section on the substrate. [Figure 9] Modified version of Figure 2 (second modified version)

[0009] Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are illustrative for illustrating the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be carried out in various other forms. Unless otherwise specified, each component may be singular or plural.

[0010] The positions, sizes, shapes, and ranges of the components shown in the drawings may not represent their actual positions, sizes, shapes, and ranges in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0011] (One embodiment of the present invention and its overall configuration) (Figure 1) The multiple circuit bodies 1 that make up the power conversion circuit are each composed of semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). Two circuit bodies 1 and one capacitor 2 connected in series form a pair, each consisting of one phase circuit, thus forming a three-phase power conversion circuit. Each circuit is connected to a positive terminal wire 3 and a negative terminal wire 4.

[0012] Circuit body 1 has three terminals: a high-voltage terminal for the main circuit (collector terminal for IGBTs, drain terminal for MOSFETs), a low-voltage terminal for the main circuit (emitter terminal for IGBTs, source terminal for MOSFETs), and a control terminal (gate terminal).

[0013] (Figure 2) The power conversion device 100 includes a plurality of circuit bodies 1 each having a plurality of power semiconductor elements, a wiring board 6 (hereinafter referred to as the board 6) that is electrically connected to the circuit bodies 1 and in which a plurality of positive electrode wirings 3 and negative electrode wirings 4 are respectively laminated in the thickness direction, and a plurality of smoothing capacitors 2 provided corresponding to the plurality of circuit bodies 1. The positive electrode wiring 3 and the negative electrode wiring 4 are laminated on each other in the thickness direction of the board 6 (the front-back direction of the paper surface in FIG. 2), and connect the capacitor 2 of each phase to the circuit body 1 (details will be described later with reference to FIGS. 4 to 8). Note that FIG. 2 shows a configuration example in which four circuit bodies 1 are arranged in parallel, and eight circuit bodies 1 are used as a one-phase circuit, and three phases are provided on the board 6. Thus, according to a desired output current value, the circuit bodies 1 may be arranged in a multi-parallel connection configuration.

[0014] As described above, the board 6 has a plurality of conductor layers in the thickness direction, and each conductor layer is laminated via a resin layer. The positive electrode wiring 3, the negative electrode wiring 4, the output wiring 7, and the signal wiring 9 are formed in the conductor layer of the board 6. The circuit bodies 1 and the capacitors 2 are connected to the positive electrode wiring 3 and the negative electrode wiring 4 by a bonding material such as solder. The circuit body 1 has a signal terminal 8 for connecting to the signal wiring 9. The positive electrode wiring 3, the negative electrode wiring 4, and the output wiring 7 are each formed thicker than the signal wiring 9 connected to the circuit body 1, corresponding to the fact that the current supplied to the load at the connection destination is larger than the other wirings.

[0015] The positive electrode wiring 3 and the negative electrode wiring 4 have through vias 5 (hereinafter referred to as vias 5). The vias 5 are provided in a region where the positive electrode wiring 3 and the negative electrode wiring 4 of each phase are not laminated on each other. The plurality of positive electrode wirings 3 or negative electrode wirings 4 are each penetrated in the thickness direction of the board 6 to form vias 5, whereby the wirings having the same potential are electrically connected to each other.

[0016] The positive electrode wiring 3 is connected to the positive electrode terminal of a DC voltage source such as a battery (not shown), and the negative electrode wiring 4 is connected to the negative electrode terminal of a DC voltage source such as a battery (not shown). Thereby, a DC voltage is supplied to each phase circuit.

[0017] The capacitor 2 is connected in parallel along the substrate 6 to satisfy a capacitor capacitance determined according to a desired input voltage fluctuation amount, and has a positive electrode terminal 10 and a negative electrode terminal 11 as terminals for connecting to the positive electrode wiring 3 and the negative electrode wiring 4 of the substrate 6.

[0018] By being connected to the positive electrode wiring 3, the positive electrode terminal 10 of the capacitor 2 is electrically connected to the high-voltage side terminal for the main circuit of the circuit body 1 on the high side (upper arm) side. Also, the positive electrode wiring 3 is connected to the positive electrode terminal 10 of the capacitor 2 of the other phase and the high-voltage side terminal for the main circuit of the circuit body 1 on the high side of the other phase. By being connected to the negative electrode wiring 4, the negative electrode terminal 11 of the capacitor 2 is connected to the low-voltage side terminal for the main circuit of the circuit body 1 on the low side (lower arm) side. The negative electrode wiring 4 is connected to the negative electrode terminal 11 of the capacitor 2 of the other phase and the low-voltage side terminal 12 for the main circuit of the circuit body 1 on the low side of the other phase. The low-voltage side terminal for the main circuit of the circuit body 1 on the high side is connected to the high-voltage side terminal for the main circuit of the circuit body 1 on the low side by the output wiring 7 of each phase. The output wiring 7 of each phase is connected to a load such as a motor not shown in the figure.

[0019] The control terminal of the circuit body 1 is connected to a control circuit not shown in the figure, and is turned on or off based on a signal input from a higher-level control device such as a microcomputer, thereby outputting an alternating current voltage to a load such as a motor.

[0020] (Fig. 3) The substrate 6 has a plurality of laminated wiring portions 15 to which a plurality of circuit bodies 1 and a plurality of smoothing capacitors 2 are respectively connected, and phase wiring portions 16 formed between the plurality of laminated wiring portions 15. In the laminated wiring portion 15, the positive electrode wiring 3 and the negative electrode wiring 4 overlap and are laminated on each other, but in the phase wiring portion 16, the plurality of positive electrode wirings 3 and the plurality of negative electrode wirings 4 are separated and wired in parallel on the plane of the substrate 6 and are laminated on each other. That is, the phase wiring portion 16 is a region where the positive electrode wiring 3 and the negative electrode wiring 4 are not laminated on each other in the thickness direction of the substrate 6.

[0021] Furthermore, the interphase wiring section 16 has vias 5 that penetrate in the thickness direction of the substrate 6, while the laminated wiring section 15 does not have vias 5. The interphase wiring section 16 improves heat dissipation by having vias 5. On the other hand, because the laminated wiring section 15 does not have vias 5, the positive electrode wiring 3 and negative electrode wiring 4 are not separated by the penetrating vias 5, thereby suppressing a decrease in the cross-sectional area of ​​the positive electrode wiring 3 and negative electrode wiring 4 and reducing inductance.

[0022] Multiple circuit bodies 1 have main circuit terminals 12 on the substrate 6. These main circuit terminals 12 are located within a region 12a perpendicular to one side defined by the distance between the positive terminal 10 and the negative terminal 11 of the smoothing capacitor 2. By arranging the main circuit terminals 12 in this way, the wiring length of the multilayer wiring connecting the capacitor 2 and the circuit bodies 1 can be shortened, thereby reducing the wiring inductance of the multilayer wiring section 15 and enabling faster switching control of the circuit bodies 1. Furthermore, switching losses generated in the circuit bodies 1 are reduced, and the entire circuit body 1 and inverter 100 can be miniaturized.

[0023] The configuration described above achieves both low inductance and high current (increased output) of the circuit board 6 while improving heat dissipation.

[0024] (Figures 4 and 5) As shown in Figure 4, in the laminated wiring section 15, for example, if the substrate 6 has four conductor layers, the first and third layers from the top surface of the substrate 6 become positive electrode wiring 3, and the second and fourth layers become negative electrode wiring 4. Thus, the laminated wiring section 15 is a region where the positive electrode wiring 3 and negative electrode wiring 4 overlap and are stacked on top of each other. On the other hand, as shown in Figure 5, the interphase wiring section 16 is a region provided between the laminated wiring sections 15, where the positive electrode wiring 3 and negative electrode wiring 4 are stacked on top of each other without overlapping. Furthermore, in the interphase wiring section 16, vias 5 provided in the thickness direction of the substrate 6 electrically connect the positive electrode wiring 3 and negative electrode wiring 4, which are at the same potential, from the top to the bottom of the substrate 6.

[0025] The vias 5 in the interphase wiring section 16 are provided in pairs or more for both the positive electrode wiring 3 and the negative electrode wiring 4. Furthermore, in the interphase wiring section 16, the vias 5 are positioned closer to the adjacent laminated wiring section 15 than to the center line 6a perpendicular to the arrangement direction of the laminated wiring section 15 and the interphase wiring section 16. This allows for an efficient reduction in the wiring temperature of the substrate 6, even with a small number of vias 5. Additionally, for laminated wiring sections 15 where vias 5 are not provided and cooling is difficult, the wiring temperature of the laminated wiring section 15 is reduced by arranging vias 5 near the laminated wiring section 15 in the interphase wiring section 16.

[0026] (First variation) (Figure 6) The stacked wiring section 15 can stack each wiring using blind vias 5a. In other words, by configuring the first and second layers from the top surface of the substrate 6 as positive electrode wiring 3 and the third and fourth layers as negative electrode wiring 4, and connecting wirings of the same potential with blind vias 5a, the positive electrode wiring 3 and negative electrode wiring 4 can be stacked without reducing the cross-sectional area of ​​the positive electrode wiring 3 and negative electrode wiring 4.

[0027] (Figure 7) A cooler 14 for cooling multiple circuit bodies 1 is positioned on one side of the substrate 6. An insulating heat dissipation member 13 is provided between the cooler 14 and the substrate 6. The heat dissipation member 13 is a material that conforms to steps and warps of the substrate 6 to improve adhesion, so a low-hardness resin or similar material is used. The cooler 14 is constructed from a material with high thermal conductivity, such as aluminum. As a result, the heat generated when current flows through the positive electrode wiring 3 and negative electrode wiring 4 is dissipated from the substrate 6 through the vias 5 of the interphase wiring section 16 to the cooler 14 via the heat dissipation member 13, thereby reducing the wiring temperature of the substrate 6.

[0028] (Figure 8) In the laminated wiring section 15, multiple positive electrode wirings 3 and negative electrode wirings 4 overlap each other in the thickness direction of the substrate 6, resulting in the wiring being stacked. On the other hand, in the interphase wiring section 16, the multiple positive electrode wirings 3 and negative electrode wirings 4 do not overlap in the thickness direction of the substrate 6, but are stacked on top of each other, and the positive electrode wirings 3 and negative electrode wirings 4 are arranged parallel to each other in the plane of the substrate 6. In addition, vias 5 are provided in the interphase wiring section 16 to connect wirings of the same potential to both the positive electrode wirings 3 and negative electrode wirings 4.

[0029] This configuration eliminates the problem of increased separation between the positive electrode wiring 3 and the negative electrode wiring 4, which was previously required by providing vias 5 on a substrate 6 where positive electrode wiring 3 and negative electrode wiring 4 were mixed. Furthermore, by arranging the positive electrode wiring 3 and the negative electrode wiring 4 in parallel in the interphase wiring section 16, the currents flowing through the positive electrode wiring 3 and the currents flowing through the negative electrode wiring 4 face each other in opposite directions, canceling out the magnetic fields and reducing inductance. In addition, the resonant current generated between each capacitor 2 (see Figures 2 and 3) arranged along the substrate 6 is suppressed, and the losses generated in the interphase wiring section 16 are reduced as the current decreases. Moreover, since the current flowing through the interphase wiring section 16 is distributed throughout all layers near the laminated wiring section 15, wiring heat generation can be reduced, improving heat dissipation.

[0030] (Second variation) (Figure 9) Figure 9 shows an example configuration in which the high-side circuit 1 and the low-side circuit 1 are integrated. This allows the circuit 1 to be easily mounted on the substrate 6, and simultaneously reduces the wiring inductance of each phase and lowers the temperature of the substrate 6.

[0031] The inverter of the present invention, as described in Figures 1 to 9 above, is not limited to three-phase.

[0032] According to the embodiment of the present invention described above, the following effects are achieved.

[0033] (1) The power conversion device 100 comprises a plurality of circuit bodies 1, each having a plurality of power semiconductor elements; a wiring board 6 electrically connected to the circuit bodies 1, on which a plurality of positive electrode wirings 3 and a plurality of negative electrode wirings 4 are stacked in the thickness direction; and a plurality of smoothing capacitors 2 provided corresponding to each of the plurality of circuit bodies 1. The wiring board 6 has a plurality of stacked wiring sections 15 to which the plurality of circuit bodies 1 and the plurality of smoothing capacitors 2 are connected, and interphase wiring sections 16 formed between the plurality of stacked wiring sections 15. In the stacked wiring sections 15, the positive electrode wirings 3 and the negative electrode wirings 4 are stacked overlapping each other, and in the interphase wiring sections 16, the plurality of positive electrode wirings 3 and the plurality of negative electrode wirings 4 are stacked separately in the plane of the wiring board 6, and the interphase wiring sections 16 have vias 5 that penetrate in the thickness direction of the wiring board 6. In this way, it is possible to provide a power conversion device 100 that improves heat dissipation while achieving both high current and low inductance of the substrate.

[0034] (2) The positive electrode wiring 3 and negative electrode wiring 4 of the interphase wiring section 16 are arranged to be parallel to each other in the plane of the wiring board 6. In this way, the current flowing through the positive electrode wiring 3 and the current flowing through the negative electrode wiring 4 are opposite to each other on the left and right sides, so the magnetic fields cancel each other out and the inductance is reduced.

[0035] (3) Multiple circuit bodies 1 have main circuit terminals 12 on the wiring board 6, and the main circuit terminals 12 are arranged in a region 12a perpendicular to one side defined by the distance between the positive terminal 10 and the negative terminal 11 of the smoothing capacitor 2. This allows the wiring length of the multilayer wiring connecting the capacitor 2 and the circuit bodies 1 to be shortened, thereby reducing the wiring inductance of the multilayer wiring section 15 and enabling faster switching control of the circuit bodies 1. In addition, switching losses generated in the circuit bodies 1 are reduced, and the entire circuit body 1 and inverter 100 can be made smaller.

[0036] (4) The interphase wiring section 16 has two or more vias 5 in each of the positive electrode wiring 3 and negative electrode wiring 4. The vias 5 are provided at positions closer to the laminated wiring section 15 adjacent to the interphase wiring section 16 than to the center line 6a of the interphase wiring section 16 which is perpendicular to the arrangement direction of the laminated wiring section 15 and the interphase wiring section 16. In this way, for the laminated wiring section 15, which is difficult to cool, the wiring temperature of the laminated wiring section 15 can be reduced by placing the vias 5 in the vicinity of the laminated wiring section 15 in the interphase wiring section 16.

[0037] (5) A cooler 14 for cooling multiple circuit bodies 1 is arranged on one side of the wiring board 6, and an insulating heat dissipation member 13 is provided between the cooler 14 and the wiring board 6. In this way, the heat generated when current flows through the positive electrode wiring 3 and the negative electrode wiring 4 is dissipated from the board 6 through the vias 5 of the interphase wiring section 16 to the cooler 14 via the heat dissipation member 13, thereby reducing the wiring temperature of the board 6.

[0038] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and combinations of other configurations can be made without departing from the spirit of the invention. Furthermore, the present invention is not limited to having all the configurations described in the embodiments described above, and may also include configurations in which some of those configurations are omitted. [Explanation of Symbols]

[0039] 1. Circuit unit (power module) 2 Capacitors 3. Positive Wiring 4. Negative wiring 5 Beers 5a Blind Beer 6 Wiring board 6a center line 7 Output Wiring 8 signal terminals 9. Signal Wiring 10 Capacitor positive terminal 11 Capacitor negative terminal 12 Circuit body main circuit terminal 12a Placement area 13 Heat dissipation components 14 Cooler 15. Laminated wiring section 16 Phase-to-phase wiring section 100 Power converter

Claims

1. Multiple circuit bodies, each having multiple power semiconductor elements, A wiring board electrically connected to the circuit body, wherein a plurality of positive and negative electrode wirings are stacked in the thickness direction, It comprises a plurality of smoothing capacitors provided corresponding to each of the plurality of circuit bodies, The wiring board has a plurality of stacked wiring sections to which a plurality of circuit bodies and a plurality of smoothing capacitors are connected, and interphase wiring sections formed between the plurality of stacked wiring sections. In the aforementioned laminated wiring section, the positive electrode wiring and the negative electrode wiring are stacked on top of each other. In the interphase wiring section, the plurality of positive electrode wirings and the plurality of negative electrode wirings are stacked separately on the plane of the wiring board. The interphase wiring section has vias that penetrate in the thickness direction of the wiring board, The aforementioned multilayer wiring section does not have vias. Power converter.

2. A power conversion device according to claim 1, The positive and negative electrode wiring of the interphase wiring section are arranged to be parallel to each other in the plane of the wiring board. Power converter.

3. A power conversion device according to claim 1, Multiple of the circuit bodies have main circuit terminals on the wiring board, The main circuit terminals are positioned within a region perpendicular to one side defined by the distance between the positive and negative terminals of the smoothing capacitor. Power converter.

4. A power conversion device according to claim 1, The interphase wiring section has two or more vias in the positive electrode wiring and the negative electrode wiring, Each of the vias is provided at a position closer to the stacked wiring section adjacent to the inter-phase wiring section than to the center line of the inter-phase wiring section which is perpendicular to the arrangement direction of the stacked wiring section and the inter-phase wiring section. Power converter.

5. A power conversion device according to claim 1, On one side of the aforementioned wiring board, a cooler for cooling multiple circuit components is arranged. An insulating heat dissipation member is provided between the cooler and the wiring board. Power converter.

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