power module

Abstract

The application relates to a power module, comprising at least one power device, and a first substrate and a second substrate arranged in mutual superposition, a driving circuit is arranged on the first substrate, the driving circuit is connected with the power device, a power circuit is arranged on the surface of the second substrate which is relatively close to the first substrate, the power circuit is connected with the power device, wherein the area of the first substrate is smaller than the area of the second substrate, the power device is arranged in a second region of the surface of the second substrate which is relatively close to the first substrate, wherein the driving circuit and the power circuit are arranged on the first substrate and the second substrate arranged in mutual superposition respectively, so that the current-carrying sectional area of the power circuit is maximized, the overall stray inductance of the power circuit is reduced, and the performance of the power module is improved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power module. Background Technology

[0002] Existing power modules typically use copper traces etched on the ceramic substrate where the power circuit is located to serve as the electrical connection carrier for the drive circuit, resulting in high parasitic inductance in the power circuit and affecting the performance of the power module. Utility Model Content

[0003] Therefore, it is necessary to provide a power module that can reduce the parasitic inductance of the power circuit.

[0004] In a first aspect, this application provides a power module, including:

[0005] At least one power device;

[0006] A first substrate, on which a driving circuit is provided, and the driving circuit is connected to a power device;

[0007] The second substrate is stacked on top of the first substrate. A power circuit is provided on the surface of the second substrate that is relatively close to the first substrate. The power circuit is connected to a power device. The area of ​​the first substrate is smaller than the area of ​​the second substrate. The surface of the second substrate that is relatively close to the first substrate includes a first region and a second region. The first region is used to characterize the area where the first substrate and the second substrate are stacked on top of each other. The second region is used to characterize the area where the first substrate and the second substrate are not stacked on top of each other. The power device is disposed in the second region.

[0008] In one embodiment, the first substrate includes:

[0009] The first metal layer, the drive circuit is set on the first metal layer;

[0010] The second metal layer is stacked on top of the first metal layer, and the second metal layer is located on the side of the first substrate that is relatively close to the second substrate.

[0011] In one embodiment, the first substrate further includes:

[0012] A ceramic layer is disposed between the first metal layer and the second metal layer.

[0013] In one embodiment, the first metal layer is provided with:

[0014] The first copper bar is used to connect to the positive terminal of the drive circuit;

[0015] The second copper bar is used to connect to the negative terminal of the drive circuit.

[0016] In one embodiment, the power module further includes:

[0017] A thermistor is located in the second region.

[0018] In one embodiment, the power module further includes:

[0019] Multiple bonding wires are used to connect the power circuit and the drive circuit to the power device.

[0020] In one embodiment, the first substrate and the second substrate are fixed together by welding or sintering.

[0021] In one embodiment, the first substrate and the second substrate are bonded together by solder paste, conductive gel or PI adhesive.

[0022] In one embodiment, the first substrate is a co-fired ceramic plate or a printed circuit board.

[0023] In one embodiment, the power device and the second substrate are connected together by silver paste or solder paste.

[0024] The aforementioned power module includes at least one power device, and a first substrate and a second substrate arranged on top of each other. A driving circuit is disposed on the first substrate and connected to the power device. A power circuit is disposed on the surface of the second substrate relatively close to the first substrate and connected to the power device. The area of ​​the first substrate is smaller than the area of ​​the second substrate, and the power device is disposed in a second region on the surface of the second substrate relatively close to the first substrate. By disposing the driving circuit and the power circuit on the first substrate and the second substrate arranged on top of each other, this application maximizes the current-carrying cross-sectional area of ​​the power circuit, reduces the overall parasitic inductance of the power circuit, and thus improves the performance of the power module. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a structural block diagram of a power module in one embodiment;

[0027] Figure 2 This is a schematic diagram of the structure of the first substrate in one embodiment;

[0028] Figure 3 This is a schematic diagram of the structure of the first copper strip and the second copper strip on the first metal layer in one embodiment;

[0029] Figure 4 This is a schematic diagram of the power module in one embodiment;

[0030] Figure 5 This is a schematic diagram of the power module in another embodiment. Detailed Implementation

[0031] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0033] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0034] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0035] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0036] Existing power modules (such as IGBT modules, SiC modules, etc.) generally use copper traces etched on the ceramic substrate where the power circuit is located as the electrical connection carrier for the drive circuit. This has at least the following problems: ① High parasitic inductance: The ceramic substrate area is limited, and the arrangement of the drive circuit on the ceramic substrate significantly encroaches on the arrangement area of ​​the power circuit, resulting in a reduction in the current-carrying cross-sectional area of ​​the power circuit and a high overall parasitic inductance of the circuit; ② Low space utilization: The arrangement of the drive circuit on the ceramic substrate increases the area of ​​the ceramic substrate, resulting in low utilization of the normal space; ③ Easy to generate electromagnetic crosstalk between circuits: The drive circuit and the power circuit are close to each other, which easily generates crosstalk; ④ Low heat dissipation efficiency: The wiring of the drive circuit reduces the width of the substrate copper at the edge of the power device, hindering the downward heat diffusion of the power device.

[0037] The power module provided in this application improves space utilization and maximizes the current-carrying cross-sectional area of ​​the power circuit by setting the drive circuit and the power circuit on the first substrate and the second substrate arranged on each other, respectively. This reduces the overall parasitic inductance of the power circuit and thus improves the performance of the power module. In addition, the increased distance between the drive circuit and the power circuit reduces electromagnetic crosstalk and improves heat dissipation efficiency.

[0038] In one exemplary embodiment, such as Figure 1 As shown, this application provides a power module, including:

[0039] At least one power device 110;

[0040] A first substrate 120 is provided with a driving circuit, which is connected to a power device 110.

[0041] The second substrate 130 is stacked on top of the first substrate 120. A power circuit is provided on the surface of the second substrate 130 that is relatively close to the first substrate 120. The power circuit is connected to the power device 110. The area of ​​the first substrate 120 is smaller than the area of ​​the second substrate 130. The surface of the second substrate 130 that is relatively close to the first substrate 120 includes a first region and a second region. The first region is used to characterize the area where the first substrate 120 and the second substrate 130 are stacked on top of each other. The second region is used to characterize the area where the first substrate 120 and the second substrate 130 are not stacked on top of each other. The power device 110 is disposed in the second region.

[0042] The number and type of power devices 110 can be set according to actual conditions and are not limited in this embodiment; the power circuit can be used to transmit and process high-power electrical energy, and the drive circuit can be responsible for controlling and driving the power devices to switch on and off. The electronic devices included in the power circuit and drive circuit can be set according to actual conditions and are not limited in this embodiment.

[0043] Specifically, Figure 1 An exemplary structural block diagram of a power circuit is shown. The second substrate 130 and the first substrate 120 are stacked on top of each other in the normal direction (thickness direction). The area of ​​the first substrate 120 and the size and shape of the second substrate 130 can be set according to the actual situation, as long as the area of ​​the first substrate 120 is smaller than the area of ​​the second substrate 130. It should be noted that the area of ​​the first substrate 120 being smaller than the area of ​​the second substrate 130 means that the projection areas of the first substrate 120 and the second substrate 130 do not completely overlap, or that the second substrate 130 has a part that is not covered by the first substrate 120, that is, the second region. The power device 110 is disposed in the second region. The power device 110 is connected to the drive circuit on the first substrate 120 and the power circuit on the second substrate 130, respectively.

[0044] For example, the power device can be a semiconductor switching device, which is the core device for realizing power conversion in the entire power module.

[0045] In this embodiment, by integrating the drive circuit on the first substrate and the power circuit on the second substrate, the first and second substrates are stacked on top of each other in the normal direction. This eliminates the need to etch copper traces on the second substrate as electrical connection carriers for the drive circuit, thereby maximizing the current-carrying cross-sectional area of ​​the power circuit and reducing the overall parasitic inductance of the power circuit. At the same time, the stacked design of the first and second substrates reduces the required area and improves the utilization rate of the normal space compared to the traditional single ceramic substrate. It also increases the distance between the drive circuit and the power circuit, reducing the generation of electromagnetic crosstalk and improving the performance of the power module.

[0046] In one embodiment, the first substrate includes:

[0047] The first metal layer, the drive circuit is set on the first metal layer;

[0048] The second metal layer is stacked on top of the first metal layer, and the second metal layer is located on the side of the first substrate that is relatively close to the second substrate.

[0049] Specifically, the first metal layer serves as the conductive layer of the driving circuit, on which the driving circuit is disposed, and the second metal layer serves as the back of the first substrate, used to connect and fix the second substrate.

[0050] In this embodiment, by providing a first metal layer and a second metal layer on a first substrate, with a drive circuit on the first metal layer and the second metal layer used to connect and fix the second substrate, isolation is achieved between the drive circuit and the power circuit on the second substrate, reducing electromagnetic crosstalk and improving the performance of the power module.

[0051] In one embodiment, the first substrate further includes:

[0052] A ceramic layer is disposed between the first metal layer and the second metal layer.

[0053] Specifically, the ceramic layer is disposed between the first metal layer and the second metal layer, serving to connect, fix, and isolate the first metal layer and the second metal layer.

[0054] For example, such as Figure 2 As shown, the first substrate includes a first metal layer 1a, a ceramic layer 1b, and a second metal layer 1c stacked on top of each other. The first metal layer 1a serves as a conductive layer for the drive circuit, where the gate and Kelvin source electrode regions of 4-8 power devices can be arranged, connecting the gate and Kelvin source of each power device in parallel, and providing a lead-out area for the drive signal, connecting each power device in parallel to the signal terminal of the power module. The ceramic layer 1b is stacked between the upper and lower metal layers, serving to connect, fix, and isolate the two metal layers. The second metal layer 1c serves as a back-side soldering and fixing metal layer for connecting and fixing the second substrate.

[0055] In one embodiment, the first metal layer is provided with:

[0056] The first copper bar is used to connect to the positive terminal of the drive circuit;

[0057] The second copper bar is used to connect to the negative terminal of the drive circuit.

[0058] Specifically, the gate of each power device is connected to the positive terminal of the drive circuit, and the Kelvin source of each power device is connected to the negative terminal of the drive circuit. It can be understood that the gate of each power device can be connected to the first copper bar, and the Kelvin source of each power device can be connected to the second copper bar. The first copper bar and the second copper bar are used to connect to an external power supply (the voltage of the external power supply is set according to the actual situation, and is not limited in this embodiment) to supply power to each power device.

[0059] For example, such as Figure 3 As shown, a first copper strip 1aa and a second copper strip 1ab are disposed on the first metal layer. The shapes of the first copper strip 1aa and the second copper strip 1ab can be set according to the actual situation, and are not limited in this embodiment.

[0060] In one embodiment, the power module further includes:

[0061] The thermal device is located in the second region.

[0062] The specific type of thermistor can be set according to the actual situation, and is not limited in this embodiment, as long as it can realize the function of monitoring the temperature of the power device.

[0063] Specifically, the thermistor can be a temperature monitoring device, which is set on the second region of the second substrate to indirectly monitor the temperature level of the power device during operation, so as to ensure that the power device operates within a safe operating temperature range and realize the stable conversion function of the power module.

[0064] In this embodiment, a thermistor is provided to monitor the temperature level of the power device during operation, thereby improving the operational stability of the power module.

[0065] In one embodiment, the power module further includes:

[0066] Multiple bonding wires are used to connect the power circuit and the drive circuit to the power device.

[0067] The number of bonding wires can be set according to actual conditions, and is not limited in this embodiment.

[0068] Specifically, the bonding wires are used to provide interconnections between power devices and power circuits, to provide interconnections between power devices and drive circuits to receive drive signals, and to provide connections from thermistors.

[0069] For example, the thermistor can be connected to the controller via a bonding wire. The controller controls the operating state of the power module according to the temperature information transmitted by the thermistor. Similarly, the drive circuit and the power circuit can be connected to the controller via bonding wire to realize the operation control of the power device.

[0070] To facilitate understanding by those skilled in the art, the structure of the power module is described below with reference to a specific example, such as... Figure 4 As shown, Figure 4 An exemplary perspective view of a power module is shown, wherein 1 is a driving substrate (first substrate), 2 is a power substrate (second substrate), 3 is a power device, 4 is a thermistor, 5 is a bonding wire, and 6 is a device connection layer.

[0071] like Figure 4As shown, the power substrate provides the mounting and process positions for power devices, thermistors, the drive substrate, and bonding wires. It serves as the conductive carrier for the power circuit and provides corresponding power output to the process area. The power devices can be semiconductor switching devices, which are the core components for power conversion in the entire power module. The thermistors can be temperature monitoring devices, indirectly monitoring the temperature level of the power devices during operation to ensure that the power devices operate within a safe operating range and achieve stable conversion function of the power module. The bonding wires provide connections from the power devices in the power circuit to the AC output electrode and the negative terminal of the bus, provide interconnection between the power devices and the drive substrate for drive signals, and provide connections from the thermistors. The device connection layer is used to realize the mounting connection and conductivity between the power devices or thermistors and the power substrate. The device connection layer can be replaced by solder paste.

[0072] Furthermore, Figure 5 An exemplary top view and side view of a power module are provided, wherein 1 is a driving substrate (first substrate), 2 is a power substrate (second substrate), and 7 is a driving substrate connection layer for connecting and fixing the driving substrate and the power substrate. The driving substrate connection layer can be replaced by solder paste, conductive gel or PI glue.

[0073] In one embodiment, the first substrate and the second substrate are fixed together by welding or sintering.

[0074] In one embodiment, the first substrate and the second substrate are bonded together by solder paste, conductive gel or PI adhesive.

[0075] It is understood that the first substrate and the second substrate can be connected in other ways, not limited to the methods mentioned above, as long as the first substrate and the second substrate can be connected to each other.

[0076] In one embodiment, the first substrate is a co-fired ceramic plate or a printed circuit board.

[0077] Specifically, the first substrate can be a low-temperature co-fired ceramic plate (LTCC) or a printed circuit board (PCB).

[0078] In one embodiment, the power device and the second substrate are connected together by silver paste or solder paste.

[0079] It is understood that the power device and the second substrate can be connected in other ways, not limited to the methods mentioned above, as long as the power device and the second substrate can be connected to each other.

[0080] For example, the manufacturing process of the power module can be as follows: applying and printing silver paste on the mounting positions of the power device, thermistor and the drive substrate (first substrate) on the power substrate (second substrate) to form a device connection layer and a drive substrate connection layer; baking the printed silver paste to cure it; mounting the power device, thermistor and drive substrate; sintering the power device, thermistor and drive substrate to the power substrate by pressure low temperature sintering, and using metal bonding wires to supplement the circuit connection between the power substrate and the drive substrate.

[0081] In the description of this specification, references to terms such as "some embodiments," "other embodiments," and "ideal embodiments" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A power module, characterized in that, include: At least one power device; A first substrate, on which a driving circuit is disposed, the driving circuit being connected to the power device; A second substrate is arranged on top of the first substrate. A power circuit is provided on the surface of the second substrate that is relatively close to the first substrate. The power circuit is connected to the power device. The area of ​​the first substrate is smaller than the area of ​​the second substrate. The surface of the second substrate that is relatively close to the first substrate includes a first region and a second region. The first region is used to characterize the area where the first substrate and the second substrate are superimposed. The second region is used to characterize the area where the first substrate and the second substrate are not superimposed. The power device is disposed in the second region.

2. The power module according to claim 1, characterized in that, The first substrate includes: A first metal layer, wherein the driving circuit is disposed on the first metal layer; A second metal layer is disposed on top of the first metal layer, and the second metal layer is located on the first substrate on the side relatively close to the second substrate.

3. The power module according to claim 2, characterized in that, The first substrate further includes: A ceramic layer is disposed between the first metal layer and the second metal layer.

4. The power module according to claim 2, characterized in that, The first metal layer is provided with: The first copper bar is used to connect to the positive terminal of the drive circuit; The second copper bar is used to connect to the negative terminal of the drive circuit.

5. The power module according to claim 1, characterized in that, The power module also includes: A thermistor is disposed in the second region.

6. The power module according to claim 1, characterized in that, The power module also includes: Multiple bonding wires are used to connect the power circuit and the drive circuit to the power device.

7. The power module according to claim 1, characterized in that, The first substrate and the second substrate are fixed together by welding or sintering.

8. The power module according to claim 1, characterized in that, The first substrate and the second substrate are connected together by solder paste, conductive gel or PI glue.

9. The power module according to claim 1, characterized in that, The first substrate is a co-fired ceramic plate or a printed circuit board.

10. The power module according to claim 1, characterized in that, The power device and the second substrate are connected together by silver paste or solder paste.

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