Highly symmetrical current-sharing silicon carbide power module

Abstract

The invention provides a highly-symmetrical current-sharing silicon carbide power module, and belongs to the technical field of power electronic devices. A first conductive power layer and a second conductive power layer are of interdigital structures and are arranged in a nested manner; the total number of interdigitals of the first conductive power layer and the second conductive power layer is an odd number; the first conductive power layer and the second conductive power layer are symmetrical about the center line of the DC + conductive power layer and the DC-conductive power layer. The silicon carbide power chips are symmetrically arranged on the first conductive power layer and the second conductive power layer; current flowing through the first conductive power layer and the second conductive power layer of the silicon carbide power chip is equal in magnitude and opposite in direction. All components of the silicon carbide power module are in a highly symmetrical state in space, so that the current flowing through all silicon carbide power chips is equal when the module operates, the same operating conditions of all the chips are ensured, and the problem of current sharing of a multi-chip module is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of power electronic devices, and more specifically, relates to a highly symmetrical current-sharing silicon carbide power module. Background Art

[0002] As core components for controlling and converting electrical energy, power semiconductor devices are widely used in power management, automotive electronics, industrial control, wastewater treatment, renewable energy and other fields, playing an indispensable role in a variety of occasions and working conditions.

[0003] As a representative of the third-generation semiconductor materials, silicon carbide has the advantages of high temperature, high speed, high efficiency and high reliability. Compared with traditional silicon materials, as a wide bandgap material, silicon carbide has lower leakage current under high temperature conditions and higher thermal conductivity, which helps to support high current density applications and can work normally at higher ambient temperatures; it has lower energy loss, which helps to minimize power loss; it has a higher switching frequency, which reduces the size of large peripheral passive components; it has a smaller die size and lower parasitic capacitance, which brings lower switching losses, allowing power converters to operate at higher switching frequencies and speeds.

[0004] In high-current, high-power application scenarios, silicon carbide power modules mostly use multi-chip parallel connection. However, due to the high switching speed of silicon carbide power chips, they are more sensitive to parasitic parameters during the switching process. At the same time, multiple chips mean that the overall module has a larger parasitic inductance and greater losses, making it difficult to achieve the current balance effect of a single chip. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of this application is to provide a highly symmetrical current-balancing silicon carbide power module, which aims to solve the problem that the silicon carbide power chip has a high switching speed and is sensitive to parasitic parameters during the switching process, resulting in large parasitic inductance and loss of multiple chips, making it difficult to form current balance in a single chip.

[0006] To achieve the above-mentioned object, the present application provides a highly symmetrical current-sharing silicon carbide power module, comprising: a DC+ conductive power layer, a DC- conductive power layer, a gate conductive power layer, an AC conductive power layer, a first conductive power layer, and a second conductive power layer;

[0007] A DC+ conductive power layer, a gate conductive power layer, a DC- conductive power layer and an AC conductive power layer are sequentially arranged in a clockwise direction to form a closed rectangle; the first conductive power layer and the second conductive power layer are interdigitated structures, and the two are nested; the total number of interdigitated fingers of the first conductive power layer and the second conductive power layer is an odd number; the first conductive power layer and the second conductive power layer are symmetrical about the midline of the DC+ conductive power layer and the DC- conductive power layer;

[0008] The silicon carbide power chip is symmetrically placed on the first conductive power layer and the second conductive power layer; the current of the silicon carbide power chip flowing through the first conductive power layer and the second conductive power layer is equal in magnitude and opposite in direction;

[0009] The DC+ conductive power layer is used as the connection layer of the DC+ pole of the silicon carbide power chip; the DC- conductive power layer is used as the connection layer of the DC- pole of the silicon carbide power chip; the gate conductive power layer is used as the gate connection layer of the silicon carbide power chip; and the AC conductive power layer is used as the connection layer of the AC pole of the silicon carbide power chip.

[0010] Further preferably, the highly symmetrical current-equalizing silicon carbide power module also includes: a lower conductive layer and a ceramic layer; the lower conductive layer, the ceramic layer, the DC+ conductive power layer, the DC- conductive power layer, the gate conductive power layer, the AC conductive power layer, the first conductive power layer and the second conductive power layer together constitute a DBC structure.

[0011] Further preferably, the highly symmetrical current-sharing silicon carbide power module further comprises a third conductive power layer, a fourth conductive power layer, a first conductive power resistor and a second conductive power resistor; the third conductive power layer is located between the gate conductive power layer and the outermost side of the first conductive power layer, and the fourth conductive power layer is located between the AC conductive power layer and the outermost side of the first conductive power layer; the third conductive power layer and the fourth conductive power layer are symmetrical about the center line of the DC+ conductive power layer; the first conductive power resistor and the second conductive power resistor are symmetrical about the center line of the DC+ conductive power layer;

[0012] The first conductive power resistor is used to connect the third conductive power copper layer with the gate conductive power layer; the second conductive power resistor is used to connect the fourth conductive power copper layer with the AC conductive power layer.

[0013] Further preferably, the silicon carbide power chip is welded to the first conductive power layer and the second conductive power layer via a nano silver solder layer.

[0014] Further preferably, the current-sharing silicon carbide power module further comprises: a first DC+ power terminal, a second DC+ power terminal, a first AC power terminal, a second AC power terminal, a first DC- power terminal, a second DC- power terminal, a first gate power terminal, and a second gate power terminal;

[0015] The DC+ conductive power layer has a first DC+ power terminal and a second DC+ power terminal at both ends; the DC- conductive power layer has a first DC- power terminal and a second DC- power terminal at both ends; the gate conductive power layer has a first gate power terminal and a second gate power terminal at both ends; the AC conductive power layer has a first AC power terminal and a second AC power terminal at both ends;

[0016] The first DC+ power terminal and the second DC+ power terminal are used to lead out the DC+ pole of the silicon carbide power chip; the first AC power terminal and the second AC power terminal are used to lead out the AC pole of the silicon carbide power chip; the first DC- power terminal and the second DC- power terminal are used to lead out the DC- pole of the silicon carbide power chip; the first gate power terminal and the second gate power terminal are used to lead out the gate of the silicon carbide power chip.

[0017] Further preferably, the number of the silicon carbide power chips is at least 16.

[0018] Further preferably, each silicon carbide power chip is provided with a bonding wire, and the bonding wire is one of gold, aluminum, copper, silver and tungsten.

[0019] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0020] The present application provides a current-sharing silicon carbide power module, in which all components of the silicon carbide power module are highly symmetrical in space, so that the current flowing through all silicon carbide power chips of the module is equal when the module is running, ensuring that all chips operate under the same conditions, thereby solving the current-sharing problem of multi-chip modules.

[0021] The present application discloses a highly symmetrical current-equalizing silicon carbide power module. In the silicon carbide power module, the currents in the two paths flowing through the silicon carbide power chip are equal in magnitude and opposite in direction under normal working conditions, and a "mutual inductance cancellation" working condition is formed inside the module as a whole, which greatly reduces the parasitic inductance of the module, reduces the turn-on loss, conduction loss and turn-off loss of the silicon carbide power chip when the module is running, reduces heat accumulation, improves the output efficiency of the power module, increases working efficiency, and improves the operating stability of the power module.

[0022] The present application provides a highly symmetrical current-sharing silicon carbide power module. The silicon carbide power module used can use at least 16 silicon carbide power chips. The number of chips can be increased symmetrically, which increases the application scenarios of the module and improves the overall working life of the module. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a highly symmetrical current-sharing silicon carbide power module structure at an engineering view angle of 45° provided in an embodiment of the present application;

[0024] Figure 2 It is a schematic diagram of a highly symmetrical current-sharing silicon carbide power module structure at an engineering view angle of 135° provided in an embodiment of the present application;

[0025] Figure 3It is a side view of a highly symmetrical current-sharing silicon carbide power module structure provided by an embodiment of the present application;

[0026] Figure 4 It is a top view of a highly symmetrical current-sharing silicon carbide power module structure provided in an embodiment of the present application;

[0027] Marking Description:

[0028] 1-lower conductive copper layer; 2-ceramic layer; 3-DC+ conductive power copper layer; 4-gate conductive power copper layer; 5-DC-conductive power copper layer; 6-first conductive power copper layer; 7-second conductive power copper layer; 8-AC conductive power copper layer; 9-first conductive power resistor; 10-second conductive power resistor; 11-nanosilver solder layer; 12-silicon carbide power chip; 13-bonding wire; 14a-first DC+ power terminal; 14b-second DC+ power terminal; 15a-first AC power terminal; 15b-second AC power terminal; 16a-first DC-power terminal; 16b-second DC-power terminal; 17a-first gate power terminal; 17b-second gate power terminal; 18-third conductive power copper layer; 19-fourth conductive power copper layer. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0030] like Figures 1 to 4 As shown, the present application provides a highly symmetrical current-sharing silicon carbide power module, wherein the lower conductive copper layer 1 is directly connected to the ceramic layer 2; the ceramic layer 2 is directly connected to the DC+ conductive power copper layer 3, the gate conductive power copper layer 4, the DC- conductive power copper layer 5, the first conductive power copper layer 6, the second conductive power copper layer 7, the AC conductive power copper layer 8, the third conductive power copper layer 18 and the fourth conductive power copper layer 19 respectively; 16 silicon carbide power chips 12 are evenly distributed on the first conductive power copper layer 6 and the second conductive power copper layer 7, with 8 chips on each conductive power copper layer; the 16 silicon carbide power chips 12 are respectively connected to different conductive power copper layers through bonding wires 13 to form a conductive loop; the first conductive power copper layer 16 is connected to the second conductive power copper layer 17, and the second conductive power copper layer 18 is connected to the second conductive power copper layer 19. The third conductive power copper layer 18 is connected to the gate conductive power copper layer 4 through the first conductive power resistor 9; the fourth conductive power copper layer 19 is connected to the AC conductive power copper layer 8 through the second conductive power resistor 10; the DC+ conductive power copper layer 3 is provided with a first DC+ power terminal 14a and a second DC+ power terminal 14b at both ends; the DC- conductive power copper layer 5 is provided with a first DC- power terminal 16a and a second DC- power terminal 16b at both ends; the gate conductive power copper layer 4 is provided with a first gate power terminal 17a and a second gate power terminal 17b at both ends; the AC conductive power copper layer 8 is provided with a first AC power terminal 15a and a second AC power terminal 15b at both ends;

[0031] The lower conductive copper layer 1, the ceramic layer 2 and all the conductive power copper layers together form a DBC structure;

[0032] The lower conductive copper layer 1 is used to improve thermal conductivity, reduce contact resistance, and increase power capacity;

[0033] The ceramic layer 2 is used to improve thermal conductivity and heat dissipation, provide good electrical insulation performance, reduce stress caused by thermal expansion mismatch, protect the chip from damage, have high mechanical strength and good reliability, can remain stable in extreme environments such as high temperature and high current, and is suitable for packaging of high-power electronic devices;

[0034] The DC+ conductive power copper layer 3 is used to provide efficient heat conduction and electrical connection, enhance heat dissipation performance, and is used as a connection layer for the DC+ pole of the silicon carbide power chip;

[0035] The gate conductive power copper layer 4 is used to provide efficient heat conduction and electrical connection, enhance heat dissipation performance, and is used as a gate connection layer of the silicon carbide power chip;

[0036] The DC-conductive power copper layer 5 is used as a connection layer for the DC-pole of the silicon carbide power chip, providing efficient heat conduction and electrical connection, and enhancing heat dissipation performance;

[0037] The first conductive power copper layer 6 and the second conductive power copper layer 7 output a finger structure, which is used to make the current of the silicon carbide power chip flowing through the first conductive power copper layer 6 and the second conductive power copper layer 7 equal in magnitude and opposite in direction;

[0038] The silicon carbide power chips placed on the first conductive power copper layer 6 and the second conductive power copper layer 7 need to be placed symmetrically;

[0039] The first conductive power copper layer 6 is used to place half of the silicon carbide power chip in the silicon carbide power module, providing efficient heat conduction and electrical connection;

[0040] The second conductive power copper layer 7 is used to place half of the silicon carbide power chip in the silicon carbide power module, providing efficient heat conduction and electrical connection, and enhancing heat dissipation performance;

[0041] The AC conductive power copper layer 8 is used as a connection layer for the AC pole of the silicon carbide power chip, providing efficient heat conduction and electrical connection, and enhancing heat dissipation performance;

[0042] The first conductive power resistor 9 is used to provide electrical connection, connecting the third conductive power copper layer and the gate conductive power copper layer;

[0043] The second conductive power resistor 10 is used to provide electrical connection, connecting the fourth conductive power copper layer and the AC conductive power copper layer;

[0044] The nano silver solder layer is used as a soldering material for the silicon carbide power chip and the conductive power copper layer. It has excellent electrical conductivity, can ensure good electrical connectivity, and effectively transmit current. Silver is one of the metals with the highest known thermal conductivity. Therefore, the nano silver solder can effectively dissipate heat during the welding process, reduce thermal resistance, and improve heat dissipation performance.

[0045] Bonding wires are used to provide electrical connections and can withstand certain mechanical stresses and temperature changes to ensure the stability and reliability of the circuit;

[0046] The first DC+ power terminal and the second DC+ power terminal are used to lead out the DC+ pole; the first AC power terminal and the second AC power terminal are used to lead out the AC pole; the first DC- power terminal and the second DC- power terminal are used to lead out the DC- pole; the first gate power terminal and the second gate power terminal are used to lead out the gate; the third conductive power copper layer is used as an intermediate connection layer of the gate conductive power copper layer; the fourth conductive power copper layer is used as an intermediate connection layer of the AC conductive power copper layer. Further preferably, the bonding wire can be one of gold, aluminum, copper, silver and tungsten.

[0047] Further preferably, the silicon carbide power chip 12 is soldered on the first conductive power copper layer 6 and the second conductive power copper layer 7 respectively through the nano silver solder layer 11;

[0048] Further preferably, the 16 silicon carbide power chips 12 are symmetrically distributed along the plane formed by the center line of the DC+ conductive power copper layer 3 and the center line of the DC- conductive power copper layer 5;

[0049] Further preferably, the lower conductive copper layer 1, the ceramic layer 2, the first conductive power copper layer 6, the second conductive power copper layer 7, the gate conductive power copper layer 4, the AC conductive power copper layer 8, the third conductive power copper layer 18, the fourth conductive power copper layer 19, the eight power terminals 14a-17b, the first conductive power resistor 9, the second conductive power resistor 10, and the bonding wire 13 are all symmetrically distributed along the plane formed by the center line of the DC+ conductive power copper layer 3 and the center line of the DC- conductive power copper layer 5;

[0050] The lower conductive copper layer 1, the ceramic layer 2, the DC+ conductive power copper layer 3, the gate conductive power copper layer 4, the DC- conductive power copper layer 5, the first conductive power copper layer 6, the second conductive power copper layer 7, the AC conductive power copper layer 8, the first conductive power resistor 9, the second conductive power resistor 10, the nano silver solder layer 11, the silicon carbide power chip 12, the bonding wire 13, the 8 power terminals 14a-17b, the third conductive power copper layer 18 and the fourth conductive power copper layer 19 are all arranged in the epoxy resin.

[0051] Further preferably, the number of the silicon carbide power chips 12 is at least 16, and the silicon carbide power chips can be added in a symmetrical distribution according to actual conditions.

[0052] In summary, compared with the prior art, the present application has the following advantages:

[0053] The silicon carbide power module used in this application has all components highly symmetrical in space, so that the current flowing through all silicon carbide power chips of the module is equal when it is running, ensuring the same operating conditions for all chips, solving the current sharing problem of multi-chip modules, and at least 16 silicon carbide power chips are used at the same time, which increases the application scenarios of the module and improves the overall working life of the module.

[0054] In the silicon carbide power module adopted in the present application, under normal working conditions, the currents in the two paths flowing through the silicon carbide power chip are equal in magnitude and opposite in direction, and a "mutual inductance cancellation" working condition is formed inside the module as a whole, which greatly reduces the parasitic inductance of the module, reduces the turn-on loss, conduction loss and turn-off loss of the silicon carbide power chip when the module is running, reduces heat accumulation, improves the output efficiency of the power module, increases working efficiency, and improves the operating stability of the power module.

[0055] The silicon carbide power module used in the present application can use at least 16 silicon carbide power chips, and the number of chips can be increased symmetrically to adapt to more working occasions.

[0056] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0057] In addition, in the present application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0058] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0059] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, verticality, etc. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense, and allow a small amount of deviation, approximation to symmetry, approximation to equality, approximation to parallelism, approximation to verticality, etc. are all possible. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0060] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A highly symmetrical current-sharing silicon carbide power module, characterized in that: include: A DC+ conductive power layer, a DC- conductive power layer, a gate conductive power layer, an AC conductive power layer, a first conductive power layer, and a second conductive power layer; A DC+ conductive power layer, a gate conductive power layer, a DC- conductive power layer and an AC conductive power layer are sequentially arranged in a clockwise direction to form a closed rectangle; the first conductive power layer and the second conductive power layer are interdigitated structures, and the two are nested; the total number of interdigitated fingers of the first conductive power layer and the second conductive power layer is an odd number; the first conductive power layer and the second conductive power layer are symmetrical about the midline of the DC+ conductive power layer and the DC- conductive power layer; The silicon carbide power chip is symmetrically placed on the first conductive power layer and the second conductive power layer; the current of the silicon carbide power chip flowing through the first conductive power layer and the second conductive power layer is equal in magnitude and opposite in direction; The DC+ conductive power layer, DC- conductive power layer, gate conductive power layer and AC conductive power layer are respectively used as the DC+ pole connection layer, DC- pole connection layer, gate connection layer and AC pole connection layer of the silicon carbide power chip.

2. The current-sharing silicon carbide power module according to claim 1, characterized in that: Also includes: The lower conductive layer and the ceramic layer; the lower conductive layer, the ceramic layer, the DC+ conductive power layer, the DC- conductive power layer, the gate conductive power layer, the AC conductive power layer, the first conductive power layer and the second conductive power layer together constitute a DBC structure.

3. The current-sharing silicon carbide power module according to claim 1 or 2, characterized in that: Also includes a third conductive power layer, a fourth conductive power layer, a first conductive power resistor and a second conductive power resistor; The third conductive power layer is located between the gate conductive power layer and the outermost side of the first conductive power layer, and the fourth conductive power layer is located between the AC conductive power layer and the outermost side of the first conductive power layer; the third conductive power layer and the fourth conductive power layer are symmetrical about the center line of the DC+ conductive power layer; the first conductive power resistor and the second conductive power resistor are symmetrical about the center line of the DC+ conductive power layer; The first conductive power resistor is used to connect the third conductive power copper layer with the gate conductive power layer; the second conductive power resistor is used to connect the fourth conductive power copper layer with the AC conductive power layer.

4. The current-sharing silicon carbide power module according to claim 1, characterized in that: The silicon carbide power chip is welded to the first conductive power layer and the second conductive power layer through the nano silver solder layer.

5. The current-sharing silicon carbide power module according to claim 1 or 2, characterized in that: Also includes: a first DC+ power terminal, a second DC+ power terminal, a first AC power terminal, a second AC power terminal, a first DC- power terminal, a second DC- power terminal, a first gate power terminal, and a second gate power terminal; The DC+ conductive power layer has a first DC+ power terminal and a second DC+ power terminal at both ends; the DC- conductive power layer has a first DC- power terminal and a second DC- power terminal at both ends; the gate conductive power layer has a first gate power terminal and a second gate power terminal at both ends; the AC conductive power layer has a first AC power terminal and a second AC power terminal at both ends; The first DC+ power terminal and the second DC+ power terminal are used to lead out the DC+ pole of the silicon carbide power chip; the first AC power terminal and the second AC power terminal are used to lead out the AC pole of the silicon carbide power chip; the first DC- power terminal and the second DC- power terminal are used to lead out the DC- pole of the silicon carbide power chip; the first gate power terminal and the second gate power terminal are used to lead out the gate of the silicon carbide power chip.

6. The current-sharing silicon carbide power module according to claim 1 or 2, characterized in that: There are at least 16 silicon carbide power chips.

7. The current-sharing silicon carbide power module according to claim 6, characterized in that: Silicon carbide power chips are all provided with bonding wires, which are made of one of gold, aluminum, copper, silver and tungsten.

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