High current, low switching loss SiC power module

Abstract

The present invention discloses a high current, low switching loss SiC power module. A power module includes a housing having an internal chamber and a plurality of switching modules mounted in the internal chamber of the housing. The switching modules are interconnected and configured to facilitate power switching to a load. Each of the switching modules includes at least one transistor and at least one diode. At least one transistor and at least one diode may be formed of a wide bandgap material system such as silicon carbide (SiC), thereby allowing the power module to operate at high frequencies and lower switching losses when compared to conventional power modules.

Description

[0001] This application is a divisional application, the application number of the parent application is 2015800376807, the application date is May 14, 2015, and the name of the invention is "High current, low switching loss SiC power module".

[0002] Related Applications

[0003] This application is a continuation-in-part of U.S. patent application serial number 13 / 893,998 filed on May 14, 2013, which is a continuation-in-part of U.S. patent application serial number 13 / 588,329 filed on August 17, 2012, which claims the benefit of U.S. Provisional Patent Application No. 61 / 533,254 filed on September 11, 2011, the entire disclosure of which is incorporated herein by reference. Technical Field

[0004] The present disclosure relates to a power module for controlling power delivery to a load. Background Art

[0005] As the cost of power continues to increase and environmental impact issues grow, the demand for power devices with improved performance and efficiency continues to grow. One way to improve the performance and efficiency of power devices is to manufacture the devices using silicon carbide (SiC). Compared to conventional silicon power devices, power devices made of silicon carbide (SiC) are expected to show great advantages in switching speed, power handling capabilities, and temperature handling capabilities. In particular, the high critical field and wide bandgap of SiC devices allow for increases in both performance and efficiency when compared to conventional silicon devices.

[0006] Due to inherent performance limitations in silicon, conventional power devices require bipolar structures, such as insulated gate bipolar transistors (IGBTs), when blocking high voltages (e.g., voltages greater than 5 kV). While utilizing a bipolar structure substantially reduces the resistance of the drift layer due to its conductivity modulation, the bipolar structure also suffers from relatively slow switching times. As will be clear to those skilled in the art, the reverse recovery time of the bipolar structure (due to the relatively slow diffusion of minority carriers) limits its maximum switching time, making silicon devices generally unsuitable for high voltage and high frequency applications.

[0007] Due to the above performance enhancements for SiC power devices, unipolar SiC power devices can be used to block voltages up to 10 kV or more. The majority carrier nature of such unipolar SiC power devices effectively eliminates the reverse recovery time of the device, allowing very high switching speeds (e.g., for a 10 kV blocking capability and approximately 100 mΩ*cm 2The specific on-resistance of a double diffused metal oxide semiconductor field effect transistor (DMOSFET) is less than 100ns).

[0008] Power devices are often interconnected and integrated into power modules that work to dynamically switch large amounts of power through various components such as motors, converters, generators, etc. As discussed above, due to the continued growth of power cost and environmental impact issues, there remains a continuing need for power modules that are smaller, cheaper to manufacture, and more efficient, while providing similar or better performance than their conventional counterparts. Summary of the invention

[0009] The present disclosure relates to a power module for controlling power delivery to a load. According to one embodiment, the power module includes: a housing having an internal chamber; and a plurality of switching modules mounted in the internal chamber of the housing. The switching modules are interconnected and configured to facilitate switching power to the load. Each of the switching modules includes at least one transistor and at least one diode. At the same time, the switching modules are capable of blocking 1200 volts, conducting 300 amperes and having switching losses of less than 20 millijoules. By including the switching modules in the power module so that the power module has a switching loss of less than 20 millijoules for a 1200V / 300A rating, the performance of the power module is significantly improved when compared to conventional power modules.

[0010] According to one embodiment, a power module includes a housing having an internal chamber, at least one power substrate in the internal chamber, and a gate connector. The power substrate includes a switching module on a first surface of the power substrate for facilitating switching power to a load. The switching module includes at least one transistor and at least one diode. The gate connector is coupled to a gate contact of at least one transistor via a signal path, the signal path including a first conductive trace on the first surface of the power substrate. The gate connector is connected to the gate of at least one transistor using a conductive trace on the first surface of the power substrate, reducing interference in the power module and increasing the connection reliability between the gate connector and the gate contact of at least one transistor.

[0011] According to one embodiment, a power module includes a housing having an internal chamber, a pair of output contacts, and a plurality of switching modules. The plurality of switching modules are mounted within the internal chamber of the housing and are interconnected to facilitate switching power from a power source coupled between the output contacts to a load. The pair of output contacts are arranged such that at least 150 mm of each output contact of the output contacts is within the housing. 2 The area is located less than 1.5mm from another output contact. Provide at least 150mm less than 1.5mm from another output contact 2The area of ​​each output contact reduces the leakage inductance between the output contacts, thereby increasing the performance of the power module.

[0012] Those skilled in the art will understand the scope of the present disclosure and realize additional aspects of the present disclosure after reading the following detailed description of the preferred embodiments associated with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various aspects of the disclosure and together with the description serve to explain the principles of the disclosure.

[0014] Figure 1 is a schematic diagram showing details of a power module according to one embodiment of the present disclosure.

[0015] Figure 2 It is shown by Figure 1 Graphs of the various signals generated by the power module are shown.

[0016] Figure 3 It is shown in Figure 1 A schematic diagram of details of a switching module in a power module is shown.

[0017] Figure 4 is a diagram showing an embodiment of the present disclosure Figure 1 Block diagram showing details of the power module.

[0018] Figure 5 is a diagram showing an embodiment of the present disclosure Figure 1 A plan view of a detail of a power module is shown.

[0019] Figure 6 is a diagram showing an embodiment of the present disclosure Figure 1 A plan view of further details of the power module is shown.

[0020] Figure 7 is a diagram showing an embodiment of the present disclosure Figure 1 A plan view of the outer casing of the power module is shown.

[0021] Figure 8 is a diagram showing an embodiment of the present disclosure Figure 1 A plan view of a detail of the outer housing of the power module is shown.

[0022] Fig. 9 is a diagram showing an embodiment of the present disclosure Figure 4 Block diagram showing details of a power baseplate in a power module. DETAILED DESCRIPTION

[0023] The embodiments set forth below represent information necessary to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. After reading the following description according to the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will be aware of the application of these concepts that are not specifically mentioned herein. It should be understood that these concepts and applications fall within the scope of the present disclosure and the appended claims.

[0024] It will be understood that although the terms first, second, etc. may be used to describe various elements in this article, these elements should not be limited to these terms. These terms are only used to distinguish elements. For example, without departing from the scope of the present disclosure, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element. As used herein, the term "and / or" includes any combination and all combinations of one or more of the associated listed items.

[0025] It will be understood that when an element such as a layer, region, or substrate is referred to as being "on" or extending "on" another element, it may be directly on or directly extending onto another element, or there may also be intervening elements. Conversely, when an element is referred to as being "directly on" or extending "directly" onto another element, there are no intervening elements. Likewise, it will be understood that when an element such as a layer, region, or substrate is referred to as being "on" or extending "on" another element, it may be directly on or directly extending onto another element, or there may also be intervening elements. Conversely, when an element is referred to as being "directly on" or extending "directly" onto another element, there are no intervening elements. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to another element, or there may be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0026] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element, layer or region to another element, layer or region as illustrated in the figures. It will be understood that these terms and the terms discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

[0027] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limitations of the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "an" and "the" are also intended to include plural forms. It should be further understood that when the terms "comprising", "comprising", "including" and / or "comprising" are used herein, they specify the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups thereof.

[0028] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that the terms used herein should be interpreted as being consistent with their meanings in the context of this specification and the relevant art, and not interpreted in an idealized or overly formal sense, unless explicitly defined herein.

[0029] Figure 1An exemplary power module 10 according to one embodiment of the present disclosure is shown. The power module 10 includes two switching modules SM1 and SM2, which are controlled by a control system 12 to transfer power from a power source (DC+ / DC-) to a load 14 in a controlled manner. As will be appreciated by those skilled in the art, the switching modules SM1 and SM2 form a half bridge, the details of which are discussed below. Each of the switching modules SM1 and SM2 includes at least a first transistor connected in reverse parallel to a first diode. Specifically, the first switching module SM1 includes a first transistor Q1 connected in reverse parallel to a first diode D1, and the second switching module SM2 includes a second transistor Q2 connected in reverse parallel to a second diode D2. In one embodiment, the first transistor Q1 and the second transistor Q2 are metal oxide semiconductor field effect transistors (MOSFETs). However, it will be clear to those skilled in the art that any suitable switching device, such as an insulated gate bipolar transistor (IGBT), a field effect transistor (FET), a junction field effect transistor (JFET), a high electron mobility transistor (HEMT), etc., can be used in the switching modules SM1 and SM2 without departing from the principles of the present disclosure. The first diode D1 and the second diode D2 may be Schottky diodes, and specifically junction barrier Schottky diodes. Again, it will be clear to those skilled in the art that any suitable diode device, for example, a PN diode and a PiN diode, may be used for the switching modules SM1 and SM2 without departing from the principles of the present disclosure. In one embodiment, the second diode D1 and the second diode D2 are omitted, and their functions are replaced by the internal body diodes of the first transistor Q1 and the second transistor Q2, respectively. Using the internal body diodes of the first transistor Q1 and the second transistor Q2 instead of the first diode D1 and the second diode D2 can save space and cost in the power module 10.

[0030] The gate contact G of the first transistor Q1 and the source contact S of the first transistor Q1 are coupled to the control system 12. Similarly, the gate contact G and the source contact S of the second transistor Q2 are also coupled to the control system 12. Significantly, the connection from the gate contact G of the first transistor Q1 and the second transistor Q2 to the control system 12 can be realized via relatively low-power gate connectors G1 and G2, respectively. Similarly, the connection from the source contact S of the first transistor Q1 and the second transistor Q2 to the control system 12 can be realized via low-power source return connections S1 and S2, respectively, for measuring one or more operating parameters of the first transistor Q1 and the second transistor Q2. The drain contact D of the first transistor Q1 is coupled to the positive power supply terminal DC+. The drain contact D of the second transistor Q2 is coupled to the output terminal OUT. The source contact S of the first transistor Q1 is also coupled to the output terminal OUT. The source contact S of the second transistor Q2 is coupled to the negative power supply terminal DC-. Finally, the load 14 is coupled between the output terminal OUT and the negative DC power supply terminal DC-.

[0031] The first transistor Q1, the first diode D1, the second transistor Q2, and the second diode D2 may each be a majority carrier device. The majority carrier devices generally include FETs, such as MOSFETs, HEMTs, JFETs, etc., but do not include thyristors, bipolar transistors, and insulated gate bipolar transistors (IGBTs). Therefore, when compared to conventional power modules using bipolar devices, the power module 10 may be able to operate at high switching speeds and suffer lower switching losses. In one embodiment, the first transistor Q1, the first diode D1, the second transistor Q2, and the second diode D2 are wide band-gap devices. For the purposes of this disclosure, a wide band-gap device is a semiconductor device having a bandgap greater than or equal to 3.0 electron volts (eV). For example, the first transistor Q1, the first diode D1, the second transistor Q2, and the second diode D2 may be a silicon carbide (SiC) device or a gallium nitride (GaN) device. For reference purposes, Si has a bandgap of about 1.1 eV, and SiC has a bandgap of about 3.3 eV. As discussed above, the use of SiC for the first transistor Q1, the first diode D1, the second transistor Q2, and the second diode D1 significantly reduces the switching time of each device when compared to conventional silicon (Si) IGBT-based power modules, and additionally suffers from lower switching losses. For example, if the power module 10 is rated at 1200V and 300A, then the power module 10 can maintain switching losses of less than 25 millijoules (mJ), less than 20mJ, and even less than 15mJ in various embodiments when operating between -40°C and 150°C, while also providing a low on-state voltage drop. As will be appreciated by those skilled in the art, the switching losses of the power module 10 will not drop below 1mJ. In other embodiments, the first transistor Q1, the first diode D1, the second transistor Q2, and the second diode D2 are majority carrier devices and wide bandgap devices.

[0032] In operation, the control system 12 operates the first switching module SM1 and the second switching module SM2 in a complementary manner so that when the first switching module SM1 is turned on, the second switching module SM2 is blocked, and vice versa. A graph showing the voltage at the gate contact G of the first transistor Q1, the voltage at the gate contact G of the second transistor Q2, the voltage at the output terminal OUT, and the current through the load 14 during a switching cycle of the power module 10 is shown in FIG. Figure 2During the first period T1, the first switching module SM1 is turned on, while the second switching module SM2 is blocked. Therefore, the output terminal OUT is connected to the positive power supply terminal DC+, thereby providing the positive power supply voltage to the load 14 and causing the current to flow from the positive power supply terminal DC+ through the first transistor Q1 and into the load 14. Generally, the load 14 is an inductive load, so that the current passing through the load 14 increases slowly when the first switching module SM1 is turned on.

[0033] During the second time period T2, the first switching module SM1 switches to the blocking mode. In addition, the second switching module SM2 remains in the blocking mode. During this period, due to the internal capacitance associated with each of the first switching module SM1 and the second switching module SM2, the current continues to flow from the output terminal OUT to the load 14. Specifically, about half of the current passing through the load 14 is provided by the internal capacitance of each of the switching modules SM1 and SM2. Therefore, the voltage at the output terminal OUT is converted to ground at a given rate, and the current passing through the load 14 is gradually reduced.

[0034] When the second switching module SM2 switches to the on mode in the third period T3, the output terminal OUT is coupled to the negative power supply terminal DC-, which can be grounded in some embodiments. Therefore, the current flows through the second transistor Q2 and flows into the load 14 through the output terminal OUT, making the current become more and more negative.

[0035] During the fourth time period T4, the second switching module SM2 switches to the blocking mode. In addition, the first switching module SM1 is in the blocking mode. During this period, due to the internal capacitance associated with each of the first switching module SM1 and the second switching module SM2, a negative current continues to flow from the output terminal OUT to the load. Specifically, about half of the current through the load 14 is provided by the internal capacitance of each switching module in the switching modules SM1 and SM2. Therefore, the voltage at the output terminal OUT is converted from ground to the positive power supply voltage provided at the positive power supply terminal DC+, and the current through the load 14 becomes more and more positive. Finally, during the fifth time period T5, the switching cycle restarts so that the first switching module SM1 is in the conduction mode and the second switching module SM2 is in the blocking mode.

[0036] Figure 3 Detail of the first switching module SM1 according to one embodiment of the present disclosure is shown. The second switching module SM2 may be configured similarly to the first switching module SM2, but is not shown for simplicity. Figure 3 As shown, the first transistor Q1 and the first diode D1 of the first switching module SM1 may include a plurality of transistors Q1 coupled in parallel. 1-6 and multiple reverse parallel diodes D1 1-6Specifically, multiple transistors Q1 1-6 The drain contacts D of each transistor in can be coupled together, and transistor Q1 1-6 The source contacts S of each transistor in can be coupled together, and transistor Q1 1-6 The gate contact G of each transistor can be connected through a gate resistor R G They are coupled together. Transistor Q1 1-6 Each transistor includes an anti-parallel diode Q1 coupled between a source contact S and a drain contact D thereof. 1-6 Although the six transistors Q1 1-6 Shown with six anti-parallel diodes D1 1-6 coupled in parallel, but any number of transistors and anti-parallel diodes may be used without departing from the principles of the present disclosure.

[0037] A plurality of transistors Q1 coupled in parallel are included 1-6 and multiple reverse parallel diodes D1 1-6 This allows the first switching module SM1 to handle a greater amount of power than would otherwise be possible. For example, in one embodiment, transistor Q1 1-6 Each transistor in Q1 is rated to block 1.2 kV and conduct 50 A, so that the first switching module SM1 can conduct 300 A. In other embodiments, transistor Q1 1-6 Each transistor in Q1 can be rated to block 1.2 kV and pass 40 A, so that the first switching module SM1 can conduct 240 A. In another embodiment, the transistor Q1 1-6 Each transistor in may be rated to block 1.2 kV and pass 20 A, thereby enabling the first switching module SM1 to conduct 120 A.

[0038] A gate resistor R G The gate resistor R is used to suppress any undesirable oscillations that may occur in the first switching module SM1 when the first switching module SM1 is driven at a relatively high transition speed (eg, greater than 20 V / ns). G The resistance of transistor Q1 can be 1-6 The rated current of each transistor in the first switching module SM1 and thus the rated current of all the first switching module SM1 are changed. In the embodiment in which the first switching module SM1 has a rated current of 120A, the gate resistor R G Each resistor in has a resistance between about 1Ω and 15Ω. In another embodiment in which the first switching module SM1 has a rated current of 240A, the gate resistor R GEach of the resistors has a resistance between about 1Ω and 15Ω. In yet another embodiment in which the first switching module SM1 has a rated current of 300A, each of the gate resistors has a resistance between about 15Ω and 20Ω.

[0039] Figure 4 Detailed description of a power module 10 according to an embodiment of the present disclosure is shown. Figure 4 As shown, the power module 10 includes a housing 16 provided with an internal chamber 18 holding one or more power substrates 20. Specifically, the internal chamber 18 of the housing 16 holds a first power substrate 20A, a second power substrate 20B, a third power substrate 20C, and a fourth power substrate 20D. It will be clear to those skilled in the art that the internal chamber 18 of the housing 16 can accommodate any number of power substrates 20 without departing from the principles of the present disclosure. Each of the power substrates 20 is shown to include a plurality of transistors Q, a plurality of diodes D, and a plurality of resistors R representing the main components of the first switching module SM1 and the second switching module SM2. In one embodiment, the first switching module SM1 is provided by the first power substrate 20A and the second power substrate 20B, while the second switching module SM2 is provided by the third power substrate 20C and the fourth power substrate 20D, respectively. The necessary interconnections between the components on each power substrate of the power substrate 20 can be provided by metal traces (not shown) on the surface of the power substrate 20. In addition, wire bonds (not shown) can be provided to interconnect the different power substrates 20 and to connect the power substrates 20 to one or more external connectors (not shown). The power substrate 20 may be mounted to a mounting structure 22 attached to the housing 16. In one embodiment, the mounting structure 22 is a planar heat sink that also functions to dissipate heat generated by the first switching module SM1 and the second switching module SM2.

[0040] As discussed above, the plurality of transistors Q and diodes D may be majority carrier devices, thereby reducing the switching time and loss associated with each of the transistors Q and diodes D. Therefore, the power module 10 may operate at a higher frequency and suffer less switching loss than conventional power modules. In addition, the transistors Q and diodes D may be wideband-gap devices, such as SiC devices. As discussed above, using SiC for the transistors Q and diodes D significantly reduces the switching time and switching loss of the transistors Q and diodes D, thereby increasing the performance of the power module 10.

[0041] Figure 5 Detail of an exemplary mounting structure 22 and power substrate 20 are shown according to one embodiment of the present disclosure. Figure 5As shown, the first power substrate 20A, the second power substrate 20B, the third power substrate 20C and the fourth power substrate 20D are arranged on the mounting structure 22. The first power substrate 20A includes three transistors Q1 among the six transistors of the first switching module SM1. 1-3 , three gate resistors R G And three of the six reverse parallel diodes are reverse parallel diodes D1 1-3 The second power module includes the remaining transistor Q1 of the first switching module SM1 4-6 , Gate resistor R G And the anti-parallel diode D1 4-6 Similarly, the third power module 20C includes three transistors Q2 among the six transistors of the second switching module SM2. 1-3 , three gate resistors R G And three of the six reverse parallel diodes are reverse parallel diodes D2 1-3 The fourth power substrate 20D includes the remaining transistor Q2 of the second switching module SM2 4-6 , Gate resistor R G And the reverse parallel diode D2 4-6 The thicker black lines represent wire bonds between various components in the power module 10 and between various components of the power module 10 and one or more output terminals 24. The output terminals 24 of the power module 10 include the first gate connector G1, the second gate connector G2, the first source return connector S1, and the second source return connector S2 as discussed above. Other connections between components on the power substrate 20 are provided by metal traces. Notably, a gate bus 26 is provided on the power substrate 20 and is connected to the transistor Q2 in the second switching module SM2. 1-6 The gate bus 26 runs between the gate contact G of the transistor Q2 in the second switching module SM2 and the output terminal 24 of the power module. 1-6 The gate bus 26 runs between the gate contact G of the second switching module SM2 and the second gate connector G2, and can additionally provide a low power path from the source contact S of the transistor Q21-6 in the second switching module SM2 to the second source return connector S2. The gate bus 26 is a metal trace on each power substrate of the power substrate 20, which reduces interference with the power module 10 and increases the transistor Q2 in the second switching module SM2. 1-6 The mounting structure 22 may provide a reliable connection between the gate contact and the output terminal 24 of the power module 10, especially when compared to a "cross-gate" connection used in conventional power modules. As shown, the mounting structure 22 may form all or part of a heat sink that acts to dissipate heat generated by the first switching module SM1 and the second switching module SM2.

[0042] In one embodiment, the gate bus 26 can be replaced by one or more coaxial cables to connect the transistor Q2 in the second switching module. 1-6 The gate contact G and the output terminal 24 of the power module 10. When compared to other solutions, a coaxial cable is used to connect the output terminal to the transistor Q2 1-6 The gate contacts G of the first switching module SM1 and the second switching module SM2 may provide improved isolation, thereby improving the performance of the power module 10. In addition, although the output terminals of the gate contacts G for both the switching module SM1 and the second switching module SM2 are disposed on the same side of the housing 16 of the housing power module 10, in other embodiments, they may be disposed on opposite sides of the housing 16. Disposing the output terminals 24 of the gate contacts G of the first switching module SM1 and the second switching module SM2 on opposite sides of the housing 16 may provide a shorter connection route to each of the gate contacts G of the second switching module SM2, thereby reducing interference and improving the durability of the power module 10. In addition, disposing the output terminals 24 of the gate contacts G of the first switching module SM1 and the second switching module SM2 on opposite sides of the housing 16 may reduce the transistor Q2 in the second switching module SM2. 1-6 The gate resistor R of each transistor G The required resistance of transistor Q2 is reduced because of the shorter connection path between the gate contact G and the output terminal 24. 1-6 The amount of oscillation seen.

[0043] Figure 6 1 shows further details of the housing 16, the output terminal OUT, the positive power supply terminal DC+, and the negative power supply terminal DC- according to one embodiment of the present disclosure. Figure 6 As shown, the housing 16 is substantially rectangular and includes cutouts for mounting holes M1-M4 for mounting the power module 10 to the platform. In addition, a positive power terminal DC+, a negative power terminal DC-, and an output terminal OUT are shown. As will be clear to those skilled in the art, the stray inductance across the positive power terminal DC+ and the negative power terminal DC- may result in reduced performance of the power module 10, especially under high frequency operation of the power module 10. Therefore, the positive power terminal DC+ and the negative power terminal DC- are arranged close to each other, generally spaced less than 1.5 mm apart, so as to reduce the leakage inductance across the terminals. In addition, the terminals can be made wide, generally about 33.5 mm wide, so as to maximize the area near the relative terminals. Generally, the positive power terminal DC+ and the negative power terminal DC- will have a spacing of about 150 mm within 1.5 mm of each other. 2 and 200mm 2 In one embodiment, the positive power supply terminal DC+ and the negative power supply terminal DC- will have an area of ​​about 187.31 mm within 1.5 mm of each other. 2As will be apparent to those skilled in the art, the capacitive effect created by placing the relatively large area of ​​the positive power terminal DC+ in close proximity to the larger area of ​​the negative power terminal DC- reduces the leakage inductance between the terminals, thereby improving the performance of the power module 10.

[0044] Figure 7 1 shows additional details of the housing 16 according to one embodiment of the present disclosure. Figure 7 As shown, the housing 16 includes a power substrate 20, and provides output terminals for a positive power terminal DC+, a negative power terminal DC-, an output terminal OUT, and corresponding paths to connect the first switching module SM1 and the second switching module SM2 to the control system 12. Significantly, the housing 16 and the various output terminals are industry standard, allowing the power module 10 to be used as a drop-in solution for an existing platform. In addition, a creepage divider 28 is provided between each of the positive power terminal DC+, the negative power terminal DC-, and the output terminal OUT, which increases the creepage distance between the corresponding terminals by about 50%. Therefore, the power module 10 can be used in higher voltage applications without the risk of short circuit or other damage.

[0045] like Figure 7 As shown, one or more unused terminal locations 30 may be present in the housing 16. The unused terminal locations 30 may be used to provide a Kelvin connection to one or more components of the power module 10, or may be used to provide a connection to an NTC temperature sensor module included in the power module 10 in various embodiments.

[0046] Figure 8 A cutaway view of a power module 10 according to one embodiment of the present disclosure is shown. Notably, an additional creepage separator 32 is provided between the positive power supply terminal DC+ and the negative power supply terminal DC-, which separates the respective nodes from each other and thus protects from short circuits at high voltages, while at the same time allowing the power module 10 to take advantage of the reduction in leakage inductance between the nodes discussed above.

[0047] Fig. 9 Detail of the first power substrate 20A according to one embodiment of the present disclosure is shown. The second power substrate 20B, the third power substrate 20C, and the fourth power substrate 20D may be configured similarly to the first power substrate 20A, but are not shown for simplicity. Fig. 9As shown, the first power substrate 20A is formed on a baseplate 34 (which may be copper). Those skilled in the art will appreciate that there are many different materials for the baseplate 34, all of which are covered herein. In one embodiment, the baseplate 34 is aluminum silicon carbide (AlSiC), which may be lighter than copper and provide better thermal matching with one or more attached components. The baseplate 34 may be shared between each power substrate in the power substrate 20 so that the first power substrate 20A, the second power substrate 20B, the third power substrate 20C, and the fourth power substrate 20D are all formed on the baseplate 34. A direct bonded copper (DBC) substrate 36 may be disposed on the baseplate 34. The DBC substrate 36 may include a first metal layer 38 on the surface of the baseplate 34, an insulating layer 40 on the first metal layer 38, and a second metal layer 42 on the insulating layer 40 opposite to the first metal layer 38. The first metal layer 38 and the second metal layer 42 may be, for example, copper. It will be clear to those skilled in the art that there are many different suitable materials for first metal layer 38 and second metal layer 42, all of which are contemplated herein. Insulating layer 40 may be, for example, aluminum nitride (AlN). It will be clear to those skilled in the art that there are many different suitable materials for insulating layer 40, for example, aluminum oxide (Al 2 O 3 ) or silicon nitride (Si 3 N 4 ), all of which is covered in this article.

[0048] The use of AlN for the insulating layer 40 can provide a much higher thermal conductivity when compared to conventional aluminum oxide or silicon nitride (SiN) layers. Given the relatively low resistance associated with SiC devices and the low thermal resistance of AlN, the power module 10 can handle higher currents than conventional power modules. The thickness of the insulating layer 40 can be selected based on the target isolation voltage. Due to the advantages provided by using SiC components and the AlN insulating layer 40, the power module 10 can handle more power than conventional devices of the same size and / or can be reduced to a smaller size than its conventional counterparts.

[0049] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered to be within the scope of the concepts disclosed herein and within the following claims.

Claims

1. A power module, comprising: a housing having an interior chamber; first and second terminals, wherein a portion of the first and second terminals that are opposite to each other are arranged within 1.5 mm of each other to reduce at least a portion of a leakage inductance provided across the first and second terminals of the power module; a creepage separator between the first terminal and the second terminal; and A plurality of switching modules are mounted within the internal cavity between the first terminal and the second terminal and are interconnected to facilitate switching power to a load, wherein each of the plurality of switching modules includes at least one transistor and at least one diode.

2. The power module according to claim 1, wherein: The power module is capable of blocking at least 1200 volts and conducting at least 120 amps, the power module having switching losses of less than 25 millijoules.

3. The power module according to claim 1, wherein: The at least one transistor and the at least one diode are silicon carbide devices.

4. The power module according to claim 3, wherein: The at least one transistor is a metal oxide semiconductor field effect transistor, and the at least one diode is a Schottky diode.

5. The power module according to claim 3, wherein: The at least one transistor is coupled in anti-parallel to the at least one diode.

6. The power module according to claim 1, wherein: The first terminal and the second terminal include at least 150 mm 2 area.

7. The power module according to claim 1, wherein: The at least one diode is an internal body diode of the at least one transistor.

8. The power module according to claim 1, wherein: At least one diode is external to the at least one transistor.

9. The power module according to claim 1, wherein: The power module further includes a power substrate; Each of the plurality of switching modules further comprises at least one gate resistor; and The at least one gate resistor, the at least one transistor and the at least one diode of each of the plurality of switching modules are mounted on the power substrate so that a surface of the power substrate provides electrical connections between the at least one gate resistor, the at least one transistor and the at least one diode of each of the plurality of switching modules.

10. The power module according to claim 9, wherein: The power substrate includes aluminum nitride.

11. The power module according to claim 10, further comprising: A base plate, wherein the power substrate is on the base plate, and the base plate comprises silicon aluminum nitride.

12. The power module according to claim 1, wherein: The creepage separator is part of the housing.

13. The power module according to claim 1, wherein: The creepage separator provides electrical isolation between the first terminal and the second terminal.

14. A power module, comprising: a housing having an interior chamber; a first power substrate and a second power substrate within the interior chamber; a plurality of transistors, the plurality of transistors comprising a first plurality of transistors, wherein the first plurality of transistors are on a surface of the first power substrate, the first plurality of transistors form a portion of a switching module, and the plurality of transistors further comprises a second plurality of transistors; The second plurality of transistors are on a surface of the second power substrate; and A gate connector is coupled to a gate contact of each of the first plurality of transistors via a gate connection bus comprising a gate bus conductive trace on a surface of the first power substrate extending between the first plurality of transistors and the second plurality of transistors.

15. The power module according to claim 14, wherein: The gate bus conductive trace runs between opposing sides of the first power substrate and the second power substrate.

16. The power module according to claim 14, in, The plurality of transistors are silicon carbide devices.

17. The power module according to claim 16, wherein: The gate connector is coupled to the gate contact of each of the plurality of transistors via the gate connection bus and one or more coaxial cables.

18. The power module according to claim 16, further comprising: The first terminal and the second terminal include at least 150 mm 2 area; as well as A creepage separator is between the first terminal and the second terminal.

19. The power module according to claim 16, wherein: The power module is capable of blocking at least 1200 volts and conducting at least 120 amps, the power module having switching losses of less than 25 millijoules.

20. A power module, comprising: a housing having an interior chamber; a first terminal and a second terminal; a creepage separator between the first terminal and the second terminal; as well as a plurality of switching modules mounted within the interior chamber and interconnected to facilitate switching power to a load, wherein each of the plurality of switching modules includes at least one transistor configured to conduct current in a first direction via a channel in the at least one transistor and to conduct current in a second direction opposite to the first direction via an internal body diode in the at least one transistor, A portion of the first terminals and a portion of the second terminals that are opposite to each other are arranged within 1.5 mm of each other to reduce at least a portion of the leakage inductance provided across the terminals.

21. The power module according to claim 20, wherein: The power module is capable of blocking 1200 volts and conducting at least 120 amps, the power module having switching losses of less than 25 millijoules.

22. The power module according to claim 20, wherein: The at least one transistor is a silicon carbide (SiC) device.

23. The power module according to claim 20, wherein: The first terminal and the second terminal include at least 150 mm 2 to reduce the leakage inductance between the first terminal and the second terminal, and wherein the power module is configured to operate at a switching frequency of at least 50 kHz.

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