GaN half-bridge power module with junction temperature monitoring based on silicon carbide diodes

Abstract

The application discloses a GaN half-bridge power module capable of realizing junction temperature monitoring based on silicon carbide diodes, and relates to the field of semiconductor devices.The GaN half-bridge power module comprises a substrate, a gallium nitride power device die, a silicon carbide diode die, a direct-current positive bus terminal, an alternating-current output terminal, a direct-current negative bus terminal, a driving loop gate terminal, a driving loop source terminal and a cushion block.The gallium nitride power device die and the silicon carbide diode die are placed in a three-dimensional stack mode and are fixedly connected through solder.In the dead time of the power module, the junction temperature of the gallium nitride power device die is monitored by measuring the temperature-dependent electrical parameter of the silicon carbide diode die.The temperature-dependent electrical parameter and the junction temperature are in a linear relationship, so that the simple junction temperature monitoring function without a complex peripheral conversion circuit is realized, the reverse conduction loss is reduced, the heat dissipation effect is improved, the thermal mechanical stress is reduced, and the reliability and service life of the power module are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor device technology, and in particular to a GaN half-bridge power module based on silicon carbide diodes that enables junction temperature monitoring. Background Technology

[0002] With the rapid development of the new energy industry, applications such as rail transit, drone electric drives, robot electric drives, and electric vehicles are placing higher demands on power electronic conversion systems. As the core component of inverters and electronic control systems, power modules determine the system's reliability and efficiency, and are required to possess higher power density, efficiency, and reliability. Traditional silicon devices are approaching their theoretical limits, while gallium nitride (GaN) high electron mobility transistors (HEMTs) have brought revolutionary changes to power converters due to their smaller gate charge and on-resistance. However, the faster switching speed of GaN HEMTs makes them more sensitive to parasitic parameters, easily leading to electromagnetic interference (EMI) problems; simultaneously, their smaller chip area results in increased heat flux density, requiring more stringent heat dissipation. Therefore, real-time monitoring of GaN chip junction temperature is extremely important, enabling measures to be taken before junction temperature runaway to prevent chip burnout and improve power module reliability.

[0003] Existing junction temperature monitoring technologies mainly fall into two categories: The first involves amplifying the device's turn-off delay time using external amplifier circuits to detect the junction temperature. This method is complex, heavily reliant on external circuit design, and cannot improve integration. The second method uses a hybrid neural network model that integrates data-driven and physical information to reconstruct the module's thermal field. By analyzing the mapping relationship between the NTC temperature distribution and the module's thermal field, it achieves decoupling of operating condition parameters within a specified range. However, this method can only decouple the equivalent convective heat transfer coefficient within ±20%. When heat dissipation conditions fluctuate beyond this range, the estimation accuracy drops significantly. Furthermore, it requires training based on precisely calibrated FEM simulation data, and model construction and parameter calibration require specialized knowledge and extensive experimental verification, resulting in high engineering implementation costs. Therefore, a junction temperature monitoring solution that is simple in structure, low in cost, and easy to implement is urgently needed. Summary of the Invention

[0004] To address the aforementioned challenges, this application provides a GaN half-bridge power module based on silicon carbide diodes (SiC diodes) capable of junction temperature monitoring. By stacking SiC diode dies and gallium nitride (GaN) power device dies in three dimensions, and utilizing the linear relationship between the forward conduction voltage and temperature of the SiC diode, the forward voltage of the SiC diode is directly measured during the dead time to infer the junction temperature of the GaN power device. This achieves a simple junction temperature monitoring function without the need for complex external conversion circuits, while simultaneously reducing reverse conduction losses, improving heat dissipation, and reducing thermomechanical stress, thereby enhancing the reliability and lifespan of the power module.

[0005] To achieve the above objectives, this application provides a GaN half-bridge power module based on silicon carbide diodes that enables junction temperature monitoring, comprising: substrate; Gallium nitride power device dies are disposed on a substrate; A silicon carbide diode die is disposed on top of a gallium nitride power device die; DC positive bus terminal, AC output terminal, DC negative bus terminal, drive loop gate terminal and drive loop source terminal; And pads, used to connect the substrate of the gallium nitride power device die to the source terminal of the drive loop; In this configuration, gallium nitride power device dies and silicon carbide diode dies are stacked in three dimensions and fixedly connected by solder. During the dead time of the power module, the junction temperature of the gallium nitride power device die is monitored by measuring the temperature-related electrical parameters of the silicon carbide diode die. The electrical parameters and the junction temperature are linearly related.

[0006] Preferably, the gallium nitride power device die has a lateral structure.

[0007] Preferably, the electrical parameters include forward conduction voltage, on-resistance, and leakage current.

[0008] Preferably, the thermal conductivity of the silicon carbide diode die is 370~490W / (m*K), and the coefficient of thermal expansion is 3.7~4.6ppm / K; the coefficient of thermal expansion of the gallium nitride power device die is 2.8~3.7ppm / K.

[0009] Preferably, the substrate is any one of DPC ceramic substrate, DBC ceramic substrate, AMB ceramic substrate, and PCB circuit board, and the ceramic material is any one of aluminum nitride, aluminum oxide, and silicon nitride.

[0010] Preferably, the power module includes an upper transistor and a lower transistor, both of which include a stacked structure of the gallium nitride power device die and the silicon carbide diode die.

[0011] Preferably, the pad, the DC positive bus terminal, the AC output terminal, and the DC negative bus terminal are all made of metal capable of achieving electrical connection.

[0012] Preferably, the silicon carbide diode die is a silicon carbide Schottky diode die.

[0013] Preferably, the silicon carbide diode die and the gallium nitride power device die form an anti-parallel structure, and the forward conduction voltage of the silicon carbide diode die is equal to the source-drain voltage of the gallium nitride power device die.

[0014] Therefore, the GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring described above has the following advantages: (1) This application can reduce the reverse conduction loss of gallium nitride power devices in actual converters, thereby reducing the overall power device loss.

[0015] (2) This application infers the junction temperature of a gallium nitride power device based on the forward conduction voltage of a silicon carbide diode during the dead time. This is because the forward conduction voltage of a silicon carbide diode has a good linear relationship with temperature. At the same time, measuring the forward voltage of a silicon carbide diode during the dead time can be easily achieved using existing equipment.

[0016] (3) The junction temperature detection of this application is more convenient and simple. It does not require complex external circuits. It only requires measuring the voltage of the silicon carbide diode, and the voltage of the silicon carbide diode is the source-drain voltage of the gallium nitride power device connected in reverse parallel.

[0017] (4) The area of ​​the silicon carbide diode in this application is larger than that of the gallium nitride power device, and the thermal conductivity of silicon carbide is 370 (W / m*K), which is close to the thermal conductivity of copper (370 (W / m*K)). Therefore, under the same power consumption, the heat dissipation effect is better than that of the traditional structure. In addition, the reverse conduction loss mentioned above will be reduced, thereby further reducing the junction temperature of the chip and improving the heat dissipation capability.

[0018] (5) Since the thermal expansion coefficients of silicon carbide (3.7 ppm / k) and gallium nitride (2.8 ppm / k) are very close, the matching degree of thermal expansion coefficients is extremely high. Compared with the traditional structure in which gallium nitride power devices are directly welded to copper (thermal expansion coefficient of 17 ppm / k), the thermomechanical stress on the substrate of gallium nitride power devices is reduced accordingly, which increases the reliability of gallium nitride power devices.

[0019] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a structural diagram of a GaN half-bridge power module based on a silicon carbide diode that enables junction temperature monitoring, as described in this application. Figure 2 This is a partial structural diagram of the power module in an embodiment of this application; Figure 3 This is a simulated junction temperature distribution diagram of the upper gallium nitride power device in a traditional half-bridge power module; Figure 4 The simulated junction temperature distribution of the gallium nitride power device in the upper transistor of the half-bridge power module of this application is shown. Figure 5This is a simulated junction temperature distribution diagram of the gallium nitride power device in the lower transistor of a traditional half-bridge power module. Figure 6 The simulated junction temperature distribution of the gallium nitride power device in the lower transistor of the half-bridge power module of this application is shown. Figure 7 This is a simulated thermomechanical stress distribution diagram of the substrate of the upper gallium nitride power device in a traditional half-bridge power module. Figure 8 This is a simulated thermomechanical stress distribution diagram of the substrate of the upper gallium nitride power device of the half-bridge power module of this application. Figure 9 This is a simulated thermomechanical stress distribution diagram of the substrate of the gallium nitride power device in the lower transistor of a traditional half-bridge power module. Figure 10 This is a simulated thermomechanical stress distribution diagram of the substrate of the gallium nitride power device of the lower transistor in the half-bridge power module of this application. Figure label: 1. DC positive bus terminal; 2. AC output terminal; 3. DC negative bus terminal; 4. Spacer; 5. Substrate; 6. Gallium nitride power device die; 7. Silicon carbide diode die; 8. Solder; 9. Drive loop gate terminal; 10. Drive loop source terminal. Detailed Implementation

[0021] The following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning as understood by a person of ordinary skill in the art to which this application pertains.

[0023] The terms "comprising" or "including," as used in this application, mean that the element preceding the term encompasses the element listed after the term, and do not exclude the possibility of encompassing other elements as well. The terms "inner," "outer," "upper," and "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In this application, unless otherwise expressly specified and limited, the term "attached," etc., should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can refer to a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two elements or the interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Example 1: A GaN half-bridge power module based on silicon carbide diodes that enables junction temperature monitoring, such as... Figures 1-2 As shown, it includes: substrate 5; A gallium nitride power device die 6 is disposed on the substrate 5; The silicon carbide diode die 7 is disposed on the upper part of the gallium nitride power device die 6. The use of silicon carbide diode die 7 in this application facilitates packaging and integration, and can enhance heat dissipation and reduce thermal resistance. DC positive bus terminal 1, AC output terminal 2, DC negative bus terminal 3, drive loop gate terminal 9, and drive loop source terminal 10; And pad 4, used to connect the substrate of the gallium nitride power device die 6 to the source terminal 10 of the drive loop; In this design, the gallium nitride power device die 6 and the silicon carbide diode die 7 are stacked in three dimensions and fixedly connected by solder 8. During the dead time of the power module, the junction temperature of the gallium nitride power device die 6 is monitored by measuring the temperature-related electrical parameters of the silicon carbide diode die 7. The electrical parameters are linearly related to the junction temperature and include forward voltage, on-resistance, and leakage current.

[0025] The gallium nitride power device die 6 has a lateral structure, eliminating parasitic and thermal resistance introduced by monolithic packaging. In this application, the gallium nitride power device can also be a silicon-based device, a silicon carbide device, or a gallium oxide device with a lateral structure.

[0026] The area of ​​the silicon carbide diode die 7 is larger than the area of ​​the gallium nitride power device die 6.

[0027] The thermal conductivity of the silicon carbide diode die is 370~490W / (m*K), and the coefficient of thermal expansion is 3.7~4.6ppm / K; the coefficient of thermal expansion of the gallium nitride power device die is 2.8~3.7ppm / K.

[0028] The substrate 5 can be any one of DPC ceramic substrate, DBC ceramic substrate, AMB ceramic substrate, or PCB circuit board, and the ceramic material can be any one of aluminum nitride, aluminum oxide, or silicon nitride. In practical applications, the substrate is preferably a DPC ceramic substrate, and the ceramic material is aluminum nitride.

[0029] The power module includes an upper transistor and a lower transistor, both of which include a stacked structure of the gallium nitride power device die 6 and the silicon carbide diode die 7.

[0030] The pad 4, the DC positive bus terminal 1, the AC output terminal 2, and the DC negative bus terminal 3 are made of metal that can achieve electrical connection, preferably oxygen-free copper.

[0031] The silicon carbide diode die 7 is a silicon carbide Schottky diode die.

[0032] The silicon carbide diode die 7 and the gallium nitride power device die 6 form an anti-parallel structure, and the forward conduction voltage of the silicon carbide diode die 7 is equal to the source-drain voltage of the gallium nitride power device die 6.

[0033] The silicon carbide diode in this application can also be a gallium nitride diode, a gallium oxide diode, or a diamond diode.

[0034] Example 2: To further illustrate the technical effects of the GaN half-bridge power module in junction temperature control and thermomechanical stress improvement, a simulation comparison analysis was conducted between this embodiment and a traditional half-bridge power module. The comparison results are as follows: Figures 3-10 As shown.

[0035] pass Figures 3-6 It can be seen that the junction temperature of the power module in this application can be reduced by about 7°C, demonstrating good heat dissipation. Through... Figures 7-10 It can be seen that the thermomechanical stress value of the backplane of the upper-side gallium nitride power device in this application can be reduced by about 10 MPa, and the thermomechanical stress value of the backplane of the lower-side gallium nitride power device can be reduced by about 7 MPa, which can improve the reliability of gallium nitride power devices.

[0036] Therefore, this application adopts the above-mentioned GaN half-bridge power module based on silicon carbide diodes that can realize junction temperature monitoring. By stacking silicon carbide diode dies and gallium nitride power device dies in three dimensions, and utilizing the linear relationship between the forward conduction voltage and temperature of silicon carbide diodes, the forward voltage of silicon carbide diodes is directly measured during the dead time to infer the junction temperature of gallium nitride power devices. This achieves the function of junction temperature detection with simple material costs and simple measurement methods.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of this application, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of this application.

Claims

1. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring capability, characterized in that, include: substrate; Gallium nitride power device dies are disposed on a substrate; A silicon carbide diode die is disposed on top of a gallium nitride power device die; DC positive bus terminal, AC output terminal, DC negative bus terminal, drive loop gate terminal and drive loop source terminal; And pads, used to connect the substrate of the gallium nitride power device die to the source terminal of the drive loop; In this configuration, gallium nitride power device dies and silicon carbide diode dies are stacked in three dimensions and fixedly connected by solder. During the dead time of the power module, the junction temperature of the gallium nitride power device die is monitored by measuring the temperature-related electrical parameters of the silicon carbide diode die. The electrical parameters and the junction temperature are linearly related.

2. The GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 1, characterized in that, The gallium nitride power device die has a lateral structure.

3. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 2, characterized in that, Electrical parameters include forward voltage, on-resistance, and leakage current.

4. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 3, characterized in that, The thermal conductivity of the silicon carbide diode die is 370~490W / (m*K), and the coefficient of thermal expansion is 3.7~4.6ppm / K; the coefficient of thermal expansion of the gallium nitride power device die is 2.8~3.7ppm / K.

5. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 4, characterized in that, The substrate is any one of DPC ceramic substrate, DBC ceramic substrate, AMB ceramic substrate, and PCB circuit board, and the ceramic material is any one of aluminum nitride, aluminum oxide, and silicon nitride.

6. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 5, characterized in that, The power module includes an upper transistor and a lower transistor, both of which include a stacked structure of the gallium nitride power device die and the silicon carbide diode die.

7. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 6, characterized in that, The pad, the DC positive bus terminal, the AC output terminal, and the DC negative bus terminal are all made of metal capable of achieving electrical connection.

8. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 7, characterized in that, The silicon carbide diode die is a silicon carbide Schottky diode die.

9. A GaN half-bridge power module based on silicon carbide diodes with junction temperature monitoring as described in claim 8, characterized in that, The silicon carbide diode die and the gallium nitride power device die form an anti-parallel structure, and the forward conduction voltage of the silicon carbide diode die is equal to the source-drain voltage of the gallium nitride power device die.

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