A silicon carbide MOSFET internal driver protection device

Abstract

The present invention relates to a silicon carbide MOSFET internal drive protection device, comprising a main chip and a substrate, wherein the main chip and the substrate are arranged on the same plane but at different locations on a metal plate, with a gate, a drain, a source, and a metal electrode provided on one side of the metal plate; a packaging shell provided on the outer surface of the metal plate; a first contact, a second contact, and a third contact provided on the main chip, wherein the first contact leads to the gate, the second contact leads to the drain, and the third contact leads to the source, and the first, second, and third contacts are provided in different areas of the main chip; a current limiting resistor, a thermistor, and a voltage regulator are provided on the substrate; the thermistor is connected in parallel with the voltage regulator and then in series with the current limiting resistor. The internal drive protection device effectively solves the problems of gate drive voltage breakdown and circuit heat balance by limiting the gate drive voltage and heat of the silicon carbide MOSFET, thereby improving the reliability of the power electronic converter; the silicon carbide MOSFET does not require the introduction of an external protection circuit, has a simple structure, and is easy to assemble.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon carbide, and in particular relates to a silicon carbide MOSFET internal driver protection device. Background Art

[0002] In power electronics conversion technology, high frequency, miniaturization, and high reliability are the main development directions. Currently, silicon carbide is a relatively mature semiconductor material. Compared with ordinary silicon components, it has high voltage resistance and is widely used in switching power supplies, high-frequency bridge push-pull circuits, and rectifiers. Among them, silicon carbide MOSFET, as a new power device, has the characteristics of high voltage resistance, high operating temperature, high-frequency switching speed, short body diode reverse recovery time, and low parasitic capacitance. Therefore, the use of silicon carbide MOSFET can significantly improve the power density of power electronic converters.

[0003] Silicon carbide MOSFETs (SiC MOSFETs) and silicon MOSFETs exhibit some differences in device characteristics due to differences in materials and structures. The drive circuits for silicon MOSFETs require consistency during use. Currently, the drive voltage range for silicon MOSFETs is -30V to +30V, while the drive voltage range for SiC MOSFETs is -8V to +20V, with a recommended drive voltage range of -4V to +20V. Therefore, SiC MOSFETs have a lower safety threshold than existing silicon MOSFETs. A voltage spike in the drive circuit could potentially break down the fragile gate oxide layer of the SiC MOSFET, causing circuit failure. External circuit protection is often employed, but this is limited by the parasitic inductance of distributed parameters, resulting in poor protection and an inability to address the root cause of the SiC MOSFET's poor operational stability. Furthermore, SiC MOSFETs are more heat-resistant than silicon MOSFETs and are often used in high-temperature conditions. Even with a heat sink, heat cannot be removed quickly enough, shortening the SiC MOSFET's lifespan. Consequently, an external discharge circuit is required for protection, resulting in a cumbersome design. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: in response to the above-mentioned defects, the present invention provides an internal drive protection device for silicon carbide MOSFET, which effectively solves the problems of gate drive voltage breakdown and circuit heat balance by limiting the gate drive voltage and heat of silicon carbide MOSFET, thereby improving the reliability of power electronic converters; the silicon carbide MOSFET does not require the introduction of an external protection circuit, has a simple structure, and is easy to assemble.

[0005] The present invention solves the technical problem by adopting the following technical solution: a silicon carbide MOSFET internal driver protection device, comprising a main chip and a substrate, wherein the main chip and the substrate are respectively arranged on the same plane of a metal plate, and a gate, a drain, a source and a metal electrode are provided on one side of the metal plate; and a packaging shell is provided on the outer surface of the metal plate;

[0006] The main chip is provided with a first contact, a second contact, and a third contact, wherein the first contact lead-out end is a gate, the second contact lead-out end is a drain, and the third contact lead-out end is a source, and the first contact, the second contact, and the third contact are arranged in different areas of the main chip;

[0007] The substrate is provided with a current limiting resistor, a thermistor, and a voltage-stabilizing diode; the first point of the current limiting resistor is electrically connected to the gate, the second point of the current limiting resistor is electrically connected to the second point of the thermistor, the second point of the thermistor is also electrically connected to the second point of the voltage-stabilizing diode, the first point of the thermistor is electrically connected to the first point of the voltage-stabilizing diode, the source is electrically connected to the first point of the thermistor or the first point of the voltage-stabilizing diode; the second point of the voltage-stabilizing diode is electrically connected to the first contact on the main chip, the third contact is electrically connected to the source, and the metal pole is electrically connected to the second contact; that is, the thermistor and the voltage-stabilizing diode are connected in parallel and then in series with the current limiting resistor.

[0008] The silicon carbide MOSFET is powered by a power supply. After the gate drive is powered, the current limiting resistor has a limited current, providing a gate drive voltage for the silicon carbide MOSFET. A voltage regulator tube connected in series with the current limiting resistor is introduced. When the gate drive voltage of the voltage regulator tube is a reverse negative voltage, the forward clamp of the voltage regulator tube formed by the current limiting resistor and the voltage regulator tube is amplitude limited. When the MOSFET gate drive is a positive voltage, the current limiting resistor and the voltage regulator tube constitute a reverse amplitude limit of the voltage regulator tube, thereby realizing the gate drive positive and negative pulse voltage amplitude limit, realizing the gate drive voltage amplitude limit of the silicon carbide MOSFET, and effectively solving the problem of gate drive voltage breakdown; by introducing a thermistor to control the heat of the circuit, especially when driving positively, the resistance of the thermistor is reduced, This reduces the current passing through the silicon carbide MOSFET, achieves heat balance, and is beneficial to protecting the circuit. In addition, when the circuit is negatively driven and shut down, the protection device forms a discharge loop to accelerate the shutdown, and does not require an external discharge circuit. The structure is simple and easy to use. The gate drive protection and thermal limit protection circuits formed by the current limiting resistor, the voltage regulator tube, and the thermistor are all arranged in the packaging shell. When using the protection device, there is no need to introduce an additional protection circuit, which simplifies the setting of the external circuit. The structure is simple and easy to use, and it also meets the high-frequency and miniaturization requirements of various switching power converters such as power electronics. The protection device is a special protection circuit for silicon carbide MOSFET and is not applicable to silicon MOSFET. It is special.

[0009] Furthermore, the substrate is a ceramic substrate, a polyethylene substrate, or a mica substrate, and the metal plate is a copper plate. Using a ceramic substrate, polyethylene plate, or the like as a carrier for the protection circuit formed by the electrical connection of the current-limiting resistor and thermistor provides excellent insulation performance, preventing leakage and creepage. The ceramic substrate, polyethylene plate, or mica plate also provides excellent heat dissipation, adapting to the high-temperature characteristics of silicon carbide MOSFETs. Using a copper plate as the metal plate provides both excellent electrical conductivity and heat dissipation, simplifying the area of ​​the heat sink backplane in the power electronic converter and further meeting miniaturization requirements.

[0010] Furthermore, the current-limiting resistor is a resistor chip, the thermistor is a thermistor chip, and the voltage regulator is a voltage regulator chip. The current-limiting resistor, thermistor, and the voltage regulator use corresponding functional chips, making the silicon carbide MOSFET structure smaller and also facilitating the packaging of the package housing.

[0011] Furthermore, the thermistor is an NTC thermistor, and the voltage regulator is a TVS diode. NTC thermistors can perform stably under ultra-high temperature and ultra-high voltage conditions, have a long practical life, and offer high precision, high sensitivity, and high reliability in temperature measurement, temperature control, and temperature compensation. Using a transient suppression diode (TVS), the voltage regulator can clamp high-voltage pulses from static electricity spikes in the drive circuit within a controllable range, further protecting the silicon carbide MOSFET components. This ensures stable operation and a long circuit life.

[0012] The beneficial effects of the present invention are:

[0013] 1. The silicon carbide MOSFET is powered by a power supply. After the gate drive is powered, the current limiting resistor has a limited current, providing a gate drive voltage for the silicon carbide MOSFET. A voltage regulator tube connected in series with the current limiting resistor is introduced. When the gate drive voltage of the voltage regulator tube is a reverse negative voltage, the forward clamp of the voltage regulator tube formed by the current limiting resistor and the voltage regulator tube is limited. When the MOSFET gate drive is a positive voltage, the current limiting resistor and the voltage regulator tube constitute a reverse amplitude limit of the voltage regulator tube, thereby realizing the gate drive positive and negative pulse voltage limitation, realizing the gate drive voltage amplitude limitation of the silicon carbide MOSFET, and effectively solving the problem of gate drive voltage breakdown; by introducing a thermistor to control the heat of the circuit, especially when driving positively, the thermistor resistance is reduced , thereby reducing the current passing through the silicon carbide MOSFET, achieving heat balance, which is beneficial to protecting the circuit; in addition, when the circuit is negatively driven and shut down, the protection device forms a discharge loop to accelerate the shutdown, and does not need to be connected to an external discharge circuit. The structure is simple and easy to use; the gate drive protection and thermal limit protection circuit formed by the current limiting resistor, the voltage regulator tube, and the thermistor are all arranged in the packaging shell. When using the protection device, there is no need to introduce an additional protection circuit, which simplifies the setting of the external circuit. The structure is simple and easy to use, and it also meets the high-frequency and miniaturization requirements of various switching power converters such as power electronics; the protection device is a special protection circuit for silicon carbide MOSFET, is not applicable to silicon MOSFET, and is special.

[0014] 2. Connect the first contact of the main chip to the first point of the voltage regulator tube. You can choose to work with a current-limiting resistor to effectively protect the gate oxide layer of the silicon carbide MOSFET chip from being damaged and to control the heat of the circuit to be uniform. The internal drive protection device uses a ceramic substrate, polyethylene plate, etc. as the carrier of the protection circuit formed by the electrical connection of the current-limiting resistor and the thermistor. It has good insulation performance and will not cause leakage, creepage, etc. The ceramic substrate, polyethylene plate or mica plate also has a good heat dissipation effect and can adapt to the high temperature characteristics of silicon carbide MOSFET. The copper plate is used as the metal plate, which has both good conductivity and good heat dissipation performance, which can simplify the circuit. The area of ​​the heat sink backplate is increased in the power electronic converter to further meet the requirements of miniaturization; the current limiting resistor, thermistor and voltage regulator use corresponding functional chips, making the silicon carbide MOSFET structure smaller and also facilitating the packaging of the package shell; the NTC thermistor can perform stably under ultra-high temperature and ultra-high voltage conditions, the thermistor has a long practical life, and has high precision, high sensitivity and high reliability in temperature measurement, temperature control and temperature compensation; the transient suppression diode (TVS) is used, and the voltage regulator can clamp the high-voltage pulse of the peak static electricity in the drive circuit within the control range, further protecting the silicon carbide MOSFET components, ensuring stability during use and a long circuit life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of the structure of the hidden package shell of the internal drive protection device of the present invention;

[0017] Figure 2 This is a schematic structural diagram of another angle protection device of the present invention;

[0018] Figure 3 This is a schematic diagram of the circuit of the driving protection device in the present invention;

[0019] Among them: 1 is the main chip, 11 is the first contact, 12 is the second contact, 13 is the third contact, 2 is the substrate, 21 is the current limiting resistor, 211 is the first point of the current limiting resistor, 212 is the second point of the current limiting resistor, 22 is the thermistor, 221 is the first point of the thermistor, 222 is the second point of the thermistor, 23 is the voltage regulator, 231 is the first point of the voltage regulator, 232 is the second point of the voltage regulator, 3 is the metal plate, 31 is the gate, 32 is the drain, 33 is the source, 34 is the metal electrode, and 4 is the packaging shell. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] Reference Figure 1 — Figure 3 A silicon carbide MOSFET internal driver protection device includes a main chip 1 and a substrate 2. The main chip 1 and the substrate 2 are respectively arranged on the same plane of a metal plate 3. A gate 31, a drain 32, a source 33 and a metal electrode 34 are provided on one side of the metal plate 3; and a packaging shell 4 is provided on the outer surface of the metal plate 3.

[0022] The main chip 1 is provided with a first contact 11, a second contact 12, and a third contact 13. The first contact 11 leads to a gate 31, the second contact 12 leads to a drain 32, and the third contact 13 leads to a source 33. The first contact 11, the second contact 12, and the third contact 13 are arranged in different areas of the main chip 1.

[0023] The substrate 2 is provided with a current-limiting resistor 21, a thermistor 22, and a voltage-stabilizing diode 23; the thermistor 22 is an NTC thermistor, and the voltage-stabilizing diode 23 is a TVS diode; the first point 211 of the current-limiting resistor is electrically connected to the gate 31, the second point 212 of the current-limiting resistor is electrically connected to the second point 222 of the thermistor, the second point 222 of the thermistor is also electrically connected to the second point 232 of the voltage-stabilizing diode, the first point 221 of the thermistor is electrically connected to the first point 231 of the voltage-stabilizing diode, and the source 33 is electrically connected to the first point 221 of the thermistor or the first point 231 of the voltage-stabilizing diode; the second point 232 of the voltage-stabilizing diode is electrically connected to the first contact 11 on the main chip 1, the third contact 13 is electrically connected to the source 33, and the metal pole 34 is electrically connected to the second contact 12; that is, the thermistor 22 and the voltage-stabilizing diode 23 are connected in parallel and then in series with the current-limiting resistor 21.

[0024] In order to meet the miniaturization requirement, the current limiting resistor 21 is a resistor chip, the thermistor 22 is a thermistor chip, and the voltage regulator 23 is a voltage regulator chip.

[0025] The substrate 2 is one of a ceramic substrate 2, a polyethylene plate or a mica plate. In this embodiment, in order to ensure good heat dissipation and the current limiting resistor 21 is formed by carbon deposition on the substrate 2, the substrate 2 is preferably a ceramic substrate and the metal plate 3 is a copper plate.

[0026] The silicon carbide MOSFET is powered by a power supply. After the gate drive is powered, the current limiting resistor has a limited current, providing a gate drive voltage for the silicon carbide MOSFET. A voltage regulator tube connected in series with the current limiting resistor is introduced. When the gate drive voltage of the voltage regulator tube is a reverse negative voltage, the forward clamp of the voltage regulator tube formed by the current limiting resistor and the voltage regulator tube is amplitude limited. When the MOSFET gate drive is a positive voltage, the current limiting resistor and the voltage regulator tube constitute a reverse amplitude limit of the voltage regulator tube, thereby realizing the gate drive positive and negative pulse voltage amplitude limit, realizing the gate drive voltage amplitude limit of the silicon carbide MOSFET, and effectively solving the problem of gate drive voltage breakdown; by introducing a thermistor to control the heat of the circuit, especially when driving positively, the resistance of the thermistor is reduced, This reduces the current passing through the silicon carbide MOSFET, achieves heat balance, and is beneficial to protecting the circuit. In addition, when the circuit is negatively driven and shut down, the protection device forms a discharge loop to accelerate the shutdown, and does not require an external discharge circuit. The structure is simple and easy to use. The gate drive protection and thermal limit protection circuits formed by the current limiting resistor, the voltage regulator tube, and the thermistor are all arranged in the packaging shell. When using the protection device, there is no need to introduce an additional protection circuit, which simplifies the setting of the external circuit. The structure is simple and easy to use, and it also meets the high-frequency and miniaturization requirements of various switching power converters such as power electronics. The protection device is a special protection circuit for silicon carbide MOSFET and is not applicable to silicon MOSFET. It is special.

[0027] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A silicon carbide MOSFET internal driver protection device, characterized by: It includes a main chip and a substrate, wherein the main chip and the substrate are respectively arranged in different areas of the same plane of a metal plate, a gate, a drain, a source and a metal electrode are provided on one side of the metal plate; and a packaging shell is provided on the outer surface of the metal plate; The main chip is provided with a first contact, a second contact, and a third contact, wherein the first contact lead-out end is a gate, the second contact lead-out end is a drain, and the third contact lead-out end is a source, and the first contact, the second contact, and the third contact are arranged in different areas of the main chip; The substrate is provided with a current limiting resistor, a thermistor, and a voltage-stabilizing diode; the first point of the current limiting resistor is electrically connected to the gate, the second point of the current limiting resistor is electrically connected to the second point of the thermistor, the second point of the thermistor is also electrically connected to the second point of the voltage-stabilizing diode, the first point of the thermistor is electrically connected to the first point of the voltage-stabilizing diode, the source is electrically connected to the first point of the thermistor or the first point of the voltage-stabilizing diode; the second point of the voltage-stabilizing diode is electrically connected to the first contact on the main chip, the third contact is electrically connected to the source, and the metal pole is electrically connected to the second contact; that is, the thermistor and the voltage-stabilizing diode are connected in parallel and then in series with the current limiting resistor.

2. The silicon carbide MOSFET internal driver protection device according to claim 1, characterized in that: The substrate is one of a porcelain substrate, a polyethylene plate or a mica plate, and the metal plate is a copper plate.

3. The silicon carbide MOSFET internal driver protection device according to claim 1, characterized in that: The current-limiting resistor is a resistor chip, the thermistor is a thermistor chip, and the voltage-stabilizing diode is a voltage-stabilizing diode chip.

4. The silicon carbide MOSFET internal driver protection device according to claim 1, characterized in that: The thermistor is an NTC thermistor, and the voltage regulator is a TVS tube.

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