Power device control system and method regulated and controlled by laser

Abstract

The invention relates to a laser-regulated power device control system and method in the technical field of semiconductor control. The system comprises a power semiconductor device; the laser emitting unit is used for emitting laser to a light-transmitting irradiation area of the power semiconductor device according to the temperature data of the power semiconductor or the conduction state of the power semiconductor device, the laser emitted by the laser emitting unit penetrates through the light-transmitting irradiation area and then irradiates a drift area of the power semiconductor device, and electron-hole pairs are generated; the laser control unit is used for controlling start and stop of the laser emission unit and laser emission power, laser emitted by the laser emission unit has photon energy used for exciting carriers in a drift region, and the photon energy is higher than a material band gap of the drift region in the power semiconductor device or higher than defect state excitation energy of a material in the drift region. The problem that increase of on-resistance along with increase of temperature rise cannot be fundamentally relieved in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor control technology, and in particular to a laser-regulated power device control system and method. Background Art

[0002] In medium- and high-voltage power electronics applications, silicon carbide (SiC) MOSFET devices, for example, have been widely used in various high-efficiency power systems due to their high breakdown electric field strength and excellent thermal conductivity. To achieve a higher voltage rating, such devices typically employ a thicker, low-doping drift region structure. This region bears the primary voltage-carrying responsibility when the device is in the on-state, so its on-resistance (Ron) is usually dominated by the drift region. However, under high-temperature operating conditions, the carrier mobility in the drift region decreases significantly, causing the device's on-resistance to increase rapidly and conduction losses to increase, further driving up the device's junction temperature and forming a positive feedback heat accumulation process. If left unchecked, this may eventually lead to device thermal runaway, seriously affecting the stability and reliability of the system.

[0003] Common solutions currently include device structure optimization (such as optimizing drift region doping and introducing superjunction charge balancing structures) or dynamic control (such as adjusting gate drive voltage). However, most of these approaches involve static design or peripheral regulation, and lack the ability to meaningfully intervene in the dynamic process of significant drift region resistance increases under high temperature conditions. Furthermore, traditional heat dissipation strategies (such as enhanced package heat dissipation and external cooling systems) often have a lag and a time-consuming response, making it difficult to promptly address the transient growth of internal hot spots in the device. This inability to break the positive feedback loop of high temperature, high on-resistance, and high heat generation leads to a critical need for an active control method that physically enhances drift region conductivity to break the vicious cycle of high temperature, high on-resistance, and high heat generation.

[0004] Currently, the closest approach is temperature-controlled drive adjustment, which uses a temperature sensor to monitor the device junction temperature and coordinates with the controller to adjust the drive waveform or shut down the device to prevent failure. However, this approach is limited to limiting the input signal or delaying failure, and cannot fundamentally alleviate the problem of increasing on-resistance with temperature rise. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a laser-controlled power device control system and method, which solves the problem that the prior art cannot fundamentally alleviate the increase of on-resistance with temperature rise.

[0006] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0007] A laser-controlled power device control system comprising:

[0008] Power semiconductor devices;

[0009] a laser emitting unit, configured to emit laser light toward a light-transmitting irradiation area of ​​the power semiconductor device according to temperature data of the power semiconductor or a conduction state of the power semiconductor device, wherein the laser light emitted by the laser emitting unit passes through the light-transmitting irradiation area and then irradiates a drift region of the power semiconductor device, thereby generating electron-hole pairs;

[0010] A laser control unit is used to control the start and stop of the laser emission unit and the laser emission power, wherein the laser emitted by the laser emission unit has a photon energy for exciting carriers in the drift region, and the photon energy is higher than the material band gap of the drift region in the power semiconductor device or higher than the energy of defect state excitation of the drift region material.

[0011] Optionally, the power semiconductor device is a vertical conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region, and a light-transmitting illumination area is also arranged on the device surface structure.

[0012] Optionally, a third electrode is further provided on the device surface structure.

[0013] Optionally, the power semiconductor device is a lateral conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode and a second electrode arranged on the device surface structure, and a light-transmitting illumination area is also arranged on the device surface structure.

[0014] Optionally, a transparent dielectric material is further provided on the light-transmitting irradiation area.

[0015] Optionally, the power semiconductor device is a vertical conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region. A passivation layer is also arranged on the upper surface of the drift region, and the passivation layer is arranged in contact with the first electrode.

[0016] Optionally, the area of ​​the light-transmitting irradiation area is greater than 10 square micrometers, and the light-transmitting irradiation area is any one of circular, rectangular, multi-point hole array, multi-circular ring, strip staggered, and multi-shape composite.

[0017] Optionally, a temperature detection unit is further included, wherein the temperature detection unit is used to detect the junction temperature, shell temperature or temperature near the heat source of the power semiconductor device to obtain temperature data.

[0018] Optionally, a device switch is also included, and the device switch is used to control the conduction of the power semiconductor device.

[0019] Optionally, the laser emitted by the laser emitting unit is at an angle of 0° to 90° to the plane where the light-transmitting irradiation area is located.

[0020] Optionally, the distance between the laser emitting unit and the drift region of the power semiconductor device is 0.01 mm to 500 mm.

[0021] A method for controlling a laser-controlled power device, the method being applied to any one of the above-described laser-controlled power device control systems, comprising the following steps:

[0022] Real-time acquisition of junction temperature, case temperature or temperature near heat source of power semiconductor devices to obtain temperature data and set temperature thresholds and safety temperature values;

[0023] determining whether the temperature data exceeds a temperature threshold; if so, activating a laser emission unit through a laser control unit, selecting a laser emission power according to a temperature-laser power mapping table, and then irradiating a drift region of the power semiconductor device with laser light;

[0024] The temperature adjustment data after laser irradiation is collected in real time, and it is determined whether the temperature adjustment data is lower than the safe temperature value. If so, the laser irradiation is stopped, otherwise the laser irradiation is continued.

[0025] A method for controlling a laser-controlled power device, the method being applied to any one of the above-described laser-controlled power device control systems, comprising the following steps:

[0026] Turning on the power semiconductor device through the device switch and starting the laser emission unit;

[0027] The laser emitting unit is used to emit laser light to the drift region of the power semiconductor device, and after the gate-source voltage of the power semiconductor device drops, the laser emitting unit is turned off.

[0028] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0029] Dynamically improve the conductivity of the device. During the conduction period of the power semiconductor device, especially under high-temperature working conditions, the laser is used to irradiate the light-transmitting area of ​​the device, thereby irradiating the drift region, and then introducing additional electrons and holes participating in the conduction in the drift region, significantly improving the equivalent conductivity of the drift region, reducing the on-resistance of the device, thereby effectively suppressing the conduction loss and enhancing the high-temperature working stability; through closed-loop temperature sensing and laser control system, the generation of electrons and holes is actively stimulated when the junction temperature of the device rises, compensating for the decrease in mobility and preventing thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a structural diagram of a power semiconductor device proposed in the first embodiment;

[0032] Figure 2 This is one of the distribution diagrams of the light-transmitting irradiation area on the device proposed in the first embodiment;

[0033] Figure 3 This is the second distribution diagram of the light-transmitting irradiation area on the device proposed in the first embodiment;

[0034] Figure 4 This is the third distribution diagram of the light-transmitting irradiation area on the device proposed in the first embodiment;

[0035] Figure 5 This is a schematic diagram of the process of forming electron-hole pairs under light, as proposed in the first embodiment;

[0036] Figure 6 This is a comparison diagram of IV curves of the SiC diode proposed in Example 1 under different laser irradiation powers;

[0037] Figure 7 This is a structural diagram of a power semiconductor device proposed in the second embodiment;

[0038] Figure 8 This is a structural diagram of a power semiconductor device proposed in the third embodiment;

[0039] Figure 9 This is a structural diagram of a power semiconductor device proposed in the fourth embodiment;

[0040] Figure 10 This is a structural diagram of a power semiconductor device proposed in the fifth embodiment;

[0041] Figure 11 This is a flow chart of a method for controlling a power device regulated by laser proposed in the sixth embodiment.

[0042] Figure numerals: 1. drift region; 2. device surface structure; 3. first electrode; 4. second electrode; 5. third electrode; 6. transparent dielectric material; 7. passivation layer; 8. light-transmitting irradiation area. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below with reference to the examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0044] Example 1

[0045] like Figure 1 As shown, a laser-regulated power device control system includes: a power semiconductor device; a laser emitting unit, which is used to emit laser light to a light-transmitting irradiation area of ​​the power semiconductor device according to temperature data of the power semiconductor or the conduction state of the power semiconductor device, wherein the laser light emitted by the laser emitting unit passes through the light-transmitting irradiation area and irradiates the drift region of the power semiconductor device, and generates electron-hole pairs; a laser control unit, which is used to control the start and stop of the laser emitting unit and the laser emission power, wherein the laser light emitted by the laser emitting unit has photon energy for exciting carriers in the drift region, and the photon energy is higher than the material band gap of the drift region in the power semiconductor device or higher than the energy of defect state excitation of the drift region material.

[0046] The present application is used to excite electrons in shallow energy defect states, impurity energy levels or interface states in the material by setting the photon energy to be greater than the intrinsic band gap of the drift region material of the power semiconductor device or higher than the energy of defect state excitation of the drift region material, so that they jump to the conduction band or participate in the conduction process, thereby generating electron-hole pairs in the power semiconductor device, increasing the carrier concentration and enhancing the conductivity.

[0047] It also includes a temperature detection unit, which is used to detect the junction temperature, shell temperature or near-heat source temperature of the power semiconductor device to obtain temperature data; it also includes a device switch, which is used to control the conduction of the power semiconductor device.

[0048] Among them, the power semiconductor device can be a lateral or vertical conductive device, and can be a three-terminal device (i.e., a device with three electrodes) such as MOSFET, JFET or IGBT, or a two-terminal device (i.e., two electrodes) such as a diode, or even a device with more electrodes. This embodiment is explained by taking the power semiconductor device as a vertical conductive device as an example. At this time, the power semiconductor device includes a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region. A light-transmitting illumination area is also provided on the device surface structure. Among them, the device surface structure referred to in this application includes a PN junction region, a gate structure, a Schottky contact region, and an ohmic contact region, etc.

[0049] When the laser emitting unit emits laser light to the light-transmitting irradiation area, its irradiation target is the drift region inside the power semiconductor device, which is arranged on the main current path between the electrodes (the main current path is as shown in FIG. Figure 1Specifically, when the laser is irradiated from above the power semiconductor device, a "light-transmitting irradiation area" is designed through the metal electrode structure (the first electrode in this embodiment), that is, a metal electrode opening area is formed, and the drift region below the light-transmitting irradiation area is directly irradiated, thereby achieving the purpose of ultimately reducing the on-resistance.

[0050] Furthermore, the area of ​​the light-transmitting illumination area can be adjusted according to the size of the power semiconductor device, and can be set to an area greater than 10 square microns. The shape of the light-transmitting illumination area can be variable, and can be any one of circular, rectangular, multi-point hole array, multi-ring, strip staggered, and multi-shape composite. The present application supports irregular custom shapes of light-transmitting illumination areas, specifically customizing arbitrary shapes according to the internal hot spots of the device, for example, it can support elliptical, polygonal, and other composite illumination windows.

[0051] like Figure 2 As shown, the light-transmitting irradiation area can be designed as multiple concentric rings or non-concentric rings. In this case, the inner diameter r of the ring can be set to 10μm~10000μm, the ring width w can be set to 10μm~10000μm, and multiple rings can be arranged at intervals.

[0052] like Figure 3 and Figure 4 As shown, the light-transmitting irradiation area can be arranged in a staggered manner using multiple strip windows; the window direction can be arranged parallel or perpendicular to the current direction to form a grid-like laser irradiation pattern; the typical strip window size can be set to a width of 10μm~1000μm and a length of 100μm~10000μm.

[0053] On the other hand, when regulating power devices, the temperature detection unit includes a temperature sensor, which monitors the junction temperature and shell temperature of the power semiconductor device in real time through the temperature sensor. The real-time temperature value T is collected by using NTC, RTD close to the chip or through the device's thermal parameters; the laser control unit controls the opening and closing of the laser emission unit and the power adjustment; the device switch outputs the gate drive signal through the control circuit to control the opening and closing of the power device. This part is a currently mature gate drive circuit, and its function is to control the opening and closing of the power device; the laser emission unit supports PWM modulation, power adjustment and trigger switch, and can be set to a controllable laser or LED array. The wavelength range is preferably 200nm~600nm, and the laser power is set to 1mW~10000mW adjustable.

[0054] When setting the installation position between the laser emitting unit and the power semiconductor device, the laser emitting unit and the power semiconductor device can be co-packaged in the same module. Specifically, the laser emitting unit and the chip are co-integrated inside the power semiconductor device or the package body. The laser passes through the preset light-transmitting irradiation area of ​​the power semiconductor device and irradiates the drift area. The light path can be controlled by combining components such as microlens arrays, collimating optical paths, and reflective lenses; the laser control signal, drive signal, and gate control can be integrated into the device. The laser emitted by the laser emitting unit is 0°~90° to the plane where the light-transmitting irradiation area is located to ensure that the light spot is concentrated in the drift area. The distance between the laser emitting unit and the drift area of ​​the power semiconductor device is 0.01mm~500mm, which is set comprehensively based on the laser beam divergence angle, the size of the light-transmitting irradiation area, and the focusing optical conditions.

[0055] The integrated setup can, on the one hand, improve system integration and reduce layout space, making it suitable for space-constrained and batch application scenarios (such as automotive and aerospace); on the other hand, it has a short optical path, fast response speed, and small EMI impact.

[0056] In addition, the laser emitting unit can also be installed separately from the power semiconductor device. In this case, the laser is installed separately on the control board or system frame, and irradiates the device through optical fiber or other optical path structures. When optical fiber is used as the optical path, it supports "one source multiple fibers", that is: the output of one laser is divided into multiple optical fibers, which illuminate multiple power devices respectively.

[0057] In this way, the laser does not need to be close to the device and can be kept away from high-heat or high-interference areas; it is easy to replace the laser individually, which improves maintenance convenience; it is more suitable for experimental verification and modular debugging; it can flexibly switch laser irradiation parameters and upgrade laser types or wavelengths; the optical fiber structure is highly standardized.

[0058] It should be noted that in the configuration where the laser and the device are installed separately, the laser can be kept at a long distance from the power device, and the system can achieve remote and precise transmission and positioning irradiation of the laser through the optical fiber structure; as for the optical fiber output structure, the laser output end is connected to a single-mode or multi-mode optical fiber, and the typical wavelength is adapted to 355nm~1000nm; the optical fiber length can be flexibly set according to the system layout, ranging from a few centimeters to tens of centimeters; the end of the optical fiber is connected to the required super-emitting device to accurately project the laser to the device illumination window; the end of the optical fiber can be fixed on the top of the device package and connected through a dedicated coupling end cap or packaging structure interface.

[0059] Furthermore, the principle of reducing on-resistance by laser irradiating the light-transmitting irradiation area is as follows:

[0060] Power semiconductor devices such as silicon carbide (SiC) MOSFETs typically have a low-doping, high-resistance structure within their internal drift region to ensure the device's required voltage withstand capability. In high-temperature environments, electron mobility (μn) decreases significantly with increasing temperature, leading to a sharp decrease in the overall conductivity (σ) in this region. This increases the device's on-resistance, power consumption, and further exacerbates the junction temperature rise, forming a vicious positive feedback loop. For example, according to the formula: , where I represents the current, R0 represents the resistance of the device at room temperature, and T0 represents the room temperature. The resistance is proportional to the mth power of the device junction temperature Tj, where m is approximately 2.0~3.0. Therefore, when the temperature rises, the device resistance increases significantly, and the power loss P also increases significantly.

[0061] According to the principle of semiconductor conduction, the material conductivity σ is given by the following formula: , where q is the basic charge; n is the free carrier concentration in the drift region; For electron mobility, under high temperature conditions, the decrease of electron mobility is inevitable, so increasing the free electron concentration n becomes the only controllable means to maintain conductivity.

[0062] This application uses laser irradiation to induce photogenerated electron-hole pairs in the drift region, significantly increasing the free carrier concentration, thereby dynamically improving the material conductivity and reducing the on-resistance. The specific physical mechanisms are as follows:

[0063] First, when the laser irradiates the light-transmitting area, laser absorption occurs. The laser with a wavelength within the absorption region of the material (e.g., the absorption region of SiC is usually less than 500 nm) is selected to ensure that the laser is effectively absorbed in the drift region. Then, electron-hole pairs are generated. Each absorbed photon excites an electron to jump from the valence band to the conduction band, forming free electrons and holes. The additional electrons and holes generated can participate in electrical conduction, thereby reducing the electrical conductivity. Finally, transient conductivity enhancement is achieved. Specifically, the electron and hole density in the drift region increases by several orders of magnitude under illumination, significantly enhancing its conductivity. For example, in a SiC device with a typical blocking voltage of 10 kV, the intrinsic doping concentration in the drift region is approximately 1×10 14 cm -3 After laser irradiation, the concentration of electrons and holes involved in conduction can be instantly increased to 1×10 15 cm -3 Above, it is improved by about one order of magnitude, thereby greatly enhancing the local conductivity. The specific improvement effect depends on the laser intensity, such as Figure 5 As shown, it represents the process of forming electron-hole pairs under light.

[0064] In order to verify the feasibility and effectiveness of the laser-controlled power device control system proposed in the present invention, this application carried out a laser irradiation experiment based on SiC power devices. A 1200V SiC Schottky diode was selected for the experiment, and the laser parameters selected were near-ultraviolet light with a wavelength of 405nm, which can be effectively absorbed by SiC; the irradiation method was that the laser irradiated the front of the device vertically; the device was unsealed or windowed to ensure that the laser acted directly on the area where the drift region was located, and then the current source output current was controlled, the forward conduction voltage drop of the device was measured, and the conduction loss was calculated. The I-V curves under no laser irradiation (natural conduction state) and laser irradiation conditions were compared to obtain experimental results.

[0065] During the experiment, the IV curve of the SiC diode was measured under different laser irradiation powers. In the experiment, the baseline I–V characteristic curve of the device in the dark state was first obtained, and then the laser irradiation power was gradually increased, and the corresponding on-state voltage changes were recorded.

[0066] like Figure 6 As shown in the figure (the dotted line is the benchmark I–V curve, and the solid line is the working state curve under different laser irradiation powers), as the laser power increases, the device conduction voltage drop shows a clear downward trend.

[0067] Specifically, by Figure 6 It can be seen that in the non-laser irradiation state, when the on-current is 0.15A, the device on-voltage is 6.0V, and the conduction loss P=U×I=0.9W; when a 405nm laser is applied with a power of 180mW and the on-current is 0.15A, the on-voltage drops to 5.0V and the conduction loss drops to 0.75W; compared with the baseline state, the device on-resistance and conduction loss decrease by about 17%.

[0068] This experiment verified that laser irradiation can instantaneously reduce the on-resistance through the photogenerated carrier mechanism, enhance the conductivity of the device, thereby reducing the voltage drop and energy loss during conduction, and forming a significant dynamic conductivity enhancement effect.

[0069] It should be noted that as the device's voltage resistance increases, the thickness of its drift region increases, the doping concentration decreases, and the proportion of the drift region in the on-resistance further increases. Therefore, this laser control mechanism has more significant improvement potential and practical value in devices with higher voltage levels (such as 10kV).

[0070] Example 2

[0071] like Figure 7As shown, compared with Example 1, the difference of this embodiment is that the power semiconductor device is configured as a three-terminal device. Specifically, a third electrode is further provided on the surface structure of the device. Through the structural setting of the power semiconductor device of this embodiment, the laser-controlled power device control system of the present invention is applicable to more power devices.

[0072] Example 3

[0073] like Figure 8 As shown, the difference between this embodiment and embodiment one is that the power semiconductor device is a lateral conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode and a second electrode arranged on the device surface structure, and a light-transmitting irradiation area is also provided on the device surface structure. Through the structural setting of the power semiconductor device of this embodiment, the laser-controlled power device control system of the present invention is applicable to more power devices.

[0074] Example 4

[0075] like Figure 9 As shown, the difference between this embodiment and embodiment 1 is that a transparent dielectric material is further provided on the light-transmitting irradiation area of ​​this embodiment, wherein the transparent dielectric material can be any one of sapphire, quartz glass, polyimide film, aluminum oxide film, etc., thereby achieving dust and pollution prevention of the device through the transparent dielectric material and enhancing the packaging strength of the device.

[0076] Example 5

[0077] like Figure 10 As shown, the difference between this embodiment and embodiment 1 is that the power semiconductor device is a vertical conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region, and a passivation layer is further provided on the upper surface of the drift region, and the passivation layer is provided in contact with the first electrode.

[0078] Therefore, through the structural setting of the power semiconductor device of this embodiment, penetrating illumination is achieved by utilizing the original passivation layer area of ​​the device without the need to set up an additional light-transmitting illumination area, making the laser-controlled power device control system of the present invention applicable to more power devices.

[0079] Example 6

[0080] like Figure 11 As shown, a method for controlling a power device controlled by laser is provided. The method is applied to the laser-controlled power device control system as described in any one of the first to fifth embodiments, and includes the following steps:

[0081] Real-time acquisition of junction temperature, case temperature or temperature near heat source of power semiconductor devices to obtain temperature data and set temperature thresholds and safety temperature values;

[0082] determining whether the temperature data exceeds a temperature threshold; if so, activating a laser emission unit through a laser control unit, selecting a laser emission power according to a temperature-laser power mapping table, and then irradiating a drift region of the power semiconductor device with laser light;

[0083] The temperature adjustment data after laser irradiation is collected in real time, and it is determined whether the temperature adjustment data is lower than the safe temperature value. If so, the laser irradiation is stopped, otherwise the laser irradiation is continued.

[0084] Specifically, the junction temperature, shell temperature or temperature near the heat source of the device is monitored in real time through the temperature sensor; temperature sampling: the real-time temperature value T is collected in real time using the NTC, RTD or device thermal parameter reverse inference mechanism close to the chip (in a system where multiple temperature signals coexist, a priority selection mechanism can be set, and the physical temperature sensor signal can be used as the default. When the sensor signal is missing or unreliable, the device thermal parameter reverse inference temperature estimation mechanism is enabled to ensure the real-time and robustness of the system control); when the temperature rises to the temperature threshold Ton (such as 100°C), the laser control unit outputs a laser on signal, where the controller can use an analog comparator combined with a logic gate to implement , or it can be sampled and judged by an MCU (such as STM32) combined with an ADC module, in which the control method is the existing conventional control method; then, after the laser receives the enable signal, it irradiates the drift region of the device with a set power (such as 20-500mW), and a temperature-laser power mapping table can also be integrated to achieve "the higher the temperature, the stronger the laser" type control; finally, the laser irradiates the drift region of the device to stimulate photogenerated electron pairs, improve conductivity, and suppress the increase in on-resistance; when the temperature drops to a safe range, that is, when it drops to the safe temperature value Toff (such as below 75°C), the laser is automatically turned off. This mode forms a closed-loop "thermal-optical-electrical" feedback loop, which is suitable for stable operation and regulation.

[0085] Example 7

[0086] A method for controlling a power device controlled by laser, the method being applied to the laser-controlled power device control system according to any one of the first to fifth embodiments, comprising the following steps:

[0087] Turning on the power semiconductor device through the device switch and starting the laser emission unit;

[0088] The laser emitting unit is used to emit laser light to the drift region of the power semiconductor device, and after the gate-source voltage of the power semiconductor device drops, the laser emitting unit is turned off.

[0089] Specifically, when the controller or driver IC sends a MOSFET gate-on signal (Vgs high level), the laser is triggered to turn on at the same time; the laser irradiates the drift region of the device only during the conduction period, providing instantaneous electron excitation and helping the drift layer to quickly establish a low on-resistance; when the MOSFET is turned off (i.e., the gate-source voltage Vgs drops), the laser is synchronously turned off. The laser can also be set to turn off in advance. This can reduce the number of excess photogenerated carriers in the device at the moment of shutdown, help accelerate the current drop, reduce the shutdown delay and tail current, thereby further optimizing the shutdown dynamic performance and system energy efficiency, while helping to reduce the shutdown time;

[0090] It should be noted that this embodiment can also achieve gate / laser joint control through logic gates, delay gates, etc., and the laser opening and closing can be synchronized with the conduction period of the power device and can also be advanced or delayed by 0.001μs~1000μs.

[0091] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A laser-controlled power device control system, characterized in that: include: Power semiconductor devices; a laser emitting unit, configured to emit laser light toward a light-transmitting irradiation area of ​​the power semiconductor device according to temperature data of the power semiconductor or a conduction state of the power semiconductor device, wherein the laser light emitted by the laser emitting unit passes through the light-transmitting irradiation area and then irradiates a drift region of the power semiconductor device, thereby generating electron-hole pairs; A laser control unit is used to control the start and stop of the laser emission unit and the laser emission power, wherein the laser emitted by the laser emission unit has a photon energy for exciting carriers in the drift region, and the photon energy is higher than the material band gap of the drift region in the power semiconductor device or higher than the energy of defect state excitation of the drift region material.

2. The laser-controlled power device control system according to claim 1, characterized in that: The power semiconductor device is a vertical conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region. A light-transmitting illumination area is also provided on the device surface structure.

3. The laser-controlled power device control system according to claim 2, characterized in that: A third electrode is also provided on the device surface structure.

4. The laser-controlled power device control system according to claim 1, characterized in that: The power semiconductor device is a lateral conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode and a second electrode arranged on the device surface structure, and a light-transmitting irradiation area is also arranged on the device surface structure.

5. The laser-controlled power device control system according to any one of claims 2 to 4, characterized in that: A transparent dielectric material is also provided on the light-transmitting irradiation area.

6. The laser-controlled power device control system according to claim 1, characterized in that: The power semiconductor device is a vertical conductive device, including a drift region, a device surface structure arranged on the upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on the lower surface of the drift region. A passivation layer is also arranged on the upper surface of the drift region, and the passivation layer is arranged in contact with the first electrode.

7. A laser-controlled power device control system according to any one of claims 2, 4 or 6, characterized in that: The area of ​​the light-transmitting irradiation area is greater than 10 square micrometers, and the light-transmitting irradiation area is any one of a circular shape, a rectangular shape, a multi-point hole array shape, a multi-circular ring shape, a strip-staggered shape, and a multi-shape composite shape.

8. The laser-controlled power device control system according to claim 1, characterized in that: It also includes a temperature detection unit, which is used to detect the junction temperature, shell temperature or temperature near the heat source of the power semiconductor device to obtain temperature data.

9. The laser-controlled power device control system according to claim 1, characterized in that: Also included is a device switch, which is used to control the power semiconductor device to be turned on.

10. The laser-controlled power device control system according to claim 1, characterized in that: The laser emitted by the laser emitting unit is at an angle of 0° to 90° to the plane where the light-transmitting irradiation area is located.

11. The laser-controlled power device control system according to claim 1, characterized in that: The distance between the laser emitting unit and the drift region of the power semiconductor device is 0.01 mm to 500 mm.

12. A method for controlling a power device regulated by laser, characterized in that: The power device control method is applied to the laser-controlled power device control system according to any one of claims 1 to 11, comprising the following steps: Real-time acquisition of junction temperature, case temperature or temperature near heat source of power semiconductor devices to obtain temperature data and set temperature thresholds and safety temperature values; determining whether the temperature data exceeds a temperature threshold; if so, activating a laser emission unit through a laser control unit, selecting a laser emission power according to a temperature-laser power mapping table, and then irradiating a drift region of the power semiconductor device with laser light; The temperature adjustment data after laser irradiation is collected in real time, and it is determined whether the temperature adjustment data is lower than the safe temperature value. If so, the laser irradiation is stopped, otherwise the laser irradiation is continued.

13. A method for controlling a power device regulated by laser, characterized in that: The power device control method is applied to the laser-controlled power device control system according to any one of claims 1 to 11, comprising the following steps: Turning on the power semiconductor device through the device switch and starting the laser emission unit; The laser emitting unit is used to emit laser light to the drift region of the power semiconductor device, and after the gate-source voltage of the power semiconductor device drops, the laser emitting unit is turned off.

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