A laser-controlled power device control system and method

Abstract

The application relates to a laser-regulated power device control system and method in the technical field of semiconductor control, which comprises a power semiconductor device, a laser emission unit for emitting laser to 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 emitted by the laser emission unit is irradiated to a drift area of the power semiconductor device after transmitting through the light-transmitting irradiation area, and an electron-hole pair is generated; and a laser control unit for controlling start-stop of the laser emission unit and laser emission power, wherein the laser emitted by the laser emission unit has photon energy for exciting carriers in the drift area, the photon energy is higher than a material band gap of the drift area in the power semiconductor device or higher than energy for exciting a defect state of the drift area material, and the problem that the prior art cannot fundamentally alleviate increase of on-resistance with temperature rise is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor control, in particular to a power device control system and method controlled by laser. BACKGROUND

[0002] In medium and high voltage power electronic applications, silicon carbide (SiC) MOSFET devices have been widely used in various high-performance power systems due to their high breakdown field strength and excellent thermal conductivity. To achieve higher voltage levels, such devices usually use a thick, low-doped drift region structure, which bears the main voltage load in the on-state of the device, so its on-resistance (Ron) is usually dominated by the drift region. However, in high-temperature working environment, the carrier mobility in the drift region decreases significantly, leading to a rapid increase in the on-resistance of the device and an increase in the on-state loss, which further drives the device junction temperature to rise, forming a positive feedback thermal accumulation process. If not intervened, it may eventually lead to thermal runaway of the device, seriously affecting the stability and reliability of the system.

[0003] Current common solutions include device structure optimization (such as optimizing drift region doping, introducing super junction charge balance structure) or dynamic control (such as adjusting gate drive voltage), however, most of these methods belong to static design or peripheral control, and they still lack substantial intervention ability for the dynamic process of significant increase in drift region resistance under high temperature conditions. On the other hand, traditional heat dissipation strategies (such as enhancing package heat dissipation, external cooling system, etc.) often have a lagging response, and the heat dissipation has a response time, making it difficult to respond to the instantaneous growth of the device internal hot spot, and it cannot break the positive feedback path of high temperature-high on-resistance-high heat, therefore, an active control means is needed to physically improve the conductivity of the drift region to break the vicious cycle of high temperature-high on-resistance-high heat.

[0004] The closest current solution is temperature-controlled drive adjustment, which monitors the device junction temperature through a temperature sensor and controls the drive waveform or turns off the device to prevent failure. However, this solution is limited to limiting input signals or delaying failure, and cannot fundamentally alleviate the problem of increasing on-resistance with increasing temperature. SUMMARY

[0005] The present application provides a power device control system and method controlled by laser to solve the problem that the prior art cannot fundamentally alleviate the problem of increasing on-resistance with increasing temperature.

[0006] To solve the above technical problems, the present application solves them through the following technical solutions:

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

[0008] A power semiconductor device;

[0009] A laser emitting unit for emitting laser to a light-transmitting irradiation region 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 emitted by the laser emitting unit is transmitted through the light-transmitting irradiation region and then irradiated to a drift region of the power semiconductor device, and generates electron-hole pairs;

[0010] A laser control unit for controlling start-stop and laser emitting power of the laser emitting unit, wherein the laser emitted by the laser emitting unit has a photon energy for exciting carriers in the 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 an energy of defect state excitation of the drift region material.

[0011] Optionally, the power semiconductor device is a vertical conduction device, comprising a drift region, a device surface structure arranged on an upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on a lower surface of the drift region, and the device surface structure further comprises a light-transmitting irradiation region.

[0012] Optionally, the device surface structure further comprises a third electrode.

[0013] Optionally, the power semiconductor device is a lateral conduction device, comprising a drift region, a device surface structure arranged on an upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode, and the device surface structure further comprises a light-transmitting irradiation region.

[0014] Optionally, the light-transmitting irradiation region further comprises a transparent medium material.

[0015] Optionally, the power semiconductor device is a vertical conduction device, comprising a drift region, a device surface structure arranged on an upper surface of the drift region, a first electrode arranged on the device surface structure, and a second electrode arranged on a lower surface of the drift region, and the upper surface of the drift region further comprises a passivation layer, and the passivation layer is in contact with the first electrode.

[0016] Optionally, an area of the light-transmitting irradiation region is greater than 10 square microns, and the light-transmitting irradiation region is in any one of a circular shape, a rectangular shape, a multi-point hole array type, a multi-circle ring type, a strip staggered type, and a multi-shape composite type.

[0017] Optionally, the device further comprises a temperature detection unit for detecting a junction temperature, a shell temperature, or a near heat source temperature of the power semiconductor device to obtain the temperature data.

[0018] Optionally, the device further comprises a device switch for controlling conduction of the power semiconductor device.

[0019] Optionally, the laser emitted by the laser emitting unit is at an angle of 0-90 degrees with the plane in which 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 0.01-500 mm.

[0021] A laser-regulated power device control method applied to the laser-regulated power device control system according to any one of the preceding items, comprising the following steps:

[0022] Real-time acquisition of the junction temperature, shell temperature or near-heat source temperature of the power semiconductor device to obtain temperature data, setting of a temperature threshold value and a safe temperature value;

[0023] Judgment of whether the temperature data exceeds the temperature threshold value, if yes, starting of the laser emitting unit through the laser control unit, and selection of the laser emitting power according to the temperature-laser power mapping table to perform laser irradiation on the drift region of the power semiconductor device;

[0024] Real-time acquisition of the temperature adjustment data after laser irradiation, and judgment of whether the temperature adjustment data is lower than the safe temperature value, if yes, stopping of the laser irradiation, and otherwise, continuous laser irradiation.

[0025] A laser-regulated power device control method applied to the laser-regulated power device control system according to any one of the preceding items, comprising the following steps:

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

[0027] Emission of laser by the laser emitting unit to the drift region of the power semiconductor device, and turning off of the laser emitting unit after the gate-source voltage of the power semiconductor device drops.

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

[0029] Dynamic improvement of the device conductive capacity, during the conduction of the power semiconductor device, especially in the high-temperature working state, the light-transmitting irradiation area of the device is irradiated by the laser, so as to irradiate the drift region, and then additional electrons and holes participating in conduction are introduced in the drift region, the equivalent conductivity of the drift region is significantly improved, the device conduction resistance is reduced, the conduction loss is effectively suppressed, and the high-temperature working stability is enhanced; through the closed-loop temperature sensing and laser control system, the generation of electrons and holes is actively excited when the device junction temperature rises, the mobility is compensated, and thermal runaway is prevented. BRIEF DESCRIPTION OF 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 irradiates from above the power semiconductor device, a "light-transmitting irradiation area" is designed through the metal electrode structure (referred to as the first electrode in this embodiment), that is, a metal electrode opening area is formed, and the area below the light-transmitting irradiation area is a drift region area that can be directly irradiated, so as to achieve the purpose of reducing the final on-resistance.

[0050] Further, the area of the light-transmitting irradiation area can be adjusted according to the size of the power semiconductor device, and can be set to be greater than 10 square microns. The shape of the light-transmitting irradiation area can be variable, and can be any one of a circular shape, a rectangular shape, a multi-point hole array type, a multi-circle ring type, a strip-shaped staggered type, and a multi-shape composite type. In this application, the shape of the irregular self-defined light-transmitting irradiation area is supported, and any shape can be customized according to the internal hot spot of the device, for example, an oval, a polygon, and an equal composite irradiation window.

[0051] As shown in Figure 2 , the light-transmitting irradiation area can be designed as a plurality of concentric circles or non-concentric circles. At this time, the inner diameter r of the circle can be set to 10 μm ~10000 μm, and the ring width w can be set to 10 μm ~10000 μm, and a plurality of rings can be arranged at intervals.

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

[0053] On the other hand, when the power device is regulated, the temperature detection unit includes a temperature sensor, which monitors the junction temperature and the shell temperature of the power semiconductor device in real time through the temperature sensor. When collecting, the real-time temperature value T is collected by using the NTC or RTD close to the chip or by collecting the thermal parameter of the device; the laser control unit controls the opening, closing and power regulation of the laser emission unit; the device switch outputs a gate drive signal through the control circuit to control the opening and closing of the power device. This part is a mature gate drive circuit at present, and the function is to control the opening and closing of the power device; the laser emission unit supports PWM modulation, power regulation and trigger switch, and can be set as a controllable laser or an LED array. The wavelength range is preferably 200 nm ~600 nm, and the laser power is set to 1 mW ~10000 mW.

[0054] In 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 in the power semiconductor device or the package, the laser passes through the light transmission irradiation area preset by the power semiconductor device, and irradiates the drift region area, and the light path can be controlled by combining elements such as microlens array, collimating light path and reflecting lens; the laser control signal, the driving signal and the gate control can be integrated in the device, the laser emitted by the laser emitting unit and the plane where the light transmission irradiation area is located are 0°-90°, so as to ensure that the light spot is concentrated in the drift region, and the distance between the laser emitting unit and the drift region of the power semiconductor device is 0.01mm-500mm, which is set comprehensively according to the laser beam divergence angle, the light transmission irradiation area size and the focusing optical condition.

[0055] Through the integrated setting, on the one hand, the system integration degree can be improved, the layout space can be reduced, and it is suitable for space limited, batch application scenarios (such as vehicle-mounted, aerospace); on the other hand, the light path is short, the response speed is fast, and the EMI influence is small.

[0056] In addition, the laser emitting unit can also be installed separately from the power semiconductor device, at this time, the laser is separately installed on the control board or the system frame, and is irradiated to the device through an optical fiber or other light path structure; when the optical fiber is used as the light path, the "one source multi-fiber" is supported, that is, one laser output is divided into multiple optical fibers, and respectively irradiates multiple power devices.

[0057] In this way, the laser does not need to be close to the device, and can be away from the high heat area or the high interference area; the laser can be easily replaced separately, improving the maintenance convenience; it is more suitable for experimental verification and modular debugging; the laser irradiation parameters can be flexibly switched, the laser type or wavelength can be upgraded; the optical fiber structure has high standardization degree.

[0058] It should be noted that in the configuration that the laser and the device are installed separately, the laser can be kept at a relatively long distance from the power device, and the system realizes remote and accurate transmission and positioning irradiation of the laser through the optical fiber structure; 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 length of the optical fiber can be flexibly set according to the system layout, and the range is from several centimeters to tens of centimeters; the optical fiber end is connected to the required super-emitter device, and the laser is accurately projected to the device light irradiation window; the optical fiber end can be fixed on the top of the device package, and is connected through a special coupling end cap or a packaging structure interface.

[0059] Further, the principle of reducing the on-resistance by laser irradiation light transmission 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] Collecting the junction temperature, shell temperature or near heat source temperature of the power semiconductor device in real time to obtain temperature data, setting a temperature threshold and a safe temperature value;

[0082] Judging whether the temperature data exceeds the temperature threshold, if yes, starting the laser emission unit through the laser control unit and selecting the laser emission power according to the temperature-laser power mapping table to irradiate the drift region of the power semiconductor device with laser;

[0083] Collecting the temperature adjustment data after laser irradiation in real time and judging whether the temperature adjustment data is lower than the safe temperature value, if yes, stopping the laser irradiation, otherwise, continuing the laser irradiation.

[0084] Specifically, the junction temperature, shell temperature or near heat source temperature of the device is monitored in real time by a temperature sensor; temperature sampling: using NTC, RTD close to the chip or device thermal parameter backstepping mechanism to collect real-time temperature value T (in a system where multiple temperature signals coexist, a priority selection mechanism can be set, and the physical temperature sensor signal can be used by default, and the device thermal parameter backstepping temperature estimation mechanism is enabled under the condition of missing or untrusted sensor signal, to ensure the real-time and robustness of system control); when the temperature rises to the temperature threshold Ton (such as 100℃), the laser control unit outputs the laser on signal, wherein the controller can use an analog comparator combined with a logic gate, or an MCU (such as STM32) combined with an ADC module for sampling and judgment, and the control method is the existing conventional control method; then, after the laser receiver receives the enable signal, the device drift region is irradiated with a set power (such as 20-500mW), and a temperature-laser power mapping table can also be integrated to realize the "the higher the temperature, the stronger the laser" type control; finally, the laser irradiates the drift region of the device to excite photoelectron pairs, improve the conductivity and suppress the rise of on-resistance; when the temperature drops to the safe range, i.e. drops to the safe temperature value Toff (such as lower than 75℃), the laser is automatically turned off, and this mode forms a closed-loop "heat-light-electricity" feedback loop, which is suitable for stable operation and adjustment.

[0085] Embodiment seven

[0086] A laser-regulated power device control method applied to the laser-regulated power device control system of any one of embodiments one to five, comprising the following steps:

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

[0088] The laser emission unit emits laser to the drift region of the power semiconductor device, and turns off the laser emission unit after the gate-source voltage of the power semiconductor device drops.

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

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

[0091] The above is only a preferred embodiment of the present application, and is not a limitation on the form and substance of the present application. It should be noted that those skilled in the art can make some improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be considered as the protection scope of the present application. For those skilled in the art, some changes, modifications and equivalent changes made by using the disclosed technical content without departing from the spirit and scope of the present application are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above-mentioned embodiments according to the essential technology of the present application are still within the scope of the technical solutions of the present application.

Claims

1. A laser modulated power device control system, characterized by, The power semiconductor device comprises: a power semiconductor device; a laser emission unit for emitting laser to the light-transmitting irradiation area of the power semiconductor device according to the temperature data of the power semiconductor or the on-state of the power semiconductor device, actively exciting the generation of electrons and holes when the device junction temperature rises, compensating for the mobility reduction, and preventing thermal runaway, wherein the laser emitted by the laser emission unit is transmitted through the light-transmitting irradiation area and then irradiates the drift region of the power semiconductor device, and generates electron-hole pairs; a laser control unit for controlling 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 the 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 the defect state excitation of the drift region material.

2. A system for controlling a power device modulated by a laser according to claim 1, wherein The power semiconductor device is a vertical conduction device, comprising 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 irradiation area is further arranged on the device surface structure.

3. A system for controlling a power device modulated by a laser according to claim 2, wherein A third electrode is further arranged on the device surface structure.

4. A system for controlling a power device modulated by a laser according to claim 1, wherein The power semiconductor device is a lateral conduction device, comprising 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, and a light-transmitting irradiation area is further arranged on the device surface structure.

5. A system for controlling a power device subject to laser regulation according to any one of claims 2 to 4, characterized in that, A transparent medium material is further arranged on the light-transmitting irradiation area.

6. A system for controlling a power device with a laser according to claim 1, wherein The power semiconductor device is a vertical conduction device, comprising 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 arranged on the upper surface of the drift region, and the passivation layer is in contact with the first electrode.

7. A system for controlling a power device subject to laser regulation 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 microns, and the light-transmitting irradiation area is any one of circular, rectangular, multi-point hole array type, multi-circle ring type, strip staggered type, and multi-shape composite type.

8. A system for controlling a power device with a laser according to claim 1, wherein Further comprising a temperature detection unit for detecting the junction temperature, shell temperature or near heat source temperature of the power semiconductor device to obtain temperature data.

9. A system for controlling a power device with a laser according to claim 1, wherein Further comprising a device switch for controlling the conduction of the power semiconductor device.

10. The system for controlling a power device with a laser according to claim 1, wherein The laser emitted by the laser emission unit is at an angle of 0°-90° with the plane where the light-transmitting irradiation area is located.

11. The system for controlling a power device with a laser according to claim 1, wherein The distance between the laser emission unit and the drift region of the power semiconductor device is 0.01mm-500mm.

12. A method of controlling a power device with laser regulation, characterized in that, The power device control method is applied to the laser-regulated power device control system as claimed in any one of claims 1-11, comprising the following steps: Real-time acquisition of the junction temperature, shell temperature or near heat source temperature of the power semiconductor device to obtain temperature data, setting of a temperature threshold value and a safety temperature value; Judging whether the temperature data exceeds the temperature threshold value, if yes, starting the laser emission unit through the laser control unit, and selecting the laser emission power according to the temperature-laser power mapping table to irradiate the drift region of the power semiconductor device with laser; Real-time acquisition of temperature regulation data after laser irradiation, and determine whether the temperature regulation data is lower than the safe temperature value, if yes, stop laser irradiation, otherwise continue laser irradiation.

13. A method of controlling a power device with a laser, characterized by, The power device control method is applied to the laser-regulated power device control system as claimed in any one of claims 1-11, comprising the following steps: Conducting the power semiconductor device through the device switch and starting the laser emission unit; Emitting laser to the drift region of the power semiconductor device through the laser emission unit, and turning off the laser emission unit after the gate-source voltage of the power semiconductor device drops.

Images