528 results about "Forward voltage" patented technology

The invention discloses a back contact battery, a manufacturing method thereof and a photovoltaic module, relates to the technical field of photovoltaic, and aims to enable the back contact battery to have a relatively low hot spot risk and improve the working reliability of the back contact battery. And meanwhile, the back contact battery has relatively high working efficiency in a forward voltage region. A back contact cell includes a semiconductor substrate, a first doped semiconductor portion, a second doped semiconductor portion, and a transparent conductive layer. In the reverse electric leakage area, the part, extending into the overlapping area from the second area, of the transparent conductive layer is a first transparent conductive part, and the first transparent conductive part is electrically connected with the first doped semiconductor part through the second doped semiconductor part. The width of the first transparent conductive part in the first direction is W1, the width of the overlapping area in the first direction is W2, and the ratio of W1 to W2 is larger than or equal to 10% and smaller than or equal to 90%.

The invention discloses a beam information on-line measurement method based on a steady-state forward voltage vector relation principle. The beam information on-line measurement method comprises the following steps: measuring a cavity incident signal Pf of a radio frequency cavity on line to obtain an original forward voltage Vf * of the radio frequency cavity; performing calibration and normalization processing on the original forward voltage Vf * to obtain a forward voltage Vf; scaling the forward voltage Vf to obtain a standardized forward voltage Uf; based on the standardized forward voltage Uf0 and Uf1 under two conditions of no beam current and beam current, respectively calculating steady-state mean values UF0 and UF1; obtaining a steady-state beam equivalent voltage VB based on the steady-state mean values UF0 and UF1; and based on the steady-state beam current equivalent voltage VB, the beam current intensity IB and the beam current synchronous phase # imgabs0 # in the steady state are obtained. Therefore, the device can be completely deployed in an FPGA chip, and beam information on-line real-time measurement can be realized at the sub-microsecond magnitude.

According to the back contact battery and the preparation method thereof provided by the invention, doping elements penetrate through the third doping region between the first doping region and the second doping region through high-temperature diffusion to form an electric leakage channel, so that a new back surface structure of the back contact battery is provided. The third doped region is formed by mixing the doping elements of the first doped region and the doping elements of the second doped region, doping of the two impurities is completed at a high temperature in one step, so that an electric leakage channel of an overlapping region is not generated, and the overlapping region of the two doped semiconductor layers with opposite conduction types in the thickness direction of the semiconductor substrate is removed, so that the conductivity of the semiconductor substrate is improved. Therefore, electric leakage loss of the back contact battery in a forward voltage area can be controlled, current in the electric leakage channel is introduced to the grid line of the first electrode or the second electrode through the electric leakage channel or the connecting electrode, the hot spot risk of the back contact battery is reduced, the safety performance of the back contact battery is effectively improved, and the service life of the back contact battery is prolonged. And the back contact battery has relatively high working performance.

The invention provides an LED lamp adaptive speed regulation heat dissipation method and system based on real-time junction temperature monitoring. The method comprises the following steps: S100, acquiring a PWM signal or an analog signal of an LED driving command signal in real time; s200, on the basis of the change of the driving instruction signal, feedforward prediction is carried out by using a dynamic thermal inertia mapping model, and a feedforward fan control quantity is generated; s300, LED junction temperature is monitored in real time through a forward voltage method, and feedback fan control quantity is generated through a feedback controller according to the deviation between the real-time junction temperature and the target junction temperature; and S400, synthesizing the feedforward control quantity and the feedback control quantity to generate a fan PWM control signal, outputting the fan PWM control signal to a fan driving circuit, and adjusting the rotating speed of the cooling fan. According to the method, driving signals and junction temperature information are processed in parallel, and feedforward and feedback control is combined, so that self-adaptive accurate regulation and control are realized, thermal load change is quickly responded, system lag is effectively inhibited, and LED heat dissipation performance is optimized.

The invention discloses a beam synchronous phase on-line measurement method, device and equipment and a medium. The beam synchronous phase on-line measurement method comprises the steps of obtaining an original cavity pressure Vc * and an original forward voltage Vf * of a radio frequency cavity; processing the original cavity voltage Vc * and the original forward voltage Vf * to obtain normalized cavity voltage Vc and forward voltage Vf; calculating steady-state values UC and UF of the cavity pressure Vc and the forward voltage Vf, and solving detuning delta omega in a steady state; carrying out linear fitting on the cavity pressure change Vcb caused by the beam current to obtain a phase angle Vcb; according to the selected time window TW, calculating a deflection angle alpha th of a phase angle Vcb caused by detuning delta omega; deducting the deflection angle alpha th from the phase angle Vcb to obtain the phase angle Vb of the beam equivalent voltage; and extracting a beam phase # imgabs0 # based on the phase Vb of the beam equivalent voltage. The calculation result of the method is not influenced by phase drift caused by environmental factors any more, and is not influenced by cavity detuning any more.

A SiC trench MOSFET with an embedded junction Schottky barrier diode (JBSD) having P-shield (PS) regions surrounding bottoms of source-body-Schottky contact (SBSC) trenches for gate oxide electric-field and switching loss reductions is disclosed. A source metal connects with the PS regions and the JBSD directly. Sidewall P (SP) regions are formed along a portion of sidewalls of the SBSC trenches to improve a tradeoff between a drain-source leakage current of the SiC trench MOSFET and a forward voltage of the JBSD. The device further comprises an N-type shield region formed below each of gate trenches for gate oxide electric field strength and specific on-resistance reductions.

The invention provides a range switching circuit, a current detection circuit and an alternating current measuring instrument, and relates to the technical field of electric measuring instruments. The range switching circuit comprises a current input port which comprises a positive terminal and a negative terminal; the current and voltage conversion unit comprises a plurality of range gating branches, each range gating branch comprises a primary coil, a dotted terminal of the primary coil is electrically connected with the positive terminal, and a synonym terminal of the primary coil is electrically connected with the negative terminal; the bidirectional voltage limiting circuit is connected in parallel with the current input port and comprises a positive voltage limiting circuit and a negative voltage limiting circuit which are connected in parallel; the input negative electrode of the compensation unit is electrically connected with the dotted terminal of the primary coil, and the input positive electrode and the output end of the compensation unit are electrically connected with the synonym terminal of the primary coil. According to the invention, the amplitude of current impact on the sampling resistor can be obviously reduced, the damage caused by inconsistent measuring range is avoided, and the overall reliability of the alternating current measuring instrument is improved.

The invention relates to the field of semiconductor device testing, and discloses a power device thermal resistance testing method and power device thermal resistance testing equipment, and the method comprises the following steps: controlling an environment to rise to a first preset temperature in a temperature gradient manner, and sequentially applying a calibration current to a power device at each temperature gradient to test a first forward voltage drop of the power device; calibrating the power device according to the temperature value of each temperature gradient and the first forward voltage drop value corresponding to each temperature gradient to obtain a temperature-voltage drop curve; controlling the environment temperature to be a second preset temperature, applying a first rated power to control the power device to reach a heat balance state, applying a calibration current to the power device to test a second forward voltage drop of the power device, and measuring the shell temperature of the power device; and obtaining the thermal resistance of the power device according to the temperature-voltage drop curve, the second preset temperature, the second forward voltage drop, the first rated power and the shell temperature of the power device. According to the invention, the problem of inaccurate thermal resistance test of the power device is solved.

The invention discloses a main circuit of a hydrogen energy hybrid power machine, which is characterized in that a chopping module is additionally arranged in a traction converter to form a boost chopping discharge circuit and a buck chopping charge circuit on a power battery side together with an electric reactor, so that the voltage output to an intermediate direct current loop by a power battery is stabilized at DC1800V; meanwhile, the circuit safety of the power battery side is improved through the stable and controllable charging circuit; the hydrogen fuel power supply module directly obtains a starting power supply from the intermediate direct current loop through the bidirectional isolated voltage boosting / reducing module, and after the hydrogen fuel power supply module is started, the stability and timeliness of forward voltage boosting control of the voltage boosting / reducing module can be improved through the stable intermediate direct current loop voltage. According to the invention, consistency control of the intermediate voltage in different power supply modes is realized, and system faults caused by inconsistency of the intermediate voltage in the same main transmission system in different power supply modes are reduced. The invention further provides a railway vehicle.

The invention relates to a driving method and system for an adjustable light source LED, and the method comprises the steps: collecting the input voltage and target brightness of a light source in real time, and calculating an initial current set value of the light source; dynamically switching a constant-current dimming strategy and a linear dimming strategy according to the dimming threshold frequency of the light source; feeding back the real-time temperature of the light source through a temperature sensor, and performing temperature compensation on the driving current of the light source to obtain compensation current; determining the driving voltage of the light source by combining the light source forward voltage and the compensation current; and the duty ratio is adjusted in real time based on PID closed-loop control to obtain a real-time duty ratio, and the light source matching target brightness is adjusted based on the real-time duty ratio and the driving voltage. According to the invention, the accuracy and reliability of LED light source adjustment can be improved.

The invention discloses an online suppression method, device and equipment for an electromechanical coupling effect of a radio frequency superconducting cavity, and a medium. The method comprises the following steps: obtaining an original cavity voltage Vc * and an original forward voltage Vf * of the radio frequency superconducting cavity; carrying out calibration and normalization processing on the original cavity pressure Vc * and the original forward voltage Vf *; the normalized cavity voltage Vc and the forward voltage Vf during electromechanical oscillation are screened out, a differential equation is established, and the dynamic detuning delta f of the radio frequency superconducting cavity during electromechanical oscillation is calculated; based on the normalized cavity pressure Vc and the dynamic detuning delta f, identifying a transfer function of a radio frequency superconducting cavity mechanical mode by using a system identification method; establishing a coupling system characteristic equation according to the transfer function of the cavity mechanical mode, the transfer function of the radio frequency superconducting cavity and the transfer function of the low-level system controller, and solving the characteristic equation to find out stability boundaries under different parameter conditions; and optimizing closed-loop control parameters according to the stability boundary, and realizing online suppression of the electromechanical coupling effect.

The invention discloses a machine learning-based radio frequency superconducting cavity thermal quenching mode online classification method, apparatus and device, and a medium. The method comprises the steps of obtaining a cavity voltage Vc and a forward voltage Vf of a radio frequency superconducting cavity; calculating a predicted value rc of the cavity pressure amplitude according to the cavity pressure Vc and the forward voltage Vf, and comparing a deviation e between the predicted value rc and the actually measured cavity pressure amplitude value r; features Qid, Eid and Nsoft are extracted based on the actually measured cavity pressure amplitude value r and the deviation e; the extracted features Qid, Eid and Nsoft are input into a fault diagnosis model, fault classification is achieved, faults comprise non-thermal quench faults and thermal quench faults, and the thermal quench faults comprise conventional thermal quench, thermal quench caused by electric quench and soft quench. Therefore, automatic online classification of the thermal quenching mode can be realized, and second-order high-accuracy fault information feedback is provided for accelerator operators.

Provided in the present disclosure are an LED lamp bead and an LED lamp module. The LED lamp bead comprises a light-emitting body and a lamp bead holder. The lamp bead holder comprises a light-emitting-body fixing structure and a driving circuit, wherein the light-emitting-body fixing structure is configured to fix the light-emitting body, and the driving circuit is connected to the light-emitting body and is configured to drive, in response to a lamp bead trigger signal, the light-emitting body to emit light. The driving circuit comprises a power supply interface and an IC chip, wherein the power supply interface, the light-emitting body and the IC chip are sequentially connected, such that power supply currents input from the power supply interface flow through the light-emitting body to the IC chip; and the IC chip is configured to receive the lamp bead trigger signal and transmit the lamp bead trigger signal to the light-emitting body, so as to drive the light-emitting body to emit light. The power supply interface, the light-emitting body and the IC chip are sequentially connected, such that the power supply currents input from the power supply interface flow through the light-emitting body to the IC chip; correspondingly, the LED lamp bead works in a common-cathode driving mode, such that a forward voltage drop is reduced, and internal conduction resistance is also reduced, thereby ensuring the usage safety of the lamp bead.

A lighting device, such as a light-emitting diode (LED) light source, may operate in an interim operable state to avoid and / or prevent undesirable characteristics in the light emitted by the lighting device (e.g., strobing and / or flickering of a brightness of the light and / or shifting or change of a color of the light). When operating in a normal state, the control circuit may determine if a measured value of a first operational characteristic (e.g., a forward voltage of an emitter of the lighting device) is outside of a range and operate in the interim operable state if the measured value of the first operational characteristic is outside of the range. When operating in the interim operable state, the control circuit may adjust a drive current for the emitter in response to a measured value of a second operational characteristic (e.g., a forward voltage of a detector of the lighting device).

The present application relates to a trench-type Schottky barrier diode and a manufacturing method therefor. The trench-type Schottky barrier diode comprises: a substrate (170), having a first conductivity type; a first conductivity type layer (160), located on the substrate (170), the doping concentration of the first conductivity type layer (160) being less than the doping concentration of the substrate (170); a trench structure, extending from the front surface of the first conductivity type layer (160) to the substrate (170), the trench structure comprising a conductive material (140) and further comprising a dielectric layer (130) surrounding the conductive material (140) from the side surface and the bottom surface; a Schottky barrier layer (120), located on the first conductivity type layer (160) and on the trench structure; and a second conductivity type region (150), located below the trench structure, the top of the second conductivity type region (150) being in direct contact with the bottom of the dielectric layer (130), and the bottom of the second conductivity type region (150) being spaced apart from the substrate (170) by part of the first conductivity type layer (160). The present application can maintain reverse withstand voltage characteristics while reducing the on-state forward voltage drop of devices.

The invention belongs to the field of power device driving, particularly relates to the technical field of crosstalk suppression, and more particularly relates to a crosstalk suppression driving circuit. Through cooperative work of the driving module, the detection module, the buffering module and the clamping module, crosstalk is effectively suppressed while the switching speed is ensured. The driving module ensures normal switching action of the power device; the detection module converts the drain voltage change rate into a detection signal in real time, and recognizes the crosstalk risk in advance; the buffer module suppresses forward crosstalk by absorbing grid forward voltage spikes; the clamping module immediately conducts a low-impedance path from the grid electrode to the negative power supply when the detection signal exceeds a threshold value, and negative crosstalk is quickly eliminated. According to the design, the suppression circuit is only activated when the voltage change rate exceeds the standard, switching delay caused by a traditional fixed buffer circuit is avoided, accurate and rapid crosstalk suppression can be achieved, and finally the suppression effect and the system reliability are remarkably improved while the high-speed switching performance is maintained.

The invention discloses a bypass diode test method and a bypass diode test device, and belongs to the field of photovoltaic technology. The method comprises the following steps: acquiring forward voltage drop values of a bypass diode to be measured at different temperatures in a target temperature range, and determining a voltage drop and junction temperature relationship between the forward voltage drop and the junction temperature of the bypass diode; obtaining reverse withstand voltage extreme values of the bypass diode at different temperatures in the target temperature range, and determining a junction temperature withstand voltage relationship between the reverse withstand voltage and the junction temperature of the bypass diode; and determining a test result of the bypass diode according to at least one of the voltage drop junction temperature relation and the junction temperature withstand voltage relation based on the component performance parameters of the bypass diode. The method can quickly and accurately judge the safety and reliability of the bypass diode when the assembly works for a long time.

A bidirectional crosstalk suppression driving circuit suitable for a wide bandgap power semiconductor device comprises a push-pull circuit and a crosstalk suppression auxiliary circuit, the push-pull circuit is connected with the crosstalk suppression auxiliary circuit, and the crosstalk suppression auxiliary circuit is connected with a grid electrode and a source electrode of the power semiconductor device. The push-pull circuit is used for generating a driving voltage signal to drive a power semiconductor device. When the power semiconductor device is subjected to positive crosstalk, positive voltage is generated through a negative voltage capacitor in the crosstalk suppression auxiliary circuit, and the influence of negative overvoltage generated on a driving resistor when the positive crosstalk occurs is reduced; when the power semiconductor device is subjected to negative crosstalk, gate equivalent driving impedance is reduced through an RD auxiliary branch in the crosstalk suppression auxiliary circuit, and reverse overvoltage caused by negative crosstalk is reduced. The circuit has compatibility and economical efficiency, and is simple in structure and easy to operate. The method is of great significance in improving the turn-on and turn-off reliability of a power semiconductor device and guaranteeing stable operation of a system.

A resonant converter has a resonant capacitor between the input stage and the output stage. An output inductor arrangement of the output stage has a first inductor component and a second inductor component. A first output is coupled to a reference output by both of the first and second inductor components in series and connects to a first load with a first (high) forward voltage. A second output is coupled to the reference output by only one of the first and second inductor components, and connects to a second load with a second (low) forward voltage. Only one output connects to a corresponding load at one time. This enables a large output voltage range with low total harmonic distortion and / or low voltage stress on the components of the input and output stages.

The invention relates to the field of static frequency converters, and discloses a static frequency converter protection system comprising a control unit used for generating a control signal and performing bidirectional communication with a valve control unit through an optical fiber; the thyristor control unit obtains energy through a circuit and sends a first return signal after energy obtaining is completed; and the valve control unit is used as a bridge between the control unit and the thyristor control unit and is used for receiving and collecting the first return signal. When the forward voltage of the thyristor driven by the thyristor control unit exceeds a set protection value, the thyristor control unit triggers the thyristor emergently, and returns an overvoltage protection signal to the valve control unit at the same time. The valve control unit gathers overvoltage protection signals, and when the number of the thyristors subjected to overvoltage protection at the same time is larger than a tripping constant value set by the valve control unit, the valve control unit sends a tripping request signal to the control unit to inform the control unit of interlocking tripping.

The invention discloses a method, a device, equipment and a medium for on-line measurement of a flutter noise effect of a radio frequency cavity. The method comprises the following steps: acquiring an original forward voltage Vf * of the radio frequency cavity; performing calibration and normalization processing on the original forward voltage Vf * to obtain a forward voltage Vf; according to the calibrated and normalized forward voltage Vf, cavity detuning caused by a flutter noise effect is calculated; performing preliminary time-frequency analysis on the flutter noise according to the cavity detuning to obtain a frequency spectrum of the cavity detuning; decomposing the cavity detuning frequency spectrum, and accumulatively calculating the RMS of the time domain signal and the contribution value of each frequency component to the cavity detuning overall RMS from low frequency to high frequency; and based on the contribution value of the overall RMS of the cavity detuning, judging the frequency component of the cavity detuning caused by the flutter noise. Therefore, the invention can be widely applied to particle accelerators.

The invention provides a DC-DC forward boost-buck power conversion circuit based on cascaded Cuk topologies, and relates to the technical field of power electronic conversion, the circuit is mainly formed by cascading two Cuk topologies sharing one inductor, and the circuit also comprises a power supply end, a load end and a same-frequency driving signal generator. The same-frequency driving signal generator controls the two power switch tubes in the Cuk topology through a same-frequency signal, and the output voltage is adjusted by adjusting the duty ratio. The circuit not only keeps the advantage of continuous input and output current of a traditional Cuk circuit, but also converts the polarity of the output voltage from the reverse direction to the forward direction, and meanwhile, the voltage gain is remarkably improved, so that forward voltage conversion can be efficiently and smoothly realized. The circuit structure has the characteristics of high gain, forward output, continuous current, simple control and the like, and is suitable for occasions requiring high-efficiency and high-quality electric energy conversion, such as new energy power generation and energy storage, electric automobiles, precision industry and the like.

The invention relates to a power supply circuit with a monitoring function comprising a first current branch (2) with a first controllable section (20) and at least one load (21) arranged in series therewith, and a second current branch (3) with a second controllable section (30) and at least one load (31) arranged in series therewith. A controllable converter (4) is connected to the first and second current branches (2, 3) to supply a total current. A control circuit (5) with a control input, which is connected to the set input (10), wherein the control circuit (5) is coupled to the first controllable section (20) to adjust a current through the first current branch (2) depending on a provided first set signal.The second controllable branch (30) is coupled to the first current branch (2) and to the set input (10) in a dependent control loop, which is influenced by the current flowing in the first circuit (2) and the forward voltage of the two loads (21 and 31). It is configured to control a current through the second current branch (3) depending on an operating state through the first current branch (2) and a second set signal. Furthermore, a current-controlled monitoring circuit is provided, which is connected to a node between the respective current branch and the load connected in series with it. This circuit is configured to generate an error signal in response to a predefined deviation of one of the currents flowing into the current-controlled monitoring circuit, which reflects the state of the respective load.

The invention relates to the technical field of water purification, and provides a water outlet control method and device of water purification equipment. The water outlet control method of the water purification equipment comprises the following steps: acquiring a first TDS value of a water body received by a front filter element and the water outlet flow of a rear filter element; according to the water outlet flow and the water outlet time of the rear filter element, the water outlet amount of the water purification equipment is determined; determining that the first TDS value is greater than a first preset value, controlling to apply forward voltage to the capacitive deionization filter element, and controlling the reversing valve to be in a first state, so that purified water output by the capacitive deionization filter element flows to a rear filter element; and determining that the water yield is greater than the preset water yield, controlling to apply reverse voltage to the capacitive deionization filter element, and controlling the reversing valve to be in a second state, so that the wastewater output by the capacitive deionization filter element flows to the wastewater outlet. According to the method disclosed by the invention, the water path structure of the water purification equipment is optimized, and the water purification equipment can be automatically switched between a purified water outlet mode and a waste water outlet mode.

An optoelectronic module includes at least one light emitting diode that emits light with a luminous intensity during operation. The optoelectronic module also includes an integrated circuit which sets an operating current of the light emitting diode and measures a value of the forward voltage of the light emitting diode during operation. The integrated circuit determines a degradation of the light emitting diode by measuring the value of the forward voltage and increases or decreases the electrical operating current as a function of the measured value of the forward voltage, such that a change in the luminous intensity due to the degradation is at least partially compensated. The integrated circuit or a measurement-control-unit for controlling the integrated circuit includes a memory in which calibration data is stored. The calibration data comprises a value of the forward voltage of the light emitting diode as a reference value for determining the degradation.

The utility model discloses a switching-in circuit compatible with multiple voltage levels, and effectively solves the problem that a protection device circuit is not suitable for different voltage levels. Comprising an input circuit which comprises an anode input port and a cathode input port; the resistance voltage division circuit comprises a positive voltage division resistor and a negative voltage division resistor; the level adjusting circuit comprises a linear voltage regulator, the linear voltage regulator comprises a voltage stabilizing input port, a voltage stabilizing output port and an adjusting port, the adjusting port is connected with a first adjusting resistor and a second adjusting resistor, one end of the first adjusting resistor is connected with the negative electrode input port, and the other end of the first adjusting resistor is connected with the negative electrode output port. One end of the second adjusting resistor is connected in parallel with the voltage stabilization output port; according to the utility model, the structure is ingenious, the use is convenient, through the arrangement of the jumper wire and the linear voltage regulator, not only can adjustment be carried out according to different voltage class inputs, the damage of high voltage to components be prevented, but also the versatility of the equipment circuit is improved.

The invention relates to the technical field of lamp bead active heat dissipation, and discloses an LED lamp bead active heat dissipation system and method, and the method comprises the steps: injecting a micro-current pulse into a PN junction of an LED chip through a constant current source, collecting a forward voltage drop sampling value, and collecting a substrate temperature sampling value; calculating a junction temperature value based on the forward voltage drop sampling value, and calculating a junction-to-case temperature difference value and a substrate temperature rise rate value; setting an early-warning state identifier when the junction-to-case temperature difference value exceeds an early-warning threshold value and the duration meets a preset duration, setting an alarm state identifier when the junction-to-case temperature difference value exceeds an alarm threshold value, and shielding thermal runaway detection when the substrate temperature rise rate value exceeds an environment thermal shock threshold value and the junction-to-case temperature difference value is smaller than an environment exclusion threshold value; when the state identification is the normal state identification, calculating a first compensation current value; and when the state identification is the early warning state identification, a second compensation current value is calculated, and when the state identification is the alarm state identification, an alarm current limiting value is calculated, so that the working stability and long-term reliability of the LED in a wide temperature range are ensured.

The invention relates to the technical field of data processing, in particular to a high-frequency diode conduction loss characteristic test system, which comprises an acquisition module, a first judgment module, a second judgment module, a first determination module, a second determination module, an adjustment module and an output module. According to the method, multiple key data are collected, rapid screening is carried out according to forward voltage and reverse recovery charges, then, hidden defects of abnormal dynamic relevance of parameters are analyzed and identified by introducing shell temperature, and finally, a high-loss diode is obtained; the trend abnormity is identified by using the space-time distribution characteristics of the high-loss diode, and the loss reason is accurately detected through the voidage fluctuation mode; and meanwhile, based on a self-adaptive adjustment mechanism fed back by the test accuracy, a test report is finally output, so that the problems of low identification accuracy of the high-loss diode and low detection accuracy of loss reasons caused by excessive dependence on static parameters and incapability of adapting to complex and changeable working conditions are effectively solved.

An MOS junction barrier Schottky diode relates to the technical field of power semiconductor devices. The N-type substrate, the N-type epitaxial layer, the deep P region, the trench gate, the trench gate oxide layer, the conductive enhancement region and the isolation oxide layer are arranged between the cathode metal and the anode metal, the lower surface of the N-type substrate is in contact with the cathode metal, the upper surface of the N-type substrate is in contact with the lower surface of the N-type epitaxial layer, and the upper surface of the N-type epitaxial layer is in contact with the P region. The conductive enhancement region is arranged on the outer surface of the trench gate oxide layer and is in contact with the N-type epitaxial layer, and a part of the trench gate oxide layer, the conductive enhancement region, the isolation oxide layer and a part of the deep P region are respectively in contact with a part of the anode metal. According to the MOS junction barrier Schottky diode structure, the groove gate MOS structure is inserted into the adjacent P region of a traditional junction barrier Schottky (JBS) diode, so that the carrier density at a channel is improved, the channel resistance is reduced, and the reverse electric leakage characteristic and the forward voltage drop are further improved.

The invention provides a source-drain forward voltage test method for an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) thick wafer, which comprises the following steps of: providing a main die and an auxiliary die which are formed on the wafer, the wafer is provided with a back sealing structure, the main die and the auxiliary die are respectively provided with a first power MOSFET and a second power MOSFET, and the drain ends of the main die and the auxiliary die are connected; obtaining the on resistance RDSON of the auxiliary die; 0 potential is applied to the grid end of the main die, turn-on voltage is applied to the grid end of the auxiliary die, test current flows in from the source end of the main die and flows out from the source end of the auxiliary die, and the source-drain forward voltage VFSD total of the main die and the auxiliary die is obtained; the source-drain forward voltage VFSD main die of the main die is obtained, the VFSD main die = VFSD total-K * RDSON auxiliary die * I-C, K is a coefficient, C is a constant, and I is the test current value of the first power MOSFET and the test current value of the second power MOSFET. According to the invention, the influence of auxiliary Die conduction voltage drop can be eliminated, and the source-drain forward voltage of the thick wafer of the power MOSFET can be accurately measured.