254 results about "Stray inductance" patented technology

The invention discloses a novel ultra-low stray inductance and double-sided heat dissipation silicon carbide power module. The novel ultra-low stray inductance and double-sided heat dissipation silicon carbide power module comprises a power module assembly, a plastic package body and a double-sided heat dissipation assembly, the power module assembly is formed by connecting a lower bridge assembly and an upper bridge assembly which are oppositely and symmetrically arranged through a molybdenum block. During working, stray inductance in the upper bridge arm and stray inductance in the lower bridge arm are counteracted, and the stray inductance of the whole module is reduced. The power module assembly is divided into an upper layer heat dissipation water channel and a lower layer heat dissipation water channel through the two double-sided heat dissipation assemblies, so that the contact area between cooling liquid and the module is doubled, the heat dissipation capacity of the module is improved, the maximum junction temperature of the silicon carbide module is effectively reduced, and the working efficiency of the silicon carbide module is improved. The heat dissipation columns which are small in area and are distributed more densely are arranged at the bottom of the high-heat chip, the heat dissipation columns which are large in area and small in number are arranged in the low-heat area, the heat dissipation columns are reasonably arranged according to the arrangement of the chip, the situation that the overall heat exchange efficiency is affected due to excessive temperature rise of local cooling liquid is avoided, and therefore the overall heat dissipation effect is guaranteed.

The invention relates to an electronic device module, a controller and a vehicle. The electronic device module comprises two functional modules, each functional module is provided with a first terminal and a second terminal, the first terminal and the second terminal extend towards the other functional module, the ends of the two first terminals are conducted, and the ends of the two second terminals are conducted; and along the thickness direction of the first terminal, the projection of the second terminal on the first terminal is at least partially accommodated in the first terminal. According to the electronic device module, the two terminals of the two functional modules are arranged between the two functional modules, and the projection of the second terminal on the first terminal is at least partially accommodated in the first terminal, so that the magnetic field generated by the current flowing in the two first terminals can be transmitted to the two functional modules. And the magnetic field generated by the current flowing to the two second terminals can offset each other, so that the generation of stray inductance is reduced.

The invention discloses a power module. The power module comprises a direct current busbar, a radiator, an IGBT module I and an IGBT module II, the IGBT module I and the IGBT module II are respectively arranged on a mounting surface I and a mounting surface II of the radiator; the direct-current busbar comprises a direct-current busbar I, a direct-current busbar II, a direct-current busbar III and a direct-current busbar IV; the two ends of a fourth direct-current busbar are connected with the first IGBT module and the second IGBT module respectively, and the middle of the fourth direct-current busbar is connected with the middle of a third direct-current busbar. The two ends of the direct current busbar III are respectively connected with the direct current busbar I and the direct current busbar II; the direct current busbar I and the mounting surface I as well as the direct current busbar II and the mounting surface II are oppositely arranged and parallel to each other; the first direct current capacitor assembly is connected with the first direct current busbar, and the second direct current capacitor assembly is connected with the second direct current busbar. The influence of stray inductance is reduced by optimizing a current path, and the voltage spike at the switching moment is reduced due to the reduction of the stray inductance, so that the switching loss is reduced.

An embedded power module with multiple chips connected in parallel comprises a first AMB board, a chip assembly, a second AMB board and a circuit board. The first AMB board comprises a first insulating layer, a first lower copper layer and a first upper copper layer. The first upper copper layer is provided with a plurality of embedding grooves, and the chip assembly comprises a chip and a copper bar. The second AMB board comprises a second insulating layer, a second lower copper layer and a second upper copper layer. The first insulating layer is welded with the first upper copper layer, the second lower copper layer is welded with the first upper copper layer, the second insulating layer and the second lower copper layer are provided with avoiding holes, and the chip assembly is located in the avoiding holes and the embedding groove, so that double paths with double-sided heat dissipation are formed, and the heat dissipation efficiency is improved. The lower surface of the copper bar is connected to the chip, the upper surface of the copper bar is connected with the second upper copper layer, the laminated structure also shortens the vertical path of current input and output, the current loop area is reduced, and the stray inductance is effectively reduced.

The invention provides a testing device of a power semiconductor device and a testing method based on the testing device, and relates to the field of semiconductors, and the testing device comprises a first probe loop which comprises a first probe which can be separated from or electrically contacted with a tested power semiconductor device; when the first probe is in electric contact with the tested power semiconductor device, the dynamic voltage change rate applying circuit applies dynamic voltage to the tested power semiconductor device through the first probe loop; the second probe loop comprises a second probe which is electrically contacted with the tested power semiconductor device; when the first probe is separated from the tested power semiconductor device, the parameter measuring circuit measures the electrical parameters of the tested power semiconductor device through the second probe loop; and the first stray inductance of the first probe loop is smaller than the second stray inductance of the second probe loop, so that the electrical parameters of the power semiconductor device can be accurately extracted under the condition that high dV / dt dynamic voltage is applied to the power semiconductor device.

The utility model provides a power module and electronic equipment. The power module comprises a driving assembly and a power device, the driving assembly and the power device are suitable for being arranged on the same circuit board, and the driving assembly is electrically connected with the power device. Therefore, equivalently, the driving assembly and the power device are integrated on the same circuit board, the electric connection between the driving assembly and the power device can be realized on the circuit board, the overall size of the power module can be greatly reduced, the power density of the power module is improved, and meanwhile, the driving assembly and the power device are electrically connected on the same circuit board, so that the power density of the power module is improved. Therefore, the driving path of the driving assembly for the power device can be greatly shortened, stray inductance generated by the driving path is effectively reduced, the advantages of high speed and high power of the power device are fully played, and the working performance of the power module is improved.

The invention provides a power module, a motor controller and a vehicle, and relates to the technical field of vehicles, the power module comprises a circuit board layer, a chip substrate and a heat dissipation bottom plate, the circuit board layer comprises conducting layers and insulating layers which are alternately arranged in the vertical direction, and the conducting layers and the insulating layers are arranged on the uppermost layer and the lowermost layer of the circuit board layer respectively; the lowest insulating layer in the circuit board layer is marked as a first insulating layer, the conductive layer stacked on the first insulating layer in the circuit board layer is marked as a first conductive layer, the chip substrate is embedded in the first insulating layer, the heat dissipation bottom plate is arranged at the lower end of the first insulating layer, the chip substrate comprises a power chip and a mounting substrate, and the power chip is embedded in the mounting substrate. The power chip is arranged at the upper end of the mounting substrate and is electrically connected with the first conductive layer. Thus, the occupied space of the power module can be reduced, an electrical connection path between the power chip and the driving circuit and a heat dissipation path between the power chip and the heat dissipation bottom plate can be shortened, stray inductance is reduced, and the heat dissipation effect is improved.

The invention provides a multi-chip stacked double-sided heat dissipation silicon carbide power module, and relates to the technical field of chip packaging, and the power module comprises a first DBC substrate, a second DBC substrate, a negative direct current terminal, an alternating current terminal and a positive direct current terminal, and the first DBC substrate and the second DBC substrate are sequentially provided with an upper copper pattern layer, an aluminum nitride ceramic layer and a lower conductive copper layer. Wherein the upper copper pattern layers of the first DBC substrate and the second DBC substrate are oppositely arranged, and a plurality of SiC chips are arranged on the upper copper pattern layers. An upper DBC substrate and a lower DBC substrate are integrated, the DBC substrates adopt chip stacking, the number of chips connected in parallel is increased, double-face heat dissipation is achieved, more chips can be connected in parallel, and the power density of the power module is improved. The terminals are adopted to replace most of lead bonding to reduce parasitic inductance, the terminals are designed according to circuit topology to realize interconnection between chips and interconnection between the chips and the terminals, the proposed structure can effectively realize similarity of stray inductance between the chips and between the upper sides and the lower sides of the chips, and the stray inductance of the module is reduced.

The invention relates to an electric device module, a motor controller and a vehicle, the electric device module comprises a shell, a first capacitor core body and a power module, the first capacitor core body and the power module are both installed in the shell, and the first capacitor core body is electrically connected with the power module. The first capacitor core body and the power module which are designed in an integrated mode can allow a connection path between the first capacitor core body and the power module to be shortened, so that stray inductance between the first capacitor core body and the power module can be reduced, and in addition, the first capacitor core body and the power module which are designed in an integrated mode are more compact in structure, small in overall size and convenient to carry. The occupied space is small, and the volume density and the power density are large.

This invention discloses an IGBT parallel module having at least two IGBTs connected in parallel, each IGBT configured with a paired FRD; the two parallel IGBTs are designated as first and second IGBTs, and their corresponding paired FRDs are designated as first and second FRDs, respectively. A bridging FRD is also configured between the first and second FRDs; a portion of the anode pins of the bridging FRD is connected to the anode pins of the first FRD via bonding wires, and another portion of the anode pins of the bridging FRD is connected to the anode pins of the second FRD via bonding wires; when current imbalance occurs between the first and second FRDs, the bridging FRD reduces the rated current of the first and second FRDs and performs current buffering, thereby reducing the current density of each FRD; the pin connection structure of the anode of the bridging FRD makes the stray inductance of the bridging FRD greater than that of either the first or second FRD, thereby improving the softness of the reverse recovery of the first and second FRDs. This invention can prevent failure defects caused by current concentration.

The utility model discloses an SIC single-sided half-bridge module. A plurality of chips are distributed at one end of the substrate, a heat dissipation plate is fixedly arranged at the other end of the substrate, a plurality of heat dissipation supporting columns are distributed in the heat dissipation plate at intervals, the projection area of the heat dissipation supporting columns covers at least one chip, one end of each metal bonding support is connected to the substrate, and the other end of each metal bonding support is connected to the heat dissipation plate. The other end is connected to one of the chips; the chip and the substrate are electrically connected through the metal bonding support, the metal bonding support has a large contact area, heat can be effectively dispersed and transmitted to a larger area, compared with a bonding wire, the metal bonding support is lower in thermal resistance and higher in current-carrying capacity, interference among currents is facilitated due to increase of the contact area, and the current-carrying capacity of the metal bonding support is improved. Therefore, the stray inductance is reduced; according to the scheme, by arranging the position of the chip, the chip is located in the coverage range of the heat dissipation supporting columns, and therefore the heat dissipation efficiency of the module is greatly improved.

The invention belongs to the technical field of power electronics, and particularly relates to a solid-state direct-current circuit breaker module based on IGCTs, an upper pressing plate and a lower pressing plate are connected through a first screw rod, the number of first radiators is one more than that of the IGCTs, and the first radiators and the IGCTs are arranged in an overlapping mode; the number of the second radiators is one more than that of the first fast recovery diodes, and the second radiators and the first fast recovery diodes are arranged in an overlapping mode. First insulating cushion blocks are arranged between the first radiators and the lower pressing plate and between the second radiators and the lower pressing plate. Insulating cushion blocks II are arranged between the radiator I and the upper pressing plate as well as between the radiator II and the upper pressing plate and correspondingly abut against the radiator I and the radiator II through two force application mechanisms positioned on the inner side of the upper pressing plate; the piezoresistor is installed on the side, away from the first radiator, of the second radiator, the RCD protection unit is installed on the insulating plate, and the insulating plate is installed on the upper pressing plate and the lower pressing plate and located on one side of the first radiator and one side of the second radiator. The structure is compact, maintenance is easy, pressure is uniform, stray inductance is reduced, and overall stability and response speed are improved.

The application discloses a packaging structure of a power module, which comprises an insulating substrate, a plurality of base islands, a power device, a first diode, a second diode, a signal terminal, a power terminal and a plastic package body. The combination of the power device and the first diode is packaged together with the second diode, so that the stray inductance in the device is reduced, the layout and wiring are simplified, the device performance is improved, the application range of the device is wider, and the space utilization is greatly improved.

The embodiment of the utility model discloses a power module packaging structure which comprises a substrate and a power unit. Wherein the power unit comprises a first metal structure, a power device and a second metal structure which are sequentially overlapped, the second metal structure comprises a copper layer, the power unit is electrically connected with the substrate through the first metal structure, and the power unit is electrically connected with an external circuit board through the copper layer of the second metal structure. Therefore, the stray inductance of the power unit can be reduced, and the heat capacity of the power unit can be increased.

This invention relates to a testing method for an IGBT circuit system, comprising the following steps: applying a pulse signal to a single IGBT transistor; obtaining the current waveform in the overall circuit using a current probe; obtaining the voltage waveforms at locations V1, V2, and V3 of each component using a voltage probe; testing the stray inductance of the bus power supply; testing the stray inductance of the multilayer copper busbar; and testing the total stray inductance of the IGBT module under test. The advantages of this invention are: it can measure the bus capacitance, multilayer copper busbar, and total stray inductance of the IGBT module separately.

A loop-symmetrical switching device double-pulse test laminated busbar and test system, belonging to the technical field of switching device testing, solves the problem of how to reduce the stray inductance of the laminated busbar. When performing a double-pulse test on a SiC-based switching device, on the upper and lower surfaces of the laminated busbar, the current of the test loop flows from one side of the two parts divided by the insulating slot through a connecting assembly to the other side of the two parts divided by the insulating slot, thereby passing through the corresponding flexible coil current sensor to complete the collection of the loop current. On the upper and lower surfaces of the laminated busbar, the path of the equivalent current forms a loop that is symmetrical in top and bottom. The currents in the loop are equal in magnitude and opposite in direction, and the magnetic fields generated by the currents in the loop cancel each other out, thereby minimizing the current residual loop and reducing the loop stray inductance. The laminated busbar occupies a small space.

According to the packaging structure and the packaging method, in the packaging structure, a first surface and a second surface of a chip structure are electrically connected; the conductive structure is electrically connected with the first connecting end on the other side of the bonding area through the first substrate, and electric connection between the first connecting ends located on the two sides of the bonding area and between the first connecting ends located on the two sides of the bonding area and the chip structure is achieved through the first substrate, the chip structure, the conductive structure and the second substrate. The first surface and the second surface of the chip structure and the conductive structure are electrically connected in the vertical direction, so that stray inductance can be reduced; besides, a part of an electric connection path is realized through the chip structure, the second substrate and the conductive structure, so that the area occupied by the electric connection path in the first substrate can be reduced, the heat dissipation area of the first substrate is increased, the area for bonding the chip structure in the first substrate is also increased, and the heat dissipation efficiency of the first substrate is improved. The bonding number of the chip structure is correspondingly increased, the outflow capacity of the packaging structure is improved, and the performance of the packaging structure is optimized.

The invention discloses an energy storage commutation circuit and system, and the circuit comprises an energy storage module which comprises a plurality of energy storage units which are connected in series; the energy storage module is used for controlling the input and output of a plurality of energy storage units so as to generate periodic multi-level voltage; the current conversion module is connected with the energy storage module and comprises a first bridge arm group and a second bridge arm group; the auxiliary reversing module is connected in series with the plurality of energy storage units, or is connected with at least one of the first bridge arm group and the second bridge arm group; the auxiliary commutation module is used for forming a resonance circuit with stray inductance on a loop in a commutation time interval; and the commutation module is used for carrying out commutation on the multi-level voltage output by the energy storage module through the first bridge arm group and the second bridge arm group in the commutation time interval under the condition that the loop current meets the zero current condition so as to generate a single-phase alternating current voltage. According to the invention, commutation can be carried out under a zero-current condition, the turn-off loss of the device is reduced, and the service life of the device is prolonged.

The invention discloses a capacitor, which comprises a shell, a positive busbar, a negative busbar, a middle busbar, at least one capacitor core group and at least one terminal group, the positive electrode busbar, the negative electrode busbar, the middle electrode busbar and the capacitor core groups are arranged in the shell, and the capacitor core groups are matched in the shell; each capacitor core group comprises a first capacitor core and a second capacitor core which are arranged side by side, the second end of the first capacitor core of each capacitor core group is connected with the positive busbar, and the second end of the second capacitor core of each capacitor core group is connected with the negative busbar; the first end of the first capacitor core and the first end of the second capacitor core of each capacitor core group are connected with the middle pole busbar; and each terminal group is matched outside the shell, and a positive terminal, a negative terminal and a middle terminal of each terminal group are respectively connected with the positive busbar, the negative busbar and the middle busbar. The capacitor is small in overall stray inductance and good in overall performance.

An embedded packaging circuit board integrated with a driving device comprises an FR4 insulating layer, a power device is embedded in the FR4 insulating layer, and a second insulating layer is arranged on the bottom surface of the FR4 insulating layer; the circuit layer is arranged on the FR4 insulating layer, and the circuit layer is electrically connected with the power device; the driving device is arranged above the circuit layer, the driving device is electrically connected with the circuit layer, and a first insulating layer is arranged between the driving device and the circuit layer; the first insulating layer is lower than the second insulating layer in heat conductivity coefficient. According to the utility model, the heat conductivity coefficient of the first insulating layer is lower than that of the second insulating layer, so that heat can be dissipated from the lower part, the influence on the driving device is avoided, the packaging structure enables the distance between the driving device and the power device to be shorter, the signal transmission to be more stable and rapid, the shortest power path, the lowest stray inductance and the smoother waveform are realized, and the reliability of the packaging structure is improved. The switching loss is minimum, and meanwhile, the system size can be minimum.

The utility model relates to a semiconductor device and its packaging technical field, specifically disclose a kind of module terminal and HPD packaging module using laminated busbar structure, including DC terminal, DC terminal includes: two ends and chip and direct current power supply intercommunication's first component and second component, first component and second component current is opposite;First component and second component form laminated busbar structure to offset reverse current magnetic field, the partial area of first component and the overall area of second component overlap to expand magnetic field offset effective area.The utility model forms laminated busbar structure by setting first component and second component, offset the magnetic field generated by reverse current, secondly, the projection area of second component is the effective overlapping area of first component and second component, to expand the effective area of magnetic field offset as far as possible, to reduce total magnetic flux without affecting laser welding, to reduce stray inductance, improve system reliability.

A power module, a motor controller, a power assembly and a vehicle, the power module comprising a first power tube and a second power tube, the first power tube comprising a first power tube body and a first alternating current terminal, the second power tube comprising a second power tube body and a second alternating current terminal, the first power tube body and the second power tube body being stacked along a first direction. In the technical scheme of the present application, the first power tube body and the second power tube body are stacked, when the first power tube is turned on, the second power tube body connected with the first power tube body will be reversely biased, and then a recovery current opposite to the internal current of the first power tube body is generated in the second power tube body. The magnetic field generated by the opposite recovery current and the magnetic field generated by the current in the first power tube body offset each other, so as to reduce the stray inductance in the power module circuit and improve the electromagnetic compatibility of the power module.

The present invention discloses an H-bridge power unit module with ultra-high power, which includes a power unit module main body, a first bridge arm power semiconductor sub-module, a second bridge arm power semiconductor sub-module, a DC bus capacitor assembly and a DC conductive bus arranged on the power unit module main body. The first bridge arm power semiconductor sub-module and the second bridge arm power semiconductor sub-module are electrically connected through the DC conductive bus. The power unit module can maintain the power semiconductor module separately, simplify and shorten the maintenance time, improve the current sharing ability from the DC bus capacitor to the DC end of the power semiconductor, reduce the stray inductance of the DC bus easily caused by the connection between each DC bus capacitor and the semiconductor power module, reduce the sensitivity of the module voltage, avoid causing module explosion, be safer, enable the current to evenly flow into each formed P potential and N potential from each power semiconductor device, and optimize the assembly and installation time of the DC bus capacitor module.

The application discloses a detection device and method of a power conversion unit. The detection device comprises a heating current source, a measuring current source, a switch tube control unit, a conduction voltage drop measuring unit and a signal processing unit. The signal processing unit controls the switch tube control unit to turn on each switch tube in the measured bridge arm, so that the heating current is input to each switch tube for a preset time period. The switch tube control unit is controlled to turn on each switch tube in turn. The measuring current is input and the conduction voltage drop is collected during the conduction of each switch tube. Whether the current sharing characteristic of the measured power conversion unit meets the standard is determined based on the conduction voltage drops corresponding to all the switch tubes. The application can realize offline detection of the power conversion unit, and can detect at one time that the current sharing characteristic of the power conversion unit does not meet the standard due to abnormal parameters such as welding resistance and stray inductance of each parallel branch.

The invention provides a low stray inductance test system comprising a detection area in which at least one to-be-detected power device is carried. The detection module is used for detecting a level signal output by the to-be-detected power device; the connection module is connected with the output end detection module of one to-be-detected power device carried in the detection area through welding, and is used for forming a detection loop, so that the detection module obtains a level signal output by the to-be-detected power device; and the capacitor module is connected with the output end of the to-be-detected power device and is used for shortening a current path. The beneficial effects of the invention are that the stray inductance is reduced by shortening the current path; only the to-be-detected power device and the detection module need to be welded once, only the to-be-detected power device needs to be replaced in each test, and the detection module cannot be damaged due to repeated welding.

The embodiment of the invention discloses a power circuit, a motor controller and a vehicle, and belongs to the technical field of power electronics. The power circuit comprises a bus capacitor module, two ends of which are respectively connected with an anode and a cathode of an input power supply; the input end of the power module is connected with the two ends of the bus capacitor module, and the output end of the power module is connected with the motor; the low-stray-inductance capacitor module is arranged between the bus capacitor module and the power module, the two ends of the low-stray-inductance capacitor module are connected with the two ends of the bus capacitor module and the input end of the power module respectively, and the low-stray-inductance capacitor module is used for reducing system stray inductance on a commutation path of the power circuit. And the stress when the power module is turned off is reduced. The power circuit provided by the embodiment of the invention can effectively reduce the system stray inductance of the motor controller.

The invention discloses a power module stray inductance test method and test platform, and relates to the field of power module stray inductance test, the method comprises the following steps: 1, constructing a test circuit, connecting a power module to be tested and a test accompanying power module in series, and then connecting the power module to be tested and the test accompanying power module in parallel with a bus capacitor; step 2, configuring a test state, configuring an upper tube and a lower tube of the to-be-tested power module to be in a conducting state, configuring an upper tube of the accompanying test power module to be in a turn-off state, and applying a double-pulse signal to a control electrode of the lower tube of the accompanying test power module; 3, collecting test data, and collecting voltage Vds at two ends of the power module to be tested and the change rate of current flowing through the power module to be tested when the double-pulse signal controls the lower tube of the test accompanying power module to perform secondary conduction; 4, calculating a single-time stray feeling calculation value; and step 5, repeating the steps 2-4 for N times, and taking an average value of N single stray inductance calculation values obtained by N times of calculation as a power module stray inductance value obtained by measurement. The method improves the convenience and accuracy of the stray inductance test of the power module.

The invention relates to a model selection method, system and device for a DC capacitor of a photovoltaic inverter and a medium, and the method comprises the steps: obtaining a loop stray inductance value of a DC-DC loop in the photovoltaic inverter through calculation; based on the real working environment parameters of the photovoltaic inverter, calculating to obtain an impulse voltage correction value of a direct current capacitor in the photovoltaic inverter; on the basis of the impact voltage correction value and the loop stray inductance value, the impact voltage of the direct-current capacitor is obtained through calculation; and calculating an output combined voltage of a programmable power supply in the durability test platform based on the impulse voltage so as to carry out a durability test on the direct-current capacitor to obtain the direct-current capacitor meeting a preset safety requirement. According to the method and the device, the real working environment parameters are used for correction on the impact voltage simulation calculation of the direct current capacitor, so that the endurance test is carried out to obtain the direct current capacitor meeting the requirement, the safe operation level of the inverter in different working environments is effectively improved, and the problem of how to select the type of the direct current capacitor of the photovoltaic inverter is solved.

The invention discloses a novel half-bridge silicon carbide module which comprises a heat dissipation bottom plate, the upper surface of the heat dissipation bottom plate is fixedly connected with a power module and a shell, the shell is arranged around the power module, the upper portion of the shell is connected with an upper cover in a buckled mode, and the upper cover is used for protecting the power module. A space formed by the heat dissipation bottom plate, the shell and the upper cover is filled with silica gel; through the reasonable layout of the heat dissipation bottom plate, the power module, the shell and the upper cover, the circuit path is shorter and more regular, the generation of stray inductance can be effectively reduced through the shorter circuit path, the voltage spike of the module in the switching process is reduced, the switching loss is reduced, and the efficiency and the reliability of the module are improved.

The invention belongs to the technical field of electrical connection, relates to a converter cabinet, and discloses a laminated copper bar lap joint unit and lap joint structure of the converter cabinet, and the laminated copper bar lap joint unit comprises three laminated copper bars which are in lap joint with one another, namely a laminated copper bar A, a laminated copper bar B and a laminated copper bar C; one end of the laminated copper bar A is connected with an electric energy conversion unit of the traction converter, the other end of the laminated copper bar A is in lap joint with the laminated copper bar B through a bolt, and the laminated copper bar B is in lap joint with the laminated copper bar C through a bolt; the laminated copper bar B and the laminated copper bar C are provided with insulating plates used for keeping an electrical gap. The laminated copper bar is adopted, a new lap joint unit is designed through an innovative lap joint mode, and the problem that the conductivity of the copper bar is affected by the proximity effect is effectively solved; meanwhile, the laminated copper bars have the characteristic of low stray inductance, so that the peak voltage of the switching device can be effectively suppressed, the current distribution is more uniform, the current-carrying capacity is improved, and the local temperature rise of the device is prevented from being too high.