A vehicle-mounted sic DCDC converter and a new energy vehicle

Abstract

The present invention provides a vehicle-mounted SiC DCDC converter, which includes a casing, a cover, a reactor, a main control circuit board, a contactor circuit board and a film capacitor arranged inside the casing, and also includes: at least one power device, at least one The power device transfer PCB, laminated busbar, driving circuit board and spring pin; the power device transfer PCB is correspondingly arranged on the surface of the power device, and the pins of the gate G and source S of the power device are transferred to the power device PCB welding to form the first welding point, transfer the wiring on the PCB through the power device, transfer the position of the first welding point on a plane perpendicular to the pin, and expand the contact surface of the first welding point through the pad to form a welding Disk contact surface; the laminated busbar is arranged above the power device transfer PCB, and the source S and drain D of the power device are welded to the laminated busbar to form a second welding point; the drive circuit board is arranged on the laminated busbar Above the row, the drive circuit board is firmly connected to the housing; the tail end of the spring pin is welded on the drive circuit board and is arranged on the opposite side of the drive circuit board and the laminated busbar, and the spring pin has a compression-deformed head end. The drive circuit board is compressed, and is elastically connected to the contact surface of the pad through the laminated busbar to achieve elastic connection.

Description

technical field [0001] The invention relates to the field of SiC DCDC converters, in particular to a vehicle-mounted SiC DCDC converter. Background technique [0002] At present, in the application of new energy vehicle DCDC converters, the commonly used switching devices are mainly divided into two categories according to the semiconductor materials used: IGBT switching devices represented by Si semiconductor materials and SiCMOSFET power devices represented by SiC semiconductor materials. SiC power devices have the advantages of high blocking voltage, low on-state resistance, low switching loss, and high temperature resistance, which can increase the switching frequency to several times or even dozens of times of the IGBT switching frequency, effectively reducing the impact of the chopper reactor in the DCDC. Volume, weight, noise; at the same time, the reduction of on-state loss and switching loss can further reduce the design difficulty and size and weight of the heat si...

AI Technical Summary

Problems solved by technology

[0008] 2) The diameter of the source S pin, the drain D pin and the gate G pin is φ1.15mm. The pins are suitable for soldering circuit boards, and then coated with copper foil through the PCB. The current carrying of a single pin is about 25A or more. Thick copper foil is more difficult and costly. The larger area of ​​copper foil laying increases the volume of DCDC and the current carrying capacity is unevenly distributed. The current carrying capacity is not enough, and heat dissipation is difficult, causing the copper foil to burn;

[0009] 3) The drive control PCB board is welded to the gate G and source S pins, and it is extremely difficult to mass-produce, install, maintain and replace the drive control PCB board

[0010] 4) When multiple power devices are connected in parallel, due to the difference in the spatial arrangement of the devices, the paths from the drive signal to the gate G and source S pins are different, the parasitic inductance values ​​of the paths are different, and the switching delays of the parallel power devices are different, resulting in multiple parallel connections. Individual power devices cannot share current, and individual power devices generate severe heat, which reduces the overall power density of DCDC

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