Laminated busbar solution

During the switching process of high-frequency, high-power voltage-controlled power devices, due to the influence of the parasitic inductance of the busbar and the inductance of the power module itself, a high peak voltage will be generated. On the one hand, this peak voltage will increase the switching loss and make the system heat up. On the other hand, excessive peak voltage will affect the normal operation of the power module. Therefore, the peak voltage of the switching process must be limited within the allowable range. There are two ways to reduce the peak voltage during the switching process: one is to reduce the di/dt by selecting an appropriate gate drive resistor, thereby reducing the peak voltage, but the disadvantage is that the dv/dt is reduced, the turn-on time and turn-off The time is prolonged, thereby increasing the switching loss; the second is to reduce the distributed inductance (parasitic inductance) of the DC circuit power busbar, which usually uses a laminated busbar to reduce the peak voltage.

Laminated busbar, its structure is to stack two or more layers of Laminated Busbar SIC Application together, the copper plate layers are electrically isolated by insulating materials, and the conductive layer and the insulating layer are laminated into a whole through related processes. Its advantage is that the connecting line is made into a flat cross-section, which increases the surface area of the conductive layer under the same current cross-section, and at the same time, the spacing between the conductive layers is greatly reduced, and the adjacent conductive layers flow through the opposite due to the proximity effect. The currents and the magnetic fields they generate cancel each other out, so that the distributed inductance in the line is greatly reduced.