Failure analysis of copper substrate crack in high-voltage power supply

Abstract

Aiming at the crack phenomenon of a copper substrate circuit in a high-voltage power supply, the slice analysis was carried out and showed that the crack part was the dielectric layer of the copper substrate. The finite element analysis is used to study the reason for dielectric layer cracking and discuss the improvement measures from the thickness of thermal conductive gel and the layout of components. The simulations results show that the reason for dielectric layer cracking is that the surface-mounted device (SMD) is too close to the mounting hole when the copper substrate bottom is coated with thermal conductive gel, reducing the thickness of thermal conductive gel or keeping the SMD away from the mounting holes can avoid the dielectric layer cracking, but it is easier to change the location of SMD.