1. High heating device with heat sink and heat conduction plate

　　When there are a few components in the PCB that have a high heat output (less than 3), a heat sink or heat transfer tube can be added to the heating device. When the temperature cannot be lowered, a heat sink with a fan can be used to enhance the heat dissipation effect. When there are a large number of heating devices (more than 3), a large heat dissipation cover (board) can be used. It is a specialized heat sink customized according to the position and height of the heating devices on the PCB board, or different component high and low positions can be cut out on a large flat heat sink. Snap the heat dissipation cover onto the surface of each component as a whole and dissipate heat by contacting each component. However, due to poor consistency in height during component assembly and welding, the heat dissipation effect is not good. Generally, soft thermal phase change Thermally conductive pad is added on the surface of components to improve the heat dissipation effect.

　　2. Heat dissipation through the PCB circuit board itself

　　Currently, the widely used PCB boards are copper clad/epoxy glass cloth substrates or phenolic resin glass cloth substrates, as well as a small amount of paper based copper clad boards. Although these substrates have excellent electrical and processing properties, their heat dissipation is poor. As a heat dissipation pathway for high heating components, it is almost impossible to rely on the resin of the PCB itself to transmit heat, but rather to dissipate heat from the surface of the component to the surrounding air. But as electronic products have entered the era of miniaturization, high-density installation, and high heat generation assembly, relying solely on the surface of very small components for heat dissipation is not enough. At the same time, due to the widespread use of surface mounted components such as QFP and BGA, a large amount of heat generated by the components is transferred to the PCB board. Therefore, the best way to solve heat dissipation is to improve the heat dissipation ability of the PCB itself, which is directly in contact with the heating element, and transmit or emit it through the PCB board.

　　3. Adopting a reasonable wiring design to achieve heat dissipation

　　Due to the poor thermal conductivity of the resin in the board, and the copper foil circuit and holes being good conductors of heat, improving the residual rate of copper foil and increasing thermal conductivity holes are the main means of heat dissipation.

　　To evaluate the heat dissipation capacity of a PCB circuit board, it is necessary to calculate the equivalent thermal conductivity (9 eq) of a composite material composed of various materials with different thermal conductivity - an insulating substrate for PCB circuit boards.