Heatsink is often used to cool the chip which works in high frequency and high power.However

in high frequency environment

the heatsink becomes the main electromagnetic radiation source.Because the EMC capacity of system is decreased due to the heatsink

it is necessary to study the characteristics of heatsink electromagnetic radiation.In the paper

the vector FEM for heatsink is firstly introduced based on electromagnetic field theory.Then the characteristics of heatsink electromagnetic radiation are analyzed by the aspects of grounding methods

number and thickness of cooling fins changes

height of cooling fin changes.The key factors which affect the resonant frequency and the design notes of heatsink are presented.As the simulation results show

the power of electromagnetic radiation can be decreased and the resonant frequency can be improved effectively through selecting reasonable grounding method

the number and thickness of cooling fins changes have little effects on the resonant frequency and power of electromagnetic radiation

however

the power of electromagnetic radiation is impacted remarkably by the height of cooling fin changes.