| The gas discharge with micrometer distance is a kind of discharge form with micron gap.With the rapid development of microelectronic technology and MEMS,the requirement of gap between integrated circuit and electronic process products is higher and higher.When applying low voltage,it will produce high field strength and easily cause breakdown damage to these devices.At present,the research on micron gap gas discharge is not in-depth,the research on micron gap discharge experiment is less,and the theory of its discharge mechanism has not formed a relatively complete theory.Therefore,it is of great significance to study the mechanism of discharge characteristics of gas discharge with micron gap under atmospheric pressure.In this paper,the micron gap gas discharge under atmospheric pressure air environment is studied,and the discharge mechanism is analyzed by numerical calculation.Gas discharge experiments were carried out,at 1-100μm electrode gap,a large number of experiments have been carried out on electrodes of different materials and structures with DC and AC power supply.Based on the Fowler-Nordheim theory of field emission and the effect of ion enhancement,the discharge process and the mechanism of discharge characteristics are studied.First of all,the circuit diagram of the gas discharge experiment with micron gap is designed,and the experiment platform is built under atmospheric pressure.The electrode gap at 1-100μm is precisely controlled by the high-precision distance controller.Using high frequency AC power supply,the discharge experiments of plate-plate structure and needle-plate structure electrodes with electrode gap of 1-100μm were carried out.The discharge experiments of aluminum,stainless steel,brass and copper electrodes with the same gap were carried out with DC power supply.The experimental results show that the breakdown voltage deviates from the Paschen curve at 1-5μm,and the lowest breakdown voltage is about 265 V,which is lower than the lowest value of 330 V.Secondly,based on the results of discharge experiments with micron gap,the field emission F-N curve and the variation rule of field emission current density with applied voltage under different electrode gaps are obtained by using the field emission F-N theory through the calculation of pre-breakdown current value.The results show that the discharge process is dominated by field emission when the electrode gap at 1-5μm.Finally,the approximate analytical formula of the number density of cathode ions is derived by numerical calculation.Using MATLAB to calculate the number density of cathode ions,it is found that there is a high number density near the cathode at 1-5μm.Furthermore,the additional electric field generated by a large number of positive ions gathered near the cathode is further explored.It is found that the additional field has a high electric field strength through calculation.The superposition of the additional electric field and the external electric field enhances the field electron emission,thus forming the ion enhancement effect.According to the change rule of the ratio of the effective secondary emission coefficient and Townsend’s secondary coefficient with the electrode gap,the transition stage of breakdown voltage deviating from Paschen curve is further explored,and the discharge form in this transition stage is determined. |
