Perpustakaan Digital ITB

As the development of very massive technology, the trend of nanotechnology products and the microtechnology industry has developed rapidly. The actual trend of compact design of low / medium voltage equipment implies lower distances between active parts, which might be as low as few microns. Under these conditions knowledge about the breakdown voltage is needed in order to reduce losses and prevent operational failure. The breakdown voltage in gases has been successfully determined by the Paschen’s law, which relates the breakdown voltage to the distance times pressure (pd) product. Contrary to large scale electrode separations, where the breakdown voltage is well described by the Paschen’s law which relates to product of distance and pressure, the inter-electrode gaps below 10 ?m show a departure from the Paschen’s law due to the additional mechanisms of field electron emission. Some researchers observe the breakdown voltage in the micro gap with distance between 1 - 10 µm at ambient temperature, divided into three regions by using a plate needle electrode configuration. The first region is an electrode gap greater than 8 µm where this region agrees with the explanation of the Paschen’s curve due to the Townsend avalanche mechanism. The second region is the plateu region with 5 - 8 µm electrode gap which is a transition region, the existence of a field emission mechanism begins to play a role in electron release. then the third region, at the electrode gap < 5 µm, is a departure from the Paschen law, the presence of a field electron emission mechanism causes a breakdown voltage. They concluded that the effect of field emissions has caused a modification of the Paschen law. They made observations based on deviations that occurred to the left of the distorted curve caused by field emissions and they found breakdown fields from 50 - 150 x 109 V / m. However, measurements of the breakdown voltage in microgaps remains quite delicate experiment, mainly because of difficulties related to the accurate definition of the distance between the electrodes. To overcome these limitations, we propose here a reliable method based on measurements of the current amplitude and phase between current and applied voltage for AC signals. It is shown that when contact between the two electrodes occurs the current amplitude increases substantially and the phase changes abruptly to zero. Thus, no arbitrary conditions are needed to define the contact point. The system is well-defined and the procedure accuracy improved. And Dealing with this work, we also observed the distance of the micro gap based on electrical waveforms by confirming the results of the experiment by calculating the capacitance and simulation values using a needle-plate configuration where the needle is the anode and the flat electrode is the cathode. In this simulation we also compare the surface conditions in fine conditions and by adding protrusion. The protrusion is placed on a plate surface perpendicular to the needle electrode in the form of an isosceles triangle. We study the effect of protrusion on changes in the value of capacitance. And we also made observations on the breakdown voltage deviation in the gap of 1-10 µm with needle-plate electrode configuration. Micro gap distance measurement method based on waveforms by confirming the experimental results by calculating the capacitance obtained from the circuit impedance analysis results can be applied. The impact of nanoprotrusion on the surface of the electrode plate which is simulated using an isocceles geometry does not affect the capacitance value. The results of measuring breakdown voltage in the micro-gap, we found a deviation from the Pasche’s curve.