Characteristics and simulations of the planar multi-layer spiral coil and the miniature opto-electric transformer

The characteristics of a miniature optoelectric transformer (MOET) and simulations for the MOET based on the simple improved model for L, C and R of the multilayer coil with the outer closed core are shown. The circuit simulations are performed by a PSPICE simulator, and experimental results can be explained by these simulations. Simulations for a very small MOET of about 200 μm are performed and discussed. A new method to form the substantially flat spiral coil, in which anodic oxidation of the deposited Al film is used, is proposed to overcome the unevenness problem arising from increasing the etched Al coil thickness