Original Publication Date: 1985-Jul-01
Included in the Prior Art Database: 2005-Feb-18
This article describes a simplified method of fabricating a planar transformer for use on insulated, metal core circuit card substrates, such as porcelainized steel. The resultant transformer has improved primary-to-secondary isolation, resulting in higher dielectric strength and reduced primary-to-secondary capacitance. As shown in Fig. 1, transformer fabrication begins by providing cut-out holes 10 in the metal circuit card core plate 12 which will allow the transformer core and its mounting hardware to pass through the completed substrate. Also, a small slit 14 is cut in the metal core between the holes 10 such that the metal plate will not form a shorted turn in the finished transformer. As shown in Fig. 2, dielectric 16 and conductor 18 layers are then added to the core plate using any appropriate processes.