Abstract
Arc plasma spraying (APS) is an accepted method of producing coatings for many engineering applications. The wide range of materials that can be used to form the thick film coatings make this technique interesting as an alternative method of producing electrical components and circuits.The manufacturing procedure is outlined and the potential advantages of this method of making thick film resistors are listed.The effect on the physical and electrical properties of the films produced by variation of the arc plasma gun current, gas flow rate and powder particle size are reported together with the effect of varying gun/substrate distance and the topography of the substrate surface.It is shown that using a mixture of NiO and Fe3O4 powders with a particle size range of 1–20 μm it is possible to produce films on a glass substrate with sheet resistivities from 5–500 Ω/sq; temperature coefficients of resistance vary from +20 to −8 × 10−4 per ℃, depending on resistor composition and film thickness.The results given for a 10,000 hour life test carried out at 150℃ in air show a mean charge in resistance of ~−5%.It is concluded that APS offers a viable method of producing thick film resistors and conductors on low cost substrates.