Inexpensive Substrates from Moulded Glass Powder for Thin Film Potentiometers

Manufacturing of thin film potentiometers involves using very special substrates, usually with complicated shapes and explicit dimensional tolerance. Commonly, such substrates should possess holes and recesses for assembling of the terminals as well as for mounting into housing. Particular difficulties are connected with the labour and time consumption necessary for forming of the molten glass, and limited utilisation of the glass substrates for potentiometer bodies. On the other hand, this material is the best one for the thin film elements. To solve these problems with the objective of producing inexpensive glass substrates for potentiometers, different tests were carried out with moulded elements made from glass powder. The aim of this research was the optimisation of a glass frit granulation and composition of the softening agent (plasticiser) as well as a choice of the temperature profile of firing of the moulded pieces to guarantee the precise structure of the substrate, essential for its application in thin film technology.