Underlag Foer UPPBAERNING AV ELEKTRISKA KOMPONENTER, UPPVAERMNINGSENHET Foer EN SPIS OCH FOERFARANDE ATT FRAMSTAELLA ETT underlag

摘要

A substrate for supporting electrical components, such as thick film resistive heating elements, comprises a plate member (1), such as a metallic plate member, coated on one or both of its flat surfaces with a glass ceramic material (2,3). It has been found that the problems of (a) electrical breakdown between the metallic plate member (1) and the thick film resistive heating element (10,20) and (b) lack of adhesion between the thick film and the glass ceramic material can be substantially reduced or eliminated by reducing the porosity of the glass ceramic material. Methods of producing a glass ceramic layer having a low porosity, involving a two-stage heating process, are described.