Ptc heating element and electric heating device with such a ptc heating element and method for the production of a ptc heating element

Abstract

A PTC heating element has a casing that joins as a unit at least one PTC element, conductor paths electrically connected to the PTC element, and insulating layers bearing, in a heat-conductive manner against the PTC element. The PTC heating element also has contact strips which project over itself and which are electrically conductively connected to the conductor paths for energizing the PTC element with different polarities. The casing forms a receptacle space that receives the PTC element, the conductor paths, and the insulating layers. In order to improve heat decoupling from the PTC element, the receptacle, in a cross-sectional view, is defined by two oppositely disposed inner surfaces covering the PTC element and concave cavities, adjoining the inner surfaces and forming the longitudinal edges of the casing, the diameter of which is greater than the distance between the inner surfaces. The electric heating device has at least one PTC heating element arranged in a circulation chamber. Also disclosed is a method in which the casing is first formed, the PTC element, the conductor paths and the insulating layers are then introduced through an opening of the casing into the receptacle space, and the casing then is deformed by deforming forces acting upon edge regions of the casing, so that oppositely disposed inner surfaces of the casing are abutted against the insulating layers.