Process

The basis of a thick-film heating element is a stainless steel tube.

At first a ceramic isolation layer is printed on the tube. Then the layer has to be dried in a drying furnace in order to remove volatile components of the paste. Subsequently, the tube is put in a conveyor furnace. In this step the tube is exposed to a high temperature. As a result the ceramic components of the paste melt and combine to a closed-cell and smooth layer after cooling. This process is called burn-in.

After the burn-in of the isolation layer further layers can be applied. The following layers are the conducting track, a termination resistor and a final isolation layer. After each layer the tube has to be dried and burnt in.