substrate undergoes a further process step the heater surface is structured with a laser beam an uv laser with a wavelength of 355 nm is used to inscribe a pattern into the copper layer the copper layer is evaporated under the power of the laser beam so that a pattern occurs in the copper layer the inscribing process must be efficiently evaporating the copper between the structure to avoid short cuts fig3 shows an example with the laser beam the electrodes are separated from each other and a meander structure is achieved the geometrical form of the structure as such is not relevant but the structure is adapted to achieve the resistance that is optimal the laser beam must at least separate the two noses 7 that are used to contact the layer during the laser beam structure process the resistance is controlled with an ohmmeter it is an advantage that the noses are covered by copper in the sputtering process too so that the contact for the measurement can be easily realized the optimal solution is achieved if the resistance results between 5 and 30 ohms for the tracks during the inscribing operation the surface is controlled via an ir camera to avoid hot spots.