Quality control method for ultrasound welding

The invention relates to a quality control method for ultrasound welding. In order to carry out very sensitive process monitoring, the method provides for the generation of a tolerance range which is adjusted to the progress of the welding process and which is generated from measured values which influence the welding process. According to the invention, a method is proposed for quality control for ultrasound welding, wherein a measured value tolerance range is determined from measured values of executed welding processes, said measured values being associated with at least one parameter which influences the welding process and/or represents the goods of the welding process. Measured values which are associated to an identical parameter of a further welding process following thereafter are considered during the quality monitoring in such a way that the measured value tolerance range is changed in its form or composition to an average value for further welding processes, in accordance with the variance between