System for aligning patterns on a substrate using stencil lithography

The invention relates to a system for aligning two or more patterns on a substrate using vacuum stencil lithography, such as to obtain optimum alignment precision. More specifically, the invention relates to a pattern-alignment system in which a mass sensor, which can detect material emitted, is placed in a known position behind the stencil, such that the position of the stencil can be ascertained as a function of the signal emitted by the sensor.