Verfahren und Einrichtung zur Regelung eines Vakuumbedampfungsprozesses

Vacuum coating process is controlled by monitoring the changes in the back force caused by the vapour current on the material lying in the crucible(4). The force is measured by cells(5) beneath the crucible. To separate the back forces from the weight of the crucible and material lying in the crucible, instantaneous reductions in a process parameter e.g. the electron beam power are carried out. The change in the back force is then used to carry out changes to certain work parameters in order to keep the back force within a predetermined range. USE - Esp. for coating mirrors and glass sheet with functional coatings. ADVANTAGE - By monitoring and controlling the back force, high quality coatings are achieved with uniform thicknesses esp with wide area substrates. The cells measuring the force are not in direct contact with the vapour current and so are not damaged.