Electrostatic chuck for manufacturing pharmaceutical products e.g. tablets, inhaler substrate

摘要

The electrostatic chuck (620) attracts an object (680) such as a pharmaceutical tablet or pharmaceutical particles. The chuck has a floating electrode thereby providing for charge imaging for the deposition particles in a selected image. A sensing electrode senses the number of particles attracted to the objects on the chuck thus ensuring that an accurate amount is deposited. The lower conductive layer (610) of the chuck is coated with a dielectric layer (630), on top of which is an upper conductive layer (640) with two electrodes (650, 660). A second dielectric layer (670) is placed on top of the upper conductive layer (640). A voltage between 200 and 2000 volts, either DC or AC, is applied across the two electrodes of the chuck