Moving head coating apparatus and method

Abstract

The invention pertains to a coating apparatus and method in which most of the relative movement between a dispensing head and the substrate to be coated is provided by the coating head. The moving head configuration reduces the system footprint and diminishes leveling problems. A powered shuttle mechanism carries a dispensing head above a substrate to be coated while riding on a bearing located underneath the chuck holding the substrate thereby providing rigidity and reducing the system footprint. Chuck support is designed to accommodate anticipated vertical sag in the dispensing head by supporting the chuck at points along its periphery thereby permitting the chuck to sag in conjunction with the dispensing head. The shuttle mechanism is equipped with means for automatically adjusting the height of the dispensing head with respect to substrate to compensate for substrate placement error, substrate dimensional variation, and mechanical drift in the mechanical machine parts. Coating consistency is enhanced using such height adjustment. A part of the apparatus containing the fluid delivery equipment and in communication with the dispensing head may be placed on a cart and removably attached to the rest of the apparatus. There is a utility station comprising equipment for cleaning and priming the dispensing head which may be located on the removable cart. A pump in addition to main remote pumping means may be integrally mounted on the dispensing head to more precisely control fluid flow to the dispensing head. The chuck may be configured to be micro deformable so as to maintain the surface of a substrate upon it at a constant height. Fluid may be dispensed along openings of selected lengths along the length of the dispensing head using die lips attached to the dispensing head or by cutting a plurality of slots in a single dispensing head.