PLATEN DESIGN FOR FILM COATING
Original Publication Date: 1989-Oct-31
Included in the Prior Art Database: 2004-Apr-05
Xerox Disclosure Journal
A platen useful for holding a flexible substrate (film) in order to make precision thin coatings can be realized by using glass sheets as the vacuum platen.The glass sheets can be ground and polished to less than a wavelength of visible light. With such a smooth surface, a vacuum need not be applied to hold the film flat since two surfaces in such close contact do not easily separate. As an alternative, fritted glass may be used as the platen surface. Such a glass is available with 4.5 micron pores or less and a grinding or polishing of this surface would still result in at least an order of magnitude smoother surface than metal with the added advantage that a vacuum could be drawn through the glass by a chamber attached below so as to hold the film to be coated.