Vapor deposition apparatus with mask means

Claim 1

In a coating apparatus for producing coatings having a substantially uniform thickness, a vacuum chamber, a rack having a radius of greater than approximately twenty inches rotatably mounted in the chamber for rotation about a vertical axis, said rack being adapted to carry a plurality of substrates to be coated in positions spaced transversely from the axis of rotation and mounted at different angular positions on the rack ranging through the entire 360° of the rack, means for rotating the rack and the substrates carried thereby, a stationary source disposed in the chamber and containing a coating material which evaporates to produce a vapor stream directed towards all of said substrates carried by the rack, and a stationary mask disposed in said chamber between said source and said rack, said mask subtending approximately 180° and interrupting a substantial portion of the vapor stream including that portion of the vapor stream having the greatest angle of incidence with respect to the substrates carried by the rack whereby all of said substrates on said rack are sequentially coated with a coating of substantially uniform thickness, by a vapor stream that is generally normal to exposed substrates said mask being formed to permit a plurality of substrates carried by the rack and disposed at different angles to be exposed simultaneously to the vapor stream from the source, said mask including frontally protruding masking portions which are arcuate in a somewhat sinusoidal manner and which are uniformly spaced from said vapor source and the axis of rack rotation, said mask and vapor source being each transversely spaced from the axis of rack rotation and upon opposed sides of a diameter passing through said axis of rack rotation, and monitor chip means operatively associated with said mask, rack and said source so as to be directly and continuously exposed to said vapor stream.