Cooling apparatus for a web deposition system
Described are an apparatus and a method for cooling a web. The apparatus includes an inner cylinder having a void therein and configured for coupling to a gas source. The apparatus also includes an outer cylinder having an inner surface, an outer surface to support a web and apertures between the inner and outer surfaces. The outer cylinder rotates about the inner cylinder so that gas provided to the void of the inner cylinder flows through the apertures that are adjacent to the void and passes to the outer surface of the outer cylinder to increase the heat transfer between the web and the outer cylinder. The volume of gas introduced into the vacuum deposition chamber during a process run is thereby limited. Advantageously, the apparatus enables higher deposition rates and increased productivity.
1. An apparatus for cooling a web, comprising:
an inner cylinder having a void therein and configured for coupling to a gas source, the void extending along at least a portion of a length of the inner cylinder and having an arc angle with respect to a cylindrical axis of the inner cylinder; and
an outer cylinder having an inner surface, an outer surface to support a web and a plurality of apertures between the inner surface and the outer surface, the outer cylinder being concentric to the inner cylinder and rotatable about the inner cylinder, wherein a gas provided to the void of the inner cylinder flows through the apertures that are adjacent to the void and passes through the outer surface and out of the outer cylinder to thereby increase heat transfer between the web and the outer cylinder.
2. The apparatus of claim 1 further comprising a conduit coupled to the outer cylinder to pass a fluid that controls a temperature of the outer cylinder.
3. The apparatus of claim 1 wherein a temperature of the outer cylinder is less than a temperature of the web so that heat is transferred from the web to the outer cylinder to cool the web.
4. The apparatus of claim 1 wherein a temperature of the outer cylinder is greater than a temperature of the web so that heat is heat is transferred from the outer cylinder to the web to heat the web.
5. The apparatus of claim 1 further comprising a deposition source positioned to deposit a material on a surface of the web.
6. A method of cooling a web, the method comprising:
supplying a gas to a void in a first cylinder, the void having a substantially pie-shaped cross-section that extends along a length of the first cylinder and defines an arc angle with respect to a cylindrical axis of the first cylinder;
transporting a web on a portion of an outer surface of a second cylinder that is concentric with the first cylinder, the second cylinder having an inner surface and a plurality of apertures between the inner surface and the outer surface; and
rotating the second cylinder with respect to the first cylinder to flow the gas from the void through the apertures that are adjacent to the void and out of the second cylinder to thereby provide the gas between the web and the portion of the outer surface of the second cylinder to increase heat transfer between the web and the second cylinder.
7. The method of claim 6 further comprising controlling a temperature of the second cylinder.
8. The apparatus of claim 1 wherein the arc angle of the void does not exceed a wrap angle of the web.