Sputter-coating system, and vaccuum valve, transport, and sputter source

Abstract

Relatively wide workpieces, such as auto grilles, are rapidly conveyed into and from a vacuum processing chamber provided with entry and exit air locks and vacuum isolation valves, in which thin metallic coatings are deposited uniformly over workpiece surfaces. The gate member of the valve is supported for sliding vertical movement, as well as limited outward and inward movement for sealing the chamber opening, at the protruding ends of an elongated member backing the gate. Air cylinders act directly on these ends to close the gate. A linkage and air cylinder above the gate vertically propels the gate. The processing chamber is provided with several side by side arrays of sputtering sources with circular cathodes, the workpieces moving thereunder at a steady rate orthogonally to the arrays. The spacings of each source relative to the other in each array, the workpiece to source distance, and the degree of outboard placement of the outer sources relative to the workpiece edges are defined to provide both even coatings on horizontal workpiece surfaces, as well as on the vertical surfaces. A compact conveyor system with space-saving corner modules is coordinated with the valve action to maintain an even steady flow through the evacuated processing chamber for optimum coating.