Trolley Drive Mechanism
Original Publication Date: 1987-Aug-01
Included in the Prior Art Database: 2005-Feb-01
A spring-loaded drive mechanism for a trolley dome assembly is used in processing semiconductor wafers. It requires no adjustment and replaces a mechanism which required frequent adjustments to prevent wafer damage. The trolley assembly originally used requires a precise preload adjustment. This is critical for the proper operation of the dome evaporators in which the wafers are processed. Wear, along with operating temperatures, affects this adjustment. If the adjustment is loose, the drive dog contacts the center hub and pushes the loaded dome with a jarring force severe enough to displace the wafers from their nesting position. This causes misalignment of the wafers inside the mask tooling dome.