Abstract: Detrimental buildup of tramp photoresist material upon the positioning pads of a stage plate for wafer printing machines is prevented by providing an arcuate point contact surface upon the positioning pads. The wafer is supported a predetermined focal length from the photoresist light curing source by said point contact support. The arcuate surfaces do not tend to collect deposits of adherent tramp photoresist material. The arcuate positioning surfaces are formed from a smooth, hard material. Preferably, the arcuate surface is provided by a hard ball bearing recessed into the surface of the pad and is adjusted during set up by a rod applied to the inside surface of the ball bearing which remains after adjustment of the arcuate surface to the proper position and serves as a reinforcement for the arcuate surface. The surfaces of the positioning pads are preferably mechanically cut back to accommodate the arcuate positioning surface in a retrofit installation.

Abstract: Apparatus and method are disclosed for providing the transfer of a semiconductor wafer from a first to a second location. The apparatus includes a transfer arm including a plurality of apertures to facilitate the attachment of a bowed wafer, without breakage or frontside contact, to the transfer arm. The size, number and location of the apertures may be determined in accordance with the size of the wafer, the amount of bow, as well as the type of bow (i.e., simple or complex). A plurality of flexible members may be disposed in a one-to-one relationship with the apertures and utilized to achieve a secure vacuum seal of the wafer to the transfer arm.