Abstract: A transfer arm mechanism including a base assembly, a pivoting arm extending generally upwardly from the base assembly, a wafer support paddle, and mechanisms for pivoting the arm back and forth while maintaining the wafer support paddle in a horizontal plane. A base assembly includes a rotatable plate which can rotate the mechanism through 360.degree., and a support plate which can be moved up and down along guide posts attached to the rotatable plate. The mechanism for moving the wafer paddle along a horizontal plane includes a cam member attached to the support plate, and a cam follower which rolls along an upper surface of the cam member to compensate for the pivoting action of the arm assembly. A mechanism is also provided to prevent the wafer paddle from tipping which includes a drive chain extending between a gear which is rotationally fixed with respect to the support plate and a gear which is attached to a pivot pin supporting the wafer paddle.

Abstract: A pellicle mounting apparatus characterized by a pair of pellicle holder assemblies positioned on either side of a photomask holder assembly. A drive mechanism is coupled between the two pellicle holder assemblies to exert a simultaneous force on the two assemblies to drive them towards or away from the photomask holder assembly. An alignment assembly including a pair of telescopes are first aligned with pellicle holder assemblies, and then the photomask is adjusted to align it with the telescopes. Once the pellicle holder assemblies and photomask holder assembly are properly aligned, pellicles can be repeatedly and accurately attached to opposing sides of a series of photomasks.