Aligner for a substrate carrier

Abstract

A substrate aligner for a substrate carrier or cassette including an engagement assembly for moving and maintaining one or more substrates into an aligned position when closed, and an actuator assembly for opening and closing the engagement assembly. In one embodiment, the engagement assembly includes front and back engagement assemblies for mounting at opposite corners of the housing to thereby interface opposite comers of the substrates. Each engagement assembly preferably includes a roller for interfacing a corresponding edge of each the substrates, where the front assembly includes two rollers for interfacing front edges and adjacent side edges, and the back engagement assembly includes two rollers for interfacing the back edges and the opposite side edges of the substrates. In this manner, the engagement assembly interfaces all four edges of each substrate to thereby manipulate and maintain the substrates into a substantially aligned position when closed. The rollers preferably rotate to avoid scraping of the substrate edges which might otherwise generate contaminating particulate. Furthermore, the rollers have compliant outer surfaces to dampen potentially damaging forces. Thus, the compliant rollers sufficiently constrain the substrates to prevent significant movement, while also protecting the substrates from g-forces, harsh movements and vibrations during transport. The actuator assembly preferably includes a bistable, four bar linkage including two stable and locked modes corresponding to the open and closed positions. In an alternative embodiment, the housing includes back stops and front bumpers to facilitate front to back alignment, and side-mounted single-roller assemblies for lateral alignment.