Microphotosetting camera for integrated circuit stencils - has two spaced raster stages and superimposing projection system

摘要

The two spaced raster stages are positioned on either side of an objective which projects the image of one into the image of the second. The main projecting objective reproduces the superimposed images on the photographic plate. The raster stages are movable along two co-ordinates at right angles to the optical axis by a programmed controlled motor. The rasters form a pattern of numerous translucent polygonal areas. For standard patterns, one stage carries a set of normal topological shapes and the other a rectilinear window. For curved or angled lines the patterns consist of light transmitting circular areas. These are partly superimposed so that a curved line formed by two circle segments is projected. The system is claimed to improve versatility and to allow faster composition of complex large circuits.