Image Number 8 for United States Patent #6391502.
The present invention involves a photolithographic process, and apparatus and material for use therein, for producing etched or eroded areas or holes in a selected pattern on or in the surface of fine workpieces, such as small diameter tubes. One aspect of the present invention is a photolithographic process for producing a selected pattern on a nonplanar surface of a workpiece using at least one mask to define the selected pattern. The process includes the acts of applying a photoresist material to the workpiece and aligning the mask with the nonplanar surface of the workpiece. The mask may have an inner surface that corresponds to the nonplanar surface. The process may also include the acts of exposing and developing the photoresist material.