Fabrication of Parts Containing Small Features using Stereolithography

The StereoLithography (SL) process has benefited from many advances in the last four to five years. These include new resins with reduced shrinkage and curl distortion, enhanced software, and improved scanning techniques. One can produce highly accurate parts for most dimensions within a few mils of the design value as shown in numerous accuracy and benchmarking studies. SLA systems use a laser beam focused to a spot size of 200 -250 ~m. This limits the range of applications where SL can provide accurate models to parts which do not contain very small features i. e. wall thickness values less than about 300 ~m. Industries that manufacture products involving components with small features include electronics and medical. In this presentation we describe an extension of the SL technology to applications involving small features. This capability is achieved by reducing the laser focal spot size in an SLA-250 to 75 ~m. The technological principle behind the spot size reduction is described in the presentation, together with process issues and applications ofthe technology.