As imaging requirements continue to move towards finer resolution, accurate layer-to-layer alignment becomes an increasingly important factor that influences product yield. One of the major contributors to yield loss in fine-line products is the dimensional instability of the substrate. Large rigid substrates as well as flexible films often undergo slight dimensional changes as a result of the different PWB manufacturing process steps. In addition, the changes in the substrate dimensions are often non-isotropic. Manufacturers have been compensating for this problem by measuring the changes in the substrate and plotting new artwork that is matched to the dimensions of the processed substrate. This time-consuming and costly manufacturing practice can be eliminated through the use of the new Anamorphic X-Y Scaling technology that enables independent magnification compensation in two dimensions for laser projection exposures. In this paper, we present the results of studies conducted on laser projection imaging equipment and specifically review the performance of the X-Y scaling capability.
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