High-Speed, High-Resolution, Large-Area Exposure System for Printed Circuit Board Patterning

In printed circuit board manufacturing, the patterning technology determines not only the ultimate packaging density, but also the economics of the entire process via throughput and yield. Conventional contact and projection printing methods have various shortcomings such as defect generation, mask life degradation, and image field size limitation. Existing direct writing approaches with a focused beam suffer from slow speed and inefficient writing lasers, typical direct-write processing speeds being 0.5 sq. ft./min or less. This proposal presents a program for developing a novel patterning system that not only delivers high resolution over a large image field, but alos produces high exposure throughput and eliminates the shortcomings of conventional systems. It can deliver a throughput . 12 sq. ft./min (i.e., more than an order of magnitude higher than before) with 0.2 mil resolution. These results are achieved by a novel scan-and repeat exposure mechanism which enables seamless exposure of large substrates with a resolution of a few microns. In Phase I we will design a system based on the new concept and demonstrate its feasibility with a breadboard assembly. We will also prepare a cost study to compare the new technology with existing approaches. In Phase II we will design, build and evaluate a fully operational prototype system, which will be developed into a product to be introduced to market in Phase III. Anticipated Benefits: The proposed system will make it possible to print finer patterns on printed circuit boards with higher throughput and lower cost. Finer resolution translates into higher packaging density as well as superior performance, e.g., higher speed. These advances will benefit numerous electronic systems, including high-speed computers, electronics for avionics and space exploration, military electronics, mass storage systems, and instrumentation. Anvik's novel patterning system will also be highly attractive in the production of flat-panel displays, multichip modules, and high-density semiconductor chips.