W. R. Grace Co.

Francis J Rendulic

Paul A Boduch

Robert K Trasavage

Randolph H Robinson

John A Maccini

A relief printing plate is made by exposing a photopolymer layer on a support sheet to image forming projected light radiation and then removing the unexposed portions of photopolymer. The image forming projected light radiation is provided by passing ultraviolet light radiation, which has been passed first to homogenizing means and then condensing means, through image bearing means out of contact with said photopolymer layer to a projection enlargement means which projects the resultant image upon the photopolymer layer at a predetermined ratio of enlargement greater than 1:1.

Projection imaged relief printing plates

Printed circuit boards are made by imaging a liquid polymer which has been coated onto the board. The imaging is accomplished while the polymer is wet with the photo tool in a close air gap relationship with the coated board. The uncured polymer which remains liquid is removed after imaging so that the board can be processed by etch resist, plate resist, or solder mask techniques. The cured polymer is removed by stripping with an alkaline solution. The apparatus consists of single station or multi-station equipment to carry out the unit operations of maintaining the board in a set position, coating with a liquid polymer, placing a photo tool in registration with the circuit board blank and in close relationship with the coating, and imaging the liquid polymer via the photo tool to cause areas of the coating to solidify and other areas to remain liquid.

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Sudbury, MA, United States of America

Francis J Rendulic