METHOD FOR PREPARING PRINTED CIRCUIT BOARDS, METHOD FOR SELECTIVELY DEPOSITING WELDING ON PARTS OF A PRINTED CIRCUIT BOARD, DEVICE FOR PRODUCING PRINTED CIRCUIT BOARDS AND MULTI-VACUUM BOARD ASSEMBLY

摘要

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.