Substrate for printed circuit boards using photocurable resin and process for producing the same

A product by process, said product comprising a substrate for use in a printed circuit board having holes in predetermined positions and which are arranged in a predetermined manner, said substrate being comprised solely of laminated thin layers made of a photocurable resin of the same material;

• said process comprising the steps of producing the laminated thin layers each by introducing a photo-curable resin into a vessel;
• providing a masking means above and proximate to a surface of the resin;
• irradiating planar light through the masking means to cure the exposed part of said photo-curable resin to form a first formed thin layer of cured resin;
• shifting the first formed thin layer in the vertical direction to a position which allows the photo-curable resin to cover the first formed thin layer;
• irradiating planar light through the masking means to cure the exposed part of said photo-curable resin covering the first formed layer to laminate another thin layer of said photo-curable resin onto the first formed thin layer, and successively repeating the steps of shifting, covering and curing.