Future, a photograph resistive movie is printed which has the look with the circuits. Just after applying the movie, the board is subjected to UV gentle, which hardens the parts of the board that should ultimately contain the circuits. This really is performed for both sides in the board simultaneously. https://16-layer-5-order-hdi-high84837.humor-blog.com/30291547/indicators-on-ceramic-substrate-pcb-you-should-know