Abstract: In manufacturing a multi-layer printed circuit board (PCB), different processes are employed for forming inner and outer circuit layers of the PCB. Particularly, second and third inner circuit layers of the multi-layer PCB are formed with the resin build-up process through liquid epoxy coating or dry film type epoxy laminating to enable refinement of circuits provided thereon, and two outer circuit layers of the multi-layer PCB are formed on copper clad and insulating dielectric with the lamination process to improve the thermal resistance, copper peel strength, structural stiffness, thermal stress reliability, and size stability of the completed PCB. The multi-layer PCB manufactured with two different processes has improved quality and reliability, and may be manufactured at reduced cost.

Abstract: A method for applying the solder mask onto solder pad spacings of a printed circuit board, mainly referring to the use of an ink-jet printer for printing the solder mask at the dense solder pad area on a printed circuit board, so as to prevent the solder mask from being coated onto solder pads in the dense solder pad area, thus improving the reliability of assembling processes for electronic products, and further providing merits of minimizing clearances between the solder mask and solder pads and increasing the adhesion of the solder mask.

Abstract: In manufacturing a multi-layer printed circuit board (PCB), different processes are employed for forming inner and outer circuit layers of the PCB. Particularly, second and third inner circuit layers of the multi-layer PCB are formed with the resin build-up process through liquid epoxy coating or dry film type epoxy laminating to enable refinement of circuits provided thereon, and two outer circuit layers of the multi-layer PCB are formed on copper clad and insulating dielectric with the lamination process to improve the thermal resistance, copper peel strength, structural stiffness, thermal stress reliability, and size stability of the completed PCB. The multi-layer PCB manufactured with two different processes has improved quality and reliability, and may be manufactured at reduced cost.