1. Board technologies

1.1 Multilayer printed circuit board

This is a composite material (woven glass fibers and resin) on which copper interconnection conductors are etched or printed. A higher density of interconnection per unit area has been achieved by the multi-layer technology commonly used today. This consists of a stack of sheets of organic resin-based composite material (dielectric) coated with copper (two-sided circuits), photo-etched and bonded together with a sheet of thermo-adhesive resin (prepreg) by means of temperature pressing (figure