This family of printed circuit boards, one of the most advanced from a technological point of view, is used when it is necessary to solve problems of miniaturization, substantially allowing the use of the z-axis to interconnect, by means of plated through holes, the different circuit planes (layers), present in a variable number, from 4 up.
They are mainly used in the field of mobile phones and computers, but also in the on-board electronics of the automotive sector, which are becoming more and more complex.
The base laminate for the multilayer printed circuit boards is generally the FR-4, in its various shades of Tg, but for particular applications materials with polymide (or different) base can also be used.
The manufacturing process, similar the PTH printed circuit boards one, needs initially to prepare the inner part through a technique which consists in a hot-pressing of the inner layers, the partially polymerized (pre-preg) epoxyglass layers and of the copper sheet.