Multilayer Printed Circuit Boards
The sophisticated solution – Multi-layer boards are the best choice for demanding layouts, which require high-density SMT components.The increased density of the components, the reduced area that is available for the wiring as well as the targeted electric supply of individual parts require connections through multiple layers.
A 4-layer PCB, for example, consists of a solder layer, a ground plane, a signal and an assembly layer. Hotoprint produces multi-layer boards up to 12 layers.
4-8 multi-layer boards account for the largest share. Many of the technological innovations in the PCB industry happen in the multi-layer segment.
Dielectric separates the single layers when the book is compiled. These so called pre-pregs are glas fibre mats, which have been pre-impregnated with resin. They are available in clearly defined thicknesses and glas fibre types. Pre-pregs work as bonding sheets.
During the bonding process, the pre-pregs are activated under heat and pressure and in a vacuum. They melt together with the AOI-tested inner-layers. The final thickness of the multi-layer depends on the number of layers, the requirements and design specifications.