Features manufacture multilayer and General tolerances
PARAMETERS MANUFACTURE MULTILAYER
High level complexity and minimizing the space for the printed circuit boards have been the main reasons for the strong development of multiple layers printed circuit boards. The increase in the manufacturing of this kind of printed circuit boards has been constant in Lab Circuits during the last years. The classic structure of a multiple layers printed circuit board has some cores –that have the ground and signal inner layers- and the conventional component and solder faces in the outside. The cores are made by a FR4 material sheet (glass fibre and epoxy resin with two external copper layers).
The core has its own body in the manufacture process until the multilayer pressing moment takes part, this means, it goes through a dry film process, exposure and a chemical process to end up creating one only structure that combines the cores with the prepreg sheets (glass fibre fabric impregnated with epoxy resin) and external covering copper sheets. This union is achieved by high temperature lamination pressing process.
Once it has been pressed, this structure has the same process as a double-sided printed circuit board.
MULTILAYER GENERAL TOLERANCES