MULTILAYER BUILDS
This section describes the different materials available for multilayer circuit boards and the basic guidelines governing stacking possibilities.
A multilayer circuit board is made up of 3 groups of materials:
Cores: sheet of dielectric material covered with copper on both sides.
Prepreg: sheet of dielectric material pre-impregnated with resin to join the different layers of a multilayer circuit board.
Copper sheets: sheet of copper with a uniform, controlled thickness, used for the external layers of a multilayer circuit board.
Basic structures:
Basic 4-layer stack-up
Basic 6-layer stack-up
Given the wide variety of materials available, it is possible to design boards with different thicknesses and electrical specifications. Nevertheless, in order to avoid any possible difficulties in the manufacturing process or mechanical distortions in the circuit board, it is important to follow the guidelines below:
Create symmetrical builds
Do not stack more than 2 prepegs in a row
Use the same thickness of copper on symmetrical layers. Cu top=Cu bottom // Cu int.1=Cu int.2
Standard 4 layers stack-up / Thickness 0.80mm
Standard 4 layers stack-up / Thickness 1.00mm
Standard 4 layers stack-up / Thickness 1.20mm
Standard 4 layers stack-up / Thickness 1.60mm
Standard 4 layers stack-up / Thickness 2.00mm
Standard 4 layers stack-up / Thickness 2.40mm
Standard 4 layers stack-up / Thickness 3.20mm
Standard 6 layers stack-up / Thickness 1.20mm
Standard 6 layers stack-up / Thickness 1.60mm
Standard 6 layers stack-up / Thickness 2.00mm
Standard 6 layers stack-up / Thickness 2.40mm
Standard 6 layers stack-up / Thickness 3.20mm
