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:

Estructura básica de 4 capas
Basic 4-layer stack-up

 

Estructura básica de 6 capas
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:

Realizar construcciones simétricas
Create symmetrical builds

 

No apilar más de 2 prepregs consecutivos
Do not stack more than 2 prepegs in a row

 

Igualar micraje de cobre de las capas simétricas
Use the same thickness of copper on symmetrical layers. Cu top=Cu bottom // Cu int.1=Cu int.2

Cores

* Except in 0.35mm and 0.5mm, the core dielectric must be the nominal minus the corresponding microns for each side.
Nominal Thickness* 18/18µ 35/35µ 70/70µ
0.35mm
0.50mm
0.80mm
1.0mm
1.2mm
1.6mm
2.0mm
2.4mm

Prepreg

Reference Nominal Thickness
1080 0.065mm
2116 0.105mm
7628 0.175mm

Copper sheets

Copper nominal thickness 18µ 35µ 70µ


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