Printed Circuit Board layer stackup is arrangement of copper layers and dielectric layers alternatively one above the other. PCB can be from single layer to many layers. Copper layers include top, bottom, signal, power and ground layers. Dielectric layers are in the form of core and prepreg. Core is thin dielectric with copper foil bonded to both sides. Here is an example of 4 layer stackup.
PCB stack-up is an important factor in determining the EMC performance of a product.
Four factors are important with respect to board stack-up
1. The number of layers,
2. The number and types of planes (power & ground),
3. The ordering or sequence of the layers, and
4. The spacing between the layers.
There are number of dielectric materials used in PCB. The following are some of the dielectric materials used in PCB.
- Standard FR4
- Nelco N4000-6
- Isola FR408
- Rogers 4350B
The dielectric constant of each dielectric material is different.
There are lot of things to learn about Layer Stackup. Effective planning of Layer Stackup configuration is one of the important aspects in successfully designing a PCB.