Stack Up Considerations

There are a number of factors to consider when generating a multi-layer stack up for a design. 

• Design multi-layers with an even number of layers.
• Maintain a symmetrical stack up with copper balancing to reduce bow and twist.
• Balance Power and Ground layers in relation to the center of the board. 
• Determine if a core construction or foil construction should be used.

Have Impedance Requirements?

We welcome the opportunity to work with customers at the design stage of a project. Westak engineers are available to assist with impedance modeling and advise available materials to meet the design requirements. Discussions are often necessary to understand the impact of material characteristics on impedance targets and tolerances.

• Line width and dielectric thicknesses should be documented as reference dimensions only.
• It is important to consider etch factor (the effective reduction of the line width during the etching process).
• Recommended impedance tolerance is +/- 10%. A lesser tolerance is often achievable, but should be discussed with our engineering team for verification.

Have Questions?

Contact us for more information on stack up considerations and impedance modeling! 
We want to help!

The following will cause impedance results to go up:

• Dielectric constant decreases
• Dielectric thickness increases
• Line width decreases
• Line thickness decreases