Stack-ups

Quilter generates PCB candidates using standard stack-ups defined in partnership with top fabricators

Overview

Stack-ups describe how layers and materials are arranged on a printed circuit board (PCB). A complete stack-up includes the following information:

• Board thickness

• Number of layers Purpose of each layer (signal, ground, power)

• Type of material used in each layer, including key details like dissipation factor (Df) and dielectric constant (Dk)

• Thickness of each layer and copper layer

• and more!

All CAD tools supported by Quilter let you specify these details as part of your board's stack-up.

How Quilter uses stack-ups

Quilter guarantees that every candidate it generates is manufacturable by compiling for a specific stack-up that's associated with a particular fabricator profile. This also means that physics constraints that depend on stack-up details – like differential pairs and high current nets – are always tailored to the stack-up details Quilter is compiling for.

Quilter can read and write stack-up information to the native CAD files you upload and download from our platform. Stack-ups specified in input files can be used to constrain Quilter's search space, and Quilter always writes information about the stack-up it used to the downloaded board file to support a thorough design review.

Pre-supported stackups

For each layout candidate Quilter generates, it defines a specific stack-up and associated material properties. These are used to test routing strategies and complete the necessary physics calculations for implementing signals that are sensitive to physics, such as differential pairs.

We've pre-defined standard stack-ups with our preferred fabrication partners, including OSH Park, JLCPCB, MacroFab, CircuitHub, and American Standard Circuits.

Viewing stack-up details

At the bottom of the candidate reviewer, you can view the stack-up and fabricator used to create your layout candidate. To learn more about the stack-up, simply click through to our help documentation.

How to specify

As a preference

Quilter supports preferential filtering based only on layer count. On the design parameters page, select the layer counts you want to prioritize in candidate review, and Quilter will use them as filters during candidate review, which can be updated or removed.

This allows you to view 4-layer candidates across multiple fabricators, for example. We plan to add support for more stack-up related parameters, such as board thickness and copper weight, soon.

As a requirement (soon)

Coming soon, you'll be able to limit Quilter's exploration to a specific stack-up. This can be done by:

• Providing all the necessary details for your stack-up in the input file you upload to Quilter

• Choosing the "Use my custom stack-up" option on the Design Parameters page in the submission workflow

Constraining Quilter to a specific stack-up also constrains it to using the fabrication rules included in your input file. This workflow is best used for iteration and convergence, after Quilter has already had a chance to explore and identify the best combination of stack-up and fabrication rules for your design.