Placement Guide

Getting the best results out of Quilter's Placement Engine

Placement Control

Ordered from least constrained to most constrained

Schematics-based clustering

Quilter interprets explicit wire connections between components in the schematic, and attempts to place those components close together. This way the organization scheme of your schematic is represented on the board. These groups won’t have a predetermined location on the board, and will move based on the requirements of other groups.

Anchoring

If you preplace one or more components of a group within the board outline, all the other components from that group will “stick” to it. You could place a connector on the board, and if it has explicit wires in the schematic to various protection or decoupling components, they’ll automatically be placed close to the connector. Similarly you could place an IC where you’d like it to be on the board, and not worry about manually placing the passives that support it—Quilter will take care of placing them as closely together as possible.

Placement regions

Placement regions (or rooms) are a powerful tool for expressing more precise control over Quilter’s placer logic They’re especially useful when you have groups of components that need to be placed close together or far apart, like analog and digital circuits and switching converters.

Placement regions can be placed on the board in your ECAD tool or left outside the board outline, and Quilter will interpret these differently.

Region outside of board area

If the region is left off of the board, Quilter will consider any components in the region as part of a group. This works similarly to the schematics-based clustering above, and the components will be placed closely together in a location of Quilter’s choosing. You can also anchor the group by placing one or more of the components from the region onto the board.

There are a couple of advantages to this approach. First, it’s quick to apply blanket directives on your schematic to group the components, so you can manually enforce grouping behavior. Second, you save the time of planning and placing those regions on the board. Third, this light touch still allows Quilter the space to make optimization and tradeoff choices.

Region inside of board area

This is the standard approach to using rooms or regions. You create them on the board, and components that are outside of them (after Quilter’s placement) cause DRC violations. Quilter will make a best effort to fit all the components and their required clearances within the region, though it may fail if the region is too small or the clearances are too large.

Tightly controlling the location like this is important for considerations that Quilter may not have, like components that need to be close together but for which there is no Comprehension. It’s also useful for keeping noisy components like switching converters further away.

Quilter supports placement regions with multiple polygons or outlines. To use this, add the same components to both rooms/regions and they will be treated as a union. The main usage for these multipolygon regions is creating two-sided regions, where the polygons have the same shape but there’s one on the top layer and another on the bottom layer.

Region Ground Pours ** Coming Soon **

If your design has multiple ground nets and requires galvanic isolation, there will soon be an option to generate a ground pour with the same footprint as the placement region that contains the pins that connect to it. This option will be chosen in the new Ground Nets section of the Comprehensions.

Manual placement

Some components must be in a specific location, like connectors and chips with heat sinks that must align with external mechanical features. Simply place them within the board outline and Quilter will consider them “preplaced” and won’t move them.