KB: Advanced Routing Techniques for Circular PCBs Using Altium Designer

Solution Details

Designing PCBs with circular layouts provides unique problems, particularly regarding radial component arrangement and connection routing. This article delves into valuable strategies and tools in Altium Designer to streamline working on circular board layouts, focusing on radial component placement, using a polar grid, and efficient copying and rotating circuits.

Strategies for Circular Board Design in Altium Designer

Setting Up a Polar Grid for Radial Placement

The first step is to create a polar grid to ease correct component placement on a circular board. This grid design aligns components and routing radially, creating a symmetrical and orderly arrangement. Altium Designer includes a Polar Grid Editor that may be customized to match the unique requirements of your circular PCB design.

Watch this tutorial to learn how to set up a polar grid in Altium Designer:

https://www.youtube.com/watch?v=l1XVTMCUFks

For more detailed instructions, refer to the Altium documentation:

https://www.altium.com/documentation/altium-designer/pcb-grids-system#!Polar_Grid_Editor_Dlg

Utilizing Rotation for Component Placement and Routing

After setting up the polar grid, adjusting the Rotation Step in Altium Designer's preferences allows for precise control over component orientation. Setting the Rotation Step to the smallest angle required for your design will enable you to manually rotate components to the proper orientation while moving them with the Spacebar. This functionality is critical for accurately positioning and aligning components in a circular arrangement.

Learn how to adjust the Rotation Step:

https://www.altium.com/documentation/altium-designer/pcb-editor-preferences#!general_pcb:~:text=Other-,Rotation%20Step,-%E2%80%93%20shows%20the%20amount

Copying and Rotating Layouts with Copy Room Format

The Copy Room Format command is an effective tool for designs that contain repeated parts or circuits. This command replicates a piece of your layout while keeping the component arrangement and spacing consistent. However, when working with circular boards, it is critical to reproduce the design without any rotation and then apply the rotation to align it with your board's radial layout.

It is currently known that rotation cannot be done directly within the Copy Room Format command, requiring a two-step approach to get the necessary layout on circular boards.

For more information on using Copy Room Format, visit:

https://www.altium.com/documentation/altium-designer/working-with-rooms#!copying-room-formats

Limitations and Workarounds

While Altium Designer provides powerful tools for designing circular boards, limitations include the inability to specify polar coordinates numerically and the noted restriction on applying rotation during the Copy Room Format command. These limitations require creative problem-solving and sometimes manual adjustments to achieve the desired layout.

For updates and potential workarounds on these limitations, keep an eye on Altium's resources and community discussions:

https://resources.altium.com/p/circular-placement-for-multi-channel-designs-features-adscvid-2

https://bugcrunch.live.altium.com/#/idea/8457

https://bugcrunch.live.altium.com/#/idea/14570

Designing a circular PCB in Altium Designer necessitates careful planning, exact grid and rotation settings, and effective use of layout copying features. By leveraging the polar grid, adjusting rotation steps, and understanding the nuances of copying and rotating layouts, designers can confidently navigate the unique challenges of circular board design. Despite some restrictions, Altium Designer's rich toolset and active community support give an excellent foundation for generating complex and successful circular PCB layouts.