What is the use of thermal reliefs on vias for a copper pour?

My EDA software (PCAD, but I guess others do this too) adds thermal reliefs on vias in a copper pour. What's the use? Vias aren't soldered.

November 24, 2023

Easier routing and fan-out of BGAs and other dense parts. Particularly when putting planes under the BGA.
Greater heat transfer to the planes on the PCB. You see this the most on QFNs and other packages with a ground pad on the bottom of the part in the center. This pad is intended to transfer heat to vias and then to the ground plane.
There is less chance for the via to get messed up due to plating, drill accuracy issues, or other PCB manufacturing problems (not a huge benefit, but a benefit nonetheless).

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

Oliver Smith

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What is the use of thermal reliefs on vias for a copper pour?

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