I've noticed on numorous forums people having issues figuring out how to insert vias on ground plans being used for heatsinks. So I made a short tutorial video on how to implement vias on PCB heatsinks.
To start, when do you need PCB heatsinks? Firstly, you may not have room for an external heatsink. By utilizing PCB area, you can eliminate the heavy external heatsink. Secondly, you may not need to disipate alot of heat. But would like the peace of mind that your component will have a long lifespan by getting that damaging heat away. Along with these, PCB heatsinks can be fully customized in everyway. External heatsinks, on the other hand, come pre-molded so you have limited options on size, shape, thickness, and so on. If you have a large bank account and time to waste, you can design your own and have it manufactured.