I would like to lay solid vias joining a top pad with a bottom pad to produce a heatsink. This is a pretty common requirement for LEDs now. Do I ask the pcb manufacturer to make them solid or does Easypc have the facility? Also joining pads like this throws errors galore. How do I lose these errors . I have just ignored them in the drc.
Thanks Iain. How would I tackle the vias that join the pads together? I need to add a large amount. At the moment I have pad to pad errors due to the distance.
Ensure all pads are on the same net and your pad to pad errors should disappear.
Sometimes I use a large square top copper SM pad to mount a TO220 tab onto, the hole is a through hole inside the SM pad. Simply making both on the same net removes any DRC. Also on thermal pads with multiple vias to transmit the heat through the board, again tie them all to the same net and you should have no errors.
I use a special 'via' which is a single pin part with a small enough hole to always fill up with solder and pad sizes that are small enough to not cause errors if close together. These are shown on the circuit diagram as 'thermal vias' and linked to the required nets. A copper pour area is then used for the 'heatsink' on the appropriate layers (usually all).
Solid Vias in heatsink pad
Posted - 23 Aug 2010 : 17:31:06
