Normally, a power component like this would have a big pad and some heat dissipation space under the heat slug. It might even have thermal vias going to another heat pad on the back side of the board. If it’s being run at anything close to it’s full current capability, that would be a requirement. This one is probably a bit underutilized though, rendering the big pad un necessary. It’s still a good idea for mechanical strength, but in the prototype world, we don’t always follow the rules
The problem here though, is that the open vias under the part can short to the thermal pad. That’s bad mojo. Some board fab houses can put a solid coat of mask over the vias and they’ll be okay. Not all board houses will do that though, and if the board has a silver finish (this one is HASL), you wouldn’t want the vias sealed because silver vias can outgas and corrode if completely sealed.
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — Alibaba to invest $15b in tech, set up research labs around the world
Wearables — Special servo movement
Electronics — Trigger happy oscilloscope?
Biohacking — Biohacking: Visioneer – AI Glasses to Assist the Visually Impaired
Sorry, the comment form is closed at this time.