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zioandry , 04-14-2017, 11:06 AM

Hello everybody, my name is Andrea from Italy and this is my first post.
My job is design and project voip video doorphones and now my PCB design interest is growing.


So I have followed Robert's "Learning essential course" about Switching regulator and I have a couple of question coming from my experience as client of PCB designers.
In the course and in some pictures of other works Robert made (arduino project also) I can see he use to surround smd component pads with polygons. In my job experience our PCB manufacturers ask us to use thermal reliefs instead of full copper around smd pads for mass production. I actually think sometimes are right precautions in order to avoid cold soldering or tomb-stoning, but sometimes it is correct to have as much copper as you can (especially in switching layouts and with components to be dissipated). Our pcb designers generally draw polygons like Robert (full copper over pads) and our industrialization engineer (who is expert in IPC rules but not in electronic functionality) always ask them to correct with thermal reliefs.

So, I would know what do you think about this matter. Does a rule exist or the experience in both functionality problems and soldering problems can solve case by case? Are there other things to consider?

Thanks
Have a nice day and Happy Easter
Andrea

robertferanec , 04-16-2017, 11:08 AM

If your assembly house has problems with soldering, you can use thermal relief.

Our assembly house has never complained about SMD components, so we keep using direct connection. They did complain about through hole GND pins, so we use thermal relief there. If they would complain about SMD components, I would consider using thermal relief also on the polygons connecting SMD pads.