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PCB

PostPosted: Tue Feb 14, 2006 2:38 am
by JC
Hi

I've started building the a12 - first project ever. I'm down to the last two
resistors, and I suddenly notice that several holes in the pcb have (hard to explain) like "small crosshairs on a rifle" ;-) Some have 4, some have 3 or 2.

It looks sort of like this, I guess:
¤

Where the 'o' is the hole for the component, and the 'hairs' seem to connect to the rest of the pcb - they are VERY thin, so I was just wondering if it's a fault on the pcb, or if it's on purpose??

I'm a newbie at this, so I don't have a clue as to wheither it's (grounding?) or whatever??
Hope you understand the question...

PostPosted: Tue Feb 14, 2006 10:46 am
by tpryan
They're called thermal reliefs, and connect the pad to the surrounding ground plane. If it weren't done in this way, the ground plane would suck the heat away from the pad too quickly to make a good solder joint. The reliefs allow the pad to reach a higher temperature than the surrounding copper.