Square vs. round pads for +/- polarized parts

Oct 05, 2006 4 Replies

Greetings:


Is there a standard on which pad to make square vs. round for +/- on polarized caps, or for anodes/cathodes on diodes?



I am inclined to prefer square pads for + terminals and anodes, because a square is more visually similar to a plus sign.



Obviously it doesn't matter much. But it seems other folks' diodes often have the anodes round and cathodes square.



Thanks for input.


Good day! ________________________________________ Christopher R. Carlen Principal Laser&Electronics Technologist Sandia National Laboratories CA USA crcarleRemoveThis@BOGUSsandia.gov NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.

I use square pads for pin 1 on chips, resistors, and capacitors, for + on polarized capacitors, and for cathodes on diodes.

-Chuck Harris

I use square pads for "identified" pins. Pin 1 on ICs. Cathode (stripe) on diodes. And, since most electrolytic capacitors have the (-) lead identified, the (-) lead on electrolytics. I don't use tantalums, which have the (+) lead identified usually.

Jim

I use the square pads to make my life easier when I assemble the boards. Electrolytics have a long lead on +, or a rolled edge on + so I make that the square pad... besides, I am more "schematic-centric" in the way I see electronics. For electrolytics, the plus lead is what is identified on the schematic, not the minus.

-Chuck

That sorta makes sense, but as Chuck points out in his next post, some parts are identified by both a long lead and a printed marking on the body. These sometimes conflict, as with electrolytics.

But I'm beginning to think that a square pad for diode cathodes is most logical.

Good day! ________________________________________ Christopher R. Carlen Principal Laser&Electronics Technologist Sandia National Laboratories CA USA crcarleRemoveThis@BOGUSsandia.gov NOTE, delete texts: "RemoveThis" and "BOGUS" from email address to reply.

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