EEVblog Electronics Community Forum

Electronics => PCB/EDA/CAD => Topic started by: btfdev on March 28, 2012, 04:58:02 am

Title: PCB back clearance (Through Hole Design)
Post by: btfdev on March 28, 2012, 04:58:02 am

Hello team,

Just wanted to find out if there is a standard back clearance for PCB? Specially for thru-hole components?

We have a PCB that needs to fit into a very thin enclosure without much space to play around. Is 1mm enough for thru hole, provided that there is no issue with heat and electronic interference?

Thanks, BTFDev

Title: Re: PCB back clearance (Through Hole Design)
Post by: Rerouter on March 28, 2012, 06:39:51 am

if plastic, yes, 1mm is ok, if a metal case with lead free solder aim for 1.4 - 1.8mm, or put something non conductive between the board and the enclosure,

Title: Re: PCB back clearance (Through Hole Design)
Post by: markus_b on March 28, 2012, 07:08:24 am

That depends on the components. But I'm pretty sure 1mm is not sufficient. Even with a standard DIL package the pins stick out about 1.5mm on the other side. Other stuff, like connectors, often need even more room. You can manually trim them down to 1mm or so, but that only works for very small quantities and does not look professional.

If size is a problem, can you not go for SMD ?

Title: Re: PCB back clearance (Through Hole Design)
Post by: AnthonyJarmie on May 19, 2012, 02:39:43 pm

Hello friends,

Back drilling also referred to as counter boring, is a method of reducing the stub effect of a press-fit through hole or a through hole via by drilling out the desired through hole from the backside of the board to a predetermined depth, which in turn improves signal clarity. Via tuning, by adjusting clearances should be considered before reverting to back drilling.

Best regards
Anthony