PCB design: Is silkscreen on ground plane okay?

I don't see why it would be any different from any other silkscreen job. Hell, it is probably quite a bit smoother than the surface of most boards they have to screen.

Jim

Is this a fancy/expensive board? (microwaves) If so, then ask your board house, hire a consultant, or ask your colleagues.

If it's a low cost board, then I wouldn't expect any problems. (I've done it.) If there would be a problem, the board house should mention it on their web page or design guide.

That brings up an interesting point. Assuming you are working on a 2 layer board and one of them is a ground plane, how do you decide if the ground plane goes on top or the bottom? I'm also assuming that most of the parts go on the top.

My first reaction was to put the ground plane on the bottom so the pads from the chips on top don't cut holes in the ground plane.

Signals that are easy to route won't need any vias and/or won't cut up the plane as much.

This is a +/- 120 Volt DC voltage regulator taking about +/- 130 Volts DC in. The board has radial-lead electrolytics on the top that have these voltages on their non-grounded pins. If the main traces were on top, the radial-lead electrolytics could end up resting on these high-voltage traces. Though it may not be a problem in practice, the thought of this made me paranoid. There doesn't seem to be any insulation spec that I can find for the top side of the radial-lead electrolytics. So I thought it best for safety reasons to not allow the bodies of these parts to rest on high-voltage traces on the top of the board. Perhaps I'm overreacting, but let's just say I have "respect" for high voltages.

This being a DIY project, all my parts are through-hole types, so they'll have pads on top and bottom. But I agree - with lots of surface-mount parts, putting the ground plane on the bottom would be much better.

Andy

This is a DIY effort, so I'm in this by myself. It's not a microwave board or anything terribly exotic. But there are some voltages over 100 V involved - see my other reply.

Thanks. I will check the web pages of the board house.

Andy

Oops - had to fix the default setting of my newsreader :-).

Andy

Thanks!

Andy

No problem doing this. It prints nicer since you'll have very few traces on top.

My rule is that there *will* be silk on each surface components are loaded on.

Now, it is often the case that _all_ the silk information can not be placed (on dense designs) but at least some information should be on the silk for each loaded layer.

Cheers

PeteS

No problem putting silkscreen on copper. Just keep it well away from any pads that are to be soldered Cheers

Andy C wrote: