Drilling PCBs.

[bobbletrox]

Hi!  I'm gonna try to etch my first PCB in a few days, but I was just wondering;

* The smallest drill bit I can find is 1mm...will that be ok, or does it have to be 0.8mm?
* Do you drill the board after you develop it (photo resist method), or after you etch and laquer it?

Thanks!

[zener]

I would prefer .8mm but a 1mm would be no problem except that components with very thin leads such as 1/4w resisitors might become repeatedly loose as you solder it on the board.

You'll drill the board after etching. Make sure that you slightly scrub it first with scrubbing pad or sand paper before lacquering and drilling.

Zener

[bobbletrox]

thanks! :wink:

so it's drilling after laquering?  It just seems that the laquer would fill the holes in if you drill it first  :?

[BILLYL]

If you find that the 1mm is a little too bigf for those thin lead components you can use a little tape to keep them in place as you solder.  This works real well - it allows me to basically populate a board all at once and then solder all at once.

Good Luck
BILLYL

[zener]

thanks! :wink:

so it's drilling after laquering?  It just seems that the laquer would fill the holes in if you drill it first  :?

Drilling would come last (soldering of course).

[bobbletrox]

thanks!

[Bill_F]

All depends on the PCB you use for your transfer. Some of the more crowded circuits have very small pads and a 1mm might obliterate them. I just etched the board for the NeoVibe and I don't think you could use a 1mm on that, I'm worried about 8mm. For many of the simpler and less crowded boards probably 1mm would be fine.

[arielfx]

I'll tell you how I am doing my boards!
First of all there are two commonly used board types - fiberglass and phenolic.
If you have a phenolic board you can use an kind of drill but if you use fiberglass boards you should have vidia drills because the fiberglass will dull any standard drill after one board or two - after all it's glass and that's a though material, tougher than metal, but you know that...
I am using 0.7mm drills that work the best for me and they seem to be the same size as professional industry boards but I might be wrong.
I had a board drill from a friend's shop for a while... that's a small press drill that you can buy used for about 25$ even here and it goes at 5000 - 7000 rpm so you can be sure you won't kill the blades.
another option that might work is to use a dremel and a dremel press drill and insert a vidia blade there and drill at 7000 or 10,000 rpm with the dremel press drill - you'll be amazed with the 100% pro looking results!

[M.D.]

Also lots of manufacturers say that the photo resist has really good soldering properties and you can solder right through it! and it protects the circut from all sorts of stuff.

Play hard.
              Mike. :twisted:

[Samuel]

And they're right, it's true! Stuff is very easy to solder.

[keko]

I have always use 1mm drill bits...they are the smallest ones I've been able to find.

Regarding when to drill, I have to DISAGREE with others... In my experience, if your are new to this, you might consider drilling BEFORE etching. That way, if you drill a pad away, you can retouch with a Sharpie before etching. One tipo, though: be carefull not to excesively touch the board, as dust and hand's oil will make it difficult for the etchant to work (and of course you can't really clean the board once it's ready to be etched)

Good Luck
Keko

[Ansil]

purple nitrile gloves..    the last time i did boards i did the drilling first.

but i had made up some transparencies before hand that i didnt' use so i put them on the board with some clear tape and drilled out all the holes for the pads like that.  then i cleaned it and sharpied it then etched it..   the pads were great..........  btu the etchant was old or soemthing.. cause it didnt' do dick fro a while then it kicked in and killed the board..   so anyway i just cleaned it up and used it like expensive wasted time perf board