Homebrew PCBs

Which do you guys do first, etch or drill?

I was thinking that drilling first would help me line up the toner 
transfer, but I'm not sure about etching a drilled board.

Do you get excesive undercutting at the edge of the drilled hole?

-Denny

On Thu, 08 Jan 2004 23:00:54 -0000, dkesterline <desterline@...> wrote:

> Which do you guys do first, etch or drill?
>
> I was thinking that drilling first would help me line up the toner 
> transfer, but I'm not sure about etching a drilled board.
>
> Do you get excesive undercutting at the edge of the drilled hole?
>
> -Denny
>
>

Never drilled before etching.

i use the etched holes as a drilling guide (to find the center).

but i rarely make 2-sided pcbs (no tt yet at all).

i don't tink the undercut is very much.

ST

I'm in the proccess of setting up a CNC drill, the thing I'm 
concerned about is getting the etched board on the drill tblw 
acuratly. Seems it would be easier to align the TT to the holes.

Agreed about using the etched board for aligning the drill. That's 
what I do when it's by hand, I'm just tired of doing it by hand :-)

-Denny

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> On Thu, 08 Jan 2004 23:00:54 -0000, dkesterline <desterline@t...> 
wrote:
> 
> > Which do you guys do first, etch or drill?
> >
> > I was thinking that drilling first would help me line up the 
toner 

> > transfer, but I'm not sure about etching a drilled board.
> >
> > Do you get excesive undercutting at the edge of the drilled hole?
> >
> > -Denny
> >
> >
> 
> Never drilled before etching.
> 
> i use the etched holes as a drilling guide (to find the center).
> 
> but i rarely make 2-sided pcbs (no tt yet at all).
> 
> i don't tink the undercut is very much.
> 
> ST

----- Original Message ----- 

From: "dkesterline" <desterline@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, January 08, 2004 11:00 PM
Subject: [Homebrew_PCBs] Etch or drill first?


> Which do you guys do first, etch or drill?
>
> I was thinking that drilling first would help me line up the toner
> transfer, but I'm not sure about etching a drilled board.
>
> Do you get excesive undercutting at the edge of the drilled hole?

Never tried it with toner transfer, but it used to work OK many years ago
when I painted the tracks on. It was especially useful for the few
double-sided boards I made this way as it took cayer of the alignment
problem.

Leon
--
Leon Heller, G1HSM
Email: aqzf13@...
My low-cost Philips LPC210x ARM development system:
http://www.geocities.com/leon_heller/lpc2104.html

On Fri, 09 Jan 2004 02:08:13 -0000, dkesterline <desterline@...> wrote:

> I'm in the proccess of setting up a CNC drill, the thing I'm concerned 
> about is getting the etched board on the drill tblw acuratly. Seems it 
> would be easier to align the TT to the holes.
>
> Agreed about using the etched board for aligning the drill. That's what I 
> do when it's by hand, I'm just tired of doing it by hand :-)
>
> -Denny

sorry, i assumed hand drilling.

with cnc it may be much easier the other ways.

take two steel pins (broken hss drill bit shafts or so, thin nails)
and put them in the holes (snug fit that they are straight.).
punch the same two holes through in the tt paper (drill, needle, etc).
(maybe best using far apart pins for this).

then put the paper on the pcb, the pins will align the paper.
with the tip of your iron now heat between the pins, to stick the paper to 
the pcb.

remove the pins and heat like usual.

maybe that works?

Stefan

With photo sensitive boards, I have found that drilling before
developing/etching tears away a bit of the photo-sensitive coating,
causing copper to be etched away from the hole (not a good thing).  A
friend of mine that uses PNPBlue (toner transfer) says when he tried,
the little burrs kept the toner transfer paper from making good
contact around the hole.  But I bet with a _good_, high speed spindle
and real PCB carbide drill bits, it might work out O.K.  Heck, pro
shops do it without problem...  but then again, their spindles cost
orders of magnitude more than what I have (www.CNCOnABudget.com, $100
or so).

- Steven Ciciora

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> On Fri, 09 Jan 2004 02:08:13 -0000, dkesterline <desterline@t...> wrote:
> 
> > I'm in the proccess of setting up a CNC drill, the thing I'm
concerned 
> > about is getting the etched board on the drill tblw acuratly.
Seems it 
> > would be easier to align the TT to the holes.
> >
> > Agreed about using the etched board for aligning the drill. That's
what I 
> > do when it's by hand, I'm just tired of doing it by hand :-)
> >
> > -Denny
> 
> sorry, i assumed hand drilling.
> 
> with cnc it may be much easier the other ways.
> 
> take two steel pins (broken hss drill bit shafts or so, thin nails)
> and put them in the holes (snug fit that they are straight.).
> punch the same two holes through in the tt paper (drill, needle, etc).
> (maybe best using far apart pins for this).
> 
> then put the paper on the pcb, the pins will align the paper.
> with the tip of your iron now heat between the pins, to stick the
paper to 

> the pcb.
> 
> remove the pins and heat like usual.
> 
> maybe that works?
> 
> Stefan