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Yag laser?

Yag laser?

2003-06-08 by anode505

Has anyone thought of a Yag laser for PCBs?
I see people are actually 'milling' the unwanted copper off the
boards.


Yags are great for copper (On CO2 lasers, copper is a BIG no-no) and
the beam can be delivered via fiber optics with a Yag. Plus you
cna 'drill' the holes without a tool change. Get fancy and you can
adjust to focus for bigger/smaller kerfs (though not recomemned)

Nice chemical free way of doing it (at least chem free before PTHs)

Re: [Homebrew_PCBs] Yag laser?

2003-06-08 by Hans Wedemeyer

Well I posted a similar question and got the reply ... you will end up
with a PCB jigsaw....
How are you going to stop the laser burning the FR4 material ?
If you can do that I'm interested....
Hans W

anode505 wrote:

>
>
> Has anyone thought of a Yag laser for PCBs?
> I see people are actually 'milling' the unwanted copper off the
> boards.
>
>
> Yags are great for copper (On CO2 lasers, copper is a BIG no-no) and
> the beam can be delivered via fiber optics with a Yag. Plus you
> cna 'drill' the holes without a tool change. Get fancy and you can
> adjust to focus for bigger/smaller kerfs (though not recomemned)
>
> Nice chemical free way of doing it (at least chem free before PTHs)
>
>
> Yahoo! Groups Sponsor
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[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] Yag laser?

2003-06-09 by Russell Shaw

It's just a matter of testing the energy required to burn thru the copper
compared to burning thru the FR4. If (for example) it takes 1ms to burn thru
the copper and 10us to burn thru the FR4, then you could generate the burn-path
with high frequency pulsing/moving of the laser head, with an excess of 0.1us
to make sure the copper is burn right thru and 1/100th the way into the
substrate. You could try making your own pcb from a ceramic substrate that
is more resistant to laser.

Hans Wedemeyer wrote:
Show quoted textHide quoted text
> Well I posted a similar question and got the reply ... you will end up
> with a PCB jigsaw....
> How are you going to stop the laser burning the FR4 material ?
> If you can do that I'm interested....
> Hans W
>
> anode505 wrote:
>>
>>Has anyone thought of a Yag laser for PCBs?
>>I see people are actually 'milling' the unwanted copper off the
>>boards.
>>
>>
>>Yags are great for copper (On CO2 lasers, copper is a BIG no-no) and
>>the beam can be delivered via fiber optics with a Yag. Plus you
>>cna 'drill' the holes without a tool change. Get fancy and you can
>>adjust to focus for bigger/smaller kerfs (though not recomemned)
>>
>>Nice chemical free way of doing it (at least chem free before PTHs)

Re: Yag laser?

2003-06-09 by anode505

Feedrates!!!!
I'm a CNC CO2 laser tech now. We can etch material.
Its all power to speed ratios.


--- In Homebrew_PCBs@yahoogroups.com, Hans Wedemeyer <hans@c...>
wrote:
> Well I posted a similar question and got the reply ... you will end
up
> with a PCB jigsaw....
> How are you going to stop the laser burning the FR4 material ?
> If you can do that I'm interested....
> Hans W
>
> anode505 wrote:
>
> >
> >
> > Has anyone thought of a Yag laser for PCBs?
> > I see people are actually 'milling' the unwanted copper off the
> > boards.
> >
> >
> > Yags are great for copper (On CO2 lasers, copper is a BIG no-no)
and
> > the beam can be delivered via fiber optics with a Yag. Plus you
> > cna 'drill' the holes without a tool change. Get fancy and you
can
> > adjust to focus for bigger/smaller kerfs (though not recomemned)
> >
> > Nice chemical free way of doing it (at least chem free before
PTHs)
> >
> >
> > Yahoo! Groups Sponsor
> ADVERTISEMENT
> [Click Here!]
>
> >
> > Be sure to visit the group home and check for new Bookmarks and
files:
> >
> > http://groups.yahoo.com/group/Homebrew_PCBs
> >
> > To unsubscribe from this group, send an email to:
> > Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
Show quoted textHide quoted text
>
>
> [Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-09 by Mike Putnam

> Feedrates!!!!
> I'm a CNC CO2 laser tech now. We can etch material.
> Its all power to speed ratios.
>
>
I have never tried using this method, although I have quite a bit of
experience with lasers. Just off the top of my head, I see a problem. The
copper is not "even" on top of the clad. If you look at it with a magnifier,
you will see low spots and high spots. Even with varying feedrates you will
get burn marks in the substrate wherever there is a low spot in the copper.
I could be wrong about this as it is theory and not actual practice, but if
I am, could you please post a URL showing the project? I would also like to
see more on this.

-Mike

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-10 by Dave King

At 04:35 PM 09/06/03, you wrote:

> > Feedrates!!!!
> > I'm a CNC CO2 laser tech now. We can etch material.
> > Its all power to speed ratios.
> >
> >
>I have never tried using this method, although I have quite a bit of
>experience with lasers. Just off the top of my head, I see a problem. The
>copper is not "even" on top of the clad. If you look at it with a magnifier,
>you will see low spots and high spots. Even with varying feedrates you will
>get burn marks in the substrate wherever there is a low spot in the copper.
>I could be wrong about this as it is theory and not actual practice, but if
>I am, could you please post a URL showing the project? I would also like to
>see more on this.
>
>-Mike

I know this is really off topic for the group but have either one of you
tried to cut say
through a few feet of styrofoam? Always been curious if a laser would work
in place
of a hotwire saw.

Dave

Re: Yag laser?

2003-06-10 by anode505

True the G10 (called FR$ for some reason on a clad board) isn't
smooth. But then a laser isn't perfect either. Yeah, you'll burn
the substrate a bit (I doubt more the the 'milling' style) But I
doubt you would go through it. A little clean up might be needed.


Now to find a customer with a Yag......

--- In Homebrew_PCBs@yahoogroups.com, "Mike Putnam" <circuit@g...>
wrote:
>
> > Feedrates!!!!
> > I'm a CNC CO2 laser tech now. We can etch material.
> > Its all power to speed ratios.
> >
> >
> I have never tried using this method, although I have quite a bit of
> experience with lasers. Just off the top of my head, I see a
problem. The
> copper is not "even" on top of the clad. If you look at it with a
magnifier,
> you will see low spots and high spots. Even with varying feedrates
you will
> get burn marks in the substrate wherever there is a low spot in the
copper.
> I could be wrong about this as it is theory and not actual
practice, but if
> I am, could you please post a URL showing the project? I would also
like to
Show quoted textHide quoted text
> see more on this.
>
> -Mike

Re: Yag laser?

2003-06-10 by anode505

Beam divergance would kill you. THe beam will grow in size as it
travels. If it grows, the engery is displaced over a bigger area,
and will need more time to 'cut' Our lasers do have 'adaptive
optics' a mirror that bends to control the beam's waist (and
autofucus) But to hold a beam's size for a few feet, itsn't
practicle.
A waterjet has a better chance, but that still a prob.
How about a hot knife/wire?


Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, Dave King <KingDWS@S...> wrote:
>
> I know this is really off topic for the group but have either one
of you
> tried to cut say
> through a few feet of styrofoam? Always been curious if a laser
would work
> in place
> of a hotwire saw.
>
> Dave

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-10 by Dave King

At 03:49 AM 10/06/03, you wrote:
>Beam divergance would kill you. THe beam will grow in size as it
>travels. If it grows, the engery is displaced over a bigger area,
>and will need more time to 'cut' Our lasers do have 'adaptive
>optics' a mirror that bends to control the beam's waist (and
>autofucus) But to hold a beam's size for a few feet, itsn't
>practicle.
>A waterjet has a better chance, but that still a prob.
>How about a hot knife/wire?

We do use a hot wire cutter. It has two problems one is
a practical cutting length of about 4 feet and for tapered or
twisted shapes the result depends on the two operators.

There are the odd commercial cnc machine out there
(real big $$) but it would be nice to have a cnc laser. I
didn't know you would have problems with beam dispersion
over such a short run hadn't heard that before.

I was thinking it might not be possible because of the
depth of the cut and the way the material vaporizes. Thats
really all the hot wire does is vaporize the material area
immediately around the wire.

Oh well learn something everyday.

Thanks

Dave

Re: Yag laser?

2003-06-10 by John Myszkowski

In practice, the laser is always focused to do work. Otherwise the
beam is too weak to burn through much.
I tried to burn through styrofoam with and without focusing. The
focused beam has a "waist" where it is focused to a tiny spot with
extremely high energy/area ratio.
The unfocused beam has enough power to go through the foam, but it is
slow and dirty. Instead simply vaporizing the material, it melts it
and gives off a LOT of noxious fumes (even with ventilation). It is
slow. It is not even because of the foam's density variations. Sort
of like cutting through wood, but worse (faster).
While the beam melts through the denser pellets in the foam, it
generates localized hot spots that melt surrounding material.

The only way to do it is to use a focused bem with a LONG focal
point. The longer the FP, the longer the waist part that does all the
cutting.

With the YAG, you could cut copper by pulsing and checking the light
return (feedback or reflection) from the material during the pulse.
There is always scattered light from the point where the laser
impacts. When much lower scattered light (reflection) is detected,
then you are through the copper layer. Just move to the next point
and start popping the copper.

I think the best use of laser would be to vapourize the resist, which
could simply be a varnish or paint. That way you could easily use a
low power CO2 laser.

An even easier, (and cheaper) application of lasers would be to
expose the photoresist directly with a low power UV laser or even
better (and MUCH MUCH cheaper) is to use a focused UV LED. Just place
the PCB material on the pen plotter. Replace the pen with an LED and
go fo it!...


John Myszkowski...
=========================



Show quoted textHide quoted text
> didn't know you would have problems with beam dispersion
> over such a short run hadn't heard that before.
>
> I was thinking it might not be possible because of the
> depth of the cut and the way the material vaporizes. Thats
> really all the hot wire does is vaporize the material area
> immediately around the wire.
>
> Oh well learn something everyday.
>
> Thanks
>
> Dave

Re: Yag laser?

2003-06-10 by anode505

--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:

> With the YAG, you could cut copper by pulsing and checking the
light
> return (feedback or reflection) from the material during the pulse.
> There is always scattered light from the point where the laser
> impacts. When much lower scattered light (reflection) is detected,
> then you are through the copper layer. Just move to the next point
> and start popping the copper.

Not too sure if I'd pulse here, depends on the power of the Yag
>
> I think the best use of laser would be to vapourize the resist,
which
Show quoted textHide quoted text
> could simply be a varnish or paint. That way you could easily use a
> low power CO2 laser.

Dangerous! (I'd use paint or a graphite spray) That way you
are 'basically' etching copper with a CO2. Keep in mind all the
mirrors in a CO2 are copper, because it reflects that part or the
spectum (10600nm) *so* well. (sure there are a few laysers of
special coatings, but its the copper that actually reflecting)

The idea of the Yag for this, was to avoid chemicals, and be a bit
quicker, 'etch' and drill all in one step.

Time to go find some surplus Yag crystals on E-Bay :)
But I think this is getting a bit out of hand/usefulness.
Maybe in time.....

Re: Yag laser?

2003-06-11 by John Myszkowski

That is the idea, get rid of the resist. The laser would stop at the
copper. Dangerous? No more than playing with lasers in the first
place. Not if you use proper shielding (acrylic is used for CO2 laser
beam shielding)... and I did say low power...

Problem with yag is that it is hard to pulse. Pulsing with a flash
lamp, yes. But other than that it gets hairy.

I have a low power CO2 (20W) that I have been experimenting with.

I have played with YAG (and other crystals too). I am waiting for a
electronic system like a high power (20 to 100W) laser diode for
under $1K. Expect that should happen pretty soon. Much less
maintenance and longer life of the "tool".

Like I suggested, the UV LED (in a plotter) may work quite nicely for
those not afraid to use simple chemicals. The UV LEDs cost under $3
each.


John M...
=================




Show quoted textHide quoted text
> Keep in mind all the
> mirrors in a CO2 are copper, because it reflects that part or the
> spectum (10600nm) *so* well. (sure there are a few laysers of
> special coatings, but its the copper that actually reflecting)
>
> The idea of the Yag for this, was to avoid chemicals, and be a bit
> quicker, 'etch' and drill all in one step.
>
> Time to go find some surplus Yag crystals on E-Bay :)
> But I think this is getting a bit out of hand/usefulness.
> Maybe in time.....

Re: Yag laser?

2003-06-12 by crankorgan

> Has anyone thought of a Yag laser for PCBs?
> I see people are actually 'milling' the unwanted copper off the
> boards.
>
>
> Yags are great for copper (On CO2 lasers, copper is a BIG no-no)
and
> the beam can be delivered via fiber optics with a Yag. Plus you
> cna 'drill' the holes without a tool change. Get fancy and you can
> adjust to focus for bigger/smaller kerfs (though not recomemned)
>
> Nice chemical free way of doing it (at least chem free before PTHs)


Here is a high speed PCBoard drilling machine that uses a

laser.http://www.hitachidigital.com/laser.html



John

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-13 by stefan_trethan@gmx.at

> > Has anyone thought of a Yag laser for PCBs?
> > I see people are actually 'milling' the unwanted copper off the
> > boards.
> >
> >
> > Yags are great for copper (On CO2 lasers, copper is a BIG no-no)
> and
> > the beam can be delivered via fiber optics with a Yag. Plus you
> > cna 'drill' the holes without a tool change. Get fancy and you can
> > adjust to focus for bigger/smaller kerfs (though not recomemned)
> >
> > Nice chemical free way of doing it (at least chem free before PTHs)
>
>
> Here is a high speed PCBoard drilling machine that uses a
>
> laser.http://www.hitachidigital.com/laser.html
>
>
>
>

really nice thing...

but seems they also don't drill the copper - they use co2 laser...


i wonder how it is possible to drill the resin and the glassfibers in a so
similar time that there is a smooth nice hole drilled.


(i also don't believe the yag laser milling will work, but that's only my
opinion.....)

regards
stefan

--
+++ GMX - Mail, Messaging & more http://www.gmx.net +++
Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by crankorgan

Stefan,
Lasers can cut, drill and engrave. I mill circuit boards.
What saves me is the Mechanical Etching Bit has a tip that is
triangular. Any variation of the thickness of the copper or the board
will result in a slightly wider or narrower trace.

John








Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> > > Has anyone thought of a Yag laser for PCBs?
> > > I see people are actually 'milling' the unwanted copper off the
> > > boards.
> > >
> > >
> > > Yags are great for copper (On CO2 lasers, copper is a BIG no-
no)
> > and
> > > the beam can be delivered via fiber optics with a Yag. Plus
you
> > > cna 'drill' the holes without a tool change. Get fancy and you
can
> > > adjust to focus for bigger/smaller kerfs (though not recomemned)
> > >
> > > Nice chemical free way of doing it (at least chem free before
PTHs)
> >
> >
> > Here is a high speed PCBoard drilling machine that uses a
> >
> > laser.http://www.hitachidigital.com/laser.html
> >
> >
> >
> >
>
> really nice thing...
>
> but seems they also don't drill the copper - they use co2 laser...
>
>
> i wonder how it is possible to drill the resin and the glassfibers
in a so
> similar time that there is a smooth nice hole drilled.
>
>
> (i also don't believe the yag laser milling will work, but that's
only my
> opinion.....)
>
> regards
> stefan
>
> --
> +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-13 by stefan_trethan@gmx.at

yes, yes....

but on http://www.hitachidigital.com/laser.html
there is a co2.
so i assume it only drilles boards (which i think the text ob this page
says).

so i don't take this as a real-world industrial model of a "pcb laser mill".

i'm still not sure if it would work (for me the difference in
laser-resistivity of copper and board is a problem)


and i have not heared of such a unit really being used for pcb milling and i
only wanted to say http://www.hitachidigital.com/laser.html is not for
milling.

thanks

stefan

--
+++ GMX - Mail, Messaging & more http://www.gmx.net +++
Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by crankorgan

Stefan,
That's why I posted the link! Why would they just make a laser
drilling machine when they could also mill. The answer is using a
laser to mill is a dream at this time. They cut and burn. Milling is
in between.

John






Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> yes, yes....
>
> but on http://www.hitachidigital.com/laser.html
> there is a co2.
> so i assume it only drilles boards (which i think the text ob this
page
> says).
>
> so i don't take this as a real-world industrial model of a "pcb
laser mill".
>
> i'm still not sure if it would work (for me the difference in
> laser-resistivity of copper and board is a problem)
>
>
> and i have not heared of such a unit really being used for pcb
milling and i
> only wanted to say http://www.hitachidigital.com/laser.html is not
for
> milling.
>
> thanks
>
> stefan
>
> --
> +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by John Myszkowski

When the copper is coated on the surface, then it can be cut by
laser. The heat of the vapourized coating material helps cut the
copper if thin enough.
In the spec area it mentions something about "no outer layer copper".
I may mean that it is either coated copper or simpley the panels do
not have copper on them. The copper gets plated on at the same time
as the throuh-holes.
Honestly, I am just guessing as to the mahine's abilities at this
point. They are too vague in the specs, unless you are familiar with
the system. It could be anything.

John M...
============



Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> yes, yes....
>
> but on http://www.hitachidigital.com/laser.html
> there is a co2.
> so i assume it only drilles boards (which i think the text ob this
page
> says).
>
> so i don't take this as a real-world industrial model of a "pcb
laser mill".
>
> i'm still not sure if it would work (for me the difference in
> laser-resistivity of copper and board is a problem)
>
>
> and i have not heared of such a unit really being used for pcb
milling and i
> only wanted to say http://www.hitachidigital.com/laser.html is not
for
> milling.
>
> thanks
>
> stefan
>
> --
> +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by crankorgan

John,
But the whole idea is not at the hobby level. Anything is
possible with big bucks. I think the original question was directed
at a hobby process that can be done in a person's home.

John


--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> When the copper is coated on the surface, then it can be cut by
> laser. The heat of the vapourized coating material helps cut the
> copper if thin enough.
> In the spec area it mentions something about "no outer layer
copper".
> I may mean that it is either coated copper or simpley the panels do
> not have copper on them. The copper gets plated on at the same time
> as the throuh-holes.
> Honestly, I am just guessing as to the mahine's abilities at this
> point. They are too vague in the specs, unless you are familiar
with
> the system. It could be anything.
>
> John M...
> ============
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> > yes, yes....
> >
> > but on http://www.hitachidigital.com/laser.html
> > there is a co2.
> > so i assume it only drilles boards (which i think the text ob
this
> page
> > says).
> >
> > so i don't take this as a real-world industrial model of a "pcb
> laser mill".
> >
> > i'm still not sure if it would work (for me the difference in
> > laser-resistivity of copper and board is a problem)
> >
> >
> > and i have not heared of such a unit really being used for pcb
> milling and i
> > only wanted to say http://www.hitachidigital.com/laser.html is
not
Show quoted textHide quoted text
> for
> > milling.
> >
> > thanks
> >
> > stefan
> >
> > --
> > +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> > Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by anode505

Well I doubt you'd find an industrial laser milling and drilling a
PCB. Just not that practical. The current standards work fine. EPA
is the only real prob. But for a home-brew, it could be.


Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> yes, yes....
>
> but on http://www.hitachidigital.com/laser.html
> there is a co2.
> so i assume it only drilles boards (which i think the text ob this
page
> says).
>
> so i don't take this as a real-world industrial model of a "pcb
laser mill".
>
> i'm still not sure if it would work (for me the difference in
> laser-resistivity of copper and board is a problem)
>
>
> and i have not heared of such a unit really being used for pcb
milling and i
> only wanted to say http://www.hitachidigital.com/laser.html is not
for
> milling.
>
> thanks
>
> stefan
>
> --
> +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-13 by anode505

Yes, that was the reason of my post. I asked about Yag, since it is
do-able at home and is more copper freindly then a CO2.

But I guess it will remain on the back burner in whats left of my
brain. :)



-- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@k...> wrote:
Show quoted textHide quoted text
> John,
> But the whole idea is not at the hobby level. Anything is
> possible with big bucks. I think the original question was directed
> at a hobby process that can be done in a person's home.

Re: Yag laser?

2003-06-14 by yildirimalper

Hi
It says 30,000 holes/minute in the Hitachi web site.
Is it really possible.
I can not even imagine. That is 500 holes/second

Best regards,
Alper

--- In Homebrew_PCBs@yahoogroups.com, "anode505" <anode505@y...>
wrote:
>
>
> Has anyone thought of a Yag laser for PCBs?
> I see people are actually 'milling' the unwanted copper off the
> boards.
>
>
> Yags are great for copper (On CO2 lasers, copper is a BIG no-no)
and
> the beam can be delivered via fiber optics with a Yag. Plus you
> cna 'drill' the holes without a tool change. Get fancy and you
can
Show quoted textHide quoted text
> adjust to focus for bigger/smaller kerfs (though not recomemned)
>
> Nice chemical free way of doing it (at least chem free before PTHs)

Re: Yag laser?

2003-06-14 by John Myszkowski

I guess it depends on the age of the boys and the price of their
toys...? :)

Lasers are one of my hobbies, or at least they used to be. The lasers
I used were either made by me or found on a scrap heap and repaired
by me.

But you are correct, it is beyond most hobbyists abilities. I was
just trying to be helpful to the ones who can get access to the laser
type hobbies.

John mYszkowski...
======================



Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@k...> wrote:
> John,
> But the whole idea is not at the hobby level. Anything is
> possible with big bucks. I think the original question was directed
> at a hobby process that can be done in a person's home.
>
> John
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
> <myszka_us2000@y...> wrote:
> > When the copper is coated on the surface, then it can be cut by
> > laser. The heat of the vapourized coating material helps cut the
> > copper if thin enough.
> > In the spec area it mentions something about "no outer layer
> copper".
> > I may mean that it is either coated copper or simpley the panels
do
> > not have copper on them. The copper gets plated on at the same
time
> > as the throuh-holes.
> > Honestly, I am just guessing as to the mahine's abilities at this
> > point. They are too vague in the specs, unless you are familiar
> with
> > the system. It could be anything.
> >
> > John M...
> > ============
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, stefan_trethan@g... wrote:
> > > yes, yes....
> > >
> > > but on http://www.hitachidigital.com/laser.html
> > > there is a co2.
> > > so i assume it only drilles boards (which i think the text ob
> this
> > page
> > > says).
> > >
> > > so i don't take this as a real-world industrial model of a "pcb
> > laser mill".
> > >
> > > i'm still not sure if it would work (for me the difference in
> > > laser-resistivity of copper and board is a problem)
> > >
> > >
> > > and i have not heared of such a unit really being used for pcb
> > milling and i
> > > only wanted to say http://www.hitachidigital.com/laser.html is
> not
> > for
> > > milling.
> > >
> > > thanks
> > >
> > > stefan
> > >
> > > --
> > > +++ GMX - Mail, Messaging & more http://www.gmx.net +++
> > > Bitte lächeln! Fotogalerie online mit GMX ohne eigene Homepage!

Re: Yag laser?

2003-06-14 by John Myszkowski

Amazing, isn't it...

John M...
==============



--- In Homebrew_PCBs@yahoogroups.com, "yildirimalper"
<yildirimalper@y...> wrote:
Show quoted textHide quoted text
> Hi
> It says 30,000 holes/minute in the Hitachi web site.
> Is it really possible.
> I can not even imagine. That is 500 holes/second
>
> Best regards,
> Alper
>
> --- In Homebrew_PCBs@yahoogroups.com, "anode505" <anode505@y...>
> wrote:
> >
> >
> > Has anyone thought of a Yag laser for PCBs?
> > I see people are actually 'milling' the unwanted copper off the
> > boards.
> >
> >
> > Yags are great for copper (On CO2 lasers, copper is a BIG no-no)
> and
> > the beam can be delivered via fiber optics with a Yag. Plus you
> > cna 'drill' the holes without a tool change. Get fancy and you
> can
> > adjust to focus for bigger/smaller kerfs (though not recomemned)
> >
> > Nice chemical free way of doing it (at least chem free before
PTHs)

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-15 by Russell Shaw

John Myszkowski wrote:
> I guess it depends on the age of the boys and the price of their
> toys...? :)
>
> Lasers are one of my hobbies, or at least they used to be. The lasers
> I used were either made by me or found on a scrap heap and repaired
> by me.
>
> But you are correct, it is beyond most hobbyists abilities. I was
> just trying to be helpful to the ones who can get access to the laser
> type hobbies.

What power CO2 laser do you need for cutting 3mm steel/brass/aluminium?
I've got a two-stage pump that can go to 10^-4 torr. I'm designing a
cnc x-y table...

Re: Yag laser?

2003-06-15 by John Myszkowski

*** Sorry for the departure from the main topic which is "PCB" making
in a home environment... but this had to be answered.

Anyway, I do believe that lasers can be used in the home PCB making.
If not for direct machining, then in the photo exposure process.
Lasers are just to cheap to overlook entirely these days.

Trying to answer your question...
First, I would not use CO2 laser to cut metal.
The usual solution is to use plasma cutter. You can get a small one
for about $1000 and it will cut anything for you "like hot knife
through butter" and is easily controllable by a CNC setup. It is a
portable unit, while the CO2 laser head would not even fit into my
basement.

Second, I do not have personal (hands on) experience with metal
cutting laser powers necessary. The biggest CO2 I ever had was almost
4ft long and that only gave me 40Watts at its peak operating time (I
had a HeNe 6ft long that only gave me 100mW at peak time). There is
tons of laser reference material on the internet for you to read
about.

Off the top of my head, you definitely have to go into the hundreds
(or even more) Watts before you can cut metal. The usual laser used
for metal processing is YAG (Although there is many huge CO2 lasers
used for that as well ). It is the easier and cheaper laser to
operate and maintain, at least for me it was. It is also more robust
and much smaller for the same power output.



John M...
===============



--- In Homebrew_PCBs@yahoogroups.com, Russell Shaw <rjshaw@i...>
wrote:
> John Myszkowski wrote:
> > I guess it depends on the age of the boys and the price of their
> > toys...? :)
> >
> > Lasers are one of my hobbies, or at least they used to be. The
lasers
> > I used were either made by me or found on a scrap heap and
repaired
> > by me.
> >
> > But you are correct, it is beyond most hobbyists abilities. I was
> > just trying to be helpful to the ones who can get access to the
laser
> > type hobbies.
>
> What power CO2 laser do you need for cutting 3mm
steel/brass/aluminium?
Show quoted textHide quoted text
> I've got a two-stage pump that can go to 10^-4 torr. I'm designing a
> cnc x-y table...

Re: Yag laser?

2003-06-15 by twb8899

> What power CO2 laser do you need for cutting 3mm
steel/brass/aluminium?
Show quoted textHide quoted text
> I've got a two-stage pump that can go to 10^-4 torr. I'm designing a
> cnc x-y table...

I had a Mitsubishi CNC Laser for several years and have some
knowledge of how they work. This machine was a model 1212HC with a
3000 watt resonator and 48" x48" cutting table. The entire machine
installation was the size of two pickup trucks.

We used this machine mainly for cutting small stainless steel and
acrylic plastic parts. When cutting .060" stainless steel the power
levels would vary between approximately 400 and 700 watts depending
on cutting speeds. The CNC program would change power levels when
needed. Lower power and table speed is used for fine cuts with higher
power and feed rates for everything else.

A coaxial beam of cutting gas is always used with CNC CO2 lasers. We
used oxygen for most steel and stainless and sometimes nitrogen for
stainless cutting since it leaves a cleaner cut edge. Clean
compressed air or nitrogen was used for cutting plastics.

Acrylic plastic cuts well with compressed air and 75 to 150 watts for
up to .125" thick and around 200 watts for .250" thick. The power
level, frequency, duty cycle and gas pressure was fully adjustable
(even while cutting) and allowed precise control of the cut quality.

Since most of our work was small parts with fine detail we used short
focal length lenses. A 5" focal length lense was used for most work
and a 2" lens was used for super fine cutting on thin materials. A
7.5" lens was used on materials over .25" thick and up to .5" thick.
The longer focal length gave a straight cut through thicker materials
but had a wider kerf (cut width) in the material being processed.

One time we tried cutting some FR-4 double sided laminate and it
didn't work very well. It took about 900 watts to pierce through the
top copper layer and then the glass epoxy exploded into a blob since
the power level was so high and was also being reflected back from
the bottom copper layer while piercing it.

Non-ferrous metals such as aluminum, copper and brass take much
higher powers levels to pierce and cut on a CO2 laser. My experience
was that the same power level to cut .375" steel could not even
pierce through the copper on a circuit board. I don't think the CO2
laser is the best choice for cutting PWB laminates. Maybe the YAG
machines will do a better job on circuit boards.

Tom

Re: [Homebrew_PCBs] Re: Yag laser?

2003-06-15 by Russell Shaw

twb8899 wrote:
>
>
>>What power CO2 laser do you need for cutting 3mm
>>steel/brass/aluminium?
>
>
> I had a Mitsubishi CNC Laser for several years and have some
> knowledge of how they work. This machine was a model 1212HC with a
> 3000 watt resonator and 48" x48" cutting table. The entire machine
> installation was the size of two pickup trucks...

A laser cutting place near me has an x-y machine about 3m wide, 10m long, and 4-5m high.
The laser is in a hut about 2m long, and the laser looked about 4ft (hard to see inside).
The light is guided to the head thru many metres of fibre-optic cable. They can cut 10cm
of steel (a bit of beam divergence tho). The cable glowed greenish when active. IIRC, YAGs
are greenish?

Re: Yag laser?

2003-06-15 by John Myszkowski

Thanks Tom,
That was very informative.

I only have a 30" fl lens for my CO2. I have good results with
cutting .125" pvc, acrylic and similar materials. I don't have a good
ventillation system, so I avoid too much plastics cutting (at least
until I get better ventillarion and compressed air system).

Would you say that an investment in a 5" FL lens (or beter) would do
a better job for me? I only intend cutting .125" material.

I have tried cutting the FR material, but I get too much charring
with the low power.

You can drill a BARE FR board before it gets copper plated. Then send
it through the through hole plating facility and plate on the needed
copper.

John M...
===============





Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "twb8899" <twb8899@y...> wrote:
>
>
> > What power CO2 laser do you need for cutting 3mm
> steel/brass/aluminium?
> > I've got a two-stage pump that can go to 10^-4 torr. I'm
designing a
> > cnc x-y table...
>
> I had a Mitsubishi CNC Laser for several years and have some
> knowledge of how they work. This machine was a model 1212HC with a
> 3000 watt resonator and 48" x48" cutting table. The entire machine
> installation was the size of two pickup trucks.
>
> We used this machine mainly for cutting small stainless steel and
> acrylic plastic parts. When cutting .060" stainless steel the power
> levels would vary between approximately 400 and 700 watts depending
> on cutting speeds. The CNC program would change power levels when
> needed. Lower power and table speed is used for fine cuts with
higher
> power and feed rates for everything else.
>
> A coaxial beam of cutting gas is always used with CNC CO2 lasers.
We
> used oxygen for most steel and stainless and sometimes nitrogen for
> stainless cutting since it leaves a cleaner cut edge. Clean
> compressed air or nitrogen was used for cutting plastics.
>
> Acrylic plastic cuts well with compressed air and 75 to 150 watts
for
> up to .125" thick and around 200 watts for .250" thick. The power
> level, frequency, duty cycle and gas pressure was fully adjustable
> (even while cutting) and allowed precise control of the cut quality.
>
> Since most of our work was small parts with fine detail we used
short
> focal length lenses. A 5" focal length lense was used for most work
> and a 2" lens was used for super fine cutting on thin materials. A
> 7.5" lens was used on materials over .25" thick and up to .5" thick.
> The longer focal length gave a straight cut through thicker
materials
> but had a wider kerf (cut width) in the material being processed.
>
> One time we tried cutting some FR-4 double sided laminate and it
> didn't work very well. It took about 900 watts to pierce through
the
> top copper layer and then the glass epoxy exploded into a blob
since
> the power level was so high and was also being reflected back from
> the bottom copper layer while piercing it.
>
> Non-ferrous metals such as aluminum, copper and brass take much
> higher powers levels to pierce and cut on a CO2 laser. My
experience
> was that the same power level to cut .375" steel could not even
> pierce through the copper on a circuit board. I don't think the CO2
> laser is the best choice for cutting PWB laminates. Maybe the YAG
> machines will do a better job on circuit boards.
>
> Tom

Re: Yag laser?

2003-06-16 by twb8899

John,

If the 30" lens is working don't change anything unless you really
need a finer cut. The 5" lens will have a smaller kerf width which
would help with very fine inside cuts and detail if you need it. My
laser machine used "cones" to guide the assist gas (compressed air
for most plastics)into the cut. If you do something like this your
results will be even better and you should be able to cut at a higher
feed rate. We used a big dust collector that exhausted to the outside
but the plastic fumes were hard to totally remove.

This Mitsubishi machine was a gantry type with a stationary resonator
and moving optics in the X and Z axis with the work supported on a
moving table for the Y axis. The optical alignment procedure was
somewhat complex and critical for good cutting results. No fiber
optics were used in the optical path in this machine. We did use a
video camera several times to watch the beam since it could "see" at
the IR wavelength of 10.6 microns. There was also a HeNe red laser
for setting up the machine. Some of the bend mirrors were pure
silicon with a gold coating and some were copper with a coating. All
of the mirrors and lenses were liquid cooled.

Tom

--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> Thanks Tom,
> That was very informative.
>
> I only have a 30" fl lens for my CO2. I have good results with
> cutting .125" pvc, acrylic and similar materials. I don't have a
good
> ventillation system, so I avoid too much plastics cutting (at least
> until I get better ventillarion and compressed air system).
>
> Would you say that an investment in a 5" FL lens (or beter) would
do
> a better job for me? I only intend cutting .125" material.
>
> I have tried cutting the FR material, but I get too much charring
> with the low power.
>
> You can drill a BARE FR board before it gets copper plated. Then
send
> it through the through hole plating facility and plate on the
needed
Show quoted textHide quoted text
> copper.
>
> John M...
> ===============

Re: Yag laser?

2003-06-16 by John Myszkowski

Hi Tom,

I wouldn't mind the thinner kerf, also the power/area would increase
as well I suppose.

The air funnel idea is a good one. I've been thinking of implementing
something like that. How much air pressure/flow would you suggest?

I move my work in the X-Y direction (modified plotter). I want to
avoid as many optical paths as possible. In other words, the less
bends the better. I have too little power to spare as it is.

The PCB resist etch idea will probably work fine. All you need to do
is vapourize the thin resist layer. The copper won't be touched (for
obvious reasons). An acrylic cage keeps any stray beams inside the
work area.

I would love to get my hands on one of the high power laser diodes.
They would be perfect for resist etching. It would keep the overall
size of the machine to a desktop size. You could probably retrofit
any XY plotter to work with a laser "pen".

John M...
==============



Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "twb8899" <twb8899@y...> wrote:
> John,
>
> If the 30" lens is working don't change anything unless you really
> need a finer cut. The 5" lens will have a smaller kerf width which
> would help with very fine inside cuts and detail if you need it. My
> laser machine used "cones" to guide the assist gas (compressed air
> for most plastics)into the cut. If you do something like this your
> results will be even better and you should be able to cut at a
higher
> feed rate. We used a big dust collector that exhausted to the
outside
> but the plastic fumes were hard to totally remove.
> ... TOM

Re: Yag laser?

2003-06-16 by twb8899

John,

The cones on our machine were just long enough to accept a screw in
nozzle that put the gas or air output in the focal plane. The screw
in nozzle was made of brass and came with different hole sizes but
the one we used the most was .060 inches. When they wore out I would
put them in a lathe and bore the hole to a larger size, face off the
tip and use them again.

The air or gas pressures were not very high, probably around 10 to 20
psi. You can experiment with this pressure for best results. Your
cutting speed and edge quality will be greatly improved using the
compressed air.

Your moving XY table is the best way to go because trying to align
the beam with the flying optics would be difficult for a hobby setup.
The gantry table allowed a smaller machine footprint but with very
complicated alignment procedures.

I have never tried any kind of engraving or etching of PCB laminates
with a laser but your idea would probably work. Some of the big PCB
lasers use a type of "shadow mask" to drill all of the holes in one
operation. The mask is kind of like a big negative film or metal
plate with clear holes where the laser power comes through and burns
through the laminate. The available laser power is divided across all
of the openings to form the holes. I saw something like this at the
NEPCON show several years ago and it was quite expensive, more than
$600,000.

I would also like to get some high power laser diodes since I have
several really nice CNC controlled XY tables that could be
retrofitted. That would be a great machine to have around for cutting
plastics and wood.

I use dry film photoresist and silk screening for making boards and
will probably not try the laser method. Most of my boards are short
runs on photoresist and I always keep some spare coated panels handy
for a quick job. Any large jobs are run with screen printing.

Tom

--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> Hi Tom,
>
> I wouldn't mind the thinner kerf, also the power/area would
increase
> as well I suppose.
>
> The air funnel idea is a good one. I've been thinking of
implementing
> something like that. How much air pressure/flow would you suggest?
>
> I move my work in the X-Y direction (modified plotter). I want to
> avoid as many optical paths as possible. In other words, the less
> bends the better. I have too little power to spare as it is.
>
> The PCB resist etch idea will probably work fine. All you need to
do
> is vapourize the thin resist layer. The copper won't be touched
(for
Show quoted textHide quoted text
> obvious reasons). An acrylic cage keeps any stray beams inside the
> work area.
>
> I would love to get my hands on one of the high power laser diodes.
> They would be perfect for resist etching. It would keep the overall
> size of the machine to a desktop size. You could probably retrofit
> any XY plotter to work with a laser "pen".
>
> John M...
> ==============

Re: Yag laser?

2003-06-16 by John Myszkowski

Thanks Tom,

That is very useful info. I think I will make a compressed air nozzle
for my laser cutter.

Do you make PCB's for yourself or commercially?

John M...
============




Show quoted textHide quoted text
--- In Homebrew_PCBs@yahoogroups.com, "twb8899" <twb8899@y...> wrote:
> John,
>
> The cones on our machine were just long enough to accept a screw in
> nozzle that put the gas or air output in the focal plane. The screw
> in nozzle was made of brass and came with different hole sizes but
> the one we used the most was .060 inches. When they wore out I
would
> put them in a lathe and bore the hole to a larger size, face off
the
> ...
...
...
...not try the laser method. Most of my boards are short
> runs on photoresist and I always keep some spare coated panels
handy
> for a quick job. Any large jobs are run with screen printing.
>
> Tom
>
>

Re: Yag laser?

2003-06-17 by twb8899

--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> Thanks Tom,
>
> That is very useful info. I think I will make a compressed air
nozzle
Show quoted textHide quoted text
> for my laser cutter.
>
> Do you make PCB's for yourself or commercially?
>
> John M...


John,

I spent over twenty years in the printed circuit business as a
commercial shop. We made all types of rigid boards up to ten layers
and some flex boards as well. My main reason for getting into the
business was to supply boards for my own products. The idea was to
sell off the excess capacity as a job shop and get my boards at cost.

The printed circuit shop grew faster than I ever expected and it
ended up being the main part of my business. The foreign competition
got so bad in later years that I decided to quit as a job shop and go
back to being my own supplier on a much smaller basis. Most of my
boards are small and single sided with surface mount parts. Some of
the boards are RF types with two layers but don't require plated
through holes. Since my requirements are simple I was able to junk,
sell off and give away all of the big equipment while keeping only
what is needed for my production.

Here is the equipment that I now use:

Protel Autotrax (older Dos version)
Lavenir PhotoCam software (Dos,panelization for plotter)
Lavenir RPG-1622 Photoplotter (film generation)
Eskofot vertical process camera
Darkroom trays and timers etc.
Micromat MM470A CNC Drilling and Routing machines (2 units)
Nawide model 281 optical scope drill
Nawide model 281 stylus drill
Aetna Acrodrill with scope and stylus
Aetna Acrorouter (pin router)
Colight DMVL-930 1.5 kW UV exposure unit
Ashdee conveyorized UV curing unit (for soldermask)
Chemcut 315 conveyorized etcher
DuPont C Processor (spray tank for dry film developing)
Niagra and Pexto shears
Misc. silkscreen frames

That's everything I use to make boards and silkscreened control
panels. I have way to many drilling machines but I just couldn't part
with the old Nawide and Aetna machines. I'm kind of attached to them!

Tom

Re: Yag laser?

2003-06-17 by John Myszkowski

Hi Tom,

I used to work at a "job shop" too at one time, for a few years. Many
years ago and for someone other than myself, but I learned quite a
bit. The owner was quite nice and let me learn all about the
bussiness. I would have stayed or got into my own, but for the
terrible smells. After a while it got to the point that I got almost
sick just thinking of the smell... :(

I was actually doing electronic design, so I just moved to a cleaner
place to work. And that was that for the PCB manufacturing experience.

Tom, I do have one question.
What kind of table surface would you suggest for the laser cutter?
I just have a throw away cardboard surface. With the compressed air I
would think there needs to be an exit somewhere, so a metal mesh or a
perforated surface or something with negative air pressure? Is there
something that works the best?

John M...
=============




>
> John,
>
> I spent over twenty years in the printed circuit business as a
> commercial shop. We made all types of rigid boards up to ten layers
> and some flex boards as well. My main reason for getting into the
> business was to supply boards for my own products. The idea was to
> sell off the excess capacity as a job shop and get my boards at
cost.
>
> ...
...
Show quoted textHide quoted text
> TOM

Re: Yag laser?

2003-06-18 by twb8899

John,

I agree with you about the odor in a circuit board plant. The dry
film laminator was the odor that bothered me. We had all kinds of
vents and fume scrubbers but it was still bad news. I keep in touch
with some of the other shops that are still around and they tell me
it's getting real tough to get ammonium hydroxide these days. Can you
imagine exhausting some of those fumes to the outside? The cops would
accuse you of running a meth lab!

My Mitsubishi laser used brass pins about 5" long that supported the
work. They were spread out about 8" apart and screwed into a
supporting framework. These pins were hex shaped and tapered to a
point at the support end. Since they were brass the service life was
very long and we only relaced a few. Non ferrous metals are hard to
cut with a CO2 laser so the brass support pins seem to go forever.
I have seen other types of support systems that used interlocking
sheet metal pieces that were cut with the laser.

We also had a precision pin locating system for fixtures which we
used most of the time for the small parts we made. I liked this method
because we used left over drill backup boards from the Excellon
machines as fixture plates. I would clamp the masonite plate in the
laser table and add about .1 inches or so compensation (G41 or G42)to
the CNC program. Then the masonite was cut using the over compensated
program which cleared a path through the masonite plate for the laser
beam. The blanks to be cut would be taped down over the opening and
cut. It worked good and we got double duty out of the drill backup
boards.

I should mention that we knew the exact XY positions for the tooling
pins and we would cut these holes on the masonite using one of the
Excellon routers. It was real handy to have both machines since we
made laser tooling plates with the Excellon and special routing and
multilayer fixtures with the Mitsubishi laser.

John,we are really off topic on this PWB list so if you would email
me direct we could discuss these details at length.

Tom


--- In Homebrew_PCBs@yahoogroups.com, "John Myszkowski"
<myszka_us2000@y...> wrote:
> Hi Tom,
>
> I used to work at a "job shop" too at one time, for a few years.
Many
> years ago and for someone other than myself, but I learned quite a
> bit. The owner was quite nice and let me learn all about the
> bussiness. I would have stayed or got into my own, but for the
> terrible smells. After a while it got to the point that I got
almost
> sick just thinking of the smell... :(
>
> I was actually doing electronic design, so I just moved to a
cleaner
> place to work. And that was that for the PCB manufacturing
experience.
>
> Tom, I do have one question.
> What kind of table surface would you suggest for the laser cutter?
> I just have a throw away cardboard surface. With the compressed air
I
> would think there needs to be an exit somewhere, so a metal mesh or
a
> perforated surface or something with negative air pressure? Is
there
> something that works the best?
>
> John M...
> =============
>
>
>
>
> >
> > John,
> >
> > I spent over twenty years in the printed circuit business as a
> > commercial shop. We made all types of rigid boards up to ten
layers
> > and some flex boards as well. My main reason for getting into the
> > business was to supply boards for my own products. The idea was
to
Show quoted textHide quoted text
> > sell off the excess capacity as a job shop and get my boards at
> cost.
> >
> > ...
> ...
> > TOM

Re: Yag laser?

2003-06-18 by John Myszkowski

You may be right. The relevancy does seem to stretch a bit thin
here... :)

OKay I will e-mail directly if I have any more questions.

Thanks for the info and for your patience,
John M...
==============




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--- In Homebrew_PCBs@yahoogroups.com, "twb8899" <twb8899@y...> wrote:
> John,
>
> Mitsubishi laser.
> ...
> John,we are really off topic on this PWB list so if you would email
> me direct we could discuss these details at length.
>
> Tom
>
>
>