Homebrew PCBs

Several of you have written of the benefits and good quality that can 
be had by using the photoresist copper clad boards.  You now have my 
interest.

I have some of the raw materials to attempt this method including pre-
sensitized copper clad, and developer.  I even have glass plates to 
keep the transparancy in close contact with the copper.

I do not have a UV light source.  I didn't buy one as I didn't want 
to spend the money.  Some of you have told me that you made a light 
box.  What types of lights/lamps work for exposure?  I saw somewhere 
that a blacklight works.  Is this true?

Our old Diazo machine at work seems to have a long 
flourescent "black" light that it uses to expose diazo paper. 
(BLUELINE MACHINE).  How would I construct a lightbox for exposure?

Most if not all my PCB's are small.  Thje biggest board that I have 
etched was 5x7, so I don't need a giant box.

I don't need any help with making transparancies as I have access to 
a photoplotter (typesetting machine that directly exposes film).  
There are no issues with film growth as there is no heat in the 
process.  There are no issues with pinholes/banding as this is a 
professional imager used to expose printing plates for magazine 
reproduction.  All I must do is output 1-to-1 EPS file and the imager 
does the rest.

So please, if you could help me build a UV light source to expose 
small PCB's, I would appreciate it.

Thanks

Hi,
   Years ago I tried to locate a UV light to erase Eproms. I
got alot of bad info. The Blacklight for posters is not
the right wavelength. UV bulbs look like a clear florescent
light bulb. They used to come with a drop of mercury in them. After
trying to buy one, I found one in a Tropical Fish store. They
are used in a Sterilizer. Water passes past the bulb and the
germs in the water are killed. Do not look at the light while
it is on!!! It may look like it is not bright but it can give
you welders flash! You will wake up 2 o'clock in the morning with
the feeling sand is in your eyes. Be careful!

                                        John




--- In Homebrew_PCBs@y..., "johnman9146" <johnman@d...> wrote:
> Several of you have written of the benefits and good quality that 
can 
> be had by using the photoresist copper clad boards.  You now have 
my 
> interest.
> 
> I have some of the raw materials to attempt this method including 
pre-
> sensitized copper clad, and developer.  I even have glass plates to 
> keep the transparancy in close contact with the copper.
> 
> I do not have a UV light source.  I didn't buy one as I didn't want 
> to spend the money.  Some of you have told me that you made a light 
> box.  What types of lights/lamps work for exposure?  I saw 
somewhere 
> that a blacklight works.  Is this true?
> 
> Our old Diazo machine at work seems to have a long 
> flourescent "black" light that it uses to expose diazo paper. 
> (BLUELINE MACHINE).  How would I construct a lightbox for exposure?
> 
> Most if not all my PCB's are small.  Thje biggest board that I have 
> etched was 5x7, so I don't need a giant box.
> 
> I don't need any help with making transparancies as I have access 
to 
> a photoplotter (typesetting machine that directly exposes film).  
> There are no issues with film growth as there is no heat in the 
> process.  There are no issues with pinholes/banding as this is a 
> professional imager used to expose printing plates for magazine 
> reproduction.  All I must do is output 1-to-1 EPS file and the 
imager 

> does the rest.
> 
> So please, if you could help me build a UV light source to expose 
> small PCB's, I would appreciate it.
> 
> Thanks

--- johnman9146  wrote:
> Several of you have written of the benefits and good quality that
> can 
> be had by using the photoresist copper clad boards.  You now have
> my 
> interest.
-snip-
> So please, if you could help me build a UV light source to expose
> 
> small PCB's, I would appreciate it.

It has been a while since I did photoresist, but I used to use an
incandescent plant grow light. I suspect the fluorescent grow
lights give off more UV.

Steve Greenfield




=====
Steve Greenfield               // Digital photo scanning, retouching,
Polymorph Digital Photography // and photomorphing to your specs.
253/318-2473 voice           // We use the best little computer in
polymorph@...     // the world, the Amiga!
http://www.polyphoto.com/  // Based in Tacoma, WA, USA

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Even better is to get some real flourescent UV bulbs. I got mine from a
local lighting supply house. I just looked for light bulbs in the yellow
pages. The bulbs are F20T12/BL and cost me about $10 per tube when I bought
them last year. They are a 2' long bulb and go into a standard fixture that
I got at Home Depot. I added a 5 minute mechanical timer to control the
exposure.

Tim
[Denver, CO]

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

>
>It has been a while since I did photoresist, but I used to use an
>incandescent plant grow light. I suspect the fluorescent grow
>lights give off more UV.
>
>Steve Greenfield
>
>

It takes only low UV to expose the photoresist used for PCBs. So a
blacklight will work, however, anything that gives off low UV will
work. Like plant grow lights, those slightly bluish lights you can
get even at the hardware store.

Steve Greenfield

--- crankorgan <john@...> wrote:
> Hi,
>    Years ago I tried to locate a UV light to erase Eproms. I
> got alot of bad info. The Blacklight for posters is not
> the right wavelength. UV bulbs look like a clear florescent
> light bulb. They used to come with a drop of mercury in them.
> After
> trying to buy one, I found one in a Tropical Fish store. They
> are used in a Sterilizer. Water passes past the bulb and the
> germs in the water are killed. Do not look at the light while
> it is on!!! It may look like it is not bright but it can give
> you welders flash! You will wake up 2 o'clock in the morning with
> the feeling sand is in your eyes. Be careful!
> 
>                                         John
> 


__________________________________________________
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Yahoo! Tax Center - online filing with TurboTax
http://taxes.yahoo.com/

Hi John,

What you want is called a "germicidal lamp".  It is a clear glass
fluorescent lamp.  Mine is about 14 inches long.  I bought it and a
holder for about $20 (quite some time ago).  Ask for one at an
electrical supply house.

HTH

Alan  KM6VV

johnman9146 wrote:

> 
> <SNIP> 
> I do not have a UV light source.  I didn't buy one as I didn't want
> to spend the money.  Some of you have told me that you made a light
> box.  What types of lights/lamps work for exposure?  I saw somewhere
> that a blacklight works.  Is this true?
> 
> <SNIP>
> So please, if you could help me build a UV light source to expose
> small PCB's, I would appreciate it.
> 
> Thanks
>

I guess the other obvious place to look for these lamps is the supplier you 
use to purchase other PCB-making goods (board, developer, etc.). The 
suppliers I use in the UK for such materials (RS Components, Farnel, Rapid 
Electronics...) sell suitable lamps, and complete exposure units designed 
for the job too.

Regards,
Tony


At 10:23 04/04/2002 -0800, you wrote:

>Hi John,
>
>What you want is called a "germicidal lamp".  It is a clear glass
>fluorescent lamp.  Mine is about 14 inches long.  I bought it and a
>holder for about $20 (quite some time ago).  Ask for one at an
>electrical supply house.
>
>HTH
>
>Alan  KM6VV
>
>johnman9146 wrote:
> >
> > <SNIP>
> > I do not have a UV light source.  I didn't buy one as I didn't want
> > to spend the money.  Some of you have told me that you made a light
> > box.  What types of lights/lamps work for exposure?  I saw somewhere
> > that a blacklight works.  Is this true?
> >
> > <SNIP>
> > So please, if you could help me build a UV light source to expose
> > small PCB's, I would appreciate it.
> >
> > Thanks
> >
>
>
>
>To unsubscribe from this group, send an email to:
>Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

You may be able to get uv lamps from catering suppliers as we use them in uv
fly killers.
Ian

----- Original Message -----
From: "Tony Jeffree" <tony@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, April 04, 2002 7:19 PM
Subject: Re: [Homebrew_PCBs] UV Light Source for Exposing PCB's


> I guess the other obvious place to look for these lamps is the supplier
you
> use to purchase other PCB-making goods (board, developer, etc.). The
> suppliers I use in the UK for such materials (RS Components, Farnel, Rapid
> Electronics...) sell suitable lamps, and complete exposure units designed
> for the job too.
>
> Regards,
> Tony
>
>
> At 10:23 04/04/2002 -0800, you wrote:
> >Hi John,
> >
> >What you want is called a "germicidal lamp".  It is a clear glass
> >fluorescent lamp.  Mine is about 14 inches long.  I bought it and a
> >holder for about $20 (quite some time ago).  Ask for one at an
> >electrical supply house.
> >
> >HTH
> >
> >Alan  KM6VV
> >
> >johnman9146 wrote:
> > >
> > > <SNIP>
> > > I do not have a UV light source.  I didn't buy one as I didn't want
> > > to spend the money.  Some of you have told me that you made a light
> > > box.  What types of lights/lamps work for exposure?  I saw somewhere
> > > that a blacklight works.  Is this true?
> > >
> > > <SNIP>
> > > So please, if you could help me build a UV light source to expose
> > > small PCB's, I would appreciate it.
> > >
> > > Thanks
> > >
> >
> >
> >
> >To unsubscribe from this group, send an email to:
> >Homebrew_PCBs-unsubscribe@yahoogroups.com
> >
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>


---
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Hello Tim,

Thursday, April 04, 2002, 5:25:55 PM, you wrote:

TG> Even better is to get some real flourescent UV bulbs. I got mine from a
TG> local lighting supply house. I just looked for light bulbs in the yellow
TG> pages. The bulbs are F20T12/BL and cost me about $10 per tube when I bought
TG> them last year. They are a 2' long bulb and go into a standard fixture that
TG> I got at Home Depot. I added a 5 minute mechanical timer to control the
TG> exposure.

TG> Tim
TG> [Denver, CO]

And I replied:

  Just my \ufffd 0.02.

  Take a trip to the www.thinktink.com
  There are a lot of info on PCB making. I've made the axposure unit using 2
  Philips  TL20/09N  20W  tubes that are quite radiating in the UV spectrum.
  Peek  output  is  somwhere  arround 340-360nm range. the /09 type of tubes
  have  more UV radiated than /05 type. The tubes are rised approx 20cm from
  the  board covered with the artwork, and the exposure time that I use is 8
  minutes  (still  have to obtain the Stoufer gauge to determine the correct
  time),  but  nevertheless,  the boards that I make are always well exposed
  (covered with 2mm thick ordihary glass).
  The whole unit costed me arround $ 20 (DM 50.-) as follows:

  * Philips TL20/09N                                   DM 10.-
  * Balasts 20W                                        DM 10.-
  * Chipwood for box                                   DM 10.-
  * Various screws, nuts, washers                      DM  4.-
  * Starters for fluorescent lamps                     DM  2.-
  * Power cable                                        DM  2.-
  * PVC pipe 110mm dia 1m length                       DM  3.-
  * Al foil for reflectors                             DM  1.-
                            TOTAL                      DM 42.-

-- 
 Best Regards,
 Zoran A. Scepanovic
 mailto:zasto@...
 http://zasto.bizhosting.com

Hello crankorgan,

Thursday, April 04, 2002, 2:57:25 PM, you wrote:

c> Hi,
c>    Years ago I tried to locate a UV light to erase Eproms. I
c> got alot of bad info. The Blacklight for posters is not
c> the right wavelength. UV bulbs look like a clear florescent
c> light bulb. They used to come with a drop of mercury in them. After
c> trying to buy one, I found one in a Tropical Fish store. They
c> are used in a Sterilizer. Water passes past the bulb and the
c> germs in the water are killed. Do not look at the light while
c> it is on!!! It may look like it is not bright but it can give
c> you welders flash! You will wake up 2 o'clock in the morning with
c> the feeling sand is in your eyes. Be careful!

c>                                         John

And I replied:

  And much worse things can happen if your tiny grey cells are on vacation:

  A nurse in one hospital thaught that she could gain some sun-tan under the
  germicidal  lamp,  so  she  went  to  a room where some of the laundry was
  stored  and  layed  down for about half hour, intremittantly observing the
  'not  so  intense'  blue light which in fact is almost pure UV-C (peak for
  germicidal lamps is arround 237nm - ideal for UV-EPROM erasing).
  She  was severe burnt and her staring to the lamp gaved her 60% sight loss
  (permanent).

-- 
 Best Regards,
 Zoran A. Scepanovic
 mailto:zasto@...
 http://zasto.bizhosting.com

>
>
>
>So please, if you could help me build a UV light source to expose 
>small PCB's, I would appreciate it.
>
>Thanks
>

there was a recent thread on aus.electronics USENET group about this.
search subject "UV Light Box Plans" in 
 http://groups.google.com/groups?num=25&hl=en&group=aus.electronics&safe=off&start=25

For my UV source I use 400W standard HID mercury vapor flood lamp. 
Exposure is 90 sec at 400 mm distance from the lamp. 175 W would be more 
suitable.

Actualy the germicidal lamp tube is made of quartz not glass and thats why
the cost so much.

Glass in general is not very transparent to UV.

Had mine since the days of th PROM burner for the Altair 8800.


Hugh

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

From: "Alan Marconett KM6VV" <KM6VV@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Thursday, April 04, 2002 12:23 PM
Subject: Re: [Homebrew_PCBs] UV Light Source for Exposing PCB's


> Hi John,
>
> What you want is called a "germicidal lamp".  It is a clear glass
> fluorescent lamp.  Mine is about 14 inches long.  I bought it and a
> holder for about $20 (quite some time ago).  Ask for one at an
> electrical supply house.
>
> HTH
>
> Alan  KM6VV
>
> johnman9146 wrote:
> >
> > <SNIP>
> > I do not have a UV light source.  I didn't buy one as I didn't want
> > to spend the money.  Some of you have told me that you made a light
> > box.  What types of lights/lamps work for exposure?  I saw somewhere
> > that a blacklight works.  Is this true?
> >
> > <SNIP>
> > So please, if you could help me build a UV light source to expose
> > small PCB's, I would appreciate it.
> >
> > Thanks
> >
>
>
>
> To unsubscribe from this group, send an email to:
> Homebrew_PCBs-unsubscribe@yahoogroups.com
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>

Hi Hugh,

Yes, quite true!  I'd forgotten about that!  and I'm with you on the
Altair's too.  I have a pair still stashed in the garage.  I've used my
lamp for erasing EPROMS for years, and recently for erasing PIC's.

And for others reading, just operate the lamp in a box, or in a spare
bathroom/photolab (I hang a warning sign on the door!).  As has been
noted, it's dangerous to expose your eyes to the light, and no doubt
will also cause severe sunburns.

Alan  KM6VV


Hugh Prescott wrote:

> 
> Actualy the germicidal lamp tube is made of quartz not glass and thats why
> the cost so much.
> 
> Glass in general is not very transparent to UV.
> 
> Had mine since the days of th PROM burner for the Altair 8800.
> 
> Hugh
> 
> ----- Original Message -----
> From: "Alan Marconett KM6VV" <KM6VV@...>
> To: <Homebrew_PCBs@yahoogroups.com>
> Sent: Thursday, April 04, 2002 12:23 PM
> Subject: Re: [Homebrew_PCBs] UV Light Source for Exposing PCB's
> 
> > Hi John,
> >
> > What you want is called a "germicidal lamp".  It is a clear glass
> > fluorescent lamp.  Mine is about 14 inches long.  I bought it and a
> > holder for about $20 (quite some time ago).  Ask for one at an
> > electrical supply house.
> >
> > HTH
> >
> > Alan  KM6VV
> >
> > johnman9146 wrote:
> > >
> > > <SNIP>
> > > I do not have a UV light source.  I didn't buy one as I didn't want
> > > to spend the money.  Some of you have told me that you made a light
> > > box.  What types of lights/lamps work for exposure?  I saw somewhere
> > > that a blacklight works.  Is this true?
> > >
> > > <SNIP>
> > > So please, if you could help me build a UV light source to expose
> > > small PCB's, I would appreciate it.
> > >
> > > Thanks

>And for others reading, just operate the lamp in a box, or in a spare
>bathroom/photolab (I hang a warning sign on the door!).  As has been
>noted, it's dangerous to expose your eyes to the light, and no doubt
>will also cause severe sunburns.
>
>Alan  KM6VV

Gotta chirp in the middle here ;-]

I purchased a metal tool box, a germ light, and a electric timer a few years
back. I wired the whole thing up inside so that when close the lamp
is located just above the removable tray which has some contact foam
glued in place. I put the parts to be exposed/erased on the foam, close the lid
(which still has the padlock hasp on it if needed), plug it into the socket,
give the timer a twist and wait till it goes ding.

The lid seals well enough that no light escapes but a strip of door seal would
fix a toolbox with a poor fit. Other than the timer knob and the cord 
everything
fits inside the box and is protected. When done with it will easily stuff 
into a
closet. If you are doing stuff at home and have prying little fingers about 
aka
mutant rugrats aka kids you can put a lock on the hasp walk away from it
and not worry about them getting hurt or exposed.

I can't rem what the timer was from but it went to 45 or 60 minutes. Anyway 
this
has worked quite well for big and small batches for 11 years (getting old)

Dave

Hi Dave,

Yeah, my kids are grown up!  In fact, the oldest is in grad school, and
borrowed my "eraser", and my PIC programmer!  I got my lamp in '77, so I
think it's paid for it's self!

Your box sounds good.  I'll get around to it!

Alan  KM6VV


Dave King wrote:

> 
> >And for others reading, just operate the lamp in a box, or in a spare
> >bathroom/photolab (I hang a warning sign on the door!).  As has been
> >noted, it's dangerous to expose your eyes to the light, and no doubt
> >will also cause severe sunburns.
> >
> >Alan  KM6VV
> 
> Gotta chirp in the middle here ;-]
> 
> I purchased a metal tool box, a germ light, and a electric timer a few years
> back. I wired the whole thing up inside so that when close the lamp
> is located just above the removable tray which has some contact foam
> glued in place. I put the parts to be exposed/erased on the foam, close the lid
> (which still has the padlock hasp on it if needed), plug it into the socket,
> give the timer a twist and wait till it goes ding.
> 
> The lid seals well enough that no light escapes but a strip of door seal would
> fix a toolbox with a poor fit. Other than the timer knob and the cord
> everything
> fits inside the box and is protected. When done with it will easily stuff
> into a
> closet. If you are doing stuff at home and have prying little fingers about
> aka
> mutant rugrats aka kids you can put a lock on the hasp walk away from it
> and not worry about them getting hurt or exposed.
> 
> I can't rem what the timer was from but it went to 45 or 60 minutes. Anyway
> this
> has worked quite well for big and small batches for 11 years (getting old)
> 
> Dave