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PICList Thread
'[EE]: Making PCBs...'
2002\03\06@124032 by Pic Dude

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Couldn't find a good answer to this in the archives or web, so...

Trying to figure out how to make professional-quality PCB's at home.
These will be one-offs, so I'm avoiding the option of using a PCB service.
But I would like them to look professional.

The Ferric Chloride etch method is great, and I have all the stuff for
that, but I always have 2 problems: drilling holes neatly, and laying
out the pattern onto the board.

For the holes, I've circumvented the problem by surface-mounting my
components.  It takes up a little more space, but I can mount one
circuit on top, and another on the back of the PCB, so I can actually
save space.  For more complex circuits requiring a dual-sided PCB,
this is not so great though.  Here's an example...
http://www.avn-tech.com/stuff/speedo_conv_pcb.jpg

The real problem is laying out the pattern on the board. I can draw
some nice board layouts using a CAD program etc, but I've been using
rub-on transfers to create the circuit, and it never looks professional.
Been looking at the photo-sensitive board process, but that probably
means I need a laser printer.  Most photo-copier places won't let me
put any special paper in their machines.

However, I've heard/read that with the photo-sensitive process, once
I get a transparency with the circuit on it, I can lay the pattern out
under the sun, and don't even need a UV lamp.  (Lots of sun here
in Texas!)

I've seen the iron-on transfer system, but from the instructions, they
seem like they would be a major hassle to get perfect.

Any thoughts, or options I may be missing here? My priorities are low
equipment/materials cost.  Labor is not a problem ... see, getting
laid-off is not all bad.   :-)


Cheers.

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2002\03\06@125222 by Nick Veys

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For ease, nothing beats the iron-on transfer method.  You can use glossy
ink jet paper, laser print the layout on it and iron it onto the
copper-clad.  It takes a bit of finesse but once you figure it out you
can get pretty fine traces on there consistantly.

The light-sensitive transfer methods work too, but the boards are more
expensive...

As far as drilling holes?  Use a layout program that will put a hole in
the pad for you, then your drill just slips in and you can't possibly
make a mistake without trying.  I use a Dremel with tiny bits, but a
normal drill would work too.

For layout software, I highly recommend Eagle (http://www.cadsoft.de).  Their
trial version is fully featured, doesn't expire, or nag.  Just has a
size and quantity limit for boards, which is almost always big enough
for hobby projects.  It has an autorouter, etc...  Very nice for what it
is.  Learning curve isn't sharp at all either.

.....nickKILLspamspam@spam@veys.com | http://www.veys.com/nick

> {Original Message removed}

2002\03\06@133647 by mike

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On Wed, 6 Mar 2002 11:47:53 -0600, you wrote:

>Couldn't find a good answer to this in the archives or web, so...
http://www.netcomuk.co.uk/~wwl/pcbs.html has tons of info on making good homebrew PCBs.

>The real problem is laying out the pattern on the board. I can draw
>some nice board layouts using a CAD program etc, but I've been using
>rub-on transfers to create the circuit, and it never looks professional.
>Been looking at the photo-sensitive board process, but that probably
>means I need a laser printer.  Most photo-copier places won't let me
Laser print on Tracing paper, with UV exposure on presensitised
laminate.  I've heard of good results on certain inkjets as well, but
used lasers are very cheap nowadays. You need 600DPI.

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2002\03\06@141623 by Colin Constant

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All is not lost if you just have an inkjet printer.  In the past, I've printed
the pattern on special inkjet overhead transparency film.  You have to fiddle
with the settings but it can work really well.  As a bonus you can print a
multi-colour "silk screen" layer to glue on.  However, inkjet transparency film
tends to be pricey.

Or, you can just print on high quality inkjet paper, and get a photocopy place
to copy it onto transparency film.

For drilling I use a Dremel single speed (these are said to run at 35,000 now)
and drill press accessory. I made a little transfer table to keep the holes
lined up.  I use a 1/32 in. drill in a 1/32 in. collet for most stuff.

In the drawing, I like to use a 0.01 hole size for all pads, to help line up
the drill.

Hope this helps a little,
Colin

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2002\03\06@142703 by Mitch Miller

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On Wed, 6 Mar 2002, Pic Dude wrote:

> Couldn't find a good answer to this in the archives or web, so...
>
> The Ferric Chloride etch method is great, and I have all the stuff for

That's mostly what I use, too.  Works great, and even better if you warm
it slightly.

> that, but I always have 2 problems: drilling holes neatly,

I use a Dremel tool with the Dremel brand drill press, and an appropriatly
sized carbide bit.  Works GREAT!

> and laying out the pattern onto the board.

I've used Eagle for my board layout (although it took me quite a while to
become proficient with it), and print using an injket printer to an inkjet
style transparency.  Then I use the photosensitive process for exposing
and printing the board.

>
> For the holes, I've circumvented the problem by surface-mounting my
> components.  It takes up a little more space, but I can mount one
> circuit on top, and another on the back of the PCB, so I can actually
> save space.

I've had good luck with some 1208 and 0806 components, even some 0603
parts, and usually save space.

For more complex circuits requiring a dual-sided PCB,
> this is not so great though.  Here's an example...
> http://www.avn-tech.com/stuff/speedo_conv_pcb.jpg

So far, I've been able to get what I need to do on a single-sided board.
Haven't tried DS yet.

-- Mitch

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2002\03\06@143456 by Simon-Thijs=20de=20Feber?=

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I make my layout with protel98, a crakced version.
Such a tool is to my opinion a must.

From Protel i print my layouts to PDF so i can print
them at work on a good laser printer.
The paper i use is X-Y stable and can be bought from
different electronic stores (elecexp.com has it).
The paper is quite expensive 1 dollar a piece but it
is worth it.
Exposure i do with a facial suntan light (or how do
you call them). Nothing fancy so far.

With single sided PCB's you just place the PCB and
layout under a glass frame (photo frame with glass).
This ensures that the film is evenly pressed onto the
PCB, apply some pressure to it.

When doing dubble sided;
Take a spare of PCB and tape on ech side the layout.
First stick one side then align the secodn to the
first before taping.
You've a sandwich now where in between you can stick
your to be exposed PCB.
Take a fewmore pieces of tape and stick them on
strategic places on the layout and to be exposed PCB.
This ensures that it is stable when turning teh PCB
when doing the second exposure.
3 to 4 minutes exposure is for my kind of PCB's fine.

developing can be done with standard stuff from your
el. store.

Etching i do with some other stuff then that ferro
chloride. It leaves nasty orange brown staines ;-) .
The stuff i use it saltlike. I will try to find out.
When the stuff is at 40-50 degree celsius , it works
best. Use an air pump to move the water.

The results are good. 12 mil traces are fine and i can
make ssop foorprints just great.

via's are a problem. just take a piece of wire and
solder on both sides !


grtz

Simon























--- Pic Dude <picdudespamspam_OUTAVN-TECH.COM> wrote: > Couldn't
find a good answer to this in the archives
{Quote hidden}

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2002\03\06@145415 by Rick C.

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I've been making hunderds of pcb's at home for the last 30 years. They look
professional. I even make engineering prototype boards for some of the
companys in the area.

Here's my technique:
Use a good cad program to lay out your board. I started out with Wintek's
Smartwork. Then graduated to Tango which I use today. It runs in DOS or a
Windows shell. There is a Windows version but I like the DOS version. Before
CAD, I used the old cut and paste tape layout on mylar. I made hundreds of
double sided boards that way.

All artwork  was outputted 2:1 (twice the size). I then took the artwork down
to the local printers in town and had them reduce it to a negative film. A 12"
X 12" film cost me about $14.00 to produce. Smaller sizes I could have done
for about $6.00. Find a good small printing shop in your town and make friends
with the cameraman. Sometines I could have the artwork reduced while I waited.
In and out in 10 minutes!

I used to sensitize my own boards and still do but I like the consistancy of
Kepro's boards. http://www.kepro.com
A 12X12 single sided board is part # S1-1212G. You can buy smaller pieces but
the big ones are cheaper per sq in. The cost of the material is a little high
but the consistency is better.
Boards are here: http://www.kepro.com/cclad-s.htm
I use an old paper cutter to cut the size board I need. Just cut it about 1/4
inch larger all around.
A local photo shop is where you will find a contact frame to hold the film
against the board for exposure. Expose the board for about 12 minutes under a
#2 photoflood. Develop the board with methelyene chloride or the stuff Kepro
sells. I think its Tolulene.

I use Sodium Persulfate (or Amonium Persulfate) also available from Kepro for
etching. Ferric Chloride is messy, stains and is hard to dispose of. S.P. is
clear and looks like blue Windex glass cleaner when spent. I etch the board in
a glass dish with a heat lamp overhead or hot plate under it. It takes about
10 minutes to etch.

Once etched, I use some old developer solvent to remove the resist. Some
people leave the resist on the board to keep it shiny but it's a little harder
to get solder to flow onto the pad if you're not careful.

I use a Dremel drill and drill press to drill the holes. Use a good carbide
bit to drill clean holes. Bits are also available from Kepro. #67 (.032") bit
for most components and #65 (.035) for headers and 1N4001 size leads.

I use a variac to slow the speed down on the drill. No need to run it at
10,000 rpm when a third of that will still cut a smooth hole. Just be careful,
the bits are fragile and will snap if you look at them wrong. I still have two
bits I've been using for over 10 years! Still sharp.

A small table top circular/belt sander will finish the edges to professional
looks.

If anyone wants, I'll put pictures and directions on the web for those that
want to see the process more clearly.

Good luck,
Rick


Pic Dude wrote:

{Quote hidden}

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2002\03\06@145823 by Joan Ilari

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I also make use of the iron transfer method, the same trick to drill holes,
the same software and I am completely satisfied.

Joan

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2002\03\06@163356 by Paul Hutchinson

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> I make my layout with protel98, a crakced version.
> Such a tool is to my opinion a must.

I agree, a good PCB CAD package is a must but...

Stealing software is just plain wrong.

Telling everyone about the piracy in a public forum like the PICList is not
a good idea. I'm tempted to forward your message with email address intact
to Protel but, I won't.

Paul
A worker at a company that buys Protel software.

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2002\03\06@171155 by Pic Dude

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Awesome info.  I'll summarize the responses here.  Keep in mind
that I only make about 3 or 4 PCB's per year, so my choices are
based on this super-low-volume.

- Layout:  Eagle seems to be the popular choice, and I actually
have/use it.  Like Vern Jones though, I've also used Visio in the
past with nice results.  However, UNLIKE Simon-Thijs de
Feber, I don't use cracked SW.  I'll stick with Eagle.

- Transfer to PCB:  Here's the critical part.  Most of the options
require a good printer.  Even with an inkjet process, I may need
to upgrade cause 600dpi is recommended.  I like Rick C's idea
of printing 2:1 and scaling down on a copier.  I might pick up some
inkjet transparencies to test what quality I get with my 18th-
century 300-dpi DJ500.  Where I live now, it's a bit remote from
a lot of services (like the nearest Kinko's is 17 miles away), and
I generally do this stuff late at night, so I prefer to be self-sufficient.
That said, I'll avoid the camera/negative-film processes.  Also, it
seems that my fear of the dry iron-on system is a bit unwarranted,
so I'm going to try that first -- I'll either find a friend with a laser
printer, or see if Mail Boxes etc will let me copy onto it.  If that
does not work so well for me, I'll try transparencies and invest
in some UV lamps, etc.

- Etching:  Ferric chloride.  Got all that, heat lamps, etc.  No need
to change this.

- Drilling:  Seems all I need is a good drill press for my Roto-Zip,
so I might actually start making my boards the real way (with
holes).  :-)  I do however, save a bunch of costs with my
pseudo-surface-mount technology using NON-SMT components.

Questions:
- With the dry-transfer system, I'll be printing on the glossy side,
right?  If so, that means I need to mirror my image then, right?

- What's a good source for the small (1/32") drill bits.

- What about cutting boards?  I just use a hacksaw, but it takes
some work to get it straight.  Anything better/easier?


Thanks much everyone!
-Neil.





{Original Message removed}

'[OT]: Re: [EE]: Making PCBs...'
2002\03\06@171659 by Tony Nixon

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Paul Hutchinson wrote:
>
> > I make my layout with protel98, a crakced version.
> > Such a tool is to my opinion a must.
>
> I agree, a good PCB CAD package is a must but...
>
> Stealing software is just plain wrong.
>
> Telling everyone about the piracy in a public forum like the PICList is not
> a good idea. I'm tempted to forward your message with email address intact
> to Protel but, I won't.
>
> Paul
> A worker at a company that buys Protel software.

It won't make any difference. I approached Protel once and they simply
don't care as they know there are cracks out there for thier products.
That's something you can't stop.

--
Best regards

Tony

mICros
http://www.bubblesoftonline.com
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'[EE]: Making PCBs...'
2002\03\06@173750 by Joan Ilari

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Nick,

I have seen your page explaining the pcb manufacturing process : VERY GOOD !
(http://www.veys.com/nick/electronics_tutorials/howto/tut2/ )
It is a pity I haven't seen it a couple of years ago when I started with
this
method to manufacture my pcbs ! It would have spared me a lot of trial and
error hours :-(

I STRONGLY RECOMMEND THIS METHOD to anyone home-making his/her pcbs !

Some points about the process that I would like to highlight :

- To take out the toner when the pcb is finished it is much easier to use
acetone (industrial or even of the kind the women use for removing the
paint from the nails : more expensive) than grinding the pcb.

- It is very important to use the appropriate paper. Do not spare on the
paper : with glossy photoprint paper the success is guaranteed. I can make
pcbs with tracks going through 2 IC pads (2.54 mm distance) without too
much trouble.

- As a reference : stay with the iron (full power) over the pcb board face
up
covered with a piece of cloth 1.5 minutes, moving the iron so as to achieve
a more uniform heating (not all the iron base has the same temperature) and
strongly press the iron against the board. Do not stay too much time or you
risk the toner spreading too much and getting tracks too wide.

- To remove the paper it is better (according to my experience) to use very
hot water instead of cold water. In a couple of minutes the paper peels-off
without having to touch at it.

>
> For ease, nothing beats the iron-on transfer method.  You can use glossy
> ink jet paper, laser print the layout on it and iron it onto the
> copper-clad.  It takes a bit of finesse but once you figure it out you
> can get pretty fine traces on there consistantly.
>

Cheers


  Joan Ilari

  Barcelona (Spain)    Tel. +34 93 431 96 39
  RemoveMEjoanEraseMEspamEraseMEilari.org

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2002\03\06@175642 by chucksea

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What's a good source for Ammonium Persulphate?

Digi-key doesn't have it listed and I haven't found it locally yet.

thanks
chuckc

{Original Message removed}

2002\03\06@180307 by Rick C.

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I used to buy it at "hamfests" years ago but it seems a little scarce. Sodium
Persulfate is also available at Kepro.
http://www.kepro.com/chemetch.htm
Rick

chucksea wrote:

> What's a good source for Ammonium Persulphate?
>
> Digi-key doesn't have it listed and I haven't found it locally yet.
>
> thanks
> chuckc
>
> {Original Message removed}

2002\03\06@180323 by Chris Loiacono

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>
> - To take out the toner when the pcb is finished it is much
> easier to use
> acetone (industrial or even of the kind the women use for removing the
> paint from the nails : more expensive) than grinding the pcb.

Acetone and similar hydrocarbon solvents will break down the pcb resin of
many glass and paper composites. That surface will then invite contaminants,
including whatever you washed off with it - a good reason why all the
packaged transfer systems suggest scrubbing.
{Quote hidden}

As the toner heats more & more, the viscosity drops, allowing the pressure
from
the iron to spread it farther. If the temperature is controlled between 420
& 450 deg F.
and the pressure on the iron doesn't change, the traces should spreadless
than 5 mils.
How about movement of the transfer image while moving the iron?
I have done this w/o moving the iron (small boards only, of course) then
applying even
pressure with a small brayer to ensure good transfer.


>
> - To remove the paper it is better (according to my
> experience) to use very
> hot water instead of cold water. In a couple of minutes the
> paper peels-off
> without having to touch at it.

I think the cold water is intended to "set" the toner by cooling it rapidly.
But I'm sure hot water removes the paper better. I have done cold, then hot.
>
> >
> > For ease, nothing beats the iron-on transfer method.  You
> can use glossy
> > ink jet paper, laser print the layout on it and iron it onto the
> > copper-clad.  It takes a bit of finesse but once you figure
> it out you
> > can get pretty fine traces on there consistantly.

The blue stuff seems to be pretty reliable also, but nothing beats Advanced
circuits doing them 2 up for $28 US with silk and mask with real through
holes. Nobody on tis list can set up to do an iron on board for the
equivalent cost in time. I figured the last iron on board I did, at about
1.25 x 2 cost me about the equivalent of $750 in billable time. Now I will
only do thismethod when I have nothing else to do.

PS, thanks for the nice description & summary.

Chris
> >
>

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2002\03\06@180515 by Rick C.

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P.S. Sodium Persulphate comes as a white powder like salt. Really safe to
handle. Just mix a few teaspoons with water, drip a drop of catalyst into it and
you're ready to go.
Rick

chucksea wrote:

> What's a good source for Ammonium Persulphate?
>
> Digi-key doesn't have it listed and I haven't found it locally yet.
>
> thanks
> chuckc
>
> {Original Message removed}

2002\03\06@182025 by Dan Larson

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injectorall.com


They have all of the supplies you need. They also sell their blank
sensitied boards through digi-key, though you still need to buy chemicals
from them. I am using their process with good success down to .01". It
took a some experimenting to get it right, but I learned few things that
can save you the trouble:

1) Use a *real* UVB bulb. (FT8-15 BL {white coating, similar to
                          grow lights}, *NOT* FT8-15 BLB {black light for posters})
2) Fresh chemicals
3) Heated solution ( I place my etchign tank in a tub full of hot water,
                    using one of those plastic Rubber-Maid "cereal"
                    containers.)
4) Aggitated solution (I use a fish tank air pump and air stone)


I am printing my transparencies on a laser printer using 3m laser transparencies.
I do my layouts with Eagle CAD.

Good luck!

Dan
KC0LUY

On Wed, 6 Mar 2002 16:58:53 -0600, chucksea wrote:

>What's a good source for Ammonium Persulphate?
>
>Digi-key doesn't have it listed and I haven't found it locally yet.
>

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2002\03\06@184017 by Mike Mansheim

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> - Transfer to PCB:  Here's the critical part.  Most of the options
> require a good printer.  Even with an inkjet process, I may need
> to upgrade cause 600dpi is recommended.  I like Rick C's idea
> of printing 2:1 and scaling down on a copier.  I might pick up some
> inkjet transparencies to test what quality I get with my 18th-
> century 300-dpi DJ500.  Where I live now, it's a bit remote from
> a lot of services (like the nearest Kinko's is 17 miles away), and
> I generally do this stuff late at night, so I prefer to be
> self-sufficient.

You could scale a 2:1 inkjet output onto a transparency at Kinko's, plus
Kinko's (at least the ones around here) are open 24 hours.  You could
print and be ready with a transparency in less than an hour at any time
of the day or night.

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2002\03\06@190320 by Vern Jones

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Try web_tronics   http://www.web-tronics.com

Vern

chucksea wrote:
>
> What's a good source for Ammonium Persulphate?
>
> Digi-key doesn't have it listed and I haven't found it locally yet.
>
> thanks
> chuckc
>
> {Original Message removed}

2002\03\06@190512 by Herbert Graf

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> -----Original Message-----
> From: pic microcontroller discussion list
> [PICLISTSTOPspamspamspam_OUTMITVMA.MIT.EDU]On Behalf Of Paul Hutchinson
> Sent: Wednesday, March 06, 2002 16:31
> To: spamBeGonePICLISTSTOPspamspamEraseMEMITVMA.MIT.EDU
> Subject: Re: [EE]: Making PCBs...
>
>
> > I make my layout with protel98, a crakced version.
> > Such a tool is to my opinion a must.
>
> I agree, a good PCB CAD package is a must but...
>
> Stealing software is just plain wrong.
>
> Telling everyone about the piracy in a public forum like the
> PICList is not
> a good idea. I'm tempted to forward your message with email address intact
> to Protel but, I won't.

       FWIW I don't believe forwarding the message to Protel would do anything,
while they certainly would care they will almost certainly not see it worth
pursuing. TTYL

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2002\03\06@191750 by Rick C.

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I hope I didn't scare everyone away from the idea of using a film
transparency for making pcb's. Actually it's one of the easiest parts of
making a pcb. This can be done for one board or a hundred. Plus, you can
keep it for years and still use it over again. I can go from a schematic
designed in the morning to an etched, drilled, stuffed and working project
board (~100 parts) in the same morning!

Just print your circuit board to your printer 2X. If the print spans two
pages, just cut and cellophane tape the board prints together. Sometimes
I'll put 4 to 6 small layouts (same or different circuits) on one page. One
suggestion also, put text on the circuit side so you know which way you
expose the board. I put the project name and version on the board and
elsewhere I put a date code (RC020306) for today. This way if you make a
second or more revision, you know which was the last. I learned the hard way
when I made 20 boards of a previous version and had to eat them.

Finding a printer in town is pretty easy too. Just about every print shop
has a floor camera to make the negative. Local newspapers have them too.
Like I said in a previous post, make friends with the camera man and you can
probably have it made while you wait. Just have them make a "50% reduction
to a negative film" such as Kodalith Ortho Type III or equivalent. Make sure
they expose it "read side down". This way if you look at the emulsion side
(the dull side), the printing looks reversed (mirrored). That's all there is
to it!
Rick


Mike Mansheim wrote:

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2002\03\06@193034 by Colin Constant

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Please respond to pic microcontroller discussion list <spamBeGonePICLISTspamKILLspamMITVMA.MIT.EDU>

Sent by:    pic microcontroller discussion list <.....PICLISTspam_OUTspamMITVMA.MIT.EDU>


To:    TakeThisOuTPICLIST.....spamTakeThisOuTMITVMA.MIT.EDU
cc:     (bcc: Colin Constant-NR/RMD/Raytheon/CA)

     I'll try transparencies and invest
     in some UV lamps, etc.

You might not need UV lamps.  The brand of boards I use (MG Chemicals) used to
be UV sensitive and I used a halogen desk lamp. They've changed to fluorescent
sensitive so now I have a fluorescent desk lamp.

     Questions:
     - With the dry-transfer system, I'll be printing on the glossy side,
     right?  If so, that means I need to mirror my image then, right?

No. You draw the pattern looking at the top of the board (actually, through the
top of the board) and when you print, you place the ink side against the bottom
of the board; so it's right way up. Same for photo method.

     - What's a good source for the small (1/32") drill bits.

I get mine at Home Hardware here.  They have them in HSS and carbide.

     - What about cutting boards?  I just use a hacksaw, but it takes
     some work to get it straight.  Anything better/easier?


I've used a hacksaw and miter box, and the paper cutter.  Paper cutter wins.
I'm about to experiment with a Dremel and cutoff wheel. They make standard,
fibreglass re-enforced, carbide, and diamond.


     Thanks much everyone!
     -Neil.

Colin





{Original Message removed}

2002\03\06@194142 by Bill Brooks

flavicon
face
> I've used a hacksaw and miter box, and the paper cutter.  Paper cutter
wins.
> I'm about to experiment with a Dremel and cutoff wheel. They make
standard,
> fibreglass re-enforced, carbide, and diamond.

I've used a cutoff wheel with my Dremel, and decided to try something else
next time.  At least when I tried it, there was WAY too much dust created,
and
that stuff can't be healthy.

I've never thought of a paper cutter, and I would've thought the boards too
brittle for that.  I'm definitely giving that a shot next time!

Thanks for all the great tips!

Bill.

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2002\03\06@201315 by kent

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face
Hi all,

I make double sided PCBs with a very simple technique.

1) Print both sides on a transparency with a HP deskjet (710C in my case)
Set for monochrome, manual contrast, max ink and best quality = drenched in ink.
Dry slow under a lamp (20 cm/60W) and AVOID FINGERPRINTS.

2) Expose a double sided photosensitive PCB on one side, develop and etch.
The type that Future Active sells is fine. Or Newark. Or Farnell.

3) Rinse, dry.

4) Drill a few marker holes, fit the other side of the PCB using these. Fix with tape.

5) Cover the etched side with the protective plastic that covered the side originally.
(The other side will have holes in it)

6) Expose, develop, etch.

Buy (BUY) a print layout program with an autorouter that does not have an affinity
for vias.

The resolution of this method is good for 10-12 mil tracks and gaps.

Kent

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2002\03\06@210922 by Olin Lathrop

face picon face
> The blue stuff seems to be pretty reliable also, but nothing beats
Advanced
> circuits doing them 2 up for $28 US with silk and mask with real through
> holes. Nobody on tis list can set up to do an iron on board for the
> equivalent cost in time. I figured the last iron on board I did, at about
> 1.25 x 2 cost me about the equivalent of $750 in billable time. Now I will
> only do thismethod when I have nothing else to do.

You should also check out http://www.pcbexpress.com.  They have the best prices
I've found for prototype quantities if you want solder mask on one side and
silk screen on the top.  The places that advertise real cheap boards just
want to give you bare copper, or aren't so competitive anymore after they
add solder mask and silk screen.


********************************************************************
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(978) 742-9014, RemoveMEolinspamspamBeGoneembedinc.com, http://www.embedinc.com

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2002\03\06@211130 by Pic Dude

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>  ...  They've changed to fluorescent
> sensitive so now I have a fluorescent desk lamp. ...

Sweet!

> I've used a hacksaw and miter box, and the paper cutter.  Paper cutter
wins.

You mean a paper guillotine!?!?!?  If that's what you mean, it would be
awesome, especially since I can never get it to cut paper perfectly straight
anyway.

Cheers.


{Original Message removed}

2002\03\06@230103 by Nick Veys

flavicon
face
Not neccessarily off-topic.  Researching PCB houses like Advanced
Circuits, I'm trying to get an exact value for the MIL measurement.
I've found multiple conflicting sources, some saying 1mil = .001" and
others saying 1mil = 1um.

Just wondering if someone can clear that up for me. :)  Thanks!

TakeThisOuTnickspamspamveys.com | http://www.veys.com/nick

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2002\03\06@231112 by Sean H. Breheny

face picon face
Hi Nick,

1 mil, in the PCB context, is definitely .001 inch. In machining, I think
it is now called a thou it avoid confusion with millimeter or micrometer.

Sean

At 09:57 PM 3/6/02 -0600, you wrote:
{Quote hidden}

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2002\03\07@004422 by Dave King

flavicon
face
At 04:44 PM 3/6/02 -0800, you wrote:
> > I've used a hacksaw and miter box, and the paper cutter.  Paper cutter
>wins.
> > I'm about to experiment with a Dremel and cutoff wheel. They make
>standard,
> > fibreglass re-enforced, carbide, and diamond.
>
>I've used a cutoff wheel with my Dremel, and decided to try something else
>next time.  At least when I tried it, there was WAY too much dust created,
>and
>that stuff can't be healthy.
>
>I've never thought of a paper cutter, and I would've thought the boards too
>brittle for that.  I'm definitely giving that a shot next time!
>
>Thanks for all the great tips!
>
>Bill.

If you want to really cut em apart borrow a metal shear. Way back in the
middle ages I was handed
a stack of etched pcb's with about 8 boards to a sheet. The fellow I worked
for pointed me at his 3
foot metal cutting shear and told me to go at er. I would have thought it
would have splintered the
fiberglass base it didn't. It makes very short work of the job and clean
edges. We also used a guillotine
paper chopper a few times too.

Dave

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2002\03\07@041407 by Tal Bejerano - AMC

flavicon
face
I try the protel pcb sw.

WOW!
what a mess!
what a size!
what a price!

i stick with Eagle even it's lite version.

Regards

Tal Bejerano
AMC - ISRAEL


{Original Message removed}

2002\03\07@064501 by mike

flavicon
face
On Wed, 6 Mar 2002 16:18:40 -0600, you wrote:

>Awesome info.  I'll summarize the responses here.  Keep in mind
>that I only make about 3 or 4 PCB's per year, so my choices are
>based on this super-low-volume.
>
>- Layout:  Eagle seems to be the popular choice, and I actually
>have/use it.  Like Vern Jones though, I've also used Visio in the
>past with nice results.  However, UNLIKE Simon-Thijs de
>Feber, I don't use cracked SW.  I'll stick with Eagle.
>
>- Transfer to PCB:  Here's the critical part.  Most of the options
>require a good printer.  Even with an inkjet process, I may need
>to upgrade cause 600dpi is recommended.  I like Rick C's idea
>of printing 2:1 and scaling down on a copier.  I might pick up some
>inkjet transparencies to test what quality I get with my 18th-
>century 300-dpi DJ500.  Also try tracing paper - it's MUCH cheaper, and often better for this
sort of work.

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2002\03\07@064923 by mike

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On Wed, 6 Mar 2002 17:01:15 -0800, you wrote:

>Hi all,
>
>I make double sided PCBs with a very simple technique.
>
>1) Print both sides on a transparency with a HP deskjet (710C in my case)
>Set for monochrome, manual contrast, max ink and best quality = drenched in ink.
>Dry slow under a lamp (20 cm/60W) and AVOID FINGERPRINTS.
>
>2) Expose a double sided photosensitive PCB on one side, develop and etch.
>The type that Future Active sells is fine. Or Newark. Or Farnell.
>
>3) Rinse, dry.
>
>4) Drill a few marker holes, fit the other side of the PCB using these. Fix with tape.
>
>5) Cover the etched side with the protective plastic that covered the side originally.
>(The other side will have holes in it)
>
>6) Expose, develop, etch.
A rather long-winded way to do it. Just carefully align and staple the
2 artwork sheets together to form an envelope just larger than the
PCB, expose each side, being careful when turning over not to let the
board slip - then you develop & etch both sides at the same time.

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2002\03\07@082739 by Rick C.

flavicon
face
Hi. Octavio. There's no exact amount that can be used because it all depends on
how many boards you want to etch, how much copper you want to remove, and how
big your glass tray is (amount of water). For one or two 3x5" single sided
boards, I use a 9X9" glass casserole dish with about 3/4" of water. I scoop
about 4 tablespoons of Sodium Persulphate into the water and 1 drop of catalyst.
I order my S.P. from http://www.kepro.com The catalyst comes in a small bottle
when you buy the S.P. If you use a lot of copper grounding in your layout, it
means less etching and your etchant will last longer. You can continue to etch
with S.P. until it turns a pretty blue. When that happens, your through with the
etchant. Sometimes I try to stretch the etchant and it just stops working. I
will quickly start another batch to finish the job. The instructions say the
solution won't last long but I've made a board, and come back a few days later
and used the same solution again to finish another board. Using too much S.P.
will speed the etching process but it's wasteful.

To speed up the etching process, I suspend the glass tray above a hot plate.
Don't let the glass come in contact with the heating element. It will crack. I
also agitate the board in the solution and lift the board our every few seconds
to get oxygen to it. I use a long narrow strip of pcb material to lift the board
and let it slowly fall back into the solution. Try not to scratch the resist.
Single sided boards seem to etch quickly when you place the board copper side
down in the tray. Good ventilation is a good idea too.
Rick


Hi Rick, I'm interested in doing this, could you
please let me know how much sodium persulfate
you put in the water?


Friendly Regards

O. N.


"Rick C." wrote:

> I hope I didn't scare everyone away from the idea of using a film
> transparency for making pcb's. Actually it's one of the easiest parts of
> making a pcb. This can be done for one board or a hundred. Plus, you can

.............

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2002\03\07@090758 by Olin Lathrop

face picon face
> Not neccessarily off-topic.  Researching PCB houses like Advanced
> Circuits, I'm trying to get an exact value for the MIL measurement.
> I've found multiple conflicting sources, some saying 1mil = .001" and
> others saying 1mil = 1um.

For PC boards I've only ever heard of a "mil" being 1/1000 inch.


********************************************************************
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(978) 742-9014, .....olin@spam@spamEraseMEembedinc.com, http://www.embedinc.com

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'[EE]: Re: Making PCBs...'
2002\03\07@095926 by James Paul

picon face
All,

Indeed a 'MIL' is 1/1000 inch, 1um is a micrometer or 1 'MICRON',
and 1000 angstroms is 1 millimeter.

                                            Regards,

                                              Jim




{Quote hidden}

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2002\03\07@102627 by John Walshe

flavicon
face
I'm sure you meant 1000Angstrom is 1 Micron    (1x10E-9m* 1000 = 1x10E-6m)

> All,
>
>  Indeed a 'MIL' is 1/1000 inch, 1um is a micrometer or 1 'MICRON',
>  and 1000 angstroms is 1 millimeter.
>
>                                              Regards,
>
>                                                Jim
>

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'[EE]: Making PCBs... (my convoluted method)'
2002\03\07@103039 by Eric / N3VUZ

flavicon
face
I'll throw my hat in the ring and share how I make my PCBs.
This is my "shade tree mechanic" approach to making boards.
Your individual results may vary, use at your own risk.

..use the Lite version of Eagle, too bad the full version is
  so $$$ for the hobbyist. ;)
  hint for eagle: I'd pay $300 for a hobbyist version, can't
  afford $600+

..put 4 mounting holes in each corner and use them for reference points.

http://ciux.citx.com/eworld/images/binary/board2.jpg

..mark each side with text showing solder and component side.

..print the board on regular copy machine transparencies,
   one sheet per board side on a laser printer
  (even low end lasers like mine!).

..take the transparency, tape them together with masking
  tape (just a little so you can take it apart)

..masking tape them to a thin piece of plywood,
  drill the reference/mounting holes straight thru the
  transparency and the wood.

..find some long nails, drive them thru the holes in the wood,
  just so they "peek" thru the other side

..you now have a "jig" to lay your transparency on.

..cut your unexposed positive board, making it a little bigger
  than the transparency   this will help in handing the board
  during the development process.

..lay the transparency on the newly cut board, drill your
  reference/mounting holes.  test fit the board on the jig,
  then test fit the transparency over the board.

------------- clean/unscratched Plexiglass
------------- transparency
------------- pc board
------------- plywood "jig"

..separate the transparencies, expose your boards.
  pay attention to the orientation for the transparency
  on the component side and solder side

voila! http://ciux.citx.com/eworld/images/binary/board2.jpg

- you can make "standard" sized plywood mounts for your board needs
- save your transparency for future needs or selling on ebay ;)
- I use one of those fluorescent UV lights from Digikey, 4" for 3 minutes.
- I use FeCl, but it's pretty messy. I want to try the clear method one day.

Eric / N3VUZ

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'[EE]: Re: Re: Making PCBs...'
2002\03\07@103416 by James Paul

picon face
John,

Yes I did.   Thanks for noticing that.

                         Thanks and Regards,

                                Jim

{Quote hidden}

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'[EE]: Making PCBs... (my convoluted method)'
2002\03\07@103837 by Eoin Ross

flavicon
face
Still Eagle is bloody CHEAP compared to $7000 + for Protel99SE

(and I think its gone up in price since then)

>>> spamBeGoneevbspam_OUTspamRemoveMECITX.COM 03/07/02 10:27AM >>>
<snip>

..use the Lite version of Eagle, too bad the full version is
  so $$$ for the hobbyist. ;)
  hint for eagle: I'd pay $300 for a hobbyist version, can't
  afford $600+
<snip>
Eric / N3VUZ

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'[EE]: Re: Making PCBs...'
2002\03\07@103843 by Douglas Butler

flavicon
face
1000nm (nano meters) is 1 micron.
Angstrom doesn't fit the usual sequence of thousands: 10000Angstrom is 1
micron, also 1 A = 10E-10 meters or one hundred millionth of a
centimeter.

Sherpa Doug

> {Original Message removed}

2002\03\07@105654 by John Walshe

flavicon
face
You are so right Doug - I should have paid closer attention before
correcting James
Are you sure about the centimetre bit though?
> 1000nm (nano meters) is 1 micron.
> Angstrom doesn't fit the usual sequence of thousands: 10000Angstrom is 1
> micron, also 1 A = 10E-10 meters or one hundred millionth of a
> centimeter.
>
> Sherpa Doug
>
> > {Original Message removed}

2002\03\07@111736 by Douglas Butler

flavicon
face
Yes, a centimeter is 1E-2, one hundred millionth is 1E-2 x 1E-6 for
1E-10 total.
I got the centimeter bit from the dictionary to confirm my memory before
I wrote.
That explains why only optical guys use Angstroms.

Sherpa Doug

> {Original Message removed}

'[OT]: Making PCBs...'
2002\03\07@114201 by Bob Barr

flavicon
face
On Wed, 6 Mar 2002 21:57:55 -0600, Nick Veys wrote:

>Not neccessarily off-topic.  Researching PCB houses like Advanced
>Circuits, I'm trying to get an exact value for the MIL measurement.
>I've found multiple conflicting sources, some saying 1mil = .001" and
>others saying 1mil = 1um.
>
>Just wondering if someone can clear that up for me. :)  Thanks!
>

NASA may be able to help. I seem to recall that they had a 'units'
problem on one of the Mars probes. :=)

"Hey, Joe. Is Mars a gazillion miles away or is it a gazillion
kilometers?"


Regards, Bob
>nickspam@spam@veys.com | http://www.veys.com/nick

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'[EE]: Re: Making PCBs...'
2002\03\07@121707 by Mitch Miller

flavicon
face
On Thu, 7 Mar 2002, Douglas Butler wrote:

> Yes, a centimeter is 1E-2, one hundred millionth is 1E-2 x 1E-6 for
> 1E-10 total.

Ummm ... isn't 1E-2 x 1E-6 = 1E-8?  Or did I miss something?

-- Mitch

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2002\03\07@122544 by Douglas Butler

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face
1E-2 x 1E-6 x 1E-2 = 1E-10

One hundred (1E-2) x millionth (1E-6) of a Centimeter (1E-2)= 1E-10
meters

Sherpa Doug


> {Original Message removed}

2002\03\07@123206 by Mitch Miller

flavicon
face
On Thu, 7 Mar 2002, Douglas Butler wrote:

> 1E-2 x 1E-6 x 1E-2 = 1E-10
>
> One hundred (1E-2) x millionth (1E-6) of a Centimeter (1E-2)= 1E-10
> meters

I knew I had to be missing something ... I thought the One hundred you
were referring to _was_ the centi part ... now I'm up to speed.

-- Mitch

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'[PICLIST] Making PCBs...'
2002\03\07@125545 by Olin Lathrop

face picon face
>  and 1000 angstroms is 1 millimeter.

An angstrom is 10E-10 meters, or 1/10 nanometer.  1000 angstroms therefore =
100 nanometers = .1 micrometers = .0001 millimeters.  The angstrom is an old
unit hanging around from nuclear physics.  Today the preferred units are the
nanometer and the femtometer.


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'[EE]: Re: Making PCBs...'
2002\03\07@125548 by Olin Lathrop

face picon face
> I'm sure you meant 1000Angstrom is 1 Micron    (1x10E-9m* 1000 = 1x10E-6m)

Which isn't right either, since 1 angstrom is .1 nanometers.


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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@132940 by Vit

picon face
Bob wrote:

NASA may be able to help. I seem to recall that they had a 'units'
problem on one of the Mars probes. :=)

"Hey, Joe. Is Mars a gazillion miles away or is it a gazillion
kilometers?"
----------------------------------------------------------------------------
-------------

Hello All,

Recently I had a discussion with one of my friends about the Metric System
in the US.  As we all know, it is now the primary system of measurements in
public schools.  I still distinctly remember how a teacher in Advanced
Algebra solved a simple mathematics problem.  In his solution, a guy ran 200
km to work every morning.  He was pretty embarrassed when I informed him
that 200km is almost 100 miles.  AFAIR, he forgot to divide the answer by
60.  Anyway...

Can somebody tell me if the US is planning to gradually switch to the metric
system?  I mean, it must be pretty confusing for the scientists at NASA to
use both systems.

Sincerely,

Vitaliy

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2002\03\07@133540 by Dale Botkin

flavicon
face
On Thu, 7 Mar 2002, Vit wrote:

> Can somebody tell me if the US is planning to gradually switch to the metric
> system?  I mean, it must be pretty confusing for the scientists at NASA to
> use both systems.

Yes, from school I do remember we are plannning to switch to the metric
system.  I believe we're supposed to be done some time in the late
1970s...


8)

Dale

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'[PICLIST] Making PCBs...'
2002\03\07@141801 by Mitch Miller

flavicon
face
On Thu, 7 Mar 2002, Olin Lathrop wrote:

> Today the preferred units are the
> nanometer and the femtometer.

So, what sort of measurement might one be making to warrant documenting
the result in femtometers?

-- Mitch

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2002\03\07@144002 by Bob Blick

face picon face
On Thu, 7 Mar 2002, Mitch Miller wrote:
> > nanometer and the femtometer.
>
> So, what sort of measurement might one be making to warrant documenting
> the result in femtometers?

manometers are for male measurements and femtometers are for female
measurements, duh!

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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@144412 by Bob Barr

flavicon
face
On Thu, 7 Mar 2002 12:33:45 -0600, Dale Botkin wrote:

>On Thu, 7 Mar 2002, Vit wrote:
>
>> Can somebody tell me if the US is planning to gradually switch to the metric
>> system?  I mean, it must be pretty confusing for the scientists at NASA to
>> use both systems.
>
>Yes, from school I do remember we are plannning to switch to the metric
>system.  I believe we're supposed to be done some time in the late
>1970s...
>

Yep, we're inching toward it but we've got miles to go. :=)


Regards, Bob

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'[PICLIST] Making PCBs...'
2002\03\07@145709 by Douglas Butler

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Why I used femtometers just last Tuesday to measure the equatorial bulge
of an electron due to its spin...

Sherpa Doug ;-)

> {Original Message removed}

'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@145715 by Mitch Miller

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face
On Thu, 7 Mar 2002, Vit wrote:

> As we all know, it is now the primary system of measurements in
> public schools.

Hmmm ... I have a child in public schools, and although they're learning
the metric system, I'm not aware of it as being the "primary" system.
From the work I've seen they seem to be teaching both equally.

-- Mitch

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'[PICLIST] Making PCBs...'
2002\03\07@145718 by Saurabh Sinha

picon face
lol ..
Well manipulated Bob.

femtometers: A metric unit of length equal to one quadrillionth of a meter
nanometer: A metric unit of length equal to one billionth of a meter

Saurabh


{Original Message removed}

'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@145722 by Mitch Miller

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On Thu, 7 Mar 2002, Dale Botkin wrote:

> On Thu, 7 Mar 2002, Vit wrote:
>
> > Can somebody tell me if the US is planning to gradually switch to the metric
> > system?  I mean, it must be pretty confusing for the scientists at NASA to
> > use both systems.
>
> Yes, from school I do remember we are plannning to switch to the metric
> system.  I believe we're supposed to be done some time in the late
> 1970s...

Hahaha ... yeah, I remember that.  In fact, I was in elementary school (in
Canada) when Canada switched to metric.

So, I'm thinking about this ... why is it that beverages are the only
thing where metric seems to have stuck?  Ex: 2l bottles of soda, 750ml
bottles of liquor.

-- Mitch

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'[PICLIST] Making PCBs...'
2002\03\07@145725 by Mitch Miller

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On Thu, 7 Mar 2002, Bob Blick wrote:

> On Thu, 7 Mar 2002, Mitch Miller wrote:
> > > nanometer and the femtometer.
> >
> > So, what sort of measurement might one be making to warrant documenting
> > the result in femtometers?
>
> manometers are for male measurements

Hey, now, no need to get personal! <g>

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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@145734 by Mitch Miller

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On Thu, 7 Mar 2002, Bob Barr wrote:

> On Thu, 7 Mar 2002 12:33:45 -0600, Dale Botkin wrote:
>
> >On Thu, 7 Mar 2002, Vit wrote:
> >
> >> Can somebody tell me if the US is planning to gradually switch to the metric
> >> system?  I mean, it must be pretty confusing for the scientists at NASA to
> >> use both systems.
> >
> >Yes, from school I do remember we are plannning to switch to the metric
> >system.  I believe we're supposed to be done some time in the late
> >1970s...
> >
>
> Yep, we're inching toward it but we've got miles to go. :=)

That would be kilometers ... <g>

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2002\03\07@150908 by Sean H. Breheny

face picon face
One of the reasons why I use both systems is that I find a foot to be a
very convenient measure for everyday applications. For example, as I look
around me in the room, most objects that I might handle are approximately 1
foot in largest dimension, like books, the phone, an umbrella, sheets of
paper, etc. A meter is just a little too big for typical objects.

Likewise, a centimeter is just a little too small. I can say a pen is about
6 inches long, rather than having to say 15 centimeters. For objects that
fit in your hand, but aren't very small, the dimension in inches would be
in the single digits, whereas the dimension in centimeters would span the
range from the single digits up to two digits.

I think this comes from the fact (AFAIK) that the English or imperial
system of feet, inches, etc., is based on human dimensions and the linear
measure of the metric system is based on the dimensions of the earth
(originally), so it has less direct bearing on human everyday use. It would
have been nice, I think, if the metric system had used the foot (or some
similar unit, perhaps a third or a half of the present meter) as the basis
unit and THEN used powers of ten to derive other units from it.

As for the other units, like gallons vs. liters, I don't think there would
be any disadvantage to the metric system in these, as long as we don't have
to pay the same for a liter of gas as we now do for a gallon, like you
Europeans ;-)

Sean

At 11:40 AM 3/7/02 -0800, you wrote:
{Quote hidden}

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2002\03\07@150911 by Stuart Meier

flavicon
picon face
>
> So, I'm thinking about this ... why is it that beverages are the only
> thing where metric seems to have stuck?  Ex: 2l bottles of soda, 750ml
> bottles of liquor.

Prefer my beer in Pints please!

Stuart
{Original Message removed}

2002\03\07@152749 by gacrowell

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face
Likewise, thousandths of an inch are simply convenient to work in.  Its easy
to work in 'whole' thousandths, i.e., mils.  It works well for mechanical
tolerances, and for pcb work.  Just about the only time you have to go to
decimal fractions of a mil is when you're trying to match some metric
equivalent.

GC

{Original Message removed}

2002\03\07@153620 by Vit

picon face
> > As we all know, it is now the primary system of measurements in
> > public schools.
>
> Hmmm ... I have a child in public schools, and although they're learning
> the metric system, I'm not aware of it as being the "primary" system.
> From the work I've seen they seem to be teaching both equally.
>
> -- Mitch

Mitch - you're right, they're used interchangeably.  My bad.  :-)

Vitaliy

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'[EE]: Making PCBs...'
2002\03\07@155404 by Joan Ilari

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> > - To take out the toner when the pcb is finished it is much
> > easier to use
> > acetone (industrial or even of the kind the women use for removing the
> > paint from the nails : more expensive) than grinding the pcb.
>
> Acetone and similar hydrocarbon solvents will break down the pcb resin of
> many glass and paper composites. That surface will then invite
> contaminants,
> including whatever you washed off with it - a good reason why all the
> packaged transfer systems suggest scrubbing.

Never have had any problem (and when the transfer fails, I clean the board
with
acetone and let's start again !)

> > - To remove the paper it is better (according to my experience) to use
very
> > hot water instead of cold water. In a couple of minutes the paper
peels-off
> > without having to touch at it.
>
> I think the cold water is intended to "set" the toner by cooling
> it rapidly.
> But I'm sure hot water removes the paper better. I have done
> cold, then hot.

Toner melts at a temperature much higher than hot water. Hot water helps
the paper to peel-off. Never had any problem with hot water (hot water = 50
oC)

> The blue stuff seems to be pretty reliable also, but nothing beats
Advanced
> circuits doing them 2 up for $28 US with silk and mask with real through
> holes. Nobody on tis list can set up to do an iron on board for the
> equivalent cost in time.

Me yes. This means :
1) I am very fast :-), or
2) I am very bad paid :-(
Decide for yourself

> I figured the last iron on board I did, at about 1.25 x 2 cost me about
> the equivalent of $750 in billable time. Now I will only do this method
> when I have nothing else to do.

To get 750$ in billable time I must work for more than one week :-(

Note : iron method is the only one which allows me to start a board friday
evening and get it working sunday morning ! There is not a such fast service
in Internet.

Joan

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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@160212 by Bob Barr

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On Thu, 7 Mar 2002 14:03:19 -0600, Mitch Miller wrote:

>On Thu, 7 Mar 2002, Bob Barr wrote:
>
>> On Thu, 7 Mar 2002 12:33:45 -0600, Dale Botkin wrote:
>>
>> >On Thu, 7 Mar 2002, Vit wrote:
>> >
>> >> Can somebody tell me if the US is planning to gradually switch to the metric
>> >> system?  I mean, it must be pretty confusing for the scientists at NASA to
>> >> use both systems.
>> >
>> >Yes, from school I do remember we are plannning to switch to the metric
>> >system.  I believe we're supposed to be done some time in the late
>> >1970s...
>> >
>>
>> Yep, we're inching toward it but we've got miles to go. :=)
>
>That would be kilometers ... <g>


Hmmm, inching toward the use of kilometers?? I don't know, but
somehow, that sounds a bit self-contradictory. :=)


Regards, Bob

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'[EE]: Re: Making PCBs...'
2002\03\07@171907 by michael brown

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> > Yes, a centimeter is 1E-2, one hundred millionth is 1E-2 x 1E-6 for
> > 1E-10 total.
>
> Ummm ... isn't 1E-2 x 1E-6 = 1E-8?  Or did I miss something?
>
> -- Mitch

His example was in octal.  ;-D

michael brown

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'[EE]: Making PCBs...'
2002\03\07@181118 by Vit

picon face
> Note : iron method is the only one which allows me to start a board friday
> evening and get it working sunday morning ! There is not a such fast
service
> in Internet.
>
> Joan

I wonder why no one mentioned using a pen plotter to make PCBs.  It should
be faster than the iron-on method.  I'll let you know for sure when I get my
shipment of copper clad boards.  :-)

Vitaliy

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2002\03\07@183445 by Dale Botkin

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face
On Thu, 7 Mar 2002, Vit wrote:

> I wonder why no one mentioned using a pen plotter to make PCBs.  It should
> be faster than the iron-on method.  I'll let you know for sure when I get my
> shipment of copper clad boards.  :-)

Beats heck out of me.  I published a web page detailing how I did it back
in '95 or so...  and posted to a reflector of some sort or other before
that, ISTR.  Pen plotters were pretty scarce and expensive at the time.
Now they're just getting scarcer.  I looked for a new one a few years ago
and was shocked, it's almost like they never existed.  Everything ie
either large-format inkjet or a vinyl sign cutter now.

Dale

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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\07@205729 by Pic Dude

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face
I agree that each system has its place, but I'd like to see a decision
to use one system, whichever it is.  Ever work on a Ford Mustang?
You need both US and metric tools.  BTW, the metric bolts are
not just on the foreign-outsourced parts.

Cheers.


----- Original Message -----
From: "gacrowell" <EraseMEgacrowellSTOPspamspamRemoveMEMICRON.COM>
To: <spam_OUTPICLISTRemoveMEspamEraseMEMITVMA.MIT.EDU>
Sent: Thursday, March 07, 2002 2:15 PM
Subject: Re: [OT]: US and Metric System (was: Making PCBs...)


> Likewise, thousandths of an inch are simply convenient to work in.  Its
easy
> to work in 'whole' thousandths, i.e., mils.  It works well for mechanical
> tolerances, and for pcb work.  Just about the only time you have to go to
> decimal fractions of a mil is when you're trying to match some metric
> equivalent.
>
> GC
>
> {Original Message removed}

'[PICLIST] Making PCBs...'
2002\03\08@034711 by Peter L. Peres

picon face
>On Thu, 7 Mar 2002, Olin Lathrop wrote:
>
>> Today the preferred units are the
>> nanometer and the femtometer.
>
>So, what sort of measurement might one be making to warrant documenting
>the result in femtometers?

Wavelengths of radiation, distances inside atoms, and other such. CMOS
fabrication technology talks in nanometers all the time anyway. fm is not
so far away.

Peter

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2002\03\08@040843 by Spehro Pefhany

picon face
At 10:10 AM 3/8/02 +0200, you wrote:

>Wavelengths of radiation, distances inside atoms, and other such. CMOS
>fabrication technology talks in nanometers all the time anyway. fm is not
>so far away.

I made a control driver box for the research branch of the Smithsonian,
they are dealing in femtometres, but I calculated it was a couple of decades
before it would have much relevance for semiconductors (applying Moore's
law). Not so long, I guess.

Best regards,

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'[OT]: re: Making PCBs...'
2002\03\13@075242 by ards, Justin P

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(new tag)

Wow, and I do mean WOW.

just how many femtometers did you measure for the equatorial bulge.

I thought these really small particles were nice and round.  On that point
is there anything in nature that is perfectly straight or perfectly round.

I keep looking but everything seems to have some irregularity

Just curious

Justin

{Original Message removed}

2002\03\13@114749 by Michael Vinson

picon face
Justin Richards wrote:
>[In response to Sherpa Doug's tongue-in-cheek comment:
>>"Why I used femtometers just last Tuesday to measure the equatorial bulge
>>of an electron due to its spin..."]

>Wow, and I do mean WOW.
>just how many femtometers did you measure for the equatorial bulge.
>I thought these really small particles were nice and round.  On that point
>is there anything in nature that is perfectly straight or perfectly round.

I managed to restrain myself from commenting on Sherpa Doug's
earlier comment, but now I just have to say something.

Electrons, and other sub-atomic particles, are NOT, repeat NOT,
"little chunks of stuff", like teeny-tiny BBs or something. They
just are not. It's a little harder to say what they ARE: the very
successful theory of quantum electrodynamics describes electrons
as quantum excitations of the "electron field" (whatever that means),
or equivalently by complex probability amplitudes governed by the
Dirac equation (whatever THAT means). Our experience with macroscopic
things (like BBs) makes it very difficult to visualize the sub-atomic
world, so it is hard to say what electrons "really" "look like". But
it is not so hard to say what they are not, and that is little tiny
classical things like BBs or billiard balls. For one thing, BBs and
billiard balls don't exhibit wave-like interference and diffraction
(at least not at macroscopic scales) or quantized spin, which electrons
and the like do.

Sorry about all that.

Michael V (resident physicist)

Thank you for reading my little posting.


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2002\03\13@123013 by Chris Loiacono

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At the risk of sounding both ignorant and arrogant, what is the practical
application of measuring sub-atomic particle equatorial bulges?

Chris

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2002\03\13@124424 by Bob Barr

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face
On Wed, 13 Mar 2002 12:28:49 -0500, Chris Loiacono wrote:

>At the risk of sounding both ignorant and arrogant, what is the practical
>application of measuring sub-atomic particle equatorial bulges?
>

The heck with atoms, I'm concerned enough about my own 'equatorial
bulge'. Although, I must admit, I can measure it quite easily in
inches. There just seems to be more and more of them lately. :=)


Regards, Bob

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2002\03\13@124806 by Douglas Butler

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I though I rile a few physicists with that comment.  But I missed
Justin's reply.  At the quantum level shapes and sizes of things become
meaningless in the conventional sense.  Even those ball-and-stick models
of molecules are more poetic license than anything else.

In high school my physics teacher had an explaination of electron spin.
Imagine a thin spinning hoop of fixed rim velocity.  Now shrink the
hoop, maintaining mass and rim velocity, untill the radius is near zero.
RPMs go to infinity, but energy, mass and gyroscopic effects are fine.
He also challenged us to design an experiment to prove the red shift was
not caused by photons loosing some percentage of their energy over
millions of years of flight.

Sherpa Doug

> {Original Message removed}

2002\03\13@125405 by Douglas Butler

flavicon
face
I believe in the book "Fantastic Voyage" they mentioned that everything
looked fuzzy because of the quantum effects becoming noticeable to the
shrunken crewmen.

It helps if you electropolish your electrons before you try to measure
them. ;-)

Sherpa Doug

> {Original Message removed}

2002\03\13@131242 by Jon Baker

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face
> He also challenged us to design an experiment to prove the red shift was
> not caused by photons loosing some percentage of their energy over
> millions of years of flight.

Is there a proof for this?

Jon Baker

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2002\03\13@133254 by Douglas Butler

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The closest I have seen is that the red shift is constant for all
colors, not proportional to the energy in that color.  That just means
the energy loss is linear, not exponential.

He was a great physics teacher.  One homework assignment was to assume
you had a lump of negative mass, and describe how it would behave in
everyday curcumstances using F=MA, laws of gravity etc....  It would sit
on the bottom side of a table.  If you dropped it, it would fall.  When
it hit the ground it would burrow to the center of the earth.  You would
have to push it into the ground to stop it.

Sherpa Doug

> {Original Message removed}

2002\03\13@135638 by Pic Dude

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"...I can measure it quite easily in inches"

You mean attoparsecs/1.2, right?  :-)


----- Original Message -----
From: "Bob Barr" <EraseMEbbarrRemoveMEspamCALIFORNIA.COM>
To: <spamPICLIST.....spamspamMITVMA.MIT.EDU>
Sent: Wednesday, March 13, 2002 11:36 AM
Subject: Re: [OT]: re: Making PCBs...


On Wed, 13 Mar 2002 12:28:49 -0500, Chris Loiacono wrote:

>At the risk of sounding both ignorant and arrogant, what is the practical
>application of measuring sub-atomic particle equatorial bulges?
>

The heck with atoms, I'm concerned enough about my own 'equatorial
bulge'. Although, I must admit, I can measure it quite easily in
inches. There just seems to be more and more of them lately. :=)


Regards, Bob

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2002\03\13@140029 by Mark Perri

picon face
I don't think electrons actually spin -- it's just a convenient way to
think about them.

Also I've never heard of a photon losing energy.  If you're just talking
about a regular red shift (doppler effect), then it's just caused by an
object moving relative to the observer, not a photon losing energy.
Mark

At 12:39 PM 3/13/02 -0500, you wrote:
{Quote hidden}

> > {Original Message removed}

2002\03\13@141226 by Dal Wheeler

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face
Might not be directly related to this but there is some very cool new
applications relating to electron spin directions.  Look up spintronics
under darpa projects.  There was a very interesting series of lectures at
SDSU given by the head of the project on one of the cable university
channels a while back.

-Dal
----- Original Message -----
From: Chris Loiacono <chrisspam_OUTspam@spam@MAIL2ASI.COM>


> At the risk of sounding both ignorant and arrogant, what is the practical
> application of measuring sub-atomic particle equatorial bulges?
>
> Chris

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2002\03\13@142058 by Chris Loiacono

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And you guys really had me thinking I haven't been keeping up with my
reading...
(I thought I was keeping up with nanotube transistors, and then .....)
C
{Quote hidden}

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2002\03\13@143936 by Douglas Butler

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face
The standard theory is that the red shift is caused by the expanding
universe producing a Doppler shift.  Even back in the 1970's when I was
in high school that was generally accepted.  But my physics teacher was
proposing an alternate theory and challenging his students to prove it
wrong.

You don't want to believe something just because you read it in a text
book.  What would have happened if Galileo had just believed what he
read about the earth being the center of the universe?  He wouldn't have
been tortured or imprisoned and would have lived a long and happy life!
;-)

Back to reading these (sacred) IC data sheets...

Sherpa Doug

{Quote hidden}

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2002\03\13@145351 by Herbert Graf

flavicon
face
Hmm, AFAIK electrons DO have angular momentum, in the macro world we live in
that means spin, is it different in the quantum world? TTYL

> {Original Message removed}

2002\03\13@152050 by Michael Vinson

picon face
Herbert Graf wrote:
>Hmm, AFAIK electrons DO have angular momentum, in the macro world we live
>in
>that means spin, is it different in the quantum world?

In a word, yes. Quantum spin exhibits the phenomenon known as
"space quantization", meaning that if you choose an axis and
measure the "spin" angular momentum of, say, an electron about
that axis, you will always get + or - 1/2 of Planck's constant.
If you think about it, that is really weird. What if you had
chosen an axis at 45 degrees from the first one? Then classically
you would expect to measure 1/sqrt(2) of the value you got from
the first axis, but in fact you will STILL get only + or - 1/2
of Planck's constant. There is no classical model of literal
spinning that will have this behavior. Thus physicists give up
on trying to think of the electron as a little "chunk of stuff"
and just accept that things are different in the subatomic world.

Michael V

Thank you for reading my little posting.


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2002\03\13@165840 by Spehro Pefhany

picon face
At 02:31 PM 3/13/02 -0500, you wrote:
>The standard theory is that the red shift is caused by the expanding
>universe producing a Doppler shift.

Maybe it's almost time to change the subject header? ;-)

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
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'[EE]: Making PCBs... (was: Re: Re: [OT]: re'
2002\03\13@180846 by Pic Dude

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This email is about making PCB's... no, really!  So the subject tag
has been changed.  Experiences, tips and questions within.  Long
email, so excuse the shorthand english, which in some circles may
be referred to as "nano-english". :-)

(1) Toner-transfer:  Good.  Need some practice, though.  Definitely for
one-offs.

(2) Datak incandescent-resist.  Having probs sourcing these.  Datak's web
site claims Austin dealers, but dealers say no more.  Other dealers only
have remnants left (no discounts), not sure which, and are dropping the
Datak line.  Still looking.

(3) So I splurged $32 for the MG UV lamp.  Also picked up one
photo-resist board and developer.  Result:  98.273% perfect.

(3a) First tricky part was lining up the transparency with the PCB.
It just kept slipping when I put the lexan over it.  (If it were the Datak
boards, I would've ruined it after taking so long to get it right.)  So I
thought of a good way to line these up.  Other than the "envelope"
technique a la Mike Harrison, a piece of scrap board in an "L"-shape
can be stuck to the inside of the envelope. The board to be etched
would then be slipped in the middle until it's corner nestles neatly in
the inside-corner of the "L".  Perhaps I should get royalties for
this idea?

(3b) Another thing I thought of was to get some mirrors and
expose both sides at the same time.  Why?  Cause even after
marking the board so I know how to align side 2 after etching
side 1, I lost it and had to think carefully and pray a lot.  Luckily
I got it right.  Anyone have a simple mirror setup you can
explain?  If not, I expect royalties for this idea too. :-)

(3c) Instructions: 5 mins min exposure.  Me: 1 side @  8 mins,
other @ 11 mins.  After developing, few fading traces on one side,
and the other has an light-blue shady region. Fading traces fixed
with etch-resist pen -- easy.  Other became a noticeable prob
after etching as there was unwanted copper in an area approx
1/4" dia.  I just scraped that off with a knife.

(3d) So this was successful, and nice, but I need practice.

(4)  Was looking at PCB services and thinking that I would like
to use them someday.  However, the ones I've found are steep.
Custom PCB's prices are not bad (DIY) service, but they are
not setup for this now (ran out of positive process chemicals).
Doh!  Plus the Malaysia thing is odd.  Express PCB is okay,
though I'd prefer to get less (eg: no holes) and pay less.
Advanced circuits is very expensive for 1 or 2 boards.

Any other recommendations?  My prefs would be 2 sides, no
soldermask or screen, and NO holes.  I would panelize/array
and scoring would be nice, but not necessary.  Thru-plating
doesn't apply w/no holes, and any board type/thickness is fine.
Again, biggest priority is a price that can me measured in
femto-dollars.  :-)

Cheers,
-Neil.




{Original Message removed}

'[OT]: re: Making PCBs...'
2002\03\13@181854 by Mike Mansheim

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> At the risk of sounding both ignorant and arrogant, what is the
> practical application of measuring sub-atomic particle equatorial
> bulges?

I thought that was a joke when written - sure seems to have caused some
serious discussion!
(or, I'm misreading the replies and the joke's on me)

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'[EE]: Making PCBs... (was: Re: Re: [OT]: re'
2002\03\13@182955 by Cliff Griffin

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Injectorall has some good info on their web site--they make photo-resist
boards. http://www.injectorall.com/pckits.htm I talked to the guy on the
phone, and he suggested using a hole punch to put some holes in vacant
places on the board, and use scotch tape to secure it to the board. That
prevents it from slipping after you have it aligned.

Cliff


{Original Message removed}

2002\03\13@185420 by Pic Dude

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Cool, but ouch.  Just called them after seeing your email and the guy
was telling me that it would be expensive -- some few hundred dollars
just for tooling.  He'll get back to me with something more official though.

I thought about the scotchtape but wasn't sure if I should left the tape
touch side 1 while side 2 was being exposed.

Cheers,
-Neil.



{Original Message removed}

2002\03\13@185649 by kben

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Hi Neil, check out http://www.olimex.com/pcb/index.html
$26 for double sided & $8 for delivery (10 Days).
Best of all, Olimex has been given the PICLIST seal of approval
from an earlier thread. Also, Olimex is providing a free
board once a month for the PCB contest, so if you win every
month you never have to pay for a board !!!

>Any other recommendations?  My prefs would be 2 sides, no
>soldermask or screen, and NO holes.  I would panelize/array
>and scoring would be nice, but not necessary.  Thru-plating
>doesn't apply w/no holes, and any board type/thickness is fine.
>Again, biggest priority is a price that can me measured in
>femto-dollars.  :-)
>
>Cheers,
>-Neil.

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2002\03\13@190053 by Cliff Griffin

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Wow, he must not want to sell much. I was going to order a starter kit from
him, just so I didn't have to run around town finding all the right stuff.
He talked me out of it. I ended up spending a couple hundred at Gateway
Electronics anyway! (but it wasn't ALL board related.) I just didn't want to
get in the middle of something and wish I had just one more thing.

Cliff


{Original Message removed}

'[OT]: re: Making PCBs...'
2002\03\14@042657 by Alan B. Pearce

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>"...I can measure it quite easily in inches"

>You mean attoparsecs/1.2, right?  :-)

Actually I thought the measurement unit was "cans of beer" :)))))

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'[OT]: US and Metric System (was: Making PCBs...)'
2002\03\20@122131 by John Ferrell

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And it becomes a non-issue in the machine shop. All you have to do to change
systems is insert the 127/100 gear set in the lathe.
{Original Message removed}

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