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slikscreen

slikscreen

2004-04-19 by lostwabbit2001

how can i make a componit silkscreen for a pcb? Thank you

Re: [Homebrew_PCBs] slikscreen

2004-04-19 by Stefan Trethan

On Mon, 19 Apr 2004 02:22:19 -0000, lostwabbit2001
<lostwabbit2001@...> wrote:

> how can i make a componit silkscreen for a pcb? Thank you
>
>

perhaps with silkscreen printing ? ;-)

3 other ideas that spring to mind:

Plotter (multicolor, slow)
toner transfer (black, maybe slightly conductive)
various "transfer sheets" like t-shirt transfer

ST

Re: [Homebrew_PCBs] silkscreen

2004-04-19 by John Johnson

On one board I did, I printed the silkscreen layer on my ink jet onto
paper. When the board was finished and inspected, I glued it down on
top of the board using a glue stick, spray adhesive would work too.
Component legs go through the paper. Looks pretty good, actually.

Regards,
JJ

On Sunday, Apr 18, 2004, at 22:22 US/Eastern, lostwabbit2001 wrote:

> how can i make a componit silkscreen for a pcb? Thank you
>
>
>
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Re: [Homebrew_PCBs] silkscreen

2004-04-19 by Leon Heller

----- Original Message -----
From: "John Johnson" <johnatl@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, April 19, 2004 11:40 AM
Subject: Re: [Homebrew_PCBs] silkscreen


> On one board I did, I printed the silkscreen layer on my ink jet onto
> paper. When the board was finished and inspected, I glued it down on
> top of the board using a glue stick, spray adhesive would work too.
> Component legs go through the paper. Looks pretty good, actually.

Not much good for SMD, though. 8-)

Leon

Re: component ledgends --was silkscreen

2004-04-19 by wheedal99

> > how can i make a componit silkscreen for a pcb? Thank you
> >
> >
>
> perhaps with silkscreen printing ? ;-)
>
> 3 other ideas that spring to mind:
>
> Plotter (multicolor, slow)
> toner transfer (black, maybe slightly conductive)
> various "transfer sheets" like t-shirt transfer

I remember someone suggesting ink jet "water slip" paper that
modelers use for decals. That would get you color as well as speed.
Still would have difficulty doing smt --although you can solder
through it.

How wide tracks

2004-04-20 by Anthony Toft

is there a formula for how wide tracks should be? I need to make
tracks capable of carrying 7+A at 12v How fat should they be?
--
Anthony Toft <toftat@...>

Re: How wide tracks

2004-04-20 by ballendo

Hello,

The ""bible" for pcb design is "Printed Circuits Design" by Gerald
Ginsberg. Published by McGraw Hill, I paid 5 bucks for myt copy of
the '91 edition. You can pick up a copy inexpensively at ABEBOOKS.com
or similar.

Another decent book is Tim Williams, "The Circuit Designers Companion"

Ginsbergs book has several nomographs, one of which answers what
you've asked. But there ar additional considerations. Is the trace by
itself--means away from other traces? How much temperature rise can
you allow? Is the trace on an internal or external layer? What is the
copper "ounce" rating?

From page 40, the three nomographs will get you where you need to be.
Assuming external layer, nothing REALLY close by, and a worst case
temp rise of 60 degrees C. 7 amps requires a 70mil cross section.
With one ounce copper, that's a trace about .053 wide... With 2 oz.,
you need .028-.030 width.

At 20 degrees rise, you need 150 cross mils. So that's a trace
about .120 wide in 1 oz. copper. In 2 oz., it's only .060 wide.

Hope this helps,

Ballendo

P.S. Did you try putting "required PCB trace width" into a search
engine?

FWIW, there is a formula, but the nomographs are easier to use. The
formula is in ANSI/IPC D-949

--- In Homebrew_PCBs@yahoogroups.com, Anthony Toft <toftat@c...>
wrote:
> is there a formula for how wide tracks should be? I need to make
> tracks capable of carrying 7+A at 12v How fat should they be?
> --
> Anthony Toft <toftat@c...>

Re: [Homebrew_PCBs] How wide tracks

2004-04-20 by Stefan Trethan

You can find such things in "design rules" in the links section.

ST

On Mon, 19 Apr 2004 22:32:37 -0400, Anthony Toft <toftat@...>
wrote:

> is there a formula for how wide tracks should be? I need to make
> tracks capable of carrying 7+A at 12v How fat should they be?

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by Stefan Trethan

> What is the
> copper "ounce" rating?
>

I ask this question myself pretty often.
Which genius had the idea to measure a layer thickness in weight?
What is is? oz/sq feet, or sq inch, or whatever?
I have no idea at all ow much1 oz is.
Of course i can find out.


I really hate to annoy you but i also really hate the imperial units
system.
please try to at least write the complete unit if you need to use imperial
units.


the standard thicknesses in metric system are 18um, 35um and i think 72um.
which are micrometer, happenig to be 1m divided by 1000000 or 0,001mm
isn't that nice?


I wonder if i will live to the day when we finally all use 1 units system.

ST

Re: How wide tracks - link to calculator

2004-04-20 by Dave Mucha

--- In Homebrew_PCBs@yahoogroups.com, "Phil" <phil1960us@y...> wrote:
>

http://www.geocities.com/CapeCanaveral/Lab/9643/TraceWidth.htm


> --- In Homebrew_PCBs@yahoogroups.com, Anthony Toft <toftat@c...>
> wrote:
> > is there a formula for how wide tracks should be? I need to make
> > tracks capable of carrying 7+A at 12v How fat should they be?
> > --
> > Anthony Toft <toftat@c...>

Yup,

that's the calculator I use too.

Don't forget that you can tin the trace and make it thicker or lay a
copper wire on it and tin that and make a fat trace. Also, some
people use both the top and bottom of the board for beefing up power
traces.

I did a stepper motor driver and used a second board, kinda like a
home-brew 4 sided board and ran huge pins to connect the two boards.

Dave

Re: How wide tracks

2004-04-20 by Steve

--- In Homebrew_PCBs@yahoogroups.com, mpdickens <md30022@y...> wrote:
>
> --- Stefan Trethan <stefan_trethan@g...> wrote:
>
> > I have no idea at all ow much1 oz is.
> > Of course i can find out.
>
> 1 gram is 0.03527396 ounces.
>

Yes, but how thick is that? 1 ounce / square inch? If so, how thick is
that? 1 ounce / square foot?

Steve

Re: [Homebrew_PCBs] Re: How wide tracks - link to calculator

2004-04-20 by Stefan Trethan

>
> Don't forget that you can tin the trace and make it thicker or lay a
> copper wire on it and tin that and make a fat trace.


But don't do that with HF currents, the skin effect will displace

your current to the wall and you effectively increase the resistance.

Have read this somewhere - they have tried but i don't remember where.

ST

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by Stefan Trethan

> 1 gram is 0.03527396 ounces.
>
> Regards
>
> Marvin Dickens
>
>

Thank you very much Marvin, i thought the line "of course i can find out"
would prevent people from being too helpful...

I know it is simple to convert units with google.

thanks anyway ;-)

ST

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by Stefan Trethan

> Yes, but how thick is that? 1 ounce / square inch? If so, how thick is
> that? 1 ounce / square foot?
>
> Steve
>

well, you need the specific gravity...
In metric system even that would be darn easy...

thanks for putting the calc int he links section steve.

Found the following on the page i listed there:
(Remark: 1 oz = > 35µ; 2 oz => 70µ; 3 oz => 105µ Cu)

don't you have 18u boards?
i think they are mainly intended for plating but i have a huge amount of
them
and don't plate them. they work sufficiently for the low current stuff, and
they etch faster.



ST

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by mpdickens

--- Stefan Trethan <stefan_trethan@...> wrote:

> Thank you very much Marvin, i thought the line "of
> course i can find out"
> would prevent people from being too helpful...

Both systems are taught in the schools here in
America, so I knew the answer without thinking about
it. Besides, I could not help myself when I saw your
post ;)

Regards

Marvin Dickens

=====
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Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by Stefan Trethan

> Both systems are taught in the schools here in
> America, so I knew the answer without thinking about
> it. Besides, I could not help myself when I saw your
> post ;)
>
> Regards
>
> Marvin Dickens

Come on Marvin, you ain't knowing the conversion ratio from gram to ounces
with 8 decimals after the comma, "without thinking"?
I bet one free google search you looked that one up 8-)

ST

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by John Johnson

On Tuesday, Apr 20, 2004, at 04:31 US/Eastern, Stefan Trethan wrote:
> I wonder if i will live to the day when we finally all use 1 units
> system.

Man I hope so. This is getting really old. Inches have been based on SI
since 1887 or so.

Regards,
JJ

Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-20 by mpdickens

--- Steve <alienrelics@...> wrote:
> > 1 gram is 0.03527396 ounces.
> >
>
> Yes, but how thick is that? 1 ounce / square inch?
> If so, how thick is
> that? 1 ounce / square foot?

Using the weight per square inch (Or centimeter or
whatever) the thickness can easily be determined.

Regards

Marvin Dickens



=====
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If you use linux, get counted at:
http://www.linuxcounter.org




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Re: [Homebrew_PCBs] Re: How wide tracks

2004-04-21 by mpdickens

--- Stefan Trethan <stefan_trethan@...> wrote:

> Come on Marvin, you ain't knowing the conversion
> ratio from gram to ounces
> with 8 decimals after the comma, "without thinking"?
> I bet one free google search you looked that one up
> 8-)

You got me on that one: I keep a cheat sheet with the
fractions that I would have a reason to use and are
rediculously long :)

Marvin

=====
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If you use linux, get counted at:
http://www.linuxcounter.org




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Re: How wide tracks - link to calculator

2004-04-21 by ballendo

>In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
>Also, some people use both the top and bottom of the board for
>beefing up power traces.

Be careful! You're making capacitors...

Ballendo

Re: [Homebrew_PCBs] Re: How wide tracks - link to calculator

2004-04-21 by Stefan Trethan

On Wed, 21 Apr 2004 07:21:19 -0000, ballendo <ballendo@...> wrote:

>> In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
>> Also, some people use both the top and bottom of the board for
>> beefing up power traces.
>
> Be careful! You're making capacitors...
>
> Ballendo
>

shorted capacitors... wow.. wonder what the capacitance may be.. must be
huge..

ST

Re: [Homebrew_PCBs] Re: How wide tracks - link to calculator

2004-04-21 by Vasile Surducan

On Wed, 21 Apr 2004, ballendo wrote:

> >In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
> >Also, some people use both the top and bottom of the board for
> >beefing up power traces.
>
> Be careful! You're making capacitors...
>
actually this wouldn't be an impediment but an improvement for the
supply lines...

top 10 wishes,
Vasile
http://surducan.netfirms.com

RE: [Homebrew_PCBs] Re: How wide tracks - botom and top layer = 1 conductor?

2004-04-21 by Willy Gooris

Hi,
Do you really think You make capacitors? I thought that the definition
of a capacitor is: two conductors separated by a nonconductor. The last
part is trough, but the said 2 conductors are not two conductors, but
one conductor split in two pads (bottom- and top layer) because on
either end and even on other places where they are soldered together. At
VERY high frequencies this might be not completely right thou.

-----Original Message-----
From: ballendo [mailto:ballendo@...]
Sent: woensdag 21 april 2004 9:21
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] Re: How wide tracks - link to calculator


>In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
>Also, some people use both the top and bottom of the board for
>beefing up power traces.

Be careful! You're making capacitors...

Ballendo




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Re: How wide tracks - link to calculator

2004-04-21 by Phil

Maybe an inductor...

However, I think the reasoning goes - if you are making one "trace"
(er connection) that can carry a lot of current, you will need a
return path of similar capacity *somewhere*. Now, if those two are
of a large area and happen to be on opposite sides of the board you
WILL get a capacitor that may need to be taken into account in the
design.

Watching out for board level capacitance is worthwhile.

--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
<stefan_trethan@g...> wrote:
> On Wed, 21 Apr 2004 07:21:19 -0000, ballendo <ballendo@y...> wrote:
>
> >> In Homebrew_PCBs, "Dave Mucha" <dave_mucha@y...> wrote:
> >> Also, some people use both the top and bottom of the board for
> >> beefing up power traces.
> >
> > Be careful! You're making capacitors...
> >
> > Ballendo
> >
>
> shorted capacitors... wow.. wonder what the capacitance may be..
must be
> huge..
>
> ST