Homebrew PCBs

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

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

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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----- 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

> > 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.

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@...>

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...>

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...>

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?

> 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

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

> I have no idea at all ow much1 oz is.
> Of course i can find out.

1 gram is 0.03527396 ounces. 

Regards

Marvin Dickens

 


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--- 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

--- 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

>
> 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

> 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

> 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 = > 35\ufffd; 2 oz => 70\ufffd; 3 oz => 105\ufffd 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

--- 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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> 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

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

--- 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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--- 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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>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

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

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

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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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