Homebrew PCBs

A quick check of the archives did not show that anyone had tried this, so I will relay this little test I just did.

I was thinking about making a flex ribbon for a small lcd display I bought. I decided to do a quick test with some copper foil tape and 1 mil kapton tape. 
I laminated the sticky sides of the copper tape and kapton tape   together. Since I was doing a quick and lazy test, I just used a permanent marker to create some linear traces like you would see on a regular ribbon connector.
Again, because I was doing a very quick test, I etched the traces in ferric chloride that I did not bother to heat, though I did use the bubbler.
After about 15 minutes, the copper was etched away sufficiently. The trace quality was low, because of the quick and dirty nature of this test, however the traces were bonded to the kapton tape  and were continuous. 
I was surprised to see that the adhesive on the kapton was still effective in the areas where the copper was etched away as well. 
With this test, I am confident that this method would be viable for creating custom flex circuit connectors.

This is remarkably useful!  I've often wanted to rework flex cables, but it
had never occurred to me that there was a viable homebrew way of doing this.


Let us know how your results look if you repeat with printed traces and
heated FeCL.

-Andrew

On Sun, Jul 11, 2010 at 5:15 PM, javaguy11111 <javaguy11111@...>wrote:

>
>
> A quick check of the archives did not show that anyone had tried this, so I
> will relay this little test I just did.
>
> I was thinking about making a flex ribbon for a small lcd display I bought.
> I decided to do a quick test with some copper foil tape and 1 mil kapton
> tape.
> I laminated the sticky sides of the copper tape and kapton tape together.
> Since I was doing a quick and lazy test, I just used a permanent marker to
> create some linear traces like you would see on a regular ribbon connector.
> Again, because I was doing a very quick test, I etched the traces in ferric
> chloride that I did not bother to heat, though I did use the bubbler.
> After about 15 minutes, the copper was etched away sufficiently. The trace
> quality was low, because of the quick and dirty nature of this test, however
> the traces were bonded to the kapton tape and were continuous.
> I was surprised to see that the adhesive on the kapton was still effective
> in the areas where the copper was etched away as well.
> With this test, I am confident that this method would be viable for
> creating custom flex circuit connectors.
>


[Non-text portions of this message have been removed]

What started me looking at this is that I bought a PSOC5 developer board for testing and wanted to hook up an LCD display to it. Sparkfun had some Nokia displays for 2.95 that I wanted to use. The problem is that they have no connectors. Just bare ITO traces, which have an oddball spacing of 1.15mm. 

The next issue is to figure out how to bond the connector to the ITO.
3M sells an anisotropic conductive adhesive, but they charge several hundred dollars for a hundred feet.  Mechanical would be  another option, but I just do not like that in this case.

My thought is to make my own anisotropic conductive using powder coating paint mixed with some conductive powder such as graphite or copper. A combination of heat and pressure would bond the flex connector to the ITO and conductive particles would be trapped between the copper and ITO connectors.  Another experiment to perform.

In the mean time, since I just want to play with my LCD and PSOC5 board and not get sidetracked on other things, I am going the silver epoxy route to attach the wires to the ITO.

I will do some more experimenting with flex cables and bonding at some point in the future.



--- In Homebrew_PCBs@yahoogroups.com, Andrew Villeneuve <andrewmv@...> wrote:

>
> This is remarkably useful!  I've often wanted to rework flex cables, but it
> had never occurred to me that there was a viable homebrew way of doing this.
> 
> 
> Let us know how your results look if you repeat with printed traces and
> heated FeCL.
> 
> -Andrew
> 
> On Sun, Jul 11, 2010 at 5:15 PM, javaguy11111 <javaguy11111@...>wrote:
> 
> >
> >
> > A quick check of the archives did not show that anyone had tried this, so I
> > will relay this little test I just did.
> >
> > I was thinking about making a flex ribbon for a small lcd display I bought.
> > I decided to do a quick test with some copper foil tape and 1 mil kapton
> > tape.
> > I laminated the sticky sides of the copper tape and kapton tape together.
> > Since I was doing a quick and lazy test, I just used a permanent marker to
> > create some linear traces like you would see on a regular ribbon connector.
> > Again, because I was doing a very quick test, I etched the traces in ferric
> > chloride that I did not bother to heat, though I did use the bubbler.
> > After about 15 minutes, the copper was etched away sufficiently. The trace
> > quality was low, because of the quick and dirty nature of this test, however
> > the traces were bonded to the kapton tape and were continuous.
> > I was surprised to see that the adhesive on the kapton was still effective
> > in the areas where the copper was etched away as well.
> > With this test, I am confident that this method would be viable for
> > creating custom flex circuit connectors.
> >
> 
> 
> [Non-text portions of this message have been removed]
>

If it just the glass you're connecting to, I have used a heatseal flex,
which I adhere to the glass with a soldering iron heating a thin metal bar
(a piece of the stainless steel stiffener in a windscreen wiper blade is
about right for the soldering iron I use).
I used it to repair calculator, meters and phone displays.
 
Your spacing is not an issue, just use some 1mm heatseal and cut it on a
diagonal. It won't take much of an angle to get the correct alignment.
 
The joint is fragile, and has a tendency to peel away if there is any
tension on it. I find it is best supported by a piece of foam, clamped in
place to the LCD bezel.
 
(The stuff I have was a sample I got years ago from Shin-Etsu in Japan.)
 
Bruce

From: javaguy11111
Sent: Tuesday, 13 July 2010 10:45 PM

What started me looking at this is that I bought a PSOC5 developer board for
testing and wanted to hook up an LCD display to it. Sparkfun had some Nokia
displays for 2.95 that I wanted to use. The problem is that they have no
connectors. Just bare ITO traces, which have an oddball spacing of 1.15mm. 

The next issue is to figure out how to bond the connector to the ITO.
3M sells an anisotropic conductive adhesive, but they charge several hundred
dollars for a hundred feet. Mechanical would be another option, but I just
do not like that in this case.

My thought is to make my own anisotropic conductive using powder coating
paint mixed with some conductive powder such as graphite or copper. A
combination of heat and pressure would bond the flex connector to the ITO
and conductive particles would be trapped between the copper and ITO
connectors. Another experiment to perform.

In the mean time, since I just want to play with my LCD and PSOC5 board and
not get sidetracked on other things, I am going the silver epoxy route to
attach the wires to the ITO.

I will do some more experimenting with flex cables and bonding at some point
in the future.





[Non-text portions of this message have been removed]

Heat seal flex sounds interesting, but I do not see any places that sell it. 

I did find a place that sells hot melt powder, but none of their distributors seem to sell it.  The site is 

http://www.lancergroup.com/lancer/ink_catalog/additives_bases/catalog5b.html

It is the H-10 powder. I have sent them email to find out who carries it.
I may buy some and experiment, in spite of my earlier comment.

I figure if you can mix this with some copper powder of a comparable size and stick it to some kind of temporary adhesive backer(like tape), then you may be able to accomplish the same thing that 3M does, but wants to charge several hundred for. 

--- In Homebrew_PCBs@yahoogroups.com, "Bruce Tunnicliffe" <bruce@...> wrote:

>
> If it just the glass you're connecting to, I have used a heatseal flex,
> which I adhere to the glass with a soldering iron heating a thin metal bar
> (a piece of the stainless steel stiffener in a windscreen wiper blade is
> about right for the soldering iron I use).
> I used it to repair calculator, meters and phone displays.
>  
> Your spacing is not an issue, just use some 1mm heatseal and cut it on a
> diagonal. It won't take much of an angle to get the correct alignment.
>  
> The joint is fragile, and has a tendency to peel away if there is any
> tension on it. I find it is best supported by a piece of foam, clamped in
> place to the LCD bezel.
>  
> (The stuff I have was a sample I got years ago from Shin-Etsu in Japan.)
>  
> Bruce
>  
> From: javaguy11111
> Sent: Tuesday, 13 July 2010 10:45 PM
> 
> What started me looking at this is that I bought a PSOC5 developer board for
> testing and wanted to hook up an LCD display to it. Sparkfun had some Nokia
> displays for 2.95 that I wanted to use. The problem is that they have no
> connectors. Just bare ITO traces, which have an oddball spacing of 1.15mm. 
> 
> The next issue is to figure out how to bond the connector to the ITO.
> 3M sells an anisotropic conductive adhesive, but they charge several hundred
> dollars for a hundred feet. Mechanical would be another option, but I just
> do not like that in this case.
> 
> My thought is to make my own anisotropic conductive using powder coating
> paint mixed with some conductive powder such as graphite or copper. A
> combination of heat and pressure would bond the flex connector to the ITO
> and conductive particles would be trapped between the copper and ITO
> connectors. Another experiment to perform.
> 
> In the mean time, since I just want to play with my LCD and PSOC5 board and
> not get sidetracked on other things, I am going the silver epoxy route to
> attach the wires to the ITO.
> 
> I will do some more experimenting with flex cables and bonding at some point
> in the future.
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
>

Has anyone ever tried this?

http://www.instructables.com/id/DIY-Flexible-Printed-Circuits/

My previous employer had several xerox printers and I always wanted to try it, but had no need or idea where to get the FPC.

PG

On 14/07/2010, at 12:45 AM, javaguy11111 wrote:

> 
> 
> What started me looking at this is that I bought a PSOC5 developer board for testing and wanted to hook up an LCD display to it. Sparkfun had some Nokia displays for 2.95 that I wanted to use. The problem is that they have no connectors. Just bare ITO traces, which have an oddball spacing of 1.15mm. 
> 
> The next issue is to figure out how to bond the connector to the ITO.
> 3M sells an anisotropic conductive adhesive, but they charge several hundred dollars for a hundred feet. Mechanical would be another option, but I just do not like that in this case.
> 
> My thought is to make my own anisotropic conductive using powder coating paint mixed with some conductive powder such as graphite or copper. A combination of heat and pressure would bond the flex connector to the ITO and conductive particles would be trapped between the copper and ITO connectors. Another experiment to perform.
> 
> In the mean time, since I just want to play with my LCD and PSOC5 board and not get sidetracked on other things, I am going the silver epoxy route to attach the wires to the ITO.
> 
> I will do some more experimenting with flex cables and bonding at some point in the future.
> 
> --- In Homebrew_PCBs@yahoogroups.com, Andrew Villeneuve <andrewmv@...> wrote:
> >
> > This is remarkably useful! I've often wanted to rework flex cables, but it
> > had never occurred to me that there was a viable homebrew way of doing this.
> >

> Heat seal flex sounds interesting, but I do not see any places that sell it.
>
> I did find a place that sells hot melt powder, but none of their
> distributors seem to sell it.  The site is

> http://www.lancergroup.com/lancer/ink_catalog/additives_bases/catalog5b.html
>
> It is the H-10 powder. I have sent them email to find out who carries it.


Try a scrapbooking / art craft shop.

They sell 'embossing' powder which sounds like that stuff.  That has a fairly
low melt temperature.

Tony

--- In Homebrew_PCBs@yahoogroups.com, Tony Smith <ajsmith@...> wrote:
>
> > Heat seal flex sounds interesting, but I do not see any places that sell it.
> >
> > I did find a place that sells hot melt powder, but none of their
> > distributors seem to sell it.  The site is
> 
> > http://www.lancergroup.com/lancer/ink_catalog/additives_bases/catalog5b.html
> >
> > It is the H-10 powder. I have sent them email to find out who carries it.
> 
> 
> Try a scrapbooking / art craft shop.
> 
> They sell 'embossing' powder which sounds like that stuff.  That has a fairly
> low melt temperature.
> 
> Tony
>
Thanks. Found the adhesive powder online at advancedscreen.com and some 325 mesh copper powder at chemicalstore.com. So I guess I will be doing some experimenting after all.

> > > I did find a place that sells hot melt powder, but none of their
> > > distributors seem to sell it.  The site is
> >
> > >
> http://www.lancergroup.com/lancer/ink_catalog/additives_bases/catalog5b
> .html
> > >
> > > It is the H-10 powder. I have sent them email to find out who
> carries it.
> >
> >
> > Try a scrapbooking / art craft shop.
> >
> > They sell 'embossing' powder which sounds like that stuff.  That has
> a fairly
> > low melt temperature.
> >
> > Tony
> >
> Thanks. Found the adhesive powder online at advancedscreen.com and some
> 325 mesh copper powder at chemicalstore.com. So I guess I will be doing
> some experimenting after all.


Also have a look at http://nonconductiveplating.com/

This is like that conductive ink you use to fix traces.  It's used to spray
on non-metallic items (wood, plastic etc) so you can electroplate them.
Might be flexible and ok for low currents.  It's certainly cheaper than the
conductive ink.

Tony

As a side note, powered hot-melt adhesive would be hard to apply 
evenly.  If you only wanted to do bonding (without needing the 
conductive additive) I would suggest using photo-mount paper available 
from camera/photo supply stores.  This is a very thin (probably about 1 
or 2 milli-inches) sheet of hot-melt on a carrier release paper and 
especially good on paper and archival mounting of photos in scrapbooks, 
etc.

Another technique for conductive traces was to add graphite powder to 
epoxy.  Totally load the harder with graphite to form a paste then add 
the other part (the resin) and use immediately.  Adding the graphite to 
the resin was not recommended as it could case the resin to harden.   As 
a thought, use a two-part urethane and add the graphite to it, and 
screen print it.  This is essentially what some some of the flexible LCD 
flex connectors are, screen printed conductive graphite ink on plastic 
(polyester or Kapton).  You could also use a solvent based carrier 
vehicle if you wanted to -- the key would be to really load it up with 
graphite.

Regards,
Charles Patton

The idea is to mix the copper and adhesive powders together and then pull off a single layer with tape. I would then tack the exposed side down, pull off the tape and then attach the other side. This is basically what is done with the 3M tapes.

The real trick may be finding a tape that is less sticky than the adhesive when I tack the exposed side down. I am thinking the adhesive on post-it notes may work.

I experimented with the graphite and epoxy, but never could get a conducting connection. I think the epoxy just completely coats and insulates the graphite so current is unable to flow. By doing a single powder layer of adhesive and copper I am hoping I can keep the conducting sides exposed.

--- In Homebrew_PCBs@yahoogroups.com, "Charles R. Patton" <charles.r.patton@...> wrote:

>
> As a side note, powered hot-melt adhesive would be hard to apply 
> evenly.  If you only wanted to do bonding (without needing the 
> conductive additive) I would suggest using photo-mount paper available 
> from camera/photo supply stores.  This is a very thin (probably about 1 
> or 2 milli-inches) sheet of hot-melt on a carrier release paper and 
> especially good on paper and archival mounting of photos in scrapbooks, 
> etc.
> 
> Another technique for conductive traces was to add graphite powder to 
> epoxy.  Totally load the harder with graphite to form a paste then add 
> the other part (the resin) and use immediately.  Adding the graphite to 
> the resin was not recommended as it could case the resin to harden.   As 
> a thought, use a two-part urethane and add the graphite to it, and 
> screen print it.  This is essentially what some some of the flexible LCD 
> flex connectors are, screen printed conductive graphite ink on plastic 
> (polyester or Kapton).  You could also use a solvent based carrier 
> vehicle if you wanted to -- the key would be to really load it up with 
> graphite.
> 
> Regards,
> Charles Patton
>