Robert Baer wrote:

The silver conductive epoxy is extremely conductive, and even tho i
never measuresd the resistivity, i would wager that it is better than
copper if used properly.

Just another point of reference. From:
http://www.efunda.com/materials/solders/tin_lead.cfm
Eutectic tin lead solder has a conductivity of about 1.44*10^-5 ohm cm,
or 8.5 times that of copper.

Ron H wrote:
The 3M conductive adhesives like the 9703 work well. Not sure how they do it
but it conducts in the Z axis ( thru the adhesive ) but not accross the
surface direction ( X & Y axis ). It's a pressure sensitive transfer
adhesive ( tape that you stick on then peel off the paper carrier leaving
the adhesive behind)
I have a roll of that. Very pricey. It contains lots of short bits
of very fine copper wire precisely aligned through the thickness of
the adhesive gel. The wires do not contact each other, so there is no
conductive path along the gel.

X-Y axis Insulation Resistance = 3.4 x 10 to the 14th Ohms/square
Z axis Contact Resistance = 1.25 milliOhm-in2

Pretty neat stuff!

Definitely. Sort of the dual of enameled wire. Conducts only at
right angles to the length.

On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" wrote:

The 3M conductive adhesives like the 9703 work well. Not sure how they do it
but it conducts in the Z axis ( thru the adhesive ) but not accross the
surface direction ( X & Y axis ). It's a pressure sensitive transfer
adhesive ( tape that you stick on then peel off the paper carrier leaving
the adhesive behind)

X-Y axis Insulation Resistance = 3.4 x 10 to the 14th Ohms/square
Z axis Contact Resistance = 1.25 milliOhm-in2

Pretty neat stuff!

Ron H.


Sounds VERY interesting! I have some clients that need to mount
components that can't stand the heat of soldering. The only problem
might be "tenacity"... how much "shake, rattle and roll" can it take?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

Jim Thompson wrote:
On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" wrote:


The 3M conductive adhesives like the 9703 work well. Not sure how they do it
but it conducts in the Z axis ( thru the adhesive ) but not accross the
surface direction ( X & Y axis ). It's a pressure sensitive transfer
adhesive ( tape that you stick on then peel off the paper carrier leaving
the adhesive behind)

X-Y axis Insulation Resistance = 3.4 x 10 to the 14th Ohms/square
Z axis Contact Resistance = 1.25 milliOhm-in2

Pretty neat stuff!

Ron H.



Sounds VERY interesting! I have some clients that need to mount
components that can't stand the heat of soldering. The only problem
might be "tenacity"... how much "shake, rattle and roll" can it take?

Its glorifies scotch tape:
http://multimedia.mmm.com/mws/mediaw...4spSxgrOkF W-

I read in sci.electronics.design that wrote (in
.com) about 'epoxy
instead of solder?', on Thu, 6 Oct 2005:

Robert Baer wrote:

The silver conductive epoxy is extremely conductive, and even tho i
never measuresd the resistivity, i would wager that it is better than
copper if used properly.

Just another point of reference. From:
http://www.efunda.com/materials/solders/tin_lead.cfm
Eutectic tin lead solder has a conductivity of about 1.44*10^-5 ohm cm,
or 8.5 times that of copper.

resistivity, not conductivity.
--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Just go to 3m.com and search for "conductive adhesive" or "9703"


"Jim Thompson" wrote in message
news
On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" wrote:

The 3M conductive adhesives like the 9703 work well. Not sure how they do
it
but it conducts in the Z axis ( thru the adhesive ) but not accross the
surface direction ( X & Y axis ). It's a pressure sensitive transfer
adhesive ( tape that you stick on then peel off the paper carrier leaving
the adhesive behind)

X-Y axis Insulation Resistance = 3.4 x 10 to the 14th Ohms/square
Z axis Contact Resistance = 1.25 milliOhm-in2

Pretty neat stuff!

Ron H.


Sounds VERY interesting! I have some clients that need to mount
components that can't stand the heat of soldering. The only problem
might be "tenacity"... how much "shake, rattle and roll" can it take?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.




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On Thu, 06 Oct 2005 19:28:54 -0700, Jim Thompson
wrote:

On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" wrote:

The 3M conductive adhesives like the 9703 work well. Not sure how they do it
but it conducts in the Z axis ( thru the adhesive ) but not accross the
surface direction ( X & Y axis ). It's a pressure sensitive transfer
adhesive ( tape that you stick on then peel off the paper carrier leaving
the adhesive behind)

X-Y axis Insulation Resistance = 3.4 x 10 to the 14th Ohms/square
Z axis Contact Resistance = 1.25 milliOhm-in2

Pretty neat stuff!

Ron H.


Sounds VERY interesting! I have some clients that need to mount
components that can't stand the heat of soldering. The only problem
might be "tenacity"... how much "shake, rattle and roll" can it take?

...Jim Thompson

Conductive adhesives have been discussed in Advanced Packaging
magazine (IIRC, might have been another trade mag) and the main
problems preventing widespread replacement of solder are not adhesion
but high initial resistance (not suitable for the current required by
large processors etc), and worse, gradual increase in resistance over
time especially at higher temperatures and humidities due to slow
oxidation of the conductors as water vapor and oxygen diffuse through
the adhesive polymers. Not ready for prime time now, and might not be
for a long time due to the lack of candidate impermeable adhesive
polymers. Suitable now for low power apps in benign envireonments
where long life is not important.

John Woodgate wrote:
I read in sci.electronics.design that wrote:


Just another point of reference. From:
http://www.efunda.com/materials/solders/tin_lead.cfm
Eutectic tin lead solder has a conductivity of about 1.44*10^-5 ohm cm,
or 8.5 times that of copper.

resistivity, not conductivity.

Thank you.

On 6 Oct 2005 09:59:53 -0700, "w2aew" wrote:
Wow,

Despite the less than stellar support for the concept, I'm going to go
ahead and try it anyway. I found a company in CA that makes 2
different types of epoxy, just for this purpose. The guy says it will
work and the curing time is short and not temperature sensitive
(unlike solder paste).

He's sensing me samples of both types although the spec's aren't
available due to translation problems (the stuff is imported, and no
English translation of the spec sheets exists).

I'm going to give it a try on through hole components first, then will
play with some smt once I get some experience under my belt.

I'll post a message with the results back here is there is any
interest.

Regards,

T

I read in sci.electronics.design that TRABEM wrote (in
) about 'epoxy instead of
solder?', on Sat, 8 Oct 2005:
He's sensing me samples of both types although the spec's aren't
available due to translation problems (the stuff is imported, and no
English translation of the spec sheets exists).

What language(s) is it in?
--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk