epoxy instead of solder?
Unknown
components to a printed circuit board?
Seems like a great idea, especially if it works well:>:
T
John Fields
---
Aside from the resistivity of the epoxy, the largest problem I see
is throughput. That is, where are you going to store all those
boards while the epoxy is curing?
Plus, it makes it really messy for the salvagers/recyclers.
--
John Fields
Professional Circuit Designer
Joerg
> Aside from the resistivity of the epoxy, the largest problem I see
> is throughput. That is, where are you going to store all those
> boards while the epoxy is curing?
>
Then there is the stench that most epoxies let off. Mostly of the not so
healthy kind.
Regards, Joerg
Dr. Anton T. Squeegee
says...
> Has anyone tried Masterbonds conductive epoxy for attaching SMT
> components to a printed circuit board?
>
> Seems like a great idea, especially if it works well:>:
Not really. Consider the angle of serviceability. It's easy enough
to use a 'HoTweezer' station to replace a bad chip component secured
with solder. It's darn near impossible to replace the same component if
secured with Epoxy.
Also, I'm not convinced that "conductive" Epoxy really is. I'd
want to see some real numbers on resistance per cm/squared on the stuff
before I even consider it for any sort of repair work.
Any job worth doing is worth doing right. If you're trying to
attach surface-mount components, invest in the proper
soldering/desoldering equipment instead of looking for impractical
shortcuts. It may cost more at the get-go, but it'll cost a lot less in
the long run.
Keep the peace(es).
--
Dr. Anton T. Squeegee, Director, Dutch Surrealist Plumbing Institute.
(Known to some as Bruce Lane, ARS KC7GR,
kyrrin (a/t) bluefeathertech[d=o=t]calm -- www.bluefeathertech.com
"If Salvador Dali had owned a computer, would it have been equipped
with surreal ports?"
Mochuelo
<Spammers...@dev.null> wrote:
>In article <jlc8k15onbl8um0se...@4ax.com>, TRABEM <>
>says...
>
>> Has anyone tried Masterbonds conductive epoxy for attaching SMT
>> components to a printed circuit board?
>>
>> Seems like a great idea, especially if it works well:>:
>
> Not really. Consider the angle of serviceability. It's easy enough
>to use a 'HoTweezer' station to replace a bad chip component secured
>with solder. It's darn near impossible to replace the same component if
>secured with Epoxy.
>
> Also, I'm not convinced that "conductive" Epoxy really is. I'd
>want to see some real numbers on resistance per cm/squared on the stuff
>before I even consider it for any sort of repair work.
No, conductive epoxy is used in many microwave circuits, because heat
would ruin the characteristics of the very thin microstrip substrate.
Other than for that, I would not use it.
Robert Baer
I do not know about Masterbonds conductive epoxy(ies), but i have
used silver conductive epoxy.
1) EXPENSIVE, 2) good for short-term and medium-term repair, but no
where as reliable as a solder connection.
Robert Baer
> In article <jlc8k15onbl8um0se...@4ax.com>, TRABEM <>
> says...
>
>
>>Has anyone tried Masterbonds conductive epoxy for attaching SMT
>>components to a printed circuit board?
>>
>>Seems like a great idea, especially if it works well:>:
>
>
> Not really. Consider the angle of serviceability. It's easy enough
> to use a 'HoTweezer' station to replace a bad chip component secured
> with solder. It's darn near impossible to replace the same component if
> secured with Epoxy.
>
> Also, I'm not convinced that "conductive" Epoxy really is. I'd
> want to see some real numbers on resistance per cm/squared on the stuff
> before I even consider it for any sort of repair work.
>
> Any job worth doing is worth doing right. If you're trying to
> attach surface-mount components, invest in the proper
> soldering/desoldering equipment instead of looking for impractical
> shortcuts. It may cost more at the get-go, but it'll cost a lot less in
> the long run.
>
> Keep the peace(es).
>
>
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.
Robert Baer
First time i heard that Kapton or Teflon was heat sensitive...
John Popelish
> 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.
Here are some examples of silver epoxies:
http://news.thomasnet.com/fullstory/460221
10^-3 ohm cm
http://www.mgchemicals.com/products/8331.html
2*10^-2 ohm cm
http://bondline.net/datasheets/2072.pdf
4*10^-4 ohm cm
http://bondline.net/datasheets/2080.pdf
5*10^-3 ohm cm
http://bondline.net/datasheets/2111.pdf
2*10^-4 ohm cm
http://bondline.net/datasheets/2120.pdf
5*10^-3 ohm cm
Copper:
http://www.lehighton.com/AppNotes/CuMetallization/cumetallization.html
1.68*10^-6 ohm cm
According to these sources, copper is about 100 to 10,000 times as
conductive as silver filled epoxy.
Tim Shoppa
> attaching SMT components to a printed circuit board?
> Seems like a great idea, especially if it works well:>:
Sounds like a terrible idea. The surface tension of solder and the
solder mask/PCB landing on the circuit board interact very nicely to
make sure that a blob of solder and the part itself stays on exactly
the right spot when you solder on a SMT component (either hand
soldering or toaster-oven style). None of that is working to your
advantage when you use epoxy.
Hand-soldering even fine-pitch (0.5mm) SMT stuff is not a big deal to
do by hand with even primitive (e.g. just a weller soldering iron and a
fine-tip point and some solder wick) tools. BGA's will require a
toaster oven though :-).
Tim.
w2aew
are available with different termination platings/coatings for such an
application, but they are harder to come by. It won't work as well if
you use devices with terminations intended for soldering.
Ron H
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.
x-- 100 Proof News - http://www.100ProofNews.com
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jpop...@rica.net
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.
John Popelish
> 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)
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.
Jim Thompson
>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 Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
John Popelish
> On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" <rnh...@attbi.com> 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/mediawebserver.dyn?444444VTd894fPm4zPm444spSxgrOkFW-
John Woodgate
<1128646392.6...@g47g2000cwa.googlegroups.com>) about 'epoxy
instead of solder?', on Thu, 6 Oct 2005:
--
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
Jeff B
"Jim Thompson" <thegr...@example.com> wrote in message
news:o7nbk1pnnqu85udf6...@4ax.com...
Glen Walpert
<thegr...@example.com> wrote:
>On Thu, 6 Oct 2005 19:35:36 -0500, "Ron H" <rnh...@attbi.com> 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 Popelish
> I read in sci.electronics.design that jpop...@rica.net 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.
Unknown
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
John Woodgate
<qutfk11t776t59eft...@4ax.com>) 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?
Richard H.
> 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).
Hopefully they've taken the time to write / translate / send you an MSDS
for it...
Richard
Steve Nosko
We looked into it and didn't find anything which looked promising and
neither did the industry. For non critical circuitry, I suspect there is
possibilities
My idea (which was chuckeled at) was " conductive Velcro" Make parts with
the loops and boards with the hooks. Easy repair, eh? Zip off the old,
stuff on the new... No heat, no time to cure...
Imagine a demo of this compared to solder in the early days...
Let's look at the options for electronics assembly. Well you have two
choices:
1- Dip everything in molten lead.
2- stuff 'n go.
Which do you pick...Hmmm difficult chioce, eh?
Ther ewas also something called "particle interface". Many small sharp
conductive points on the PCB, but how to anchor the parts. This was
intended for test fixtures.
73, Steve, K9DCI
Steve Nosko
"John Fields" <jfi...@austininstruments.com> wrote in message
news:haf8k1hs7u06ru7lg...@4ax.com...
In a production line they would probably use UV curing epoxies. They
already do, but not for solder substitute.
73, Steve, K9DCI