Runny but fast-cure conductive epoxy?

Too bad someone doesn't make a UV curable conductive epoxy.

tm

Yeah. Someone has a patent though but that's all I know about it:

But UV-curable dielectric are available:

That's how bonding is sometimes done. But I neither have the equipment nor the time for lengthy science experiments. I don't mind the soldering but the bond strength on these experimental devices is so weak that merely touching the gold wires with a Weller tip can (and have) make the bond fail. It's like trying to attach a postage stamp with the bucket of a Caterpillar.

Why not use a gold-plated FFC jumper and wire-bond directly to that? Thermal conductance and flexibility will be reasonably similar.

Cheers

Phil Hobbs

FFC cable is much too stiff and mechanically heavy. I have strands of really thin litz wire that work nicely. I'd just like to bond them without using heat.

Maybe some solder with a really low melting point would work although the Weller won't go below 350F which is still similar to a hot barbecue.

Well, the idea may be toast anyhow because I need it tomorrow morning and it seems there's air shipping restrictions placed on such stuff now:

We've used these

MFR1 LOCTITE 3880 10.6G SYRINGE RS HUGHES MFR2 TRA CON TRA-DUCT 2902 2G 2-PART PACKETS MFR3 HYSOL KS4008 5.6 OZ. WOLCOTT PARK

and you might try the Trace Technologies 2505-N conductive pen, intended to repair PCB traces.

You might give MasterBond a call.

They have an applications engineer available by phone.

Just for the hell of it, could you ask for something _normal_ from time to time?

:)

I can ship you the Trace conductive pen, for tomorrow AM delivery.

It will cost you, in a liquid currency.

You can buy bismuth solder paste with a melting point down around 140 C. You should be able to melt all your junctions at once by passing a heat gun over them for a second.

Ultrasonic bonder, followed by a hydrogen torch to 'cut' the Au wire and make a small ball for the next bond

Ugh! Most conductive epoxies are NOT terribly conductive. If you want to drain off static charges, it works, but for conducting any real current, it usually doesn't work well. Part of it may be not breaking through oxides on the wires. I have gotten some silver paint that sort of worked better. The stuff we've used most recently was MG Chemicals Silver Conductive Epoxy, but as I say, good for draining static charges only. I doubt you'll get anywhere near a few Ohms with any conductive epoxy.

Jon

The serious silver-filled stuff is pretty good, numbers like 0.001 ohm-cm.

It's nearly standard to bond gold wire to a PCB pad (like a lot of chip-on-board items); can you use an intermediary circuit board?

That would be no problem :-)

But what is conductive pen? Can that hold a couple of very thin wires together at a point where they cross, like solder?

Ah, this is what a Trace pen is:

I think those won't hold wires together that are in the air though. Also it should not be shipped for next day air because it's not legal to be carried on aircraft for safety reasons.

Is any of the other three real runny and somewhat fast curing? I only need it to hold the wires together in the air, no additional component weight snce that is going to be on a mechanically supported carrier.

Yeah: Can I have fries with that? :-)

Just came back from our local Mexican place, had a nice burger with Jalapenos, home made fries and the whole nine yards. And a Negra Modelo from tap.