George Herold wrote:
On Jan 20, 11:32 pm, Phil Hobbs
wrote:
I have a partly-baked idea for improving temperature controllers, but it
requires a bunch of nickel plated polyimide film--say 3 to 8 mils thick,
with 40 microinches of electroless nickel on it.

I need to pattern it and then solder to it. Copper is too conductive,
which is a pity, since I already have a roll of polyimide with 1/2 oz Cu
on it.

I haven't found anybody that's interested in supplying it in engineering
quantities (say 10 square feet).

Anyone here have a favourite shop that does nickel plating on plastic?

Thanks

Phil Hobbs



I assume aluminized mylar won't work. I didn't know you could nickle
plate onto plastic? Could you get a local electroplater to put nickel
on aluminized mylar and solder to that?

George H.

Thanks.

I'm planning to use it as a really big RTD, so I need a continuous film
of reasonably pure metal with reasonably uniform thickness. The films
have a tendency to crack if the base layer is too thin or too flexible,
which is bad. If I roll it into a cylinder with the metal side in, I'll
put enough of a compressive preload on the nickel to keep it from
cracking under temperature cycling. When the process is better
developed, it might be useful to do the plating on the outside of a
cylinder, so that there'll be a preload when it straightens out.

I'm not sure what temperature the plating is done at, but for lower
temperatures there should be a compressive preload anyway, due to the
differential thermal expansion.

I have a roll of copper-clad polyimide, which is beautiful stuff, in
fact about 250 times too good for this job--the copper is 12 times too
thick and 20 times too conductive. A 40 microinch nickel film is just
the ticket.

Mylar isn't really solderable--it isn't refractive enough. Indium might
work.

Cheers

Phil

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
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