Non-Chemical Removal of rubber backing on a telecom board type of chip

[crip53]

Hi all,
Got a bit of a poser.
Have a sample telecom board from back in the late 70's to early 80's with some nice little standard shaped gold chips, etc.
However, there are two other types that have me a tad baffled because they share a gray, rubberized coating. One of the chip types is a white ceramic standard looking chip that pops apart in two no problem.
It is the bottom half that has a white coated rubberized cover over the gold pin circuits, and the other chip is built different. It is a thin retangular verticle standing 'chip' the used about a dozen silver legs, but has a gray rubberized coating on the back side, that when peeled away reveals a nice gold circuit too. The white front has the AT&T logo and numbers on it.
My question is, Is there a chemical that you know of that will strip that rubber backing off without harming the gold circuitry?
So far I have just used a razor blade to get a corner started, and pulled some off, but that method does a lousy job since it tears and hugs the pins to.
Never saw this kind of thing, so any help would be appreciated.
Thanks in advance :lol:

 

[macfixer01]

Hi all,
Got a bit of a poser.
Have a sample telecom board from back in the late 70's to early 80's with some nice little standard shaped gold chips, etc.
However, there are two other types that have me a tad baffled because they share a gray, rubberized coating. One of the chip types is a white ceramic standard looking chip that pops apart in two no problem.
It is the bottom half that has a white coated rubberized cover over the gold pin circuits, and the other chip is built different. It is a thin retangular verticle standing 'chip' the used about a dozen silver legs, but has a gray rubberized coating on the back side, that when peeled away reveals a nice gold circuit too. The white front has the AT&T logo and numbers on it.
My question is, Is there a chemical that you know of that will strip that rubber backing off without harming the gold circuitry?
So far I have just used a razor blade to get a corner started, and pulled some off, but that method does a lousy job since it tears and hugs the pins to.
Never saw this kind of thing, so any help would be appreciated.
Thanks in advance :lol:

I've had some of those chips too and the only way I found to remove the coating was to peel it off as you did. I really didn't try any chemicals though. It's some type of early conformal coating material, and has a rubbery consistency. It's sort of like the black rubbery sealant on the bottom of dip switch modules to allow flow soldering. My guess would be try different organic solvents like MEK, Acetone, Toluene, Lacquer Thinner, anything you might have around already. You might get lucky. Just do it outdoors or in a well ventilated area.

macfixer01

 

[crip53]

My first thought was acetone. Just thought I'd check the forum first.
Thanks