That conductive stuff on circuit boards

[Mark Healey]

I have a keyboard controller that I'm going to re-purpose (not a Mame
controller). The membranes from the original keyboard were friction
fitted to some traces of black conductive stuff on the card. Will solder
stick to this stuff.

If it doesn't what is the safest way to remove it? What is a good
solvent to try?



--
Mark Healey
marknews@healeyopolis.com

 

[Eeyore]

Mark Healey wrote:

I have a keyboard controller that I'm going to re-purpose

I wish I knew what that meant !

(not a Mame controller).

What's a "Mame controller" btw ?

The membranes from the original keyboard were friction
fitted to some traces of black conductive stuff on the card. Will solder
stick to this stuff.

No.

The 'black conductive stuff' is carbon.

If it doesn't what is the safest way to remove it? What is a good
solvent to try?

I'm not aware of any solvent for carbon. Abrasive removal is likely the only
way.

Graham

 

[Rich Grise]

On Thu, 11 Oct 2007 07:37:57 +0100, Eeyore wrote:

Mark Healey wrote:

I have a keyboard controller that I'm going to re-purpose

I wish I knew what that meant !

It means to stop using it for its original purpose and apply it to
a different purpose.

(not a Mame controller).

What's a "Mame controller" btw ?

MAME is "Multiple Arcade Machine Emulator" - you can play old classic
arcade-type video games on your computer, if you have the ROM images
from the original.

Here's my MAME hack:
http://mysite.verizon.net/richgrise/KeyZilla/

But my edge connector is gold flash over nickel, and solders like
a dream.

The membranes from the original keyboard were friction
fitted to some traces of black conductive stuff on the card. Will solder
stick to this stuff.

No.

The 'black conductive stuff' is carbon.

If it doesn't what is the safest way to remove it? What is a good
solvent to try?

I'm not aware of any solvent for carbon. Abrasive removal is likely the only
way.

Like an "ink eraser", maybe?

I'd just toss it and get ahold of a keyboard that's got a gold edge
connector - they're about five bucks new, or free if you know where
to shop! ;-)

Cheers!
Rich

 

[HapticZ]

re-use of these proprietary nightmares is possible, but intense and tedious.
i use those tiny pushbutton switches to replace the "gone-bad"
carbon/membrane buttons.

membrane hand controllers are nasty short term junk, made to give the
factories endless job security. i hate them.

you may break the carbon, just scribe through it with a pointy object enough
to break the route.. they do not solder, tried again and again many, many
ways NO DICE. no flux or other joins carbon and tin unless you heat it to
about 2000 degrees, but then you end up with an entire carbon pile of junk
anyway.

you may subvert this problem by using something called "Nickle Print" or
some name like that. it is a paint like conductive stuff in a 2-3 ounce
bottle, abt $5-10 buks US dollars. GC electronics, (its not Walmart
stuff), go to a real hobby shop, electronics shop, or EBAY!

http://www.abra-electronics.com/catalog/chemicals/22_201.html

i use that silver plated Kynar wire for prototyping ( wire/wrapped) for
point to point. clean the carbon you want to connect to, strip about .0625
inches (1/16) of insulation from the end, put down a pinhead spot of the
nicklepaint, secure the wire with tape or better, use hot melt glue to
secure, do NOT glue over the paint, it MUST dry BEFORE you use it! most
times it works 99 percent of the time, otherwise you usually put another dot
of nicklepaint on it and dry, other wise, start over. PREPARATION is the
key to success here!

at purchase, immediatly dissasseble them, get to the point between the
contact and those shitty carbon dots and spray some real silicone
lubricant, do NOT use the silicone crap found in Auto supply stores, that
has petroleum product in it that will ruin the menbrane. better yet get
some fuser silicone lube from someone who has one of those monstrous Office
max or Copy Max or Staples duplicating machines. that comes in huge
bottles, they always throw 10 percent away each time they refill.

its gooey, sticky, but it never dries or ever migrates. it displaces
moisture and keeps the switches perfect for YEARS! but you will never be
able to paint anything it touches either.



"Mark Healey" <die@spammer.die> wrote in message
newsan.2007.10.11.05.08.27@spammer.die...

I have a keyboard controller that I'm going to re-purpose (not a Mame
controller). The membranes from the original keyboard were friction
fitted to some traces of black conductive stuff on the card. Will solder
stick to this stuff.

If it doesn't what is the safest way to remove it? What is a good
solvent to try?



--
Mark Healey
marknews@healeyopolis.com