Synth-DIY Yahoo! Groups Archives

Thread

Membrane-switch material/process on PCB's

2003-05-23 by Neil

There is a special type of material that is used on PCB's for membrane-switch
contacts. I believe it's carbon, and usually laid out in some "interlocking"
fashion to ensure contact/bridging when the membrane touches it. Seems to be
made directly on the PCB. Anyone know what this is, and how it's made?

No, I don't need any, but would like to know what it is exactly and how it's
done.

I'm sure I have something with it here, and will take a pic when I find it.

Cheers,
-Neil.

Re: [Homebrew_PCBs] Membrane-switch material/process on PCB's

2003-05-23 by JanRwl@AOL.COM

In a message dated 5/23/2003 3:21:22 AM Central Standard Time,
cobra_neil@... writes:

> There is a special type of material that is used on PCB's for
> membrane-switch
> contacts.

Neil: The only such stuff I am aware of is "conductive rubber" which the
membrane presses onto GOLD-plated contacts on the PCB. These are usually several
interwoven "fingers" so that even a small % of contact by the rubber
"plunger" causes a "make".

[Non-text portions of this message have been removed]

Re: [Homebrew_PCBs] Membrane-switch material/process on PCB's

2003-05-24 by Ron Amundson

----- Original Message -----
From: JanRwl@...
To: Homebrew_PCBs@yahoogroups.com
Sent: Friday, May 23, 2003 6:33 PM
Subject: Re: [Homebrew_PCBs] Membrane-switch material/process on PCB's

In a message dated 5/23/2003 3:21:22 AM Central Standard Time,
cobra_neil@... writes:

> There is a special type of material that is used on PCB's for
> membrane-switch
> contacts.

Neil: The only such stuff I am aware of is "conductive rubber" which the
membrane presses onto GOLD-plated contacts on the PCB. These are usually several
interwoven "fingers" so that even a small % of contact by the rubber
"plunger" causes a "make".

I've also seen screen printed conductive ink on the pcb. The gold plating with conductive rubber seems to be a better solution, but perhaps someone else can expand the discussion. Maybe its a cost issue?
Ron

[Non-text portions of this message have been removed]

Re: Membrane-switch material/process on PCB's

2003-05-24 by rolanyang

I've seen very simple ultra-low profile switches
on some PCB's.
The mechanism seems to be a flexible concave piece
of metal which, when pushed down, "pops" into the
depressed state, but has enough springiness to
pop back up when released. The buttons are usually
taped to the board with a strip of adhesive tape.