Adam, I really don't have experience here. The conductive rubber that
is typically found in keypads/keyboards, etc, has too much resistance. As
far as BGAs, I could look into it but I was hoping that someone would
speak up and give the details. My `gut feeling' is that there is a good
reason this technology is not being used in test and programming sockets.

   - Tom

At 11:07 AM 8/26/99 -0400, Adam Davis wrote:
>I've heard they have test and programming sockets at a huge expense.  I've
also
>heard of a less expensive methed, but requires some specialized materials:
>
>Think of a rubber pad, about the same width and length of the BGA, and about
>1-5mm thick.  The rubber pad is conductive vertically (through the pad)
but not
>horizontally(along the lendth and width of it).  Place the pad on a pcb
with the
>bga pattern on it, and press the bga against the pad.  Assuming it's all
lined
>up, you're all set.
>
>I've seen strips of rubber which are used in older calcs to connect the
pcb with
>the lcd.  I assume the rubber pad has the same pronciples...
>
>-Adam
>
>Tom Handley wrote:
>>
>>    Wagner, I was thinking of those DIP-SOIC adapters where you have to
>> solder the SOIC. I think they were around 6-$10 depending on size. This
>> is single qty.
>>
>>    If you are talking about sockets, that's another story. They are
>> expensive. Your idea about replacing a spring contact sounds interesting
>> but it depends on the application. It seems to me that there would still
>> be too much resistance for many applications. The expensive sockets are
>> intended as universal test sockets. The conductive rubber approach would
>> limit it's application. This is really outside of my expertise but I was
>> wondering what they use in Ball Grid Arrays? Can those `conductive bumps'
>> be applied to a socket and at what cost?
>>
>>    - Tom


------------------------------------------------------------------------
Tom Handley
New Age Communications
Since '75 before "New Age" and no one around here is waiting for UFOs ;-)