🚀 go-pugleaf

Folks,

I am looking for high density board stacking connectors.
All of my boards will be identical and be about 2.5 inches
square.  The idea is to pass the control, data, and address
busses from one board to the next, indefinitely (at least
from a mechanical standpoint).  Two possible ways of doing
this are:

1.  Using through-hole technology, where the pins from the
    receptacle on the top of the board go through the holes 
    in the board and are soldered to the bottom; the pins
    continue and are used to mate with the receptacle on the
    top of the next board.  And so on.  Kind of like the 
    picture below (Side View).

                           _____
    ____BOARD______________|___|_<-- HEADER 
                            | |
                            | | <-- PINS  
                           _____
    _______________________|___|_
                            | |
                            | |   

2.  Doing a similar thing, but with surface mount where an
    SMT receptacle is on the top, and an SMT header on the
    bottom, and connections are made through the board using
    vias.

                    ______
    ________________|____|_
                     |__|
                    ______
    ________________|____|_
                     |__|

The problem with the first method is that I need two rows of 
40 pins/row.  Since the connector has to be less than 2.5 inches 
wide, I need .050" pins and I haven't seen anything designed to
be stacked like this with .050" centers.

The problem with the second is that I need twice as many connectors,
and allignment problems may crop up.  I found some parts from
Samtec that I could use, but they don't provide enough space between
boards.

So, if anyone knows of a connector I can use, or a company that I
could call to get a catalog, I would appreciate hearing from you.
Or, if you have a better idea altogether of how to stack these I would
like to hear it.  It doesn't matter whether you post to this group, or
mail me at randy@cmu.edu  

I already have catalogs from:

Samtec
Aries
Mil-Max Preci Dip
Hirose
Robinson Nugent
Hypertronics


Thanks in advance,
Randy Casciola
Research Engineer
The Robotics Institute
Carnegie Mellon
Pittsburgh, Pa 15213