Interface To Unknown Edge Connector

[kbarnette]

Hi all,

I have need to build a system to interface with a small board with what appears to be non-standard edge connector pins.

There are 37 pins.  The measurement from left edge of the left-side pin to the left edge of the right-side pin is 32.00mm.  Dividing that by 36, I get a pitch of 0.888888mm.

The board itself is some kind of ceramic and 1.8mm thick.  The pinout is the same on both sides of the board so even a single-sided interface would be fine.

Ultimately I need a system to accept this "card" (there are many that will need to be swapped in) and then break it out to a cable (which I can figure out).  The part I'm stuck on now is how to interface with this card edge.

[ebastler]

Hmm, that's a curious one. Could you tell us what the plug-in boards are? Maybe that helps someone to identify the connectors.

On your photo, it looks like nothing is connected at all to the card-edge pads; and you mentioned that both sides are identical with respect to connections. I am a bit confused -- are there non-obvious connections to the pads?

[kbarnette]

Thanks for the reply.  I can't be very specific about the project.  These boards are used in an aviation capacity (though what I'm building won't actually be in a plane).  The traces are internal to the board material which is a type of ceramic composite so that's why you can't see them.  Is there anything specific about the dimensions of these pads that would be helpful to figure out how to interface with them?  I initially anticipated being able to develop a plug-in solution (which I think would be ideal) but I've also been considering something with pogo pins.  I've never worked with them so I don't know what to look for on Digikey.

[sleemanj]

I'd say it's 0.035 Inch pitch.

[daqq]

If you get desperate you could use pogo pins - make a PCB with pogo pins in the right positions. You wouldn't insert the card, rather you could lay the card on the pogo pins and secure it with something. Maybe mill a holder, some kind of socket from plastic?

You can get really small pogo pins. It might cost a pretty penny, but since it's aviation-ish, money is probably not an issue.

edit:
I noticed you had this same idea 

...but I've also been considering something with pogo pins.  I've never worked with them so I don't know what to look for on Digikey.

Dunno if they have them on digikey, you should look directly at the manufacturers catalog. See manufacturers such as feinmetall ( http://www.feinmetall.com/products/contact-probes/ ) or ingun ( http://www.ingun.com/en ). I know that farnell does not stock them since there's so many of them available. I've had experience with both of these manufacturers, both are good, both will sell directly at low quantities - or rather their local distributor will . Or you can go the ebay route and order a load of crappy probes from China for a fraction of the price

See feinmetall catalog: http://www.feinmetall.com/fileadmin/Downloadseite_Dateien/Gesamtkatalog_Kontaktstifte_2015_EN.pdf

[kbarnette]

Thanks for the suggestions.  I'll dig into them once finals are over.