Hi all,
first post so be gentle
- I've been lurking around the forum for some time though!
I am laying down the groundwork for a project that uses reasonably small daughterboards (~80x45mm) which I was originally going to simply use header pins to connect to the main board. However as the project has progressed I started to consider other ways to connect - one of the main reasons for this is I want to be able to use the same daughterboards in a backplane type add-on as well as on the main board so mounting horizontally or vertically would be nice as well as the connectors being cheaper in the long run.
One of the more preferred methods would be to use the M.2 connectors found in a lot of newer hardware like SSDs and Wifi boards. I can envisage one problem with this however, the M.2 spec only has boards going as wide as 30mm (although as long as 110mm). I could swab the board layout around to be more aligned with the M.2 style (ie. 45mm wide 80mm long) however I would prefer not to if I could get away with it.
There won't be many components on the daughterboards - the heaviest would consist of 2 DIP24's, 2 DIP8, a DIP14 and a few SOIC's with a few SMD aluminium caps and the rest would be 0603's. The board will be entirely 5V with less than 500mA current and carry digital as well as analogue signals.
My main concern is with the board thickness (M.2 spec's 0.8mm thickness) and stress on the board edge connector. Unlike a usual M.2 connection, the user would be connecting/disconnecting more often but not a crazy amount, probably less than 100 times. The far side of the PCB would still be screwed onto the main board as with any normal M.2 SSD etc.
Would the board edge be up to this task and would there be an excessive amount of stress on the rest of the PCB? I know there have been a few topics discussing flex of 0.8mm boards and the general conclusion was it depends what's on it but generally it should be okay.
I'm not against using any other connector (or indeed retaining the header pins) but the M.2 solution is neat and cheap.
Thoughts? Entirely possible, risky or ludicrous?!