Low profile, vertical Board to Board connector for multiple STM32 daughterboards

[LMorr.3]

I have a main board with an STM32 uC which communicate with multiple STM32 uC daugtherboards over SPI.

I currently use standard male pin headers on the top of the main board, and female socket connectors on the bottom of each daughterboard. The resulting height of the 2 stacked boards needs to be decreased somehow.

Is there a better way to do this type of board-to-board connection with a lower profile than what is achieved using standard pin headers? There will be no components on the main board under the daughterboards, so can use horizontal headers instead of vertical, however it takes up too much space and I would prefer finding a lower profile vertical connector if possible.

Thank you!

[S.Ma]

Usually reusing high volume PC connectors is one option.

Consider the M.2 NGFF connector which is used to add module boards to a laptop...

M.2 - Wikipedia

Cost about 1 USD a piece, only one PCB needs it. The module uses thinner PCB.

There are different connectors with different keys and different connector height depending if the carrier board and/or the module has SMD components on both sides.

And regarding signal integrity, that's pretty better than any header of any pitch.

More difficult to do Signal Probing and debugging / hacking-soldering the connector pin will be the cost to pay.

[FBL]

Hello @LMorr.3​ 

You may refer to different partner suppliers for different types of connectors and choose the right option.