What are those black things on the board?
Those black sections are either a carbon-glue paste, or a conductive, carbon-doped elastomer. The carbon makes them (somewhat) conductive, and the rest holds it together. They then make contact by simply pressing against the silver-laden ink traces of the keyboard (in the background of your picture, I would guess).

If you want to connect to them, you're probably going to have to scrape the black paste off the contacts, until you reach bare copper, which you can then solder to.



Are you sure that is a capacitive keyboard? The keyboard membrane in the background looks like a pretty standard pressure-activated membrane switch assembly to me.