The connector on the keyboard cable isn’t very friendly to DIY projects and to be able to wire it up to a microcontroller or similar I would need a breakout board. I used the free and open source PCB software KiCad to design a simple board which I then sent to PCBWay for manufacturing. It isn’t the first time I order PCB s from them and I have always been pleased with the results. I also ordered an SMD stencil because of the surface mounted connector. When I got the delivery, it turned to be a aluminum stencil on a big frame, which is very unnecessary for my small PCB but the price was good and it was the smallest size available.
Now, to the soldering part. I don’t have any solder paste at home and I couldn’t find a store that had it in stock so I did the only thing I could, try to hand solder it. It may seem a bit crazy to hand solder SMD components, and the keyboard connector is even more crazy, the spacing between the pins are only 0.33 mm! I didn’t succeed the first time, but after many tries, I finally got it right. The first step I did was to put some solder on one of the big pads. Then I put the connector on the PCB as good as I could and then I melted the solder on the pad with the soldering iron. If it where incorrectly aligned, I adjusted it by melting the solder again and pushed the connector a little bit. When it was aligned properly, I put some solder on the rest of the four big pads. To solder the small I/O pins, I first put some solder on the tip of the soldering iron and then wiped it off, to only leave a very, very small amount of solder. I then just put the tip of the soldering iron on the pins until they all got a connection without any short circuit.
I will try to use solder paste for the next 9 boards and hope for a much easier soldering process with a more beautiful end result.