MIDIBox SID Project Blog
Wiring the Matrices
First I did the diodes and soldering just the cathodes. The top row of cathode leads I soldered by themselves. Then for each row below I bent the cathode lead so that it touched the cathode lead of the diode below it and repeating that process built the columns for my matrix. Next I added the pin headers and following a tip I found online I held them down with some of the plastic foam my components shipped with. I had to wrestle the pin headers on the edge of the matrix back into their hole after some were accidentally pulled out by the foam, but ultimately I got them all to stay in place after taping the foam down to the perfboard.
So next I needed to connect the anode leads of the diodes to their neighbor pin head. I found for this task it was easier to clip the anode lead fairly short so I could lay it down on the pad for the pin header without disturbing the ones near by. Initially I was still not cutting the leads short enough and they would extended beyond the targeted pad, but later on I started making the shorter to avoid this.
Near the end of this round of soldering I ran out of my old solder and switched to my new solder. Both solders were 63/37 mixes, 0.8mm thick, and with 2% flux, but this new solder just doesn't melt well (I thought my old solder was bad, this is worse). To finish the rows I had to turn the soldering iron up an additional 100 degrees from 760 to 860F. This seems way to hot so I think I may have to invest in higher quality solder instead of $5 spools from China.