LED Cube: Soldering SMD is not easy

Yesterday I received the last important parts which prevented me from starting to build up the concept circuitry in real hardware, namely the adapter boards for the LED driver SMD IC STP16CPS05. I also acquired a new soldering station and a fine solder tip to be able to work on the tiny contacts. I was not able to pick up solder flux and solder paste as it was not in stock but I decided in the evening that I still give it a try and solder the stuff simply with my 0.5mm solder wire.

To sum it up: it was a desaster. I had no problem with the first two opposite pins to fix the IC on the board but when I began soldering the inner pins the solder did not stick correctly, formed balls and began spanning several pins quickly. I had quite some problems getting the excess solder away from the pins and at some time even the desoldering wick became trapped between the pins. After an hour I managed to get most of the solder out of it again but the plan of ordinary soldering went down the drain. So much for that. I'll spare you the pictures of the incident and I hope that the IC and board were not damaged in the rescue process.

I now suspended the soldering activities again until I'm able to pick up proper SMD soldering equipment: solder flux, solder paste and desoldering wick with flux.

At least I did not make another mistake. Initially I planned to solder the connectors onto the adapter board prior to the IC so that I could stabilize it while soldering in the breadboard. Just later I found out that if I had done this, I wouldn't have been able to reach the IC pins anymore with the solder tip...


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When soldering SMD parts you have to take the biggest solder tip as possible to get enought heat to the soldering parts.

@Max: Yes, that's another thing I've found out via soldering instruction videos. The next time I'm at the electronics store I'll pick up one of those flat-head soldering tips. Nevertheless, as I described in my next posting, I also got acceptable results with my default pencil-tip. In fact the primary issue which was the cause of my problems was a dirty tip which I didn't recognize because of a lack of soldering practice. Well, this specific lack is now fixed ;)