A Video Demonstration of Surface Mount Soldering

Soldering is one of those topics where experience means you discount just about everything that other  people recommend. From arguments about which flux is better to which brand of solder, to soldering tips to rework stations, the entire subject is controversial.

So let's strip out the bull and just get down to some simple facts and demonstrations. 

Flux. 

If you're hand soldering a pcb and using a quality solder you hardly ever need it. With a low quality or very old solder you might need some. But not always. However, for wicking solder it's pretty much essential and useful for removing solder bridges with the iron tip.

Expensive or cheap, all flux suitable for soldering electronics works. Even rosin dissolved in methylated spirits works well. I myself can't see the point in expensive fluxes and I chose based on bang for buck.

Solder

Leave lead free soldering to the factories. 60/40 is your starting point. I wouldn't shift from that until it was necessary. If you already have a few rolls of different solder then try this: take a 10-15mm length of solder and put the tip of a hot iron on one end. Good solder will drag itself onto the tip as it melts. Or take a 10-15mm length and apply hot air or other form of heat as it rests along some copper pads on a pcb. Experiment with temperature and flux and see how it flows differently.

Iron Tip.

No evangelical prose from me. If it's hot, it will melt solder. If it's shiny, solder will flow across the tip surface. The more metal at the tip end the better. After a few weeks any tip I use looks terrible. I can clean it with a file and re-tin it. But I don't try and maintain it like a butcher does with knives. I prefer a wide knife tip and avoid long conical tips unless one is needed for access.

A demonstration.

Here are a series of video's showing one of the way's I solder surface mount components. I'm not soldering a board for NASA's Mars Rover so no need to wave a hundred lint free clothes with dubious chemicals at the PCB. Keep it simple and practice. Use TQM principles and wait for defects then decide based on how often they occur what part of the process needs modifying. If you go straight to that NASA soldering so many people try to emulate then you are never actually going to build anything.

Of course there are many ways to solder a PCB. The next example shows that getting the right temperature is more important than how you got it. It's one of my favourite methods because I find hand soldering relaxing and I can pause at any time and pack the PCB's away. For example, I might first trawl through my recycled parts tray and solder those parts on first. The following day, or when my mail order parts arrive, I can take the PCB's out and pick up where I left off.

As an aside I used my mobile phone to shoot these video's. I clamped a piece of wood to the shelf above the workspace and laid the phone down on it. Focus and lighting are note perfect. But I guess it's good enough if it held your attention to this point.