Soldering Iron Guide
Edit on GitHubChoosing an iron, tips, temperatures, and the technique that makes clean joints on the beacon's modules.
Soldering Iron Guide
A good iron and a clean tip make the difference between a tidy board and a rework session. This page covers what to buy and how to use it.
What to buy
- Minimum: a 25-40 W fixed-temperature iron. Works, but temperature control is manual (plug/unplug).
- Recommended: a temperature-controlled station (e.g. 936-style clones or the Hakko FX-888) with an adjustable range of 200-450 C.
- Tip: a conical or small chisel tip (1.0-1.6 mm) suits the module pads. A 2.4 mm chisel helps for ground pours.
Temperatures
- Lead solder (60/40): 300-330 C.
- Lead-free (SAC305): 350-380 C.
- Too hot (400+): lifted pads and burned flux.
- Too cold (under 280): dull, spiky joints and cold solder.
Technique for module pads
- Tin the tip with a little fresh solder.
- Touch the pad and the wire lead together with the tip for 1-2 seconds.
- Feed solder at the junction, not onto the tip.
- Remove the iron and let the joint cool without moving it.
- A good joint is shiny (with lead), wets both surfaces, and forms a smooth fillet.
Common defects
| Defect | Cause | Fix |
|---|---|---|
| Dull, grainy joint | Cold solder or lead-free at low temp | Reheat with flux |
| Solder bridge | Too much solder between pads | Wick it away |
| Spike | Iron removed too slowly | Less solder, faster lift |
| Lifted pad | Too hot or too long | Lower temp, shorter dwell |
Iron care
- Wipe the tip on a damp sponge or brass wool after every few joints.
- Never file a tip; a new tip is cheap.
- Keep the tip tinned when not in use to prevent oxidation.
- Unplug the station when you leave the bench.