I have a Hakko FX-888D that works great for all of my normal projects using a T18-D16 chisel tip. A few months ago, i picked up a T18-BR02 conical bent tip (OEM Hakko, not a knock-off) for some SMD work and can't seem to figure out how to use it properly. The issue i have is that the solder immediately wicks up from the fine tip to the fatter body of tip. The solder doesn't seem to stick to the tip. This makes it impossible to use this tip to solder small components or clean up solder bridges between pins on TQFP chips and other similar layouts where my chisel tip won't fit well. I've tried different fluxes, different solders and different temperatures with no success. I typically solder at 650F for SMD stuff. Any insights or wisdom about using this tip would be appreciated.
The heat transfer to the point of very fine tips is poor (since it’s so thin), so the point ends up being appreciably cooler than a fat tip would be, with the station set to the same temperature.
Turning the temperature up will let the point heat up enough for solder to “take” properly.
With that said, I really don’t like working with really fine tips. The only time it’s truly necessary is when you have to solder wires to individual tiny pins/pads. For normal IC soldering, the tip doesn’t need to be tiny. A bigger tip that can maintain heat better often works best.
Added flux is a must (I recommend a paste flux for reticent bridges), but eventually the solder is simply too “overcooked” (prolonged heating results in oxidation as well as dissolved metals from pins and pads) and will no longer flow well. If that happens, flux the joint, then flush your soldering tip with tons of fresh solder, wipe clean, and re-tin with more fresh solder. Then without delay go and fix the bridge. If it still won’t clear, you may find it necessary to flush the solder joint itself with fresh solder, then suck off the excess.
For QFPs, SSOPs, etc, I highly suggest a drag soldering tip (I think Hakko calls those the hoof tips), the kind that’s a concave bevel. It’ll suck off excess solder. If not that, then a bevel tip.
The other tip type I’ve come to adore is the PLCC knife. They’re designed for getting deep into corners of leadless packages. So it’s a “big” tip with plenty of thermal mass, but whose edge is sharp enough to get into places a fine conical or chisel can’t! I’ve found nothing better for clearing bridges from PLCCs and QFNs.