Solder and Desoldering wick sizes for smd?

[jamesmith134]

Hello!
What sizes of solder and desoldering wick should I choose for smd rework?
*Edit : Also, what is your preference ? 63/37 or 60/40?
Thanks!

[nanofrog]

You want to match the size of the pad to the size of the wick (.pdf sizing guide <other useful tidbits of info in this>), so it will depend on what packages you're trying to solder.

Based on passive packages (resistors/capacitors), the following might be of some use.

#1/White; 0402 & smaller
#2/Yellow; 0805 & 0603
#3/Green; 1206
#4/Blue; 1210
#5/Brown; 2512 & 2010
#6/Red; 1218

Chemtronics also makes a Purple size, which is meant for BGA.

#3, #4, #5 are also quite useful sizes for thru-hole pads.

At home, I compromise a bit to skip keeping every single size on hand, so I only keep a few sizes (#2 - 5, and use #2 & 3 the most).

For solder size, I use .025" wire diameter 63/37 primarily (.020' is also liked by many). If you do a lot of thru-hole, .031" is a bit more useful IMHO as it doesn't take quite as long a piece so the solder time is shorter (less to feed into the joint, so you get the heat off faster). You can also wrap a couple to three loops around your fingers of the finer diameter, then twist for larger joints (tinning thicker wire & thru-hole for example). Do note that the smaller diameter wire sizes will cost more, all other things equal.

Get good quality supplies rather than eBay specials. Works vs. lots of frustration and possibly damage. Chemtronics is top notch for wick (figure good stuff is ~$4 per 5' bobbin), and Kester will be readily available to you for solder here in the US (under $30 for a 1lb spool if you look; All-Spec and Stanley Supply would be places to look for some good deals). I prefer rosin, but will also use no-clean.

I'd recommend staying away from water soluble fluxes, as they have to be cleaned off within a few hours of soldering, or it will corrode your freshly made joints and the PCB pads.