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Can you help me please When I desoldering ic touch or other ic (u2…) I want to clean the board connections with braid desoldering but each time I damage them I use a braid to desolder and the power in my iron to weld is at 450 degrees I would be very grateful for the help you bring me
Solder wick is an really old school technique for cleaning old solder from a pcb. Think about it, people were wicking pcb’s back in the day of giant through-hole components on thick single-sided or double-sided pcb’s. A modern smartphone or tablet logic board is barely 1mm thick and has 10 layers of traces with tiny pads of ~0.3mm diameter. So what you end up having is very thin copper traces, very thin pcb’s and very high component density. The longer you apply heat to the board, the more you damage the adhesion of these tiny pads. When you add the abrasion and friction from wicking, you lift pads very easily. Additionally, I believe you are applying too much heat (450C is too high, aim for ~380, adjust as necessary) and based on your 5th picture, the tip is much too large. The J-Tip is better. What I prefer to use is a concave tip ( I use the Hakko T15-BCM2) and let the “well” suck up the excess solder on the pads. I don’t aim to scrub it clean, just keep the surface as flat as possible for the next chip.
An alternative I have used is to cut a 1 inch piece of braid and hold it in your tweezers. cover all other areas with Kapton tape except area you are working on to 1. protect other components from heat and 2. to keep the other components from moving. put flux down on pads working on and focus heat on braid. then using wick like a paint brush, lightly brush solder (Do not brush against other components) and it will soak up. I keep a few cut pieces near by to change up after piece is full of solder on tip. Just try to keep it short as an iron is better to focus heat on area you are working on and the hot air is indiscriminate and too much heat is not good for the board or for the components surrounding the area you are working on or the reverse side. Check out this video at 35 min to about 37 min. https://youtu.be/_f2SSXYIF9E
