Electronics > Beginners

What did I do wrong?

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alm:

--- Quote from: osmosis321 on February 11, 2011, 02:35:54 am ---The only good point I haven't seen mentioned so far is that you may have erred in attempting to remove that solder in the first place.

I usually just leave it on there; it protects the copper and if I want to replace the part, wouldn't you know it, the right amount of solder is already there.. all I need to do is flux it and it's ready for action.

--- End quote ---
Note that this is only true if you use hot air, since it allows you to melt the tin on all the pads at the same time. With a regular soldering iron, you would be unable to level the chip properly without removing the solder, which is why you usually start with tinning just one pad.

orbiter:
Understood alm, thanks.

orb

Alex:
Pardon me if I repeat what you guys have already suggested. I have read post 1 and 15.

The bottom row seems to be mainly connected to a large copper pour, possibly a ground plane. A lot more thermal energy need to be transferred to fully melt these joines, its like soldering a heatsink! You need to use an 'angled-face' tip with a diameter close to the pad height.

The adjacent pad should have not been damaged, probably the area got very warm and you touched that pad with the solder wick but the solder was not fully melt. Use a solder generously fluxed wick a bit narrower than the pad height.

If you must, place the board on a preheating plate (proper IR, hot air, sauce pan) at 100 deg C or so. A lot less energy will be required then to melt the solder.

To repair the pad see these excellent IPC-based videos:

https://www.youtube.com/user/SolderingGeek?blend=2&ob=1#p/u/8/meulzHIq4Us
https://www.youtube.com/user/SolderingGeek?blend=2&ob=1#p/u/9/dwrnWasLYUc
https://www.youtube.com/user/SolderingGeek?blend=2&ob=1#p/u/7/TFcPxCN93nY

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