General question: How deep does the recapping have to go?

[TechGuyVincent]

Hi all!

Sorry if posting this in the wrong section but just wondering the following:

If you are recapping and you notice corrosion on a chip - do you desolder the chip entirely (with the possibility of breaking it) or just try to neutralize the cap "juice" as much as possible using an alkaline solution and get it under there? I am all for cleaning up the board/traces and chips, but I also feel the risk is higher to break some chips if I would have to lift them completely.

Thoughs?

/V

 

[joshc]

Yeah I lift them off if the corrosion/cap goo is really bad. It's often the best way of really ensuring everything is clean, under the chip, the pads, and the chip legs. You're only going to damage stuff if you use hot air incorrectly. Sometimes the corrosion is so bad that the chips have to be replaced anyway, cap goo can eat away chip legs.

 

[TechGuyVincent]

Yeah I lift them off if the corrosion/cap goo is really bad. It's often the best way of really ensuring everything is clean, under the chip, the pads, and the chip legs. You're only going to damage stuff if you use hot air incorrectly. Sometimes the corrosion is so bad that the chips have to be replaced anyway, cap goo can eat away chip legs.

Cool! I'm using an soldering iron and a wick only - Its rather large components - but I notice that some chips have their legs "inwards" making it more difficult. I figure that I might de-solder the stuff that looks really bad but bathe the board in something that can neutralize all the capgoo aswell. Thanks for your input!

/V

 

[joshc]

The way to desolder those is with hot air really, much easier once you get the hang of it.

 

[TechGuyVincent]

The way to desolder those is with hot air really, much easier once you get the hang of it.

Thanks! I have tried in the past - but it was a cheap station and I suspect the temperature control didn't work..... I'll check it out

 

[joshc]

Thanks! I have tried in the past - but it was a cheap station and I suspect the temperature control didn't work..... I'll check it out

315C, keep the air moving around the chip, preheat around it from a distance and then you can go a bit closer to the legs for the final bit of removal. The chip can be pushed down and moved side to side but dont pull up before its free. This method has worked well for me, but you still need to be careful to not overdo it.