Author Topic: Desoldering advice needed  (Read 3669 times)

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Offline zaoka

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Desoldering advice needed
« on: September 24, 2012, 10:09:20 pm »
Does anybody have an idea how to desolder these big ICs from this multilayer, lead free board?

I have desoldering station and JBC soldering station, it does work but its very very long process. I used desoldering braid as well, applied regular solder before desoldering, used soldering paste etc. Its just hard because board just takes temperature away.

Is there any big solder iron that can melt these, one side of the IC at the time, to help with this?

 

Offline mariush

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Re: Desoldering advice needed
« Reply #1 on: September 24, 2012, 10:23:38 pm »
Add solder to each pin, then use solder wick. OR use a desoldering gun such as Hakko 808 desoldering gun.. which will pretty much suck the solder off the pins.

If you're going to do a lot of repairs, it's worth investing in such a tool.
 

Offline Astroplio

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Re: Desoldering advice needed
« Reply #2 on: September 24, 2012, 10:34:28 pm »
Hmm that is some weird setup there! Those huge heatsinks have just IC's underneath (custom-made I assume) or is it a daughter pcb board?
Do I see rivets on the heatsinks ?

Have you tried a heat gun, or you think it would damage the parts?

 

Offline T4P

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Re: Desoldering advice needed
« Reply #3 on: September 24, 2012, 11:37:25 pm »
What sort of desoldering station do you have? The original Hakko 474 sadly don't have enough thermal horsepower, the 474 CLONES do have lots of them. 70-80W
Should be enough for that heatsink, you just have to do add solder to the pins with your JBC ( lots of thermal horsepower ) and then suck them up
I very well suspect it's a DC-DC converter type package that has the heatsinks screwed on before soldering
If you're going to do a lot of repairs, it's worth investing in such a tool.
He said he has one  :P
« Last Edit: September 24, 2012, 11:40:45 pm by T4P »
 

Offline beaker353

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Desoldering advice needed
« Reply #4 on: September 25, 2012, 12:54:53 am »
Try ChipQick. It's this odd special solder that melts at so low of a temp that you have time to pull the component before it solidifies. Extract as much of the regular solder from each joint as possible. Put a bit of their flux down and load up each pin with their solder. Then quickly go to each pin in a circular order to heat them all up while providing just a tad of back pressure to pull the ic out. Pulled some chips out in the past that I thought I had no chance of getting out.

http://www.chipquik.com/

- EM
 

Offline AndyC_772

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Re: Desoldering advice needed
« Reply #5 on: September 25, 2012, 05:14:33 am »
ChipQuik is good stuff, though it can be tricky to get it all off the pins of the device when you want to re-use it. I'm not sure how useful it would be for a device with so many pins to get mobile all at the same time either; it stays liquid for quite a long time after heating with a soldering iron, but not forever.

Personally I use one of these:

http://uk.farnell.com/steinel/hg-2310lcd-eu/hot-air-gun-230v-eu-lcd/dp/1712315

...which sometimes gets some odd looks from colleagues more used to delicate little hot-air rework stations. But it's great! It takes some skill to use it correctly, of course, but with experience and care it can desolder pretty much anything.

Offline zaoka

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Re: Desoldering advice needed
« Reply #6 on: September 25, 2012, 09:46:41 pm »
I have Edsyn ZD500DX, its really powerful but not enough. Even JBC staion that I use have hard time to melt this sucker...
 

Offline T4P

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Re: Desoldering advice needed
« Reply #7 on: September 25, 2012, 09:50:22 pm »
I have Edsyn ZD500DX, its really powerful but not enough. Even JBC staion that I use have hard time to melt this sucker...
Which JBC do you use? Fuse some 63/37 solder and i doubt the ZD500DX has enough suction power and actual 90W in that tiny package
 

Offline zaoka

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Re: Desoldering advice needed
« Reply #8 on: September 27, 2012, 09:42:41 pm »
JBC AD2700 with 2245 iron.

 

Offline T4P

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Re: Desoldering advice needed
« Reply #9 on: September 28, 2012, 07:17:42 am »
JBC AD2700 with 2245 iron.
That's a good one, shouldn't be a problem at all i think
 


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