Desoldering advice needed  - Page 1
Forum section: electronics / general

author: zaoka
author_rank: Frequent Contributor
timestamp: September 24, 2012, 10:09:20 pm
content: 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?

author: mariush
author_rank: Super Contributor
timestamp: September 24, 2012, 10:23:38 pm
content: Add solder to each pin, then use solder wick. OR use a desoldering gun such asHakko 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.

author: Astroplio
author_rank: Regular Contributor
timestamp: September 24, 2012, 10:34:28 pm
content: 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?

author: T4P
author_rank: Super Contributor
timestamp: September 24, 2012, 11:37:25 pm
content: 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. 70-80WShould 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 upI very well suspect it's a DC-DC converter type package that has the heatsinks screwed on before solderingQuote from: mariush on September 24, 2012, 10:23:38 pmHe said he has one

author: beaker353
author_rank: Unknown
timestamp: September 25, 2012, 12:54:53 am
content: 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

author: AndyC_772
author_rank: Super Contributor
timestamp: September 25, 2012, 05:14:33 am
content: 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.

author: zaoka
author_rank: Frequent Contributor
timestamp: September 25, 2012, 09:46:41 pm
content: I have Edsyn ZD500DX, its really powerful but not enough. Even JBC staion that I use have hard time to melt this sucker...

author: T4P
author_rank: Super Contributor
timestamp: September 25, 2012, 09:50:22 pm
content: Quote from: zaoka on September 25, 2012, 09:46:41 pmWhich 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

author: zaoka
author_rank: Frequent Contributor
timestamp: September 27, 2012, 09:42:41 pm
content: JBC AD2700 with 2245 iron.

author: T4P
author_rank: Super Contributor
timestamp: September 28, 2012, 07:17:42 am
content: Quote from: zaoka on September 27, 2012, 09:42:41 pmThat's a good one, shouldn't be a problem at all i think