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Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 02, 2013 10:40 pm
by Flaps 30
I'm sure that many of you have different ways of removing the Atmega 64 to replace it with the m128 or just removing other SMD components. The way I have done it on two transmitters (and on the voice module WTV chip) is to use Chip Quik. On all occasions it was painless removing them and cleaning up the pads before putting the new component in place. The kit that includes flux paste isn't cheap, but IMO it is a lot cheaper than having a board that is damaged.

The iron used here (one of many) is a temperature controlled one fitted with a 5mm tip when using Chip Quik. The temperature on my iron for the removal operation was set to about 270°C (518°F ) to help reduce the chances of lifting any of the solder pads due to heat. For me it has worked every time. Just a quick go around with some solder wick before cleaning off all the old flux leaves a nice base for the new chip/component. Most people just leave their irons set for normal working which is fine.

The most difficult operation in fitting the m128 was soldering back the two switch wires and the haptic wire. To make up for aging eyes. I used some +3.5 reading glasses for desoldering. Soldering was done with a 10X Loupe for one eye.

Worth a look at the Chip Quik video. It worked as shown with me. -----> http://www.chipquikinc.com/

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Thu Jan 03, 2013 2:30 am
by ShowMaster
Thank you, great first hand description.
SM


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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 4:25 pm
by jhsa
Flaps30, What kind of ChipQuik did you use to remove the m64?
as far as I know there is one for lead free that can be used for both types of solder and the other for leaded solder.
The m64 I think is soldered with lead free solder.
My problem is that I think I've ordered the chipquik for solder with lead. "SMD1" and not the "SMD1 NL"
Just need a third opinion here if it would work.. :D

Thanks

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 5:47 pm
by Flaps 30
I used the standard Chip Quik, as I use proper (leaded) solder to fit the new components. So I wouldn't worry too much about it. I have read that there might be some issues about mixing things up, but with the leaded Chip Quik and leaded solder I don't see a problem.

I generally use Low Melting Point solder (62% Tin, 36% Lead, 2% Silver) for small SMD work, rather than my other favourite with is the standard 60/40 solder.. I do have some lead free stuff around, but that rarely sees the light of day.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 5:55 pm
by jhsa
Yes, but when you remove the chip it has lead free solder from factory. that's why I asked if there were any issues using the chipquik for leaded solder.
of course I will use leaded solder to solder the new chip on the board..

João

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 6:01 pm
by Flaps 30
With the Chip Quik mixing with the lead free solder that was used originally you have a rather odd mix of metals going on to negate any reason to stick with lead free. When you have cleaned up the pads as shown in the video, there is very little left of the original mix. Hence why I don't see any problem at all.

Have you got your Chip Quik yet João?

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 6:04 pm
by jhsa
Might get here in a couple of days.. coming from Spain

I do apologise for all the questions, but it is a complete new thing for me.. even removing a SMD chip is new for me..

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 6:16 pm
by Flaps 30
You will be amazed at how easy it is to do the job with this stuff. Turn down your iron temperature if you can, as it will help stop overheating things as it doesn't take much heat to do the job. Looking forward to your results. :)

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Wed Jan 09, 2013 6:20 pm
by jhsa
I will, thanks for the tips. I really don't want (can't afford) to mess it up.. I'm stepping on unknown ground.. ;)

João

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 2:28 pm
by jhsa
Chip Quik arrived today.. I had a pleasant surprise as it is the lead free version that works with leaded and lead free solder. So, now I just have to get rid of this cold and do it..

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 2:38 pm
by Flaps 30
Great to hear that you have got it. :) Wait for that cold to go. Nose dribbles don't make a good flux.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 2:43 pm
by jhsa
Flaps 30 wrote:Nose dribbles don't make a good flux.
Muaaaaahh haa haa ha. That was funny.. Can't stop laughing :mrgreen: :mrgreen: :mrgreen:

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 3:01 pm
by ShowMaster
Best prices I come up is $12-14.
Any better prices including shipping?
SM


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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 3:55 pm
by jhsa
I wish. The best price I could find in Europe was €21 + €2 postage.. :(
Tried Digikey, and they have a decent price (about the same as in your post) but they seem to want 18€ to post it to Germany.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sat Jan 12, 2013 5:04 pm
by mbanzi
ShowMaster wrote:Best prices I come up is $12-14.
Any better prices including shipping?
SM
There is a seller on eBay (cyberdoc or cyberdoctormd) selling 6.5" lengths of ChipQuik for $5.32 including shipping. That should be enough for 1-2 chips I think. Not sure if it's the real thing, but mine arrived yesterday, so I'll try it on something else to test before I tackle the 9x though! Do a search for "chip quik"...

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 3:35 am
by ShowMaster
I'm looking forward to what you think.
SM


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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:29 pm
by mbanzi
ShowMaster wrote:I'm looking forward to what you think.
SM
Just desoldered a smaller ATmega chip (32TQFP) using the eBay Chipquik - stuff works great, can't believe how easy that was!!!

I followed the procedure as described in the videos:

1 - Apply paste flux to all the pins (I used the flux they supplied in a syringe)
2 - I set my soldering iron to 550F (290C). They suggest 500-600F, lower is better I assume.
3 - Melt Chipquik on pins until you have a solid bead covering all of them
4 - Drag soldering iron tip over all pins
5 - Try to push chip with a toothpick, if it doesn't move go back to 4 & repeat until chip slides off pads
6 - Pick up remaining Chipquik from pads by dragging soldering iron tip lengthwise over pads
7 - Clean up flux with alchohol

Ok, now on to the ATmega64!

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:33 pm
by Flaps 30
Simple isn't it. :) We await your final result. Are you changing the mcu for the M128?

I used a lower temperature, combined with a broad tip on the iron.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:38 pm
by mbanzi
Flaps 30 wrote:Simple isn't it. :) We await your final result. Are you changing the mcu for the M128?
Yes! I'm a little more apprehensive about this mod than any other, especially after reading about the flashing problems some have been having. Fortunately I have two 9x transmitters!

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:39 pm
by Crucial

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:41 pm
by mbanzi
That's exactly what I got.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 7:50 pm
by Flaps 30
mbanzi wrote:especially after reading about the flashing problems some have been having. Fortunately I have two 9x transmitters!
Yes that does seem to be a problem for one person. I have done both of my transmitters without any problems at all, and I am just a woman. :)

Let us know how it goes..

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 8:13 pm
by ShowMaster
mbanzi wrote:
ShowMaster wrote:Best prices I come up is $12-14.
Any better prices including shipping?
SM
There is a seller on eBay (cyberdoc or cyberdoctormd) selling 6.5" lengths of ChipQuik for $5.32 including shipping. That should be enough for 1-2 chips I think. Not sure if it's the real thing, but mine arrived yesterday, so I'll try it on something else to test before I tackle the 9x though! Do a search for "chip quik"...
I couldn't find your price or cyberdoc on eBay? Could you please post a link to what you purchased.
Thank you
SM


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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Sun Jan 13, 2013 8:18 pm
by jhsa
SM, Crucial just posted the link a few posts above

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 4:27 am
by mbanzi
This is the single piece of ChipQuik I mentioned. Looks like the seller has a few variations of his username?

http://r.ebay.com/GTUKTh

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 5:19 am
by ShowMaster
Thanks everyone I found the links.
Do I want the hypodermic type flux applicator? I did find the chip quick kit at my local Fry's for $13.99+ 9% tax.
http://www.frys.com/product/2644632
Maybe for the extra few $ I'll buy it locally the first time?
I could last me a long time.
SM



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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 1:28 pm
by Flaps 30
Showmaster - I presume you are talking about flux when fitting the new chip. For that purpose I used a liquid no clean flux, that I allowed to dry before starting the soldering operations. The flux covered the PCB pads and the pins on the chip. The applicator I used was a fine point cotton bud, making sure no fibres from the bud was left on the board.

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 3:06 pm
by ShowMaster
Yes on the flux. The video shows it being applied from the syringe that come in the kit. The eBay seller shows a tube of flux or just the chip quick alloy.
SM


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Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 4:17 pm
by jhsa
Hey guys, I'm just trying to get all the info I can..
I've been watching a few videos about drag soldering.. It looks quite easy if we're generous on the flux. on most of the videos they are using an iron with a flat tip. Is that mandatory or can it be made safely with my normal pointy tip?

Also, what is the best technique for soldering the Atmega to the board.. Sorry but it is the first time I do this even if I've been soldering for a few years.

João

Re: Desoldering The Atmega Chip Using Chip Quik

Posted: Mon Jan 14, 2013 4:38 pm
by ReSt
Even though I have not yet used Chip Quick, but from my soldering experience up to now:
Don't use a thin tip. You must heat up a greater amount of solder and the pins and that needs some energy. If you have a to small tip the tip will cool down and it takes much more time to heat the solder and that stresses the chip more than a short peak of heat.

For resoldering use a thin tip and thin solder.

Reinhard

Reinhard