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General => General Technical Chat => Topic started by: tesla500 on February 20, 2010, 03:19:18 am

Title: Hot Air Rework station reccomendations
Post by: tesla500 on February 20, 2010, 03:19:18 am
I'm starting on some projects involving lots of fine pitch QFP, QFN and big BGAs, and I'm looking to buy a hot air rework station, and/or BGA rework station if the hot air rework won't work for BGAs. What would you guys recommend?

I've seen things like this hot air rework station (looks like a clone of a Haako station)
http://cgi.ebay.com/SMD-Rework-Soldering-Station-HOT-AIR-IRON-2in1_W0QQitemZ320488986185QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9ea1d649 (http://cgi.ebay.com/SMD-Rework-Soldering-Station-HOT-AIR-IRON-2in1_W0QQitemZ320488986185QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a9ea1d649)
and BGA rework station
http://cgi.ebay.com/BGA-IRDA-Welder-T870A_W0QQitemZ260553044429QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3caa2bf1cd (http://cgi.ebay.com/BGA-IRDA-Welder-T870A_W0QQitemZ260553044429QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3caa2bf1cd)
on eBay. Are those of any usable quality? How much should I be looking to spend?

David
Title: Re: Hot Air Rework station reccomendations
Post by: GeekGirl on February 20, 2010, 06:51:28 am
I have a similar Hot air rework station, it only has the hot air part, I use Hakko nozzles. It works VERY WELL, the only problem I have is that I am not doing SMD EVERYDAY, so the paste does go off (just takes a bit longer to push out the tube and needs a bit more liquid flux (but my paste is 3 years old ;) it is kept in the fridge in a bio hazard bag ;)

If you use the buy it now option, I would carefully check the tips, they are more than likely Hakko copies, I prefer ORIGINAL Hakko tips, they work very well (I have used 5 tips in the 18 years I have had my Hakko iron (I used to do production line soldering for extra money when other jobs were light on the ground)

The BGA rework station looks nice lol

I have never tried to hand solder a BGA, if I have a project that needs a BGA I have used a local assembly place to do the BGA for me (if you can find a smaller place, they will just do it for a low CASH price (I pay ~au$10 per BGA, and they Xray to check it is in place (extra au$5 for a hard copy film (never asked for it as I do not need a bit of Xray film to say it is in place, there word is good enough ;)
Title: Re: Hot Air Rework station reccomendations
Post by: djsb on February 20, 2010, 11:13:32 am
Hi,
I have used a xytronic hot air station and they are OK for low volume use.
I bought mine off THE SOLDERMAN on ebay. The company is UK based and sells quite a selection of soldering stations.
I dream of owning one of their PDR infra-red solutions. Problem is they cost around £2.5K. With one of those you can do BGA's and everything else you can think of. I used a PDR X310 workstation in my last job as a University technician (http://www.coltronics.com.au/DATA/PDRX310-IR-ReworkStation.pdf). They are a bit scary to use (lots of smoke if too much flux is used) but great for fine pitch components with hundreds of pins.
If I'm doing any surface mount stuff  I tend to hand solder (except BGA) everything under a microscope. I'm still getting used to using hot air and find it
difficult to use. I probably need more practice.
Sparkfun also has some good tutorials that are worth a look.

David.
Title: Re: Hot Air Rework station reccomendations
Post by: TheDirty on February 20, 2010, 02:49:51 pm
I have a an Aoyue 968 that I got from SRA Solder off of e-bay.  I just do singles of hobby boards and I use cheap dealextreme.com solder paste, but it works well.  QFN's are my favorite package now and I get everything in QFN when it's available.  I use a syringe with the DX solder paste and I mix the paste with flux to get it a good consistency to flow through the syringe.

The iron itself uses Hakko tips.  I ordered a few different types of hakko tips to see what works best, chisel, hoof,.... but I've just gone back to the original conical tip and I'll just leave it there.
Title: Re: Hot Air Rework station reccomendations
Post by: tesla500 on February 21, 2010, 02:44:20 am
Thanks for the suggestions people, the Aoyue 968 looks good. Couldn't find the xytronic system on eBay.

Others I've talked to have recommended having an assembly place do BGAs too, I think I'll stick to that.

Also, any recommendations on a vacuum pickup tool?

David
Title: Re: Hot Air Rework station reccomendations
Post by: David on February 21, 2010, 04:33:49 pm
I too have an Aoyue 968 and it is brilliant for the price. As previously stated, tips from other manufacturers can be bought and spares are cheap. I've also managed to get away without the use of a vacuum pick-up tool so far.

Dave
Title: Re: Hot Air Rework station reccomendations
Post by: Andrew on February 21, 2010, 06:57:47 pm
I also use an Aoyue. Dirt cheap and does the job.

However, the same hot air rework stations are sold under many different names. If you wan to get a glimpse of how they are assembled, have a look at these videos, and you get an idea why they are cheap:

Here you see the workshop where they are build:

https://www.youtube.com/watch?v=ix6KZLlDxok

And here is the company museum, showing older products:

https://www.youtube.com/watch?v=Jf24jk3mmt8

And here is where they actually assemble a hot air rework station:

https://www.youtube.com/watch?v=ma3JHdoSdjA

More of the assembly line:

https://www.youtube.com/watch?v=APHg8zpAaYA (short, just 1 min)


As a bonus, didn't Dave express little love for his Uni-T bench top multimeter in the past? Here is a video from inside the Uni-T "the best technology of China to your hands". It is a rather boring video, maybe the only interesting part is what they don't show around 6:05 to 7:00 https://www.youtube.com/watch?v=7enC1o0zlZk

Title: Re: Hot Air Rework station reccomendations
Post by: TheDirty on February 22, 2010, 02:26:31 am
Thanks for the links Andrew.  I'm surprised to see there's actually a quality control phase as short as it is.
Title: Re: Hot Air Rework station reccomendations
Post by: comox on February 24, 2010, 10:27:49 pm
I have a Weller WHA 900, but I am so crap with it that I send my surface mount stuff out to an assembly house...  For the £££ I paid for the Weller, I could have had a lifetime of surface mount assembly paid for up front!
Title: Re: Hot Air Rework station reccomendations
Post by: tesla500 on February 26, 2010, 05:30:51 am
How expensive is contracted out SMT assembly? What's a typical setup fee, and fee per board/component?

David
Title: Re: Hot Air Rework station reccomendations
Post by: comox on February 26, 2010, 10:23:51 am
In the UK I have used http://www.reflow.co.uk (http://www.reflow.co.uk)  For 3 boards comprising 1 uCU and about 10 other surface-mount components, it was £10 ($16 US) per board, exlcuding postage, which was an additional £5.   I have another round of assembly required and they have not been responding to my e-mails.... 
Title: Re: Hot Air Rework station reccomendations
Post by: free_electron on March 11, 2010, 05:02:08 pm
I use an Aoyoue handheld model 875+  (the one with the digital airflow and temperature adjustment)

i typilly tack the parts down using a regular soldering irong, flux the board really well ( kester 2133 type water soluble flux) then go over it using the auyou.
after washing the board in loukewarm water it looks like an industrially manufactured board.

If you are going the lead-free route : Try to get Sn100c or Sn99c solder paste or solder. Stay away from SAC305.