SMT REWORKING ( BGA )

Hello,

we do have very good results with a 'hot air' repair station, and poor results with a 'IR' repair station, but i have to say that the 'IR' station wasn't designed for leadfree use.

Make sure you have a good underside heater, adjustable and accurate, this is, (my opinion) a very inportant part fotr BGA repair. I do like the equipment from "PACE", but to expencive for this kind of equipment.

regards Bart

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The best station I've ever worked with is a focused IR station from PDR. The station that I had was called a; "Lightmaster Pro". They have a different model name now, but you can see a datasheet for it at:

http://www.pdr.co.uk/Datasheets/PDRX410-IR-ReworkStation.pdf

I've read some of the responses that said that they didn't have a good experience with IR, but I have to disagree with that. I think IR heating is more even and gentle than forced hot air.

I've reworked 1152-ball Xilinx BGA's with the station, and they were mounted on a PCB that had a .055" thick copper core with no problem. Yes, light colored or reflective surfaces will not absorb the IR light like dark colored components do, but that's why they supply a reusable heat transfer tape to use on components that don't absorb the IR light well.

One of our customers (Lockheed) suggested the system to me when we had problems reworking one of their assemblies with a hot air station. At that time we had a system from OK Industries (now owned by Metcal). The assembly that we were trying to rework was a RF board that was bonded down with silver conductive epoxy inside a 3/8" thick nickel plated aluminum chassis. With a hot air station we weren't even able to get the solder plastic. With the IR station, it was a piece of cake!

There's few other things I really like about the station besides it's good heating performance. One really nice thing is that you don't need any nozzles at all. You adjust the iris of the heat lamp to whatever size component you're reworking. If you have components nearby that you don't want to reflow, you just take some aluminum foil and sheild them. You have real-time PCB and component temperature monitoring with the non-contact thermocouples that the system has. Another thing that's nice is that you can actually watch a BGA drop when it reaches proper reflow temperature. Something you can't do when the BGA is covered up by a nozzle.

I paid a little over $29,000 for the Lightmaster Pro station I bought over 5-years ago, I don't know what they go for now. When I compared pricing with a hot air station in the same class, it was just about the same price, but without nozzles. I could have easily had spent another $3000 more for nozzles if I went the hot air route.

Once you work with a good focused IR light station, you will see how nice it is...

-Steve Gregory-

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I use a Liberty Bandit brand hot air rework station and have placed 676 ball BGA's with very few problems. All of our products are now RoHs. They have good product support and easy to use directions. I think this unit runs about 15,000 or so. Good luck with your choice. I haven't worked with any other rework stations so I do not have a basis for comparison.

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