advice for purchasing good equipment for reballing ps3 xbox gpu's

[crazygamer]

hi there im new to the forums actually tripped onto it when searching for some advice on lead free desoldering.
I got a reballing kit for ps3 and xbox 360 reworking and currently have about 5 ps3's and 8 xbox 360's ready to be reballed and brought back to working order so off i went using a heat gun to remove an xbox 360's gpu. well as most of you would probably suspect the board warped and i dont think i could actually get that one working again however i used this as an experimental xbox to see how well i could do well it didnt go too well so far i have managed to make the board bubble trying to heat up the solder with the heatgun so i could help out my rubbish soldering iron remove the lead free solder with desoldering wick. the wick got caught and ripped away a pad along with a good piece of the circuit trace! so i then ordered a really poor tool on ebay called a desolder vaccum pen. this helped but felt it needed to be an electronic vaccum to get the job done.
I have been wanting to get an achi ir 6000 but with the price of them it has been hard to rope together enough cash (about £500) so i have about £300 and just feel i should look into different methods and tools.
So far i have in mind an ir preheater (found one for £92) leaving me with roughly £200 left which i was thinking of using to get a hot air rework station which would comprise of a handheld heating gun with variable heat and airflow control and a decent soldering iron plus a desoldering vacuum. Any suggestions as to if i am thinking along the right lines with my alternative setup and if not some reccomendations within my budget?

 

[Sceadwian]

https://www.mpja.com/prodinfo.asp?number=16121+TL

Is something I should have bought ages ago.
Though the heat guns work well you can't temperature control them, they can't be used for solder/desoldering without a LOT of practice on junk boards. I'm JUST getting to learn how to use my for desoldering, even though the heat gun only cost 20 dollars it's well worth the comparative investment of a 100 dollar far a cheap hot air station. You should be able to get something equivalent in your area.

They offer two features that can't be overlooked.

True temperature control not wattage control, and airflow control.

 

[tunedwolf]

In order to achieve reasonably repeatable results, you need some equipment that can deliver reasonably repeatable results...
You can either build that equipment, or purchase it, like in the case of the achi rig for example. There are just some things that are better suited to the task of removing/ reballing and replacing large BGA's on any reasonable timescale and with the accuracy required both of device placement and temperature control to be successful. I wouldn't recommend that you build the equipment, the parts required are fairly expensive and unless you have machining facilities I doubt you will be able to achieve the accuracy involved easily.
Save up the extra few hundred for a rework rig, save yourself the hassle and doubt.

 

[crazygamer]

thanks i have been racking my brains for days over this and i was slowly coming to the same conclusion, i can currently get the machine for £499 so i may aswell grin and bare it for now with the tools i have and get the proper station. i did find one on ebay for £500 or best offer so ive put in an offer of £300. i know it will more than likely get refused but its worth a shot

 

[unclejed613]

i'm not so sure the hot air machines are the best way to work with BGA chips..... BGA chips are soldered onto the board using a dipping process after the SMT components have been glued in place (which is one reason it's difficult to remove them with hot air, the solder melts, but the glue doesn't)

 

[tunedwolf]

Modern surface mount placement adhesives are designed to be placed by stencil, worked at room temp, and for standard adhesives, cured at anywhere between about 100-180 degrees for a couple of mins in a curing oven.
Pretty much all of them are designed with a known themoplasticity that allows easy breakage when re-heating above 200 degrees, either with hot air tooling or infra-red.

What does tend to cause some problems, is when the rework rig, both hot air and infra-red suffer equally in this respect, is not set up correctly, does not properly pre-heat a board and step through the temperature ramping at the correct intervals or for long enough etc. This leads to solder balls melting at different rates in the cycle, and if the device is pressured to lift off early, can lead to pad damage. Adhesive dots under very large devices can sometimes suffer from the same problems, not be heated fully, and therefore will not break cleanly when expected, but this has nothing to do with the adhesive properties or the tooling used, it's the process that's flawed in some way.

 

[crazygamer]

well just ordered an achi ir 6000 had a few good days and racked up some extra cash managed to get it for £480 so not too bad

 

[tunedwolf]

Not a bad price for it. Remember to oven dry your boards before rework, say 50-60 degrees for an hour or two to help prevent warping and flux bubbles occurring. Also, never rework any board without it being fully and properly supported otherwise you run the risk of warping the board during placement. I would advise a little practise with various device sizes, scrap boards, and rework profiles before you commit to reworking a customer's board.

Let us all know how you get on with it

 

[crazygamer]

thanks for the advice i think it will definetly take me a few try's to work out the ideal reflow profiles, i still need to purchase some support jigs for the boards i will be mostly working on. so far ive found a place that does an xbox jig and ps3 jig for £30 each but im sure they would be cheaper somewhere. Also need a decent soldering station as at the moment i have only been using a soldering iron when removing anti static points from xbox 360 and wii lasers. i did try desoldering with my current iron but it only cost me £8.99 and well the saying goes "you get what you pay for" definetly seems to apply when purchasing a soldering iron! I've been slowly massing a collection of e74 xbox 360's and ylod ps3's so im going to practice on these ones once ive destroyed my testing board completly