Reballing nVidia GTX470 on the Ghetto BGA Station

[mockingbird]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

Not necessarily. I was going to say something about lead-free solder but I thought otherwise...

There are many different types of lead-free solder, and the alloy makes a heck of a difference. I just reckon that the manufacturers use the most inexpensive alloy they can find.

[diif]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

The xbox 360 was coming out of manufacture faulty. Apparently a defect rate of 68%
http://venturebeat.com/2008/09/05/xb...-console-woes/

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

a failure rate similar to surface tablets and windows installs then!

but modern lead-free solder is not brittle, it's harder than lead and resists bending that may be true.
10year old 1st gen lead-free wasnt so good, but that was also a lot to do with the fact that they only got the flux right in the last few years.

[Th3_uN1Qu3]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

I don't know... I know that i'd rather be 50C away from burning the BGA rather than 10C away. A few months ago i've soldered 3 chips as they came from the factory, with lead-free balls. Two of them worked great. But the most expensive one blew up. That coming after i'd never burned a chip for over 1 year. So i won't be doing that again.

Plus, leaded solder is still cheaper, and it's shiny. All that make a very good reason why i am going to stick with it. The military and NASA still use it - they likely have a good reason to do so.

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

it's cheaper because it's now illegal to use in the EU and China.
probably other country's too.

[diif]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

I thought it just applied to manufacturers of finished goods. It's still for sale at cpc and all the kids used it in the electronics class at my last workplace.

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

it applies from sub assembly's to finished products and even the tinning on component legs on any goods not on the exemption list.

that list is esentially military/aviation and medical.
that will change as the fluxes and solder get better until there are no exemptions.

fuji make what is probably the best solder in the world, and it's lead free.
unfortunatly it costs about $50 a roll (a small roll)
it contains stuff that sound like an alchemist would use.
http://www.fujielectric.com/solder/

[Agent24]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

fuji make what is probably the best solder in the world, and it's lead free.
unfortunatly it costs about $50 a roll (a small roll)

Does it come with a free high-end soldering station designed to work with Lead-free also? Because until then, I am using 60/40 because it's easier.

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

what soldering iron/station do you use then?

[Agent24]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

Still on my Jaycar version of a Hakko 936 and tips from eBay. Don't know who made it, if it's a clone or rebrand. Also have a Den-on SC-5000 desoldering gun.

I have learnt to use them pretty well, can work on most things, though I do use my hot air rework or a hairdryer for preheating some boards. Lead-free work is more difficult, even when using leaded solder on a board that was built with lead-free. Neither of those tools were designed for it, the Den-on was probably built before lead-free solder was even used widely.

Problem is I still only really do this for a hobby etc so I can't really justify a several-hundred dollar JBC or Metcal etc. So the cheapest option for me is to stay away from Lead-free as much as possible.

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

older than 2006?

[BigTroll]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

Ive been using a Weller WLC100 and Archer 60% tin 40% lead.

[Agent24]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

The Jaycar iron is a TS1560, which shows up in the 2005 paper catalogue, possibly earlier (interestingly the 2000 catalogue has a real Hakko 936 instead) - I think I have a 2003 copy somewhere but can't find it at the moment.

The Den-on SC-5000 is surely at least 1990s vintage, maybe even 1980s, I don't know. To give you an idea, there is practically nothing about it on the internet, only the newer SC-7000Z model.

[luke10050]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

hey, do you have a link to your setup in some form?

[Th3_uN1Qu3]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

it applies from sub assembly's to finished products and even the tinning on component legs on any goods not on the exemption list.

If it really were illegal, then why do all the big distributors and local electronics stores still carry leaded solder? Either way, unless they start making tougher BGAs, i will probably quit reballing when i will no longer be able to find leaded solder. Blowing up 1 of 3 $50 chips isn't my idea of a good yield.

fuji make what is probably the best solder in the world, and it's lead free.
unfortunatly it costs about $50 a roll (a small roll)
it contains stuff that sound like an alchemist would use.
http://www.fujielectric.com/solder/

See my point. I'll gladly pay top dollar for desoldering braid as it is essential for the work i do, and good braid cleans lots more solder than crap braid anyway. But i won't pay that much for a roll of solder.

hey, do you have a link to your setup in some form?

Who did you ask?

[luke10050]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

Who did you ask?

I was curious about your rework setup

[Th3_uN1Qu3]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

Bottom heater: 800W toaster (free)

Control for bottom heater: 555 timer driving a zero crossing triac thru an optocoupler, powered by a little mains transformer (around $5 in parts) - it's just power control, not temperature-based.

Board supports: Aluminum foil balls secured with kapton tape () Along with some other random stuff for large or odd-shaped boards.

Board protection: More aluminum foil. I usually wrap the whole board except the working area and 1-2cm around it, to avoid damaging plastic connectors.

Temperature measurement: Uni-T UT60E and UT70A multimeters, using the probes supplied with them. Around $120 each retail at the time of purchase.

I bought an Omega probe and really liked it but i broke it accidentally (it's just too thin for its own good), and decided it's not worth buying another one (or two). YMMV. Measurement method: One thermocouple on top of the die, the other on the board, close to a corner of the chip. I try to keep both temperatures the same. I've been using the same probes for 2 years and haven't noticed a reduction in accuracy, they're still just as good.

Upper heater: ZD-939B hot air rework station ($80) + 41x41mm and 45x45mm BGA nozzles with mesh (around $18 each) I'm on my second ZD-939, on the first one the heater element failed after ~4 years to an extent that it could no longer be bodged together. No replacement parts are available so i bought a new unit.

Support for hot air wand: A couple steel brackets from dismantling a 32" Samsung LCD, older model, along with some bits of Meccano that i had when i was a kid. (free)

Stencils: Direct heat stencils. I think all stencils i've bought so far have cost me a bit over $130.

Flux: AMTECH NC-559-ASM-UV at the moment (paid around $30 for 100g)

Solder balls: 63/37 Sn/Pb.

Soldering iron: Gordak 936A (around $60 IIRC), with wide chisel tip ($3).

Desoldering braid: Goot Wick 3mm ($5-$10 each, depending where you buy it).

Other tools: Vacuum pen ($10) and tweezers in various shapes and sizes.

I'll be back with pics once i get home.

All controls are manual, i'm the one turning the knobs. Timing is done with the stopwatch on my cellphone. I have briefly thought buying/building a controller to automate the process, but it would be more trouble than it's worth. Realistically speaking, each board needs a different "profile". Eyes on the meters and hands on the knobs has been working well enough that i decided not to bother.

That's about it.

[stj]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

foil balls - that's a new low for ghetto

it gives me an idea though, i wonder if i can mount a hot air unit on an old drill press.

[diif]

Re: Reballing nVidia GTX470 on the Ghetto BGA Station

I don't see why not stj
http://hackaday.com/2014/01/31/this-...our-workbench/