Author Topic: BGA replacement - what equipment and tools do I need for reliable results?  (Read 11386 times)

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Offline dicky96

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Hi guys

I want to expand the range of repairs I can undertake. Currently I'm mostly fixing TVs, Audio equipment, DJ Equipment and 'disco' lighting.  Having said that I have fixed a couple of SATA hard drive controller boards

I would like to offer repairs of Laptops. Tablet PCs, motherboards etc

I currently have a couple of faulty MAG250 IPTV boxes here

Both of these have short circuits (or low resistances) on one voltage rail or another (3.3V / vCore)

On one of them, using my bench PSU in CC mode and applying voltage to the 3.3V rail with the buck regulator inductor removed, I gradually ramped up the current to see what would getting warm. At the full 3A (V was now about 2V or so) the only thing getting warm is the big (STi7105-BUD) BGA chip on the centre of the board.

The other one has a short/fault on the vCore rail - I managed to get the 3.3V up to the correct voltage but with about 2.5A flowing - which is too much - and again only the STi7105 was  getting hot.  The oscillator was even running, but nothing else seemed to happen.

I decided I would have a go at removing one of these BGA chips with the hot air station just to see if that was really the cause of the low resistance but to be honest I couldn't even get it to come loose with any reasonable amount of heat applied. Also there are a lot of smd components on the other side of the pcb below the STi7105 and I was worried they may fall off with too much heat

However what I did notice, once the board had cooled back down is the 12 ohm low resistance on the 3.3V rail is now about 7 ohm so that has changed by heating the chip.

Out of interest I googled the STi7105-BUD and found a couple of interesting things.

http://www.alldatasheet.com/datasheet-pdf/pdf/244196/STMICROELECTRONICS/STI7105.html

Firstly it does not seem to be a programmable device but uses external Eeprom/Flash

Secondly I can get them for 7.50 euros inc postage  ;)

Sooooooooo....... I was thinking of having a go at fixing them, as much for the learning experience as anything else, and of course the ability to take on more similar repairs

Getting parts is not the problem. Question is - what equipment and techniques would I need to replace this type of chip? 

Assuming I can get the BGA chip off without breaking something, how do I get the replacement one positioned correctly to resolder?

I've watched youtube videos a-plenty of BGA reballing/resoldering but to be honest I am now more confused than when I started  :-//

Obviously you need the right tool for the right job - What investment in equipment would I have to make to be able to repair these sort of faults with an acceptable level of success? 

Pics of the STi7105 BGA and the underside of the MAG250 board showing the components beneath it.  This would be a good example of the type of repair I would like to undertake so let's start with that.

Cheers
Rich
« Last Edit: May 01, 2017, 06:14:55 pm by dicky96 »
 
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Online MagicSmoker

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Reballing is the process of putting solder balls back onto the component pads, so probably not something you need to learn right away if the goal is to merely replace components, rather than reuse them.

To replace a BGA component you need a strong and profiled flow of hot air to remove the IC, then strip as much of the old solder off the board as possible and then the tricky part - because the board is populated and likely very dense if it uses BGA components - is to reapply solder paste onto the board pads, using either a very small BGA rework stencil or an accurate solder dot dispenser (the latter requires considerably more skill to use, and is a much higher one-time cost).

Understand that this is not an easy process and most companies - mine included - choose to discard board with bad BGA components rather than rework them. That said, a few years ago everyone and his brother was offering BGA rework service for one of those game consoles that had a fatal flaw of some sort. The red circle of death or something? So repairs aren't insurmountable, either.



 

Offline dicky96

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Quote
Understand that this is not an easy process and most companies - mine included - choose to discard board with bad BGA components rather than rework them.

Thanks for the reply
I'm sure it isn't easy but if I'm the only one on this little island who can do it, then it could be quite worthwhile?

Cheers
Rich
 

Offline james_s

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The usual process for reflowing the xbox consoles and related stuff was just to squirt some flux under the BGA and heat it to reflow the existing solder. It didn't normally require removal of the chip.
 
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Offline rob77

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the real question here is "is it worth repairing a relatively cheap set-top-box ?" the cost of the repair will be on par with the cost of the new device.

you can be the pain stripper hot air "re-hot" guy doing it for $20 to try to fix a $100 set-top-box.
or you can be the repairman doing it right and ask $100 for the repair.  but who will pay you $100 to repair a $100 device ?

 

Online MagicSmoker

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The usual process for reflowing the xbox consoles and related stuff was just to squirt some flux under the BGA and heat it to reflow the existing solder. It didn't normally require removal of the chip.

I thought it was the xbox - wasn't sure, and couldn't be bothered to look it up - but I didn't know that the problem was simply a bad solder joint... and I guess M$ didn't splurge for x-ray inspection, either...

 

Online wraper

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The usual process for reflowing the xbox consoles and related stuff was just to squirt some flux under the BGA and heat it to reflow the existing solder. It didn't normally require removal of the chip.
And was a useless procedure as well. Just heating the chip would do the same job (temporarily reviving the dead IC) as the issue was not in solder joints.
 

Online wraper

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The usual process for reflowing the xbox consoles and related stuff was just to squirt some flux under the BGA and heat it to reflow the existing solder. It didn't normally require removal of the chip.

I thought it was the xbox - wasn't sure, and couldn't be bothered to look it up - but I didn't know that the problem was simply a bad solder joint... and I guess M$ didn't splurge for x-ray inspection, either...
It wasn't. Widespread myth and BS. The fact you can temporarily revive it by heating, actually without melting the solder, does not mean there is an issue with soldering
 

Offline james_s

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Well it did seem to work, my friend reflowed one, preheated the PCB from below and then heated the IC with a hot air tool and it was still working fine a year later when he sold it. I can't say for sure it was the BGA soldering but the reflow process did generally seem to fix it.
 

Offline Rasz

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1 is it worth it? this looks like $50 box
2 parts on the bottom wont fall off unless you blow really hard on them
3 remove stickers before work, bad things happen to parts that are stickered down when solder melts (hotair/owen)
4 what did you use? cheap 858 something? you will need 2 of those :D one blowing slow air from the bottom to heat pcb up to ~150, other set to max  fast air from the top, or buy a real hotair, like Quick 861Dw


btw Xbox 360 was actually cracked solder joints, not the chip
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Offline dicky96

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the real question here is "is it worth repairing a relatively cheap set-top-box ?" the cost of the repair will be on par with the cost of the new device.

you can be the pain stripper hot air "re-hot" guy doing it for $20 to try to fix a $100 set-top-box.
or you can be the repairman doing it right and ask $100 for the repair.  but who will pay you $100 to repair a $100 device ?

Yes I was using an 858 - but your suggestion of using two sounds useful   :)

Regards is it worth it -  I was mostly asking about these techniques and equipment required....and just putting these boxes as an example

However let's just talk about that a little - Is it worth it? -  does the answer not depend on where you are?

Little islands in the sun for 330 days a year = 800k happy healthy and nicely tanned residents plus 4x that many in tourists a year, and plenty of bars and hotels/apartments with TV and IPTV and stuff to generally break down in the heat etc....but when it goes wrong, try get that replacement 100 euros box here without paying about 30% more in import duty and waiting about 3-4 weeks to clear customs.  Or just fly back over to UK/mainland EU and bring one back yourself, don't forget to add your flight tickets to the cost. And AFAIK no one on this island can do this sort of repair.

Seriously guys let's talk about the technical sides of this and the investment in equipment required and then I will work out if it is a reasonable prospect or not. OK? or as they say here - Bale (pronounced like ballet)?

Rich
« Last Edit: May 01, 2017, 09:58:32 pm by dicky96 »
 

Offline RGB255_0_0

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Get a preheater, reflow oven (could be DIY), optionally/ideally an ultra sonic cleaner and a good microscope but not essential to go crazy expensive.

Louis Rossmann on YouTube has lots of videos of the equipment he has and his process as well as many others.
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Offline rob77

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if you want to seriously jump into the business and do it right then the investment will be relatively significant.

absolute minimum to fix cracked solder joints would be:

good hot-air station
preheater (at least a oven to preheat boards)
jig + stencils for re-balling chips

for more serious repair shop add a infra-red soldering station with bga alignment jig to work with bigger bga chips (it's mission impossible to "eye-ball" a 1k baller BGA without tools)

and if you plan to do BGA chip soldering for living, then definitely buy a X-ray machine for inspecting the results (even with the best IR station with the best alignment jig you can end-up with a bridge between 2 balls under the chip)

 

Offline Samogon

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if you want to seriously jump into the business and do it right then the investment will be relatively significant.

absolute minimum to fix cracked solder joints would be:

good hot-air station
preheater (at least a oven to preheat boards)
jig + stencils for re-balling chips

for more serious repair shop add a infra-red soldering station with bga alignment jig to work with bigger bga chips (it's mission impossible to "eye-ball" a 1k baller BGA without tools)

and if you plan to do BGA chip soldering for living, then definitely buy a X-ray machine for inspecting the results (even with the best IR station with the best alignment jig you can end-up with a bridge between 2 balls under the chip)

Sounds like $10k plus investment
 

Offline dicky96

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Hi guys - that's some interesting info now

I've seen a few of Louis Rossman videos on youtube and actually that was what inspired me to look at stuff again that I didn't really think was repairable before.  Actually I think he's quite a funny guy, makes me laugh sometimes.  I did see the video regards microscopes and also the one where he explains why reballing GPUs doesn't work.

What I haven't seen is one where he actually removes and replaces a large BGA - if there is such a video I would like to see that.

Regards the IR desoldering stations - what sets a good one apart from a bad one?

There seem to be various price ranges from the cheap http://www.ebay.co.uk/itm/TOP-BGA-REWORK-STATION-INFRARED-SMD-SMT-IRDA-WELDER-SOLDERING-MACHINE-T862-/292028217223?hash=item43fe3cf787:g:T-MAAOxyIv5Tj9Ui

To the reasonably priced http://www.ebay.co.uk/itm/YH-1000B-4-IN-1-SOLDERING-IRON-HOT-AIR-REWORK-PREHEATING-INFRARED-BGA-STATION-UK-/182361419231?hash=item2a75966ddf:g:O5IAAOSw44BYMur6

http://www.ebay.co.uk/itm/T-870A-Infrared-BGA-Rework-Station-IRDA-Soldering-Welder-35-50-mm-CE-/231182438589?hash=item35d38c10bd:g:ccwAAOxyoVZTJr4N

To the considerable investment http://www.ebay.co.uk/itm/DH-5860-BGA-Rework-Station-Infrared-Preheating-Remove-Soldering-Station-/222199218530?hash=item33bc1b0162:g:dU8AAOSwSv1XlxGm

I just picked these as random examples of price range from ebay

Haven't seen Dave do any eevblog videos comparing/reviewing IR soldering equipment, not that this means there aren't any

Cheers
Rich
« Last Edit: May 02, 2017, 09:46:53 am by dicky96 »
 

Offline Armadillo

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There are more equipment than those;

 

Offline dicky96

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There are more equipment than those;


That looks very nice mate - I do worry when you find a website for an item and it does not actually tell you the price but that looks expensive!

I did find a video with Louis changing a large BGA



I think he says that is a $7000 rework station.  Is that using optical 'trickery' or something to align the BGA?

Rich
« Last Edit: May 02, 2017, 01:22:18 pm by dicky96 »
 

Offline amspire

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Just so you know what the bottom of the chip looks like, I have attached a photo of the stencil template.

Louis usually doesn't use his machine for small BGA replacement, but this is a big chip. Looks like the corner pads are probably within 1mm of the edges, so if you want to have a go without expensive equipment, it may be possible to position well enough.

The heat will be a problem - you have to get it so all the joints are molten so the IC is floating and surface tension will help pull the IC into the right position.

Even if you buy balled chips, there is a good chance of a failure on the first attempt and then you have to remove the chip, reball it and try again.

You can get stencils of the right pitch very easily (this $4 kit of 27 stencils includes one that is large enough with the needed 0.5mm ball pitch: https://www.aliexpress.com/item/27pcs-Directly-Heat-Rework-BGA-Reball-Reballing-Universal-Stencil-Template-Set/32359115589.html )

You can use solder paste instead of balls - see some of Louis's recent videos. This stencil has far more holes then you need, but you can clean off any excess unattached solder balls on the bottom of the chip easily.

It is a pretty difficult chip to learn on. The chances of it working are probably not great, but if you have faulty boards, by all means have a go.
« Last Edit: May 02, 2017, 02:16:03 pm by amspire »
 

Offline Rasz

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Yes, "is it worth it" is a totally valid question no matter where you are, Manhattan or middle of nowhere prison island. You think there is a market for fast turn around IPTV boxes? order 10 from china and offer locally as a fast replacement instead of investing ~$4000 to sometimes fix $50 whatever.

rework contraptions you listed (except maybe last one) are meant for small cellphone shops, small power and working area = either wont melt solder at all, or do one spot deforming it in the process
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Offline Armadillo

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The chances of it working are probably not great, but if you have faulty boards, by all means have a go.

Imagine you spent couple of hours changing a US$200 BGA chip to find out that it is not the problem  |O.
Payback period of investment, tools, jigs and fixtures, and utilities, consumables together with technical failures need to be accounted for in the business equation aside from salaries amongst others against a probable business hindsight, need to be evaluated "carefully" and mathematically worked out. Additionally, explore the reasoning why others equal human beings have not delved into the prospect? They are lesser intelligent, maybe?
Its a probable business risk analysis that could not be diminished, apart from technical and equipment.

OK, let's get back to the equipment and technical.  :)
 

Offline dicky96

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Yes, "is it worth it" is a totally valid question no matter where you are, Manhattan or middle of nowhere prison island. You think there is a market for fast turn around IPTV boxes? order 10 from china and offer locally as a fast replacement instead of investing ~$4000 to sometimes fix $50 whatever.


I'll say it again - IPTV box was just an example of some boards I have here with faulty BGA components!!

Honestly Rasz - it's not relevant to whether it is 'worth it' any more than that.... and it seems as good choice a choice as any to practice on these seeing as the IPTV boxes are not valuable, the board is only 105mmx85mm, I already diagnosed the fault as best I can, and the cost of replacement parts is very low. 

Let's call it an investment in personal skills and abilities instead.  Or I'll find a photo of laptop or games console or Apple board or whatever to post here instead if that makes a difference to your opinion.  Or maybe you don't feel investing in ones betterment is a worthwhile pursuit?

Anyway - I just wanted to know is what equipment is needed, at a minimum,  for this kind of work.  And what advantage to be gained by spending a little more?  This is because the information on the net seems a little confusing to me. 

For example the cheapest IR plus preheat I can seem to find are these T862++ at about £150.   Oddly enough I don't seem able to find any real reviews of them.  A couple of videos on youtube of faulty ones and a forum post which said they were useless and damaged chips and boards.  However that could be someone not using the equipment properly. 

Maybe something that cheapo must be crap. Who knows?  My 858D hot air desolder station was really cheap but so far it has done plenty of useful work and I think it's one of the best value for money items I ever bought.  It doesn't seem to like desoldering these things though  ;)

Maybe I will decide it is all too much bother and expense to try and learn these skills.  But That still does not make asking the questions any less worthwhile
Rich
« Last Edit: May 02, 2017, 05:30:43 pm by dicky96 »
 

Offline dicky96

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Right I have done some more research now.  It seems the T862++ is not much more use than a hot air desolder station

I came across some reviews of the T870
http://www.ebay.co.uk/itm/T-890-Infrared-Bga-Rework-Station-Irda-Soldering-Welder-/382051949760?hash=item58f4121cc0:g:KawAAOSwA3dYHVRK

and T890
http://www.ebay.co.uk/itm/T-890-Infrared-Bga-Rework-Station-Irda-Soldering-Welder-/382051949760?hash=item58f4121cc0:g:KawAAOSwA3dYHVRK

It would seem the main difference is the 890 has stored (programmable?) heat profiles

At £400-£500 the T890 is about as much as I would want to spend on this project - heck I may even be able to recover that sort of expense fixing a few IPTV boxes  :P

Some forum posts on badcaps and elsewhere say these are not powerful enough for big boards and chips like laptops, others say they will desolder just about anything.  Maybe that is difference of opinion, abilities, or usage?

Some posts around the net suggest for laptop work etc you need a minimum of something like this Honton HT-R490: http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xhonton+r490.TRS0&_nkw=honton+r490&_sacat=0

So it is now a question - can I do a reasonable amount of useful work with something like a T890, and hone my skills.... or may as well not pursue this right now I think

Cheers
Rich
 

Offline Rasz

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Honestly Rasz - it's not relevant

it is, but its ok. You might think im pissing on your idea now, but you will understand in a year or two :)

For example the cheapest IR plus preheat I can seem to find are these T862++ at about £150.   Oddly enough I don't seem able to find any real reviews of them.  A couple of videos on youtube of faulty ones and a forum post which said they were useless and damaged chips and boards.  However that could be someone not using the equipment properly. 
no, they are shit toys for suckers entering cellphone repair game. Typical Chinese lets make something that _looks_  proper product.

Maybe something that cheapo must be crap. Who knows?  My 858D hot air desolder station was really cheap but so far it has done plenty of useful work and I think it's one of the best value for money items I ever bought.  It doesn't seem to like desoldering these things though  ;)

yes, its equally shit, its ok for small smd components, dip and occasional shrink wrap :)
its really not a conspiracy why experienced shops dont use them, just like you yourself discovered it cant even desolder small bga chips

Maybe I will decide it is all too much bother and expense to try and learn these skills.  But That still does not make asking the questions any less worthwhile

those skills are valuable, but obtaining them will cost real money(or lots mistakes and time), money you might not get back without proper opportunities (fixing IPTV boxes and random $150 Acer laptop is not it).
 You wont learn much using garbage like 858. Well no, you actually will learn about it being bad, just like trying to use toy rework stations will give you extensive knowledge about thermal expansion, shock, deformation, broken internal traces, fried components etc.

Proper rework equipment is expensive not because its made of some special sauce, but because of very small volume. You can build decent on the budget IR soldering station yourself with a bit of research.

examples, first one easily competes with $30K professional setups:




you can even DIY fancy alignment system on the cheap



Start with a proper hotair gun, Quick 861 < ~$300
Proper soldering iron, not 836 piece of shit chinese clone, but anything using HAKKO T12 tips, either genuine FX-951 $250, counterfeit FX-951 $100, or even $20 DIY controller https://www.banggood.com/Digital-Soldering-Iron-Station-Temperature-Controller-Kits-for-HAKKO-T12-Handle-p-993248.html
+ flux (NOT the chinese Amtech from "Califomia") + couple of shit $3 tweezer sets
+ old camcorder with TV for improvised inspection setup
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Offline Armadillo

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You can build decent on the budget IR soldering station yourself with a bit of research.


Quite a bunch of self-contradictory bullshits there;
If you profess that you can build yourself the budget IR soldering station, so why don't you build the soldering iron yourself instead of advising people to use the T12 tips and genuine soldering iron FX-951? Obviously there are heavy engineering involved even in that simple looking soldering iron "TIP" itself.
Conversely speaking, You can in fact waste your whole entire life stepping into and trying to re-create, uncover or invent what others had done, and maybe without success and face with bunch of failures because its simply not your subject OR, OR step onto the pedestal of others successes to enhance your own success and business. It all depends on your interest and what you are good at.
No, no, I don't agree with the disparaging remarks on the Chinese made products, some had used with great successes for example Jason of STS Telecom - from rags to success using chinese tools and yeah! some tools are made for the beginners to start off with.
Cheers!  :)



watch 38:40

« Last Edit: May 02, 2017, 09:10:09 pm by Armadillo »
 

Offline rob77

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No, no, I don't agree with the disparaging remarks on the Chinese made products, some had used with great successes for example Jason of STS Telecom - from rags to success using chinese tools and yeah! some tools are made for the beginners to start off with.
Cheers!  :)



watch 38:40



when he started to talk i subscribed to his channel... when he started to look for capacitors costing half a cent on donor boards.. i unsubscribed ;)
ability to work with cheap tools is essential for small business... but cheaping out on capacitors ? many places sell cut tape smd parts... you can get 1000 capacitors for $5 or even less, that's 0.5 cents a pop.... you buy 1K of each common value (100n, 1u, 2u2, 4u7, 10u) and you have a supply that will last you "forever" in a repair shop.
 


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