I will start this thread to have pertinent information about getting involved with reworking ie; reflow reball

The company i work for has been in reworking for 3 yrs now, it is the bulk of our business

The benefit of reworking is fixing things that would otherwise be unfixable or too expensive to replace

Some examples:

CPU socket is faulty ie; wont detect CPU you can replace that with a fresh socket or put fresh balls on the socket

Laptops without power, many laptops have the SB chip which is the main chip on the board that controls i/o functions that will have the solder joints go faulty and by performing reworking on it power is restored

Note: some power issues are related to QFN chips, resistors, regulators, mosfets etc and in this case a reflow or reball will do nothing

Mainboard needs to be replaced and it is expensive and will take time to order but the customer needs it now, so simply rework the GPU and not have to worry about ordering parts

Cell phones have bga related issues as do tablets

Game consoles, TVs, GPS units, Motor Vehicle Gauges etc;

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Is it worth it:

That depends on may factors such as cost, time, space etc;

You HAVE to spend at minimum a grand to get started

If you wish to talk about griddles, heat guns, ovens, etc; i simply will not offer help or support on that as its an improper repair

It WILL probably work sometimes but if it does the repair will not last and this is why bga reworking has a bad name

Those devices above are PERFECTLY fine for small components but NOT for bga components, using larger nozzles etc; is not suitable at all

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Depending on which boards you are going to rework will depend on the machine that you use, if you are going to work on cell phones then a small $300 system will work just fine and i would recommend not going bigger as the boards are very small and you want a small machine

If you are going to work on laptops and Xbox 360, then a machine with about 3 240 x 60 heaters on the bottom will be suitable i prefer 4 but 3 will do the job since those boards are not as picky

For PS3 you MUST have at minimum 4 240 x 60 heaters for the bottom as those boards have several layers in the pcb and contain large bga chips plus the board is just huge

The reason you need proper bottom heating is because of board flex or warpage, if the board is not heated evenly it will bend in certain areas or may not heat the bga chip evenly causing solder ball bridges or shorts

So with that in mind you can get a decent machine for around $700 that will support 3 heaters or maybe 4

This is a machine that will work on laptops and Xbox 360s
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For PS3s this will do
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These are the cheapest machine that you should buy anything smaller or cheaper will not be sufficient and will cost you more in the end

Now if you buy the smaller machine due to a lack of funds, you are not totally lost because you can upgrade the heaters later and then work on larger boards without issue

These are german made heaters, you know the guys that make beamers
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If you do upgrade the heaters i recommend new relays or SSR, i bought mine from amazon that were made in USA opto22, relays control the heaters basically without relays the heat will always be on

IR heaters in most machines are made in china thus they dont last as long as others and they will not provide even heating

Also these machines are made in china so they do not pass safety inspections and some have reported the wiring catching fire etc;

Now this is not often but it DOES happen, it hasnt happened to me so maybe i am just lucky

I personally rewired my machine with thicker gauge so that way it was more efficient and safer

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Next is power issues, UK have no problem you guys have 220 and is best for those in the USA you have a few options buy a 110v machine which i do not recommend it will be a huge power hog, buy a 220v machine with transformer, personally i would not do it since a transformer is another piece of equipment that could go bad and if it does you have to order another, have a 220v line installed in your place

I did it myself and no i am not a certified electrician so dont take my advice as such i simply used common sense and research

Basically all buildings have 220 in the breaker box with 3 wires going to an outlet a live, ground and neutral

The neutral is basically another ground or vice versa

So get a double pole breaker and connect 2 lives and a ground thus eliminating the extra neutral

So with 2 lives meaning 110 x 2 = 220 or 120 x 2 = 240 which is still no problem as machines are rated up to work on 240 and that is the power that aussies use

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I am not responsible if you die, this video is made by a regular guy without a electricians license

If you hire an electrician, it should cost no more than $200

Many people use dryer plugs, but check google for that

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You will need some tools and accessories as well

Flux is a MUST, and there are tons ie; Amtech, Kester, Kingbo, Magic, Super bla bla

Amtech is SUPPOSED to be the best but there are SOOOOOOOO many fakes out there and if you do get original it will cost quite a bit

I use Kingbo, but i have all of the above fluxes and that was to do some testing in the end Kingbo was overall the best mainly because it lasted up to 240c in temperature where as most would burn out at 200c which is essentially useless for reworking BUT for soldering is fine

Alcohol, Acetone, Mek are cleaning chemicals

I use denatured alcohol most of the time it removes thermal compound pretty easy and cleans residue flux without issue
Acetone is stronger so i use that if needed and finally MEK is basically Acetone but doesnt dry as quick
IPA = Alcohol but you need 99% and its either hard to find or expensive, Denatured can be found at a hardware store sooooooooo i use that

If you get a board in that was previously repaired, which we do often they probably used some weird flux or other goo and it looks so awful so you must clean it off and that is where those chemicals come into play

Cleaning the heatsinks is also needed

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Supporting the board is CRUCIAL as you could have a million dollar machine if you dont support the board it will bend and flex

For game consoles there are pre made supports that fit the specific models
Other boards mainly laptops you can use the included support system that comes with machine since they are not as large or thick as game console boards but that may change

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That is all that is needed for reflow, if you want to reball you will need the following:
Solder balls
Rework jig
Vacuum pen
Stencils
Braid

Buy it pre made, piece it together however you want to do it you need those items
[URL="http://www.ebay.com/itm/150740385232?ssPageName=STRK:MESOX:IT&_trksid=p3984.m1587.l2649"]This is a pre made kit[/URL]

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Using the machine is not super easy but not super hard and the machines above come with pre programmed profiles

A profile is basically the heating instructions you give the machine which include the temperature, time and speed
Speed is easy i just set it to 2 and its safe
Time is something you need to figure out by how long it takes to get to set point and how long you want it heated at that point
Temperature is the amount of heat generated at that time, your not going to go from 0 to 280 right away it has to be gradual or you will cause thermal shock

The pre programmed files should be used as a starting point and you will adjust the values based upon your environment, board type, flux used, machine type etc;

Most common way to control a machine is with a PID controller, they are also used in cooking and are relatively simple to use by following the manual closely

The controllers contain advanced features for fine tuning, but its best to leave them be and leave the default values set

There are then the touch screen controllers which are usually even easier to use but arent required, some of them have built in graphs to view the profile in action, the non touch models tend to offer PC control via serial or usb to start and stop the profile and watch the graph

YES its cool, but after a mth i stopped using the pc and controlled it from the controller since using a PC was just not needed

The profile is definitely a very important part of reworking as without proper instructions the machine can not do its job, and a properly set profile decides if you win or loose with repair

Many people borrow, trade, purchase profiles and this will go on for a while the fact is Joe can not use Bobs profile even if he has the same machine

His environment is different he may rework in a basement with humidity or by a lake with dry air etc;

Now there is no doubt that the profile MAY work, but it will not be optimal because you MUST develop your own and test it appropriately

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Reflow and Reball are essentially almost the same when you heat a chip and the connections are REflowed when you put new balls on a chip you have REballed it hence the terms
Now there is chip lifting and placing which is the better repair and involves reballing a chip and then reflowing it to the board

Reflow is NOT bad its simply been given a bad name and most people do not do it right as you must have the solder become liquidous for 30 to 90 sec but this is a problem for many as when the solder is liquidous they start cooling it or if they have improper equipment while the solder is liquid if the heat is not even or not properly bolted or supported it will flex

Improper equipment means you can not maintain a consistent temperature and with lead solder there is room for error at 200 to 220c but with lead free there is almost no room for error since you are close to the temperature tolerances most bga packages can go up to 250c some only 240c and since you have to hit around 235c to properly melt balls you are very close to danger zone and if your heat is not even the left side may be 245 while the right is 230c which means you may have killed the chip or the left side may be 220c and the right side is 227c so chances are the chip was not properly heated as only half the chip had the connections fixed so while it MAY work and you think you FIXED it and it will probably return to you for warranty purposes

With the the term reballing you simply do it all the same just lift so if part of the chip is not heated properly then well your going to lift traces and or pads which is EXTREMELY time consuming repair and most of the time not worth it anywho

This involves using a vacuum suction pen which grabs the chip and allows you to lift it off, these are usually calibrated with the right amount of vacuum but i dont know all the details all i know is it lifts but if there is too much resistance it generally wont allow you too but if you were using tweezers or pliers you would rip that sucker off

If you happen to get resistance when lifting which means if you lift and it doesnt just plop off then either the solder is not fully liquid or there is epoxy in the way

Epoxy is horrible and is always on laptops, usually i use some dull tweezers to remove it using an smt station with a small nozzle

So lets say you didnt lift pads but now you have to put balls on the chip so you clean the board and the chip, but its not that easy

[URL="http://www.youtube.com/watch?v=JvlDvQNq_Bg"]Cleaning vid[/URL]

Lets say you did everything right up until cleaning and you have a radio shack iron there is no way you can clean the way shown above, it will take a lot longer and you may not do a great job, or you will lift pads or damage the solder mask

Most of the time damage to pads occurs, solder mask damage is not as common and at this point you need a new chip however if this happened on the board you can now tell the customer you ruined there board as you were not qualified to do this repair

Cleaning is not DIFFICULT but it does require skill and the right tools, i was using a Hakko 937 which was so old and beat up but it worked well i bought it used off ebay just got a new tip and i was fine and for regular soldering it worked so well

For cleaning it worked but i had trouble and it took a long time to clean, i was able to improve my cleaning by using Kingbo flux and the best BGA braid i could find however i still had lifted pads and trace damage and i was unhappy and since it was MY fault i gave the customer a refurbished board

I ended up getting a better iron which supported cartridge style tips and this means the heater is in the tip but of course this is a specialty station so the tips and station are pricey but after i was able to clean a board in less time than it takes you to change channels i stopped crying on how much i spent

So if you did manage to clean it PROPERLY, since you invested time and money into the right tools and knowledge it is time to put balls on the chip

Get your girlfriend and have her do this part, they are usually better working with the balls, you need a jig and there are 2 types direct heat and non direct heat but i refer to the non as 90mm jigs and then you need direct heat stencils or 90mm stencils along with appropriate size solder balls

Usually 0.6mm, 0.5mm, 0.45mm, and 0.76mm are most common and it will say the size on the stencil, thank your local china man for that

Then you ensure everything is top notch clean and proceed to put balls on the chip, after you have it all aligned you heat the chip so the solder balls land on each pad and stay

With the fresh solder balls on the chip you place it on the board and reheat it after cool down you test and either it works or it did not

You need to align the chip PROPERLY on the board, there are many ways to do this and usually just by looking you can get it right, some boards have lines so you can position it right and others have so many balls and are huge chips it is an impossible feat and nobody can help you just takes practice

Now if you want to be a cheater, [URL="http://www.youtube.com/watch?v=7nqLN4A-HRw"]use this[/URL]

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I tend to do reflows almost all the time, and only do a reball if necessary which means the flow was not successful or the chip was fried and you need a new chip
Sometimes customers are smart and request it upfront so we do it at that point

For repairs at our store reflows last a long time and we offer a 3 mth warranty on the repair but about 2% of customers return for warranty related issues
The reballs obviously last much longer and we barely get any of those back

Now in some cases if a reflow returns, we then do the reball and its fixed which means that either the previous repair was not done properly or the solder was just too weak or contaminated or it just wanted to be a pain

Some boards will arrive previously worked on, and there will be debris underneath the chip so we have no choice but to reball as a reflow will work but the debris will be in the way of the connection causing intermittent issues

Now just because you can lift chips and reball and reflow doesnt mean you have a great repair as a reball can come back in 24 hrs just as a reflow can due to improper heating meaning the solder did not melt evenly or fully

Usually if the chip is seated lower to the board it was flown properly provided its even on all sides, if that checks out its possible the chip was dying and when the customer used it the chip finally said bye time to die

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There are tons of machines, tools and accessories out there and you can buy them from China, US, UK, Japan, Chile etc;
Knowing who to buy from and which brand is a key to success, there are fakes and cheapo products out there

I have provided my product recommendations which you are free to follow or go on your own venture

We started with a manual machine, then went semi auto and now fully auto which is mainly the machine we use now
The manual was Quartz, the semi was IR and the full is Hot Air

Personally i prefer IR, but some people are vice versa and prefer HA
In my article below i go into the better details

[URL="http://xmoddz.com/hot-air-vs-ir"]Choosing a rework station[/URL]
[URL="http://xmoddz.com/bga-rework-repair-process"]Proper reworking process[/URL]
[URL="http://xmoddz.com/bga-reworking-reball-reflow"]Reball Reflow[/URL]

More coming soon, im tired so dont reply yet until i am finished with the important info
My grammar, spelling etc; is bad i know and is why i repair and do not revise reports