Introduction: BGA Rework
This instructable shows how to do a DIY rework of BGA components, using a hothair gun and commonly available tools.
Sometimes, expecially if they develop high temperatures during normal operations, the tin solder connecting their pins with board pads tend to become unreliable.
This is due to continuous expansion/shrinking of the component and/or the board caused by heating. To make a professional repair normally an expensive equipment is required, because BGA components have a specific temperature curve for heating, soldering and cooling. But if you're trying to save an old PC or , as in my case, a satellite TV receiver, this instructable might make your day.
Have fun!
Step 1: Tools Needed
What you'll need:
- some scrap iron strips, I got mine from the one used to hold loads on pallets.
- pliers or vice
- hot air gun
- tin solder and flux
- soda can
- scissors
- some thick iron wire,(cloth hangers??)
Step 2: Let's Start
Roughly measure the lenght of your BGA chip.
Using pliers and/or a vice and a hammer, bend the strip and make it into a square,
slightly bigger than the size of your BGA . This will allow heat to flow under the chip body.
Step 3: Make a Clip
Using some iron wire, make a clip like the one shown here,
we gonna use it later on to hold everything together....
Step 4: Drink That Soda!
With the help of a cutter and/or a scissor, cut open a soda can, flatten it,
and cut a square hole, so that the square frame we made before can tight fit in the hole.
The aluminium foil will protect the rest of the board components from heat
when we'll direct hot air onto the BGA chip.
Step 5: Flux It
It's now time to let some soldering flux penetrate under the BGA chip,
with the help of a little brush, from all sides.
Step 6: Tin Solder Helps
Take a very little piece of tin solder, make it into an litlle ball, and put it aside,
it will help us during heating process, as it will indicate when the meltin temperature is reached.
Step 7: Gather the Actors
Clamp the board to your workbench so it doesn't move.
Make sure the chip stays out of table, so it can be heated from bottom.
Next, take the aluminium foil and the square frame and fix them in position
with the help of the wire clip we made at the beginning.
Finally, position the little tin ball in the center of the BGA chip.
Make sure the board is horizontal. This will prevet the tin solder ball to roll away
when the tin is melted.
Step 8: Time to Heat
Now grab your hot hair gun, set it to the lower temperature,
and start heating the board up, both from above and from the bottom side.
Then stay on the top until the tin blob start to melt.
Apply heat still for some 30 seconds after the tin blob has meltet.
When it melts, it turns into a shiny metal ball, and it has the bad habit to roll away.
Try to hold the hot hair gun perpendicular to the board and above the chip, not so close to it.
This will help keeping the tin ball on the chip.
Step 9: Cool Down
Now let the board to cool down.
If everything was done okay you have good chances to have saved your device from trash bin.
Good luck.
28 Comments
9 years ago on Introduction
proper bga reworking requires making a profile for the chipset to be reworked
using a heat gun merely provides a band aid as it can not supply the appropriate heat required which is bottom 70% and top 30%
there are several guides that involve the use of heat guns and griddles and is the reason why bga reflows and reballs have a bad name
Reply 4 years ago
The idea seems to be in heating both top and bottom of chip so as to ensure that both sides of the BGA cold solder joints re-flow (not just the top), and without losing adjacent parts.
If you use masking setup and solder paste as shown in article, and clamp board horizontally on edge of bench, any adjacent parts that flow won't move. A square tinned copper sheet (about one inch sq) under board will couple heat from a large soldering iron as measured with an infra-red thermometer above chip.
Heat bottom of board til it reads about 325 F. (near melting temp of 360-370 degrees F.). Continue while adding hot air from above (as directed in article) until 30 seconds after blob melts. That should ensure a full re-flow of BGA without causing other damage.
9 years ago on Step 8
What would happen if the "shiny metal ball" of solder was to roll off the top of the Chip ?
would it not via capillary action, dispense under the Chip messing up the BGA ??
Reply 4 years ago
A small closed loop of suitable wire (ie: lead wire from resistor) sitting on the chip and surrounding the solder blob will stop it from rolling away and causing damage. It will just flow onto the wire instead as it normally does during the "tinning" process. Keep the solder piece small enough (like 1/8" long).
5 years ago
It has been always risky for BGA soldering in PCBA prototyping& small batch production, to ensure the BGA soldering quality, it'd better checked the BGA soldering with X-ray. Details pls see my bloghttps://www.makerfabs.com/X-Ray%20Checking%20for%20BGA
13 years ago on Introduction
This is a good simple instructable. Is serves the same basic principle of a quality SM rework station. I know this because I used to build them.
Now if you could find a way to use infrared you would have a great thing.
And I would refrain from using any open flame for the heating process as the flux is flammable to open flames, just a safety suggestion.
Reply 6 years ago
This is not rework, it's reflow. a very important distinction, as they serve different purposes.
Reply 6 years ago
Ok, thanks for pointing it out, rework here is to be meant as a way to redo soldering as an attempt to make the device working again.
It is not even a machine, is a manual way to try to fix a not working part. Next step, if unsuccessful, is the waste bin.
Reply 6 years ago
You see, that's not really true, and that's kinda the point I am making. If reflowing is not successful, there is still an option to rework it by reballing the chip rather than just tossing it out.
Reballing involves melting the solder connections so as to remove the chip from the board entirely, removing the remaining solder, refluxing the board, adding new balls, remounting the chip, and melting the solder.
Reply 6 years ago
What you're saying is true, provided that you have the appropriate tools and instruments. But this is just a "see what you can do with an heat gun in you garage" kinda work. I dont have a reworking station, if I did that kind of repair professionally I'd get one, probably. And it would still require some skill to do it properly.
Reply 6 years ago
Sure. Not commenting on the instructable, just on the terminology used in this particular comment, since the distinction is important.
Especially if people then conclude that there hardware is unfixable.
Reply 6 years ago
Rework is re-flowing the solder. A Surface Mount Rework station RE-FLOWS the solder so the individual component can be removed either automatically or manually with a suction wand and replaced. This machine does not remove the solder it re-flows it for component replacement.
There is a distinct difference between rework and repair. Rework you re-flow the solder. Repair you replace the solder and component..
Reply 6 years ago
And?
"A Surface Mount Rework station RE-FLOWS the solder so the individual component can be removed either automatically or manually with a suction wand and replaced. This machine does not remove the solder it re-flows it for component replacement."
And in the above intractable the component is NOT removed, and it is NOT replaced.
The above method simply remelts the solder and then allows it to reharden, using the original solder from the original BGA.
8 years ago on Step 9
This is actually technically a re-flow, not a rework. The difference being that a rework involves completely removing the solder balls from the BGA component (in most cases being a processor of some kind) and replacing them completely.
8 years ago on Introduction
I like this idea to make solder wire as melting point detection tool. Thanks , it will be really helpful to me for motherboard repair.
Reply 8 years ago on Introduction
HI there. Thank u for your comment. Im actually working
On a more accurate temperature controller based on an arduino board
Here details of the project Im trying to replicate
http://smokedprojects.blogspot.it/2013/11/stripboard-pid-arduino-shield-hardware.html?m=1
Cheers
Angelo
9 years ago on Introduction
I have used a Pancake Grille, turn it to High or 450*F, make some Stand-off's for in my case DV4 M/B about 1" long and you can use foil tape to protect other components. This is your Pre Heater! for botton of M/B, Check Temp's with Thermal couple!!They are inexpensive to buy(Ebay)& MultiMeter, when grille gets to temp set your Project on and start Timer, Then start Heat gun< ( you should check temp setting's before <good practice on heat gun) This was to rework ATI Video Chipset(common problem W/DV4-6-9) ROSH STD No Lead makes bad solder joints... Yes remove red epoxy at conor's if any <...I mounted heat gun on old MicroFish table adjust up and down to help maintain heat..
You might look for infrared light with small computer fan say 12vcc powered by 5vcc for less RPM to blow air,,, OR toaster oven quartz element long tube fan on top ?? endless idea's
9 years ago on Introduction
Will this still work of there's epoxy on the component?
Reply 9 years ago on Introduction
Sometimes companies put epoxy all around the edges of the component to make it more "resistent" to the problem of thermal expansion/shrinkage. In order to apply my method I think such epoxy need to be removed first. With the same heatgun, heat the epoxy. Once heated, epoxy softens and can be removed with some sharp tool, making care not to damage any other component or track around
11 years ago on Step 9
hebat sekali, akan saya coba.. terima kasih