Those interested in BGA soldering may require help to rework their BGA. However, in our guide, you will learn how to rework various BGA components using many tools that are readily available to many people, as well as a hot air gun. Caution must be practiced, as high temperatures can be generated, even during routine operations.
For instance, elevated temperatures may lead to unreliability, in regards to the tin solder that affixes the pins to the board pads. Excess heat may lead to either continuous shrinking, expansion of the circuit board, or the component in question.
It should also be noted that professional repairs will generally require fairly expensive equipment because BGA components have a very precise temperature curve for cooling. Still, the guide below can be used for people who want to take matters into their own hands to salvage, say, an old satellite TV receiver or personal computer.
What You Will Need to Rework Your BGA
You will need some iron wire that is thick such as a wire clothing hanger, as well as a soda can, a pair of scissors, a hot air gun, some flux and tin solder, a vice or a pair of pliers, and some scrap iron strips. You can obtain these from pallet material that is used to keep loads intact.
Reworking Your BGA: Step 1
You will need to take your BGA chip and measure it carefully. Once you have the length, you’ll need to use a hammer and a vice to bend the strip so that a square is formed. You can also use a pair of pliers to bend the strip, or you can combine a pair of pliers with a hammer and vice combination to get the job done more effectively.
In any event, the square that you make should be slightly bigger than the actual BGA chip that you own, so that the heat will be allowed to flow beneath the chip body.
Reworking Your BGA: Step 2
Now you will need to make a clip by using some iron wire that you have at your disposal. Once you have made your clip, you should set it aside, as you will need it, later on, to hold all of the various parts and components together.
Reworking Your BGA: Step 3
Next, finish your soda off completely and use a pair of scissors or a cutter to cut open your soda can. Then, you will need to flatten the can and cut out a square hole. The reason why the hole needs to be square-shaped is so that the square frame that you made — from step 1 — can fit tightly into it.
The aluminum foil on your soda can should suffice to protect the remainder of your board components from excess heat once you begin heating the chip via your hot air gun. Heating issues should not be a problem, provided you followed all the steps carefully.
Reworking Your BGA: Step 4
At this point, your soldering flux will need to penetrate the actual BGA chip. You can aid your cause by using a small brush, ensuring to reach all sides.
Reworking Your BGA: Step 5
Next, you will need to take a tiny piece of your tin solder and roll it into a small ball. Then, set your ball aside, as you will need to return to it during the heating process.
Reworking Your BGA: Step 6
The circuit board will need to be clamped to your workbench at this point so that it doesn’t move about as you work. Ensure that the chip stays off the table so that you will be able to heat the chip from underneath easily. Next, you will need to take your square frame and your aluminum foil and set them in position using the wire clip that you made at the beginning of your project.
Take your small tin ball and set it down in the nucleus of your BGA chip. The board will need to be positioned so that the tin solder ball will not roll away once the tin has been melted sufficiently.
Reworking Your BGA: Step 7
Now comes the truly fun part, which is the heating. To begin the heating process, you will need to pull out your hot air gun, ensuring to set it to a low temperature to start. You will then need to heat the board from the bottom side as well as from above until your tin blob begins melting.
After it has melted, continue heating the area for at least an additional thirty seconds. You will know that it has melted sufficiently when the tin turns into a metallic ball that is quite shiny when it has been melted, and it will roll away if you fail to follow our steps mentioned above.
As an added tip, try and hold the gun perpendicular to the board — and above the chip — ensuring that there is an appropriate amount of distance between the chip and your hot air gun: When performed correctly the tin ball should remain on your chip instead of falling to the floor.
Reworking Your BGA: Step 8
The final step involves cooling the board. Once your board has cooled, it should be completely reworked. It will be given a new lease on life, and will not need to be thrown into a dumpster, where it would have likely been transported to a local landfill.