BGA Rework
DESCRIPTION
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!
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??)
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.
Using some iron wire, make a clip like the one shown here,
we gonna use it later on to hold everything together....
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.
It's now time to let some soldering flux penetrate under the BGA chip,
with the help of a little brush, from all sides.
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.
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.
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.
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.