As the application of chips becomes increasingly widespread across various industries, chip rework becomes particularly important. Below, Silman Tech will introduce the method and steps for soldering chips using a BGA rework station.
Firstly, place the motherboard on the soldering fixture and position the chip that needs to be soldered in the middle of the BGA rework station. Use insulating material to isolate the BGA chip that does not need heating. Heat the chip until the nearby capacitors can move back and forth, indicating that the BGA chip can be removed.
After removing the BGA chip, it is essential to clean the excess solder from the motherboard. Here’s the procedure:
- Apply a layer of solder paste and then use a soldering iron to scrape off most of the solder on the motherboard. There may still be some solder residue left on the board. Then, gently move the soldering iron with desoldering wick over the motherboard (be sure to move slowly to avoid pulling off the solder joints, especially for boards with loose solder joints). After desoldering, wipe off the remaining solder paste. If not cleaned thoroughly, the chip may have poor soldering or cold solder joints after soldering.
If you have a new chip (with solder balls attached), place it in the correct position on the motherboard and heat it. If there is no new chip available, you can remove a chip from another motherboard of the same model and replace it. After removing a chip, clean the solder from the chip using the method described above. Then, evenly apply a layer of solder paste (without impurities) to the back of the chip using a cotton swab. Place the corresponding stencil on the chip, ensuring that the stencil is clean without any solder paste or debris on the surface or inside the holes. Clean the stencil thoroughly with alcohol, then place it on the chip. Use a paper or small spoon to sprinkle solder balls onto the stencil. Since the chip has a layer of solder paste with certain adhesion, there will be a small amount of solder paste under each stencil hole, allowing each hole to evenly pick up a solder ball. This way, we have placed solder balls on the chip.
These are the steps for soldering chips using a BGA rework station.