GPU BGA Rework

  bga    bga_sc2

What is BGA

BGA or Ball Grid Array is one type of packaging for surface-mounted PCBs (where components are actually ‘mounted’ or affixed on the surface of the printed circuit board). A BGA package has no leads or pins. The Ball Grid Array gets its name because it is basically an array of metal alloy balls arranged in a grid.

BGA Soldering

During the initial stages, BGA technology was a matter of concern. People had doubts about the solderability and reliability of BGA components. In BGA, the pads are under the device and not visible hence it is necessary to ensure the correct process of soldering and inspection.

Today, BGA solder techniques are tried and tested and have been proved and trusted to be very reliable. It has also been learned that once the process is set up correctly, BGA solder reliability is much higher than that for quad flat packs (QFP) or any other SMD Package.

Reflow Soldering techniques are used to solder BGA. The reflow soldering technique is used to solder BGA because it helps the whole assembly to be brought up to a fixed temperature in order to melt the solder or solder balls underneath the BGA components.

For any BGA soldering, the solder balls on the package have a controlled amount of solder. Solder balls in various sizes of 18 mil, 24, mil 30 mil etc are available. When the Board with the solder balls and BGA Package is placed in the reflow oven, it gets heated and the solder melts. Surface tension causes the molten solder to hold the package in the correct alignment with the circuit board. It is important to take care of the composition of the solder alloy and the soldering temperature so that the solder does not completely melt, but stays semi-solid so that the solder balls stay separate from each other and do not result in any bridging.