BGA assembly or repair is one of the most difficult procedures when it comes to the printed circuit board (PCB) assembly or repair. Because BGA rework process is intended to permanently bond the PCB and their accompanying integrated circuit, getting to the connecting pins—or heating the whole device to the heating point of the solder, which might potentially destroy it—is almost difficult.
The balls of tin solder, the “ball” in the ball grid array, become unstable owing to the constant heating and shrinking of the board or its components as a result of the typical heating cycle of the board.
BGA rework methods are clearly specified, however faults and difficulties might arise during the course of a regular BGA repair or rework, necessitating further repairs or even scrapping the BGA and starting again. As a starting point, we’ll go through the stages involved in repairing a BGA first.
What is the procedure for BGA repair?
Remove all of the components, starting with the PCB. To remove the PCB, use a vacuum to warm it until the solder is molten. When removing the BGA, be aware of the risk of damaging the BGA packaging pads. In order to remove the BGA pads, you must first ensure that the BGA has been properly heated and that the solder has fully saturated and flowed.
Step two is to remove any remaining solder. A vacuum should be used to remove the old and surplus solder from the spot once it has been warmed again.
The BGA may now be reballed when the excess solder has been removed. Reballing is the process of inserting fresh spheres of solder into a BGA by the use of a stencil.
It is now possible to re-solder and re-attach the components and PCB after removing excess solder and rebalancing the BGA. As in step 1, solder may be printed onto either the PCB or BGA before soldering occurs in this phase, which is similar.
BGA rework common errors
It’s clear from the above summary how the procedure should go, however, errors still occur. Performing a BGA repair might go horribly wrong for a variety of reasons.
- Inadequate training for operators
As a result, BGA repair specialists must be highly skilled, with a proven track record of success. What materials they’re dealing with, their interactions, and how their tool selection affects these are all part of this.
It is important to have a working understanding of the BGA repair procedure and to be able to analyze a prospective repair scenario before beginning work. In order to do a successful BGA repair, the technician must be familiar with a number of details that aren’t immediately apparent when looking at the overall process.
In addition to the potential for thermal mismatch between the PCB and BGA, the likelihood of solder heat liquefying other components and suitable thermal and flow management techniques should be considered by technicians.
- Preparation Errors
Preparation is crucial, regardless of the scope of the repair, whether it’s a small fix or an all-out BGA repair. There’s a lot of planning that goes into a good BGA job, as seen above, and knowing that your technician is doing that might give you some piece of mind.
- Incorrect selection of equipment or incorrect selection of materials
If you haven’t got the correct tools, you won’t be able to accomplish your best work. Because of the repetitive nature of the labor involved in BGA rework, the BGA components a technician employs must be both adaptable and durable to meet the demands of the job.
A technician must be able to distinguish between the best and the best equipment for certain work. The ability to provide heat when and where it is needed is a key feature of the equipment you choose, so be sure it has both closed-loop thermal detection and control. If you need to remove or replace a component, be sure you have the right tools to perform the job at hand.
Having the finest equipment and not cutting shortcuts might help you avoid some of the BGA rework difficulties that you may have in the future. Excessive solder in solder joints is one of the most common BGA rework problems that may be prevented with correct material selection and equipment selection.
- The BGA Rework Profile was not properly developed
Thermal profile development is one of the most critical aspects of any BGA rework or repair. Knowing exactly what comprises a suitable thermal profile and exactly what doesn’t is essential to saving you money and labor
Repairing a BGA requires a repeatable procedure, and without correct thermal profiles for your components, you’ll have difficulty creating a method that’s both successful and repeatable.
This implies that you will have to redo the same location more often if the thermal profile isn’t properly established to prevent damage to the BGA, PCB, or other components.
Make sure that your thermocouples are situated correctly (particularly on the PCB) and then examine the data they offer you to design an appropriate thermal profile. The only way to build a consistent thermal profile is with excellent, reliable data.