BGA Rework — One of the Challenging Procedures Performed in Printed Circuit Assembly

Ball Grid Array or BGA is mostly science, with a big slice of art thrown in! Across the globe, Ball BGA is one of the most challenging procedures performed at printed circuit assembly facilities and repair depots. Implementing the techniques in a right way mainly depends in large part on the skills and knowledge of the rework technician. In spite of long-established and transparent procedures for BGA rework, yet six common mistakes can cost you.

For instance, choosing the wrong solder paste could find yourself in a sticky situation. However, you need not worry and throw out the printed circuit board assembly. The problem such as joint bridging or incorrect BGA orientation, excessive solder joint voiding and BDG pad damage can get avoided.

· Incorrect BGA orientation or joint bridging — the problem is due to increased risk of damage with each successive application of heat and additional rework thermal cycles.

· Excessive solder joint voiding — the error mostly occurs due to incorrect process parameters or choice of solder paste, can require additional rework and compromise the integrity of the attachment. Moreover, if the voiding is over 25 percent, it might result in rejection.

· BGA Pad damage during its removal process — such a problem is sometimes an unavoidable hazard as it gets worse when underfill and conformal coatings used. Moreover, it is quite a time-consuming job to repair damaged BGA pads.

Above all, you need not worry as these problems or errors are preventable. Here are the six most common rework mistakes in BGA Rework that can get avoided.

Develop Good Thermal Profile

Damage and reflow of adjacent components seen in a wrong thermal profile, therefore it is better to use a correct thermocouple placement and data analysis to develop an upright. As the assembly reflow profile, the BGA rework profile also essential, and it duplicates in most of the cases.

Insufficient Operator Training

BGA or Ball Grid Array rework technicians should fully be trained, have skilled practiced and developed as we cannot emphasize this much. The technicians should have a proper understanding of the material they are working with, process steps, the interrelationship of all factors and most importantly the tools.

Indecorous Preparation

A professional painter knows that a good, lasting paint job is 90% preparation. Likewise, if the process is going to be done right then, there is a lot of development needed just before the first heat cycle is applied to a BGA rework site. As a result, the preparation consists right from the board assembly to prevent ‘pop-corning’ and other problems to baking out moisture from the BGA device, also removal or protection of nearby heat sensitive components to avoid damage or inadvertent reflow.

Therefore, it is better if the right decisions like to use solder paste, choosing the right solder paste stencil, chemistries and alloys in advance. Overall, before the actual rework cycle begins, there is plenty of preparation to do it accurately. This medium includes an accurate assessment of such things as solder ball size; device and ball co-planarity; solder mask damage and missing or contaminated pads at the PCB assembly site.

Incongruous Equipment Selection

‘You need the right tools to do the job properly,’ an ancient saying that right fits here! The equipment used for BGA rework must have the sophistication, flexibility, and capability to sustain a controlled, predictable and repeatable process. It also includes the robustness to be able to deliver heat as the process requires, closed-loop thermal sensing & control and product handling capabilities for removal & replacement. As this is not the area to cut corners, it is better to use the most capable equipment available.

By utilizing the latest techniques, methods, and processes, PCC performs BGA reballing and reworks which include lead-free, ceramic BGAs and column grid array. Leveraging IC rescue, we safely remove misplaced BGA, reball it via laser technology and then place it in PCB accurately. Over and above we also work on all types of land grid array package or socket, be it PBGA, Hyper-BGA, CBGA, CCGA, m-SMD, LGA, High I/O FCBGA, and more. After every repair/rework we perform X-ray inspection of all BGA components to ensure 100% quality.

PCC offers fast turnaround PCB Repair and Rework services in an entirely controlled ESD compliant facility. Adhering to IPC and JEDEC workmanship standards, we specialize in both assembled and bare circuit board repair and rework, having a skilled workforce who are regularly trained and continually assessed by our in-house certified trainers.