With the invention of several modern types of components like BGA and flip-chip technologies, conventional electron microscopy inspection is not even an option, as most PCB solder connections are hidden away. Since these real-time X-ray photos become much more relevant than it has ever been.
Here’s everything you need to know about the X-ray analysis of BGA!
What's the BGA?
The Ball Grid Array is also known as BGA is a circuit element configuration on a carrier known as a surface mounting kit. This device makes a circuit structure in which there are small spaces among chips. That's why it's labeled as high packaging.
The risk of welding errors rises due to closely packed pins, particularly with early circuit installing technologies including the Pin Grid Array (PGA). That being said, the precision of the welding joints has improved with the emergence of BGA, but there is still another problem.
Due to the proximity and existence of enough spaces among the chip pins, the challenge of examining the high-density bundle persists. BGA enables the spherical joint-soldering of the points and improves the number of pins, with far more room among the pins than that of the PGA.
Soldering flaws fall under the mentioned categories:
- Dry joints owing to shortage of solder;
- Bridging/Shorts caused by excess solder;
- The vacuum caused by gas bubbles inside the weld;
- Misplacement due to incorrect positioning of components.
How to use an X-ray Machine to Inspect BGA?
To use X-ray for BGA, high resolution of about 1 micron, high magnification of about 100X to 5,000X, sophisticated specimen processing to tilt and rotate the PCB or the imaging system, as well as sophisticated image recognition software, are needed to detect dry joints. Each of these systems is merged into one system that has a user-friendly interface. Certain devices are accessible with the choice of CT for complete 3D visibility of the electrical components.
How does X-ray equipment contribute positively to the production of BGA?
Implementing X-ray in the monitoring process will help to reduce the possibility of manufacturing modules that are difficult or unaffordable to fix owing to faulty 'hidden link' devices. Misplaced system reshaping can indeed be time-intensive and can lead to other integration problems, for instance with BGA surrounding components due to the local warming. Rework can also surpass the highest limit of solder reflow cycles permitted for the double arrays.
Wrapping Up
X-rays must definitely be part of the 'first-off' testing procedure, guaranteeing that the oven profile is suitable for solderable systems. It would then be wise to inspect a range of assemblies when they go through manufacturing; just a few from the beginning, the center as well as the end are usual.
Conversely, an 'in-line' method can be used, although it is important to note that X-ray testing – even though digital – is considerably slower. In practice, the positioning of leadless devices, particularly BGAs, is very easy and typically causes few problems, so X-rays must be used carefully.
About The Author:
Aqib Ijaz is a digital marketing guru at Eyes on Solution. He is adept in IT as well. He loves to write on different topics. In his free time, he likes to travel and explore different parts of the world. You can read more of his blogs at eyesonsolution.