Automated BGA

Ball Grid Array, or BGA, is a growing and popular surface mount chip package that is finding its way into more and more electronic applications. The chip is mounted to the board using a grid of solder balls located underneath the chip as compared to the more typical packages where the leads are located on the outside of the component and clearly visible. The advantages of pursuing BGA are 1) higher density packages resulting in more complex applications in miniaturized form 2) lower thermal resistance that translates to less overheating of chips and 3) lower inductance resulting in better security and performance. One downside for the customer is the capital intensive nature of the equipment necessary to properly place, inspect, or rework BGA related assemblies.

Golden West Technology offers a full complement of manufacturing equipment that completely addresses any BGA requirements of the customer. The first requirement is to own and operate the automated fine-pitch placement equipment like GWT�s Fuji IP3 machines which contain very precise, vision placement systems. The next step is to be able to verify the solder ball contacts underneath the chip. Since the solder connections are hidden from the naked eye and even typical machine-vision inspection equipment, the only way to inspect is through powerful x-ray equipment after the reflow process.

GWT owns and operates a CR-Technology CRX-ZDOO X-Ray inspection machine. This machine has the capability to verify solder-ability, proper placement and existence of shorts. The x-ray beam is powerful enough to pass through solid materials like the PCB and the BGA chip itself to get at and produce a useful image of the integrity of the solder connections located between. During x-ray, the solder joint integrity is analyzed for voids, placement accuracy, proper reflow, solder bridges and ball integrity. Pictures are captured and x-ray software does a void analysis to measure the percent of voids in the balls. These pictures and data can be captured and sent to the customer for quality acceptance if required.

X-ray equipment has many useful purposes beyond BGA. One example would be providing a window into enclosed or potted products that obviously cannot be examined without destroying the product itself. But with x-ray inspection, one can troubleshoot and make a more educated decision on how to fix a problem with a product in the latter or finished stages of assembly. Another application would be failure analysis to determine the bonding integrity in chips or other SMT devices. All in all, GWT is excited to be able to offer to our customers this wide array of capability made possible by BGA x-ray inspection equipment.

BGA rework inevitably comes up due to the complex nature of BGA packaging and its application. As examples, GWT may get approached by a customer to fix a BGA related assembly or internal BGA adjustments may be required. In those types of situations, GWT is ready to respond with BGA rework station capability, specifically the Air-Vac DRS 24 BGA rework station. If a BGA is found to be badly soldered, the package can be lifted and removed. The BGA component can then be replaced or refurbished depending on what makes the most economic sense.