Ball Grid Array

What is a Ball Grid Array?

The Ball Grid Array or BGA, is a grid pattern of pads with balls of solder as opposed to packages using pins for connections. The circuit board contains a matching array of copper pads to complete the connection. Numerous advantages are offered by the BGA package.

• Reduced Track Density:
  BGA spreads its contacts out over the entire span of the package which reduces track density around the package.
• Increased Durability:
  BGA solder balls are much sturdier than traditional flat pin packages making them much easier to handle without risk of pin damage.
• Improved Heat Dissipation:
  Lower thermal resistance between the silicon chip and the solder balls produces a far more effective conducting of heat onto the printed circuit board.
• Higher Performance:
  With the conductors located across the bottom of the chip, shorter leads are possible within the package. Thus reducing inductance and improving performance.

BGA Solder Process

As the pads are under the device and not visible, solder reflow techniques are required. The solder balls on the package contain a very precise amount of solder. Careful control of heat results in a very reliable connection. Higher than most flat pin counterparts. This process is excellent for mass production, rework and prototyping.

BGA Solder Joint Inspection

Optical inspection of the BGA solder connection cannot be accomplished due to the connections location under the package. The connections cannot be fully tested by checking the electrical performance either. X-ray is the chosen method to inspect the integrity of the solder connection.

BGA Rework

Reworking a suspected bad component can be accomplished if the proper equipment is available. A + specialized BGA Rework station is required. Equipped with a jig fitted with infrared heater, a thermocouple to monitor the temperature and a vacuum. The solder can be melted and the component lifted for inspection or replacement.