Identify the package before discussing capability
A ball grid array uses an array of solder balls as its board connections. Package families can differ in substrate, internal construction, pitch and thermal or mechanical behavior. Plastic, ceramic and fine-pitch descriptions are not interchangeable process specifications. Package-on-package also introduces a different assembly relationship from one isolated BGA on a board.
Distinguish a BGA from an LGA, whose connections are lands rather than pre-attached solder balls, and from a QFN with its own terminal and exposed-pad arrangement. Supply the exact part number, package drawing and quantity. A general claim of “BGA capability” does not confirm suitability for every package.
Review the board and stencil as one interface
Check land geometry, mask definition, escape routing and any via-in-pad treatment against the component guidance and fabrication process. Open vias beneath solder deposits can affect solder volume; an agreed filled and capped structure is a different requirement from a hole merely covered by mask.
The assembly review also needs paste and stencil requirements, placement references, board support and access for inspection or rework. TI’s BGA application guidance connects pad design and escape routing with assembly and inspection considerations. Use the current guidance for the actual device rather than transferring numerical rules from an unrelated package.
Control handling and the measured thermal cycle
Check the component’s moisture-sensitivity information and exposure history, along with the board’s storage and handling requirements. Do not assign one bake schedule to every BGA or assume that a dry outer surface proves the package is ready for reflow.
Validate the profile on a representative assembly, considering package and board behavior, thermal mass and repeated process exposures. Record the relevant conditions and setup. If underfill or another reinforcement is specified, review its compatibility, inspection implications and effect on future rework separately.
Agree on inspection and failure disposition
Many BGA joints are hidden from ordinary optical inspection. X-ray can reveal selected joint geometry, but it does not independently prove electrical function or eliminate every possible interfacial defect. Combine the methods needed for the project, with defined coverage and acceptance criteria.
For a failed unit, determine whether the evidence supports rework, replacement or further analysis. Reballing, removing a component and replacing it are different operations with their own risks and authorization. Record the work and retest results against the board and component revision. A useful quotation includes the planned inspection and repair disposition, not just the placement charge.