Design Considerations for BGA Packaging in SMT Assembly Processes

2026-04-23

In surface mount technology (SMT), Ball Grid Array (BGA) packages are widely used in high-performance chip packaging due to their high pin density and excellent electrical and thermal performance. Since the solder joints are located on the bottom of the chip and cannot be directly inspected visually, stringent requirements are imposed on placement accuracy and process control in the SMT manufacturing process.

BGA Layout Design Requirements

(1) Place as close as possible to the conveyor edge of the PCB, as deformation during soldering is relatively lower in this area.

(2) Avoid placement near the corners of L-shaped boards or adjacent to press-fit connectors whenever possible.

(3) Avoid mirror-image layout on opposite sides of the board. If such a layout is unavoidable, the PCB thickness should be ≥2.0 mm. This recommendation is primarily based on long-term reliability considerations, supported by research findings from multiple reputable companies indicating that mirror-image BGA layouts reduce reliability by over 50%.

(4) For PBGA, avoid placement on the first assembly side (the first soldering side, typically the bottom side) if possible.

(5) Avoid placing BGAs near the separation edges of panelized boards whenever feasible.