The standard does not simply dictate a single way of doing things; rather, it offers a compendium of best practices derived from industry leaders. It addresses the entire lifecycle of the BGA, from the initial land pattern design on the printed circuit board (PCB) to the rework processes required for repairs.
The standard introduces a "flux dip and place" method for reworking BTCs. It also provides profiles for hot-air rework stations, emphasizing that the board must be preheated to 100-120°C before local reflow to avoid thermal shock. ipc-7093a pdf
| Feature | IPC-7093 (Old) | IPC-7093A (New) | |---------|----------------|------------------| | | QFNs and DFNs only | Added LGAs and other emerging BTCs | | Voiding guidance | General recommendations | Specific targets per class (1, 2, 3) | | Solder paste volume | Basic formulas | Advanced 3D solder paste inspection (SPI) criteria | | Thermal pad design | Single large pad | Multi-segmented pad arrays to reduce voiding | | Repair methods | Limited | Expanded with reballing and flux application techniques | | Board level reliability | Not covered | Added finite element analysis (FEA) guidance | The standard does not simply dictate a single
If you are currently using the old IPC-7093, you are missing out on critical void reduction techniques. The IPC-7093A PDF is a must-have upgrade. It also provides profiles for hot-air rework stations,