Ipc-7095 Pdf

The standard provides a "thermal warpage" test. Place a glass BGA dummy on a board. Run it through reflow. If the glass breaks or shows stress marks, your PCB or component is warping too much (as defined in Appendix C).

: Addresses the notorious failure where a melted solder ball and the solder paste fail to coalesce, creating a false joint that often fools visual inspection. ipc-7095 pdf

| Void Type | Maximum Allowable Void Size | Notes | |-----------|----------------------------|-------| | | ≤ 25% of ball diameter | Acceptable if not near pad edge | | Multiple voids | Sum of void areas ≤ 25% of ball cross-section | Applies to voids > 10% of ball diameter | | Void in thermal pad | Up to 50% allowed | Only for large central ground/power balls | | Edge void (pad separation) | None allowed | Causes head-in-pillow defect | The standard provides a "thermal warpage" test

: How to assess the long-term mechanical and thermal integrity of BGA joints. Key Focus: Managing BGA Voids If the glass breaks or shows stress marks,

The IPC-7095 document can typically be purchased and downloaded from the IPC website or other electronic document repositories. It is essential to ensure that you are accessing the most current version of the standard, as IPC periodically updates its publications to reflect changes in technology and best practices.

Because BGA joints are hidden, the process must be strictly controlled to ensure "quality by design".