Heat sink installation, stiffener mounting, and daughter card insertion. Logistics: Handling and drop testing during shipping. 电子工程世界（EEWorld） Technical Details Measurement:
Historically, IPC-9704 establishes a warning limit of for BGA solder joints. However, the standard teaches that this is not a universal pass/fail limit. The actual allowable strain depends on:
By following these guidelines, manufacturers can quantitatively characterize board flexure and assess the risk of damage during assembly, testing, and system integration. Key Specifications of IPC-9704A ipc-9704 pdf
: Standardizing how strain and strain rates are calculated and reported.
Before the release of IPC-9704, different companies used inconsistent strain measurement methodologies, making it impossible to compare data across the industry. This standard addresses that gap by defining: However, the standard teaches that this is not
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(published February 2012), can be downloaded for free from the JEDEC Standards site (requires a free registration/login). Purchasing Options:
IPC/JEDEC-9704A (2012) is the industry standard for measuring PCB mechanical strain during assembly to prevent damage to sensitive components like BGAs. The guidelines specify using 3-element stacked rosettes placed near component corners to measure strain during high-risk processes, such as ICT and depanelization. For further technical details, visit PCBSync . Before the release of IPC-9704, different companies used
The latest revision, , includes significant updates to address modern manufacturing challenges, including lead-free assembly and more complex components. Recommendation Gage Resistance 120Ω or 350Ω Gage Length 0.062″ (1.57mm) typical Grid Configuration Triaxial (0°/45°/90°) rosettes Compensation Self-compensating for FR-4 material