Ipc-7352 Pdf Upd 〈High Speed〉
standard, titled "Generic Guideline for Land Pattern Design," was released in
Calculation Logic: IPC-7352 simplifies pad stack calculations by removing certain fabrication and assembly tolerances that were present in IPC-7351B. Ipc-7352 Pdf
Further reading
- Official IPC-7352 standard (purchase from IPC)
- EDA vendor documentation on land pattern generators (for practical application)
- Assembly house DFM guidelines for alignment with their process
- Head-in-pillow defects (BGA issues)
- Solder bridging (fine pitch components)
- Insufficient wetting (weak solder joints)
- Toe (T) =
Jmax + 2*C + (Pp^2 + (Lmin/2)^2)^(1/2)(Simplified) - Heel (H) =
Lmin - (C + Rf)
4. Assembly Considerations
The new standard places a heavier emphasis on the relationship between the land pattern and the stencil design. It recognizes that you cannot design a pad in isolation; you must consider how the solder paste will be applied. Official IPC-7352 standard (purchase from IPC) EDA vendor
How to Implement IPC-7352
- Land Pattern Design: The standard provides guidelines for designing land patterns for LGA and BGA packages, including recommendations for pad size, shape, and layout.
- Footprint Design: The standard covers the design of footprints for LGA and BGA packages, including guidelines for footprint size, shape, and layout.
- Solder Paste and Reflow Soldering: The standard provides guidelines for solder paste application, reflow soldering, and inspection.
- Inspection and Testing: The standard covers inspection and testing methods for LGA and BGA packages, including recommendations for visual inspection, electrical testing, and reliability testing.
Mathematical Modeling: It uses a "Component and Land Pattern" (CLP) calculator approach rather than just static tables, allowing designers to calculate land patterns based on specific component tolerances and fabrication capabilities. including recommendations for pad size