SPRAAV1C May   2009  – March 2020 AM3703 , AM3715 , OMAP3503 , OMAP3515 , OMAP3525 , OMAP3530

 

  1.   PCB Design Guidelines for 0.4mm Package-On-Package (PoP) Packages, Part I
    1.     Trademarks
    2. 1  Using This Guide
    3. 2  A Word of Caution
    4. 3  A Team Sport
    5. 4  Be Wary of Quotes
    6. 5  Don’t Forget Your CAD Tools
    7. 6  Metric Vs English
    8. 7  PCB Fab Limits
    9. 8  Routing and Layer Stackup
    10. 9  OMAP35x 0.4mm Pitch
    11. 10 Pad Type
    12. 11 PCB Pad Dimensions for 0.4mm BGA Package
    13. 12 Multiple BGA Packages
    14. 13 Etch Traps and Heat Sinks
    15. 14 Vias and VIP
    16. 15 Laser Blind Vias
    17. 16 Filled Vias
    18. 17 Know Your Tools
    19. 18 BeagleBoard
    20. 19 BeagleBoard Views
      1. 19.1 Top Layer – Signal - Area Underneath the OMAP35x
      2. 19.2 Layer 2 – Ground
      3. 19.3 Layer 3 – Signal
      4. 19.4 Layer 4 – Signal
      5. 19.5 Layer 5 – Power (VDD2)
      6. 19.6 Layer 6 – Signal – Bottom Copper – Bottom Component Outlines
    21. 20 OMAP35x Decoupling
    22. 21 PCB Finishes for High Density Interconnect (HDI)
    23. 22 Real World Second Opinion
    24. 23 Acknowledgments
    25. 24 References
  2.   Revision History

2 A Word of Caution

This section discusses the BGA package and the circuit board immediately below the BGA. The guidelines do not cover all aspects of circuit board design, nor is it a discussion on how to use your favorite CAD tool.

Design of circuit boards for fine-pitch BGA packages at 0.4mm and smaller is more of an art than a science, due to the lack of published data. In many cases, 0.4mm pitch pcb fabrication technology is considered proprietary and/or advanced and may require that a non-disclosure-agreement (NDA) be executed. Therefore, the material in this document will age and go out of date quickly as more assembly houses adopt smaller pitches and PoP assembly.

Since this is a rapidly evolving technology, spend some time reading the huge number of articles, papers and company presentations on all aspects of fine-pitch board design.

When the 0.5mm pitch design guidelines were created, it was stated that the long standing rules for circuit board design were no longer applicable at these small geometries and a new batch of guidelines were established. With the release of 0.4mm pitch BGA packages, the new rules needed to be modified. This was determined through the design and assembly of TI developed evaluation module (EVM) boards and a new circuit design called the BeagleBoard.

The BeagleBoard is referenced extensively throughout this document and Part II. Be sure to obtain the Gerber files for this board at http://beagleboard.org. The files will be an invaluable reference during the design of your board. Also be sure to check for updates to this document that can be found on the beagleboard.org website as well as all TI websites for OMAP35x, Application Report Section.

It is strongly recommended that you plan on performing your own experimental layouts and prototype runs before committing to volume production to determine if: your suppliers can handle the device, you may have to change circuit board vendors, and/or find assembly shops with better equipment.

One important aspect of 0.4 mm design is the need for close cooperation among the various entities that are involved in the board design, fabrication, and assembly.