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. Using This Guide
    3. A Word of Caution
    4. A Team Sport
    5. Be Wary of Quotes
    6. Don’t Forget Your CAD Tools
    7. Metric Vs English
    8. PCB Fab Limits
    9. Routing and Layer Stackup
    10. 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

PCB Fab Limits

Most circuit board vendors publish a table that indicates various limits for drills, trace widths, thicknesses and so on. In many cases, there are different limits depending on the most important characteristic for the board. What this means is that there are tradeoffs and options for the designer to consider. Always consult with your circuit board vendor for their limits and capabilities and remember that as you approach the limit of the vendor’s equipment, yields go way down and costs go way up. Let’s look at one vendor's (vendor X) technology and capabilities:

    Standard Technology

    Usually means this is the middle of the vendor’s capability and pricing. The technology does not push the limits of the vendor’s equipment. For example, vendor X shows that a standard minimum trace width and clearance are 3 mils with 4 mil vias and 10 mil pads.

    High Yield Technology

    Loosens up the specifications to provide more clearance and wider traces resulting in lower cost per unit board and higher yields. For example, the same vendor X lists a minimum trace width and minimum clearance of 4 mils with 4 mil vias and 10 mil pads for high yield boards. However, a hi-yield board may be larger and have more layers.

    Engineering Development Technology

    Really pushes the vendor’s capabilities. It is at the limits of the vendor’s equipment. For example, vendor X lists a minimum trace width and minimum clearance of 2.5 mils with 3 mil vias and 9 mil pads.