SNVA853C December   2019  – March 2024 LMZ10500 , LMZ10501 , LMZ20501 , LMZ20502 , LMZ21700 , LMZ21701 , LMZ30604 , LMZ31506 , LMZ31520 , LMZ31530 , LMZ31704 , LMZ31707 , LMZ31710 , LMZ34202 , LMZ35003 , LMZ36002 , LMZM23600 , LMZM23601 , LMZM33602 , LMZM33603 , LMZM33604 , LMZM33606 , TLVM13610 , TLVM13630 , TLVM13640 , TLVM13660 , TLVM23615 , TLVM23625 , TPS82085 , TPS82130 , TPSM265R1 , TPSM33615 , TPSM33625 , TPSM365R3 , TPSM365R6 , TPSM53604 , TPSM5601R5 , TPSM5601R5H , TPSM5601R5HE , TPSM560R6 , TPSM63603 , TPSM63604 , TPSM63606 , TPSM63608 , TPSM63610 , TPSM84424 , TPSM84624 , TPSM846C23 , TPSM846C24 , TPSM84824

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Package Types
    1. 2.1 MicroSiP
    2. 2.2 QFN Overmolded
    3. 2.3 QFN Open Frame
    4. 2.4 Leaded
    5. 2.5 QFN-FCMOD
  6. 3Package CAD/CAE Symbols and Footprints
  7. 4Soldering
    1. 4.1 MSL Ratings
    2. 4.2 Reflow Profile
    3. 4.3 Back Side PCB Mounting Considerations
      1. 4.3.1 Method 1 - Solder Surface Perimeter
      2. 4.3.2 Method 2 - Solder Surface Area
      3. 4.3.3 Back Side PCB Mounting Evaluation of TI Modules
      4. 4.3.4 Reflow Fixture
  8. 5Rework During Prototyping
  9. 6References
  10. 7Revision History

4.3.1 Method 1 - Solder Surface Perimeter

GUID-D5EA6F19-F6D5-4710-A323-DDE13064C486-low.gifFigure 4-2 Component Held by the Solder Surface Tension Around the Pad Perimeter

This method of evaluating the back side mounting feasibility was developed by Smith, Connell, and Christian. The empirical model defines the force of the solder surface tension as a function of the overall perimeter of the component pads. The empirical model dictates 22mg/mm of maximum recommended ratio of component mass to total pad perimeter.