© 2004 – 2010

Sherlock Automated Design Analysis™

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

Model Simplifications for Rapid Assessment of Interconnects

o Unique scaling challenge of modeling the robustness of soldered interconnects of electronicso Large assembly with thousands of small solder

joints (sub mm)o Sherlock uses simplified component structures

that approximate the mass and stiffness of the electronic component without modeling the actual interconnects

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

Model Comparison

o Quarter symmetric model of BGA device under board bending moment.

o Sherlock uses package dependent board level strain fatigue models for vibration predictions

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

Models

o Board parameters are identicalo Detailed part includes individual solder joints,

die, substrate and lido Simplified part just includes substrate

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

o Identical bending moments applied to board edges

Displacement Results

≈ 2% Difference

Detailed0.2618 mm

Simplified0.2672 mm

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

Principal Board Strains

Simplified

Detailed

Similar corner PCB strains

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

Discussion

o Based on the board level deflections the difference between the two models will not have a significant impact on the dynamic response of the circuit board.

o Both models generate similar PCB strains