Sherlock Automated Design Analysis

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Sherlock Automated Design Analysis is a software tool developed by DfR Solutions [1] [2] for analyzing, grading, and certifying the expected reliability of products at the circuit card assembly level. Based on the physics of failure, Sherlock predicts failure mechanism-specific failure rates over time using a combination of finite element method and material properties to capture stress values and first order analytical equations to evaluate damage evolution. The software is designed for use by design and reliability engineers and managers in the electronics industry. DfR Solutions is based in Beltsville, Maryland, USA, and was acquired by Ansys in May 2019. [3]

Contents

Approach

Users upload either a complete design package, like ODB++ or IPC-2581, [4] or individual data packets, such as Gerber, Bill of Materials, and Pick and Place [5] files.

Sherlock incorporates stresses from a variety of environments into its physics-based prediction algorithms, including elevated temperature, thermal cycling, vibrations (random and harmonic), mechanical shock and electrical stresses (voltage, current, power). Sherlock then performs several different types of reliability analysis and provides the useful (constant failure rate) and wear out (increasing failure rate) portions of the life curve for each mechanism-component combination. The specific mechanisms that are evaluated and predicted include low-cycle solder fatigue due to thermal cycling, high-cycle solder fatigue due to vibration, solder cracking/component cracking/pad cratering due to mechanical shock or excessive flexure, lead fatigue, wire bond fatigue, via fatigue, electromigration, time dependent dielectric breakdown, hot-carrier injection, and negative bias temperature instability. Published research has indicated that the physics of failure-based predictions are highly accurate [6] and are now used to validate other techniques. [7]

These individual life curves are then summed to provide a physics-based reliability curve for the overall product. Sherlock also provides design rule checks (DRC) for board-level design (schematic and layout) and an overall reliability score. The reliability scoring, which is provided for the overall products – as well as individual scores and commentary for each area of analysis is used when physics-based quantitative predictions are not possible. The analysis is delivered both in PDF and HTML format. Depending on the types of analysis run and the data entered to create the analysis, reports can run between 20 and over 200 pages in length.

The semiconductor module is in compliance with SAE ARP 6338 [8] and is being considered as a replacement to traditional empirical reliability prediction methods (MIL-HDBK-217, [9] Telcordia SR-332, FIDES, and Siemens SN29500) in predicting the reliability of semiconductor devices.

A graphical interface allows users to examine results, make iterations, and pre-perform analyses as necessary. The software does not allow the user to make permanent changes to the electronic design. This activity takes place within the original EDA or CAD software. Sherlock is compatible with Abaqus, Ansys, and Siemens NX.

Outputs

Sherlock Automated Design Analysis produces the following outputs:

Life curves.png Sherlock map showing strain expected during impact across the PCBA.png

Version history

Sherlock Automated Design Analysis was launched in April 2011. [10] Subsequent releases include

Market acceptance

A company has reported requiring suppliers use Sherlock to reduce risk and help accelerate design validation and product verification. [11]

Related Research Articles

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<span class="mw-page-title-main">Vibration fatigue</span>

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Solder fatigue is the mechanical degradation of solder due to deformation under cyclic loading. This can often occur at stress levels below the yield stress of solder as a result of repeated temperature fluctuations, mechanical vibrations, or mechanical loads. Techniques to evaluate solder fatigue behavior include finite element analysis and semi-analytical closed-form equations.

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References

  1. Military Aerospace Electronics, "DfR Solutions launches Sherlock automated design analysis software", www.militaryaerospace.com, published 2011-04-04, retrieved 2011-10-24
  2. SMT iconnect007, "DfR Solutions Launches Sherlock", www.ems007.com, published 2011-10-06, retrieved 2011-10-24
  3. Bloomberg Businessweek, "DfR Solutions, LLC", www.bloomberg.com, retrieved 2011-10-25.
  4. "Home". ipc2581.com.
  5. "Pick and Place Report".
  6. Hillman, Craig, Nathan Blattau, and Matt Lacy. "Predicting Fatigue of Solder Joints Subjected to High Number of Power Cycles." IPC APEX (2014).
  7. Bhavsar, Nilesh R., H. P. Shinde, and Mahesh Bhat. "Determination of Mechanical Properties of PCB." Ijmer journal 2.4.
  8. Process for Assessment and Mitigation of Early Wearout of Life-limited Microcircuits, http://standards.sae.org/arp6338/
  9. "MIL-HDBK-217F. Military Handbook – Reliability Prediction of Electronic Equipment. Department of Defense, 1991". Archived from the original on 2007-03-11. Retrieved 2007-11-17.
  10. Military Aerospace Electronics,"DfR Solutions launches Sherlock automated design analysis software", www.militaryaerospace.com, published 2011-04-04, retrieved 2011-10-24
  11. M. Wagner and V. Nalla, Customer/Supplier Collaborative Accelerated Life Testing: Benefits and Considerations, International Applied Reliability Symposium, June 2014, Indianapolis, http://www.arsymposium.org/2014/abstracts/blue_s12.htm