Leveraging Physics of Failure
Instead of using statistical models to predict reliability without gaining insight into why something failed, Sherlock’s Physics of Failure-based approach leverages knowledge and understanding of the processes and mechanisms that induce failure in order to improve product performance.
Physics of Failure (PoF), or Reliability Physics, uses degradation algorithms that describe how physical, chemical, mechanical, thermal or electrical mechanisms can decline over time and eventually induce failure. The specific term arose from an attempt to better predict the reliability of early-generation electronic parts and systems; however, the concept of PoF is common in many structural fields.
Utilizing PoF and Reliability Physics, Sherlock can accurately predict the failure behaviour of next-generation components, including:
- Silicon transistors
- Wire bonds
- Solder bumps
- Die attach
- Light-emitting diodes
- Electrolytic capacitors
- Plated through-holes
- Solder joints
Accelerating Design Analytics
Unlike any other tool on the market, Sherlock uses files created by your design team to build 3D models of electronics assemblies for trace modeling, post-processing of finite element analysis and reliability predictions. This early insight translates to almost immediate identification of areas of concern and gives you the ability to quickly adjust and retest designs.
Electrical and mechanical engineers can work in tandem using Sherlock to Design for Reliability from the start of the project. Teams can use Sherlock to integrate design rules, best practices and Physics of Failure (PoF) methods, including
- 3D models of electronic assemblies for early analysis
- Trace modelling
- Post-processing of finite element simulations to identify critical components and predict time to failure
- Reliability predictions not previously possible
Sherlock also accelerates traditional design for reliability activities, including:
- Design Failure Mode and Effects Analysis (DFMEA)
- Thermal derating
- PCB Modeling and Simulation:
Sherlock automates the process, reduces required resources and provides results quicker. Design rework is accomplished within minutes, not weeks or months.
Reducing Manufacturing Risk
Design for Manufacturability (DfM) and Design for Reliability (DfR) are not mutually exclusive. Sherlock considers both to mitigate manufacturing risk by assessing solder reliability, strain measurement, suppliers, materials selection and post-assembly handling operations.
To maximize Design for Manufacturability (DfM) and Design for Reliability (DfR) in order to mitigate risk, Sherlock evaluates key components, including:
- Solder joint reliability to assure a product will function under given conditions, for a specified time, without exceeding defined failure levels
- Plated through-hole fatigue by using computerized modelling and temperature maps instead of human interfaces for accurate finite element test results
- Strain measurement during shock and vibration testing to gather data for prediction of failure probability, root causes of failure and failure events
- Material selection to align a plastic’s properties with design and functionality requirements
- Supplier analysis for building partnerships that can consistently deliver quality products and services without interruption
- Post-assembly handling operations assessment to identify areas for efficiency improvement after production
- Semiconductor wear-out, which allows manufacturers to evaluate and predict IC failures using an approach that follows SAE ARP 6338
Faster Testing
Product development requires a substantial investment of time and money — and it doesn’t guarantee passing qualification testing the first time. Sherlock reduces expensive build-and-test iterations by virtually running thermal cycling, power-temperature cycling, vibration, shock, bending, thermal derating, accelerated life, natural frequency, CAF and more so you can adjust designs in near real-time and achieve qualification in one round.
Sherlock reduces the number of required physical testing iterations and improves the chances that prototypes will pass qualification tests in the first round. Engineers can design reliability right into electronics, allowing them to:
- Build and test virtual products
- Modify designs in near real-time
- Quickly run mechanical simulations
- Identify testing opportunities
- Evaluate design choices
- Gain project-specific insights
- Align reliability goals with metrics and requirements
Using Sherlock as part of your test plan significantly reduces the time and expense of multiple iterations of each qualification test, including:
Temperature Cycling
Instead of applying and working within the parameters of traditional methods, Sherlock designs the board and applies the temperature cycle to it. Faulty components and the number and type of failures are identified with certainty, allowing for a quicker, usually less costly fix to happen earlier in the process.
Plated Through-Hole Fatigue
Instead of allowing for human interfaces when monitoring several key contributors to PCB functionality, Sherlock’s computerized modeling is based on the temperature map from the solder fatigue input, and uses board stackup to calculate barrel stress for finite test results and remedy.
Vibration and Shock
The conventional probabilistic approach to vibration and shock testing cannot pinpoint actual failure events. Sherlock calculates board strain during mechanical shock and vibration testing, and then uses the data to predict the probability of failure and determine root causes of failure and corresponding failure events.
Conductive Anodic Filament (CAF)
Sherlock gathers data on drill hole locations and diameters directly from the computerized drill files, filters them by hole size and precisely identifies a “damage zone” between a pair of holes for focused analysis. This automated CAF qualification decreases the number of failures and ensures product reliability throughout manufacturing.
Highly Accelerated Life Testing (HALT) and Highly Accelerated Stress Screening (HASS)
HALT and HASS are excellent tools for design verification in the electronics industry. HALT provides insight into margins and weak points in design, and HASS is developed by running a combined temperature cycling/vibration HALT to failure and reducing the duration by 95%. This should ensure that only 5% of the life is consumed in HASS; however, it could be beneficial to confirm this assumption through a Sherlock Physics of Failure simulation. Sherlock also allows test/validation engineers to vary aspects of the HASS profile and understand their influence on life consumed.