Contaminants and Moisture can Disrupt your Electronics
(CON 501)
Overview
Brief examination of the effects of canceling the "how to test" MIL Standards; replacements
Fallacies involved in reliability prediction
- Generally limited to component failures
- Poor documentation of intermittent or "soft" failures and No-Fault-Found issues
- Lack of root cause information regarding failures
Performance Based Specification (PBS) concepts
- DoD 5000.2-R - Department of Defense procurement requirements document
- "Top - down" lines of communication
- Long term reliability of COTS (Commercial Off The Shelf, non-developmental military hardware)
Contamination types and sources found in manufacturing and found in end-use environment
- Manufacturing/process contamination - case histories
- Operational environment contamination - case histories
Measurements of contamination levels on circuitry, at the factory and at depots close to point of use.
- Ion chromatography
- ROSE and Modified ROSE (Resistivity Of Solvent Extract)
- FTIR (Fourier Transform Infrared Spectroscopy)
- SEM (Scanning Electron Microscope)
- SIR (Surface Insulation Resistance)
- Electrochemical Migration
Effects of combining moisture + temperature + contamination + vibration + thermal stressing
- Why better than single environments
- How to combine test environments
Types of field and laboratory failures
- Intermittent and/or "soft" failures
- "Hard" failures of circuitry, of polymers, of wiring and of connectors
Effect on survivability of "power-ups" during combat and/or field deployment
- Mission readiness and completion
- Equipment "longevity"
Types of tests, their goals and their limitations: HALT, ESS, HAST, HASS, etc.
- Finding realistic failure modes
- Protocols that "mask" failure modes
Methods of tailoring lab tests; what to measure (and when to do it) during tests
- MIL-STD-810F
- Multi-channel monitoring
Testing to determine effectiveness of production conformal coatings and other forms of protection.
- Polymers - Permeability plus changes in electrical and mechanical properties
- Elastomers - Permeability plus changes in electrical and mechanical properties
Practical exercises in test tailoring
- Infant mortality
- Long term reliability
Summary
