Electronics reliability

In-field failure analysis

Understanding failure mechanisms and creating remediation plans

At some stage every company will experience in-field product failures. In some instances, it can be difficult to pinpoint the cause and predict the timing or frequency of failures across the in-field population.  The cost to remediate - for example a product recall - can be very high and can damage to a company’s brand and business. The stakes are even higher in safety critical environments, where the consequence of failures can be especially serious.

We have a track record working across a broad range of industries, including automotive, aerospace, defence, energy and medical, testing the widest possible variety of PCB assemblies. Our customers typically turn to us when:

  • the potential impact of failures is especially high
  • the environment is harsh, often high temperature, humidity or voltage
  • the nature of the failures is notoriously hard to profile, such as intermittent faults or NFF (No Fault Found)

We provide an initial triage process, usually completed within two working days:

  1. Customer provides PCB assemblies (production and failed samples) with details of environmental context and initial findings
  2. Initial review of available samples and documentation
  3. Application of NPL's knowledge of known failure modes and identifying those that are most relevant to the customer
  4. Summary of findings and recommendations for any additional testing 

We can then carry out a full investigation according to agreed scope, cost and timings.

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Our testing capability

Conditioning, ageing and stressing of electronic assemblies

  • Thermal shock – air to air capability from -70 to 300oC, with programmable dwells and rates of change of temperature of around 40oC per minute (typically used for fatigue life testing of assemblies)
  • Temperature cycling – from -65 to 200oC, with programmable dwells and ramp rates of around 10oC per minute (typically used for fatigue life testing of assemblies)
  • Humidity bias testing – from 5 to 98% relative humidity, -20 to 100oC with electrical bias to 1000 V (typically used for electrochemical reliability testing)
  • Condensation testing – condensation using custom platen to chill samples below dew point of humidity chamber
  • Thermal ageing – up to 300o
  • Power cycling – multi-channel switching and monitoring of power devices using cooling platens to increase cycle time
  • Mechanical shock testing - acceleration rate and shock pulse width accurately controlled and monitored using accelerometer and oscilloscope
  • Hot mechanical shock testing – up to 250oC
  • Shear testing of component attachments - degree of crack propagation and damage to solder joints or die attach, strength of the joint, comparison of alloys, post thermal fatigue (typically used for testing joint formation with new platings, fluxes or finishes)
  • Hot shear testing – up to 300oC
  • Pull testing – up to 300o
  • Solder joint reliability testing - low cycle fatigue, driven by the mismatch of the coefficients of thermal expansion, solder joint cracking, adhesive loss of glob tops and underfills, delamination in multilayer boards and modules
  • Reflow soldering - for sample build and simulated manufacturing conditioning

Monitoring before, during and after conditioning

  • Constant continuity monitoring – in-chamber monitoring of electrical continuity across up to 900 channels allowing simultaneous measurement for interrupts of >100 micro-seconds
  • Electrical monitoring – in-chamber monitoring using programmable multichannel switching systems for resistance and capacitance  
  • Surface insulation resistance – in-chamber leakage current detection, approaching pA, and resistance values, monitored continuously over test periods up to 1500+ hours 
  • Conductive anodic filament testing – in-chamber monitoring of printed circuit boards for leakage current due to conductive salts forming  
  • Solvent extract conductivity / ionic extraction testing - using a mixture of isopropanol and water to remove soluble contaminants providing a measure of the ionic contamination 
  • Solderability testing - performed on solder pads or component terminations
  • Tin whisker propensity – electrical monitoring of tin whisker growth, measuring wetting force and time
  • Adhesion testing – coating adhesion measurement using pneumatic or customised pull testing​


  • Micro-sectioning - metallography and micro-sectioning for image analysis of various types of components and solder joints, substrates, vials and holes. High quality polished micrographs for various investigations, including crack detection and grain structure analysis
  • Optical microscopy and image analysis – a variety of high resolution optical imaging and measurements systems
  • Scanning electron microscopy - for analysis of surfaces with complex topography with a magnification of over x 100,000, used to locate tin whiskers, examine intermetallic layers, investigate crack failure modes and general failure analysis
  • Scanning acoustic microscopy - uses ultrasonic waves reflecting or transmitting at material interfaces to study buried solid interfaces of dissimilar materials and non-destructive detection of features such as bonded interfaces, delaminated interface, voids and cracks
  • X-ray florescence - used to determine the atomic content of material, screening for ROHS compliance, thickness measurements and validation of solder content
  • Energy dispersive X-ray spectra  – electron microscopes for image and elemental analysis
  • X-ray radiography – nano-focus X-ray inspection
  • Fourier-transform infrared spectroscopy with microscope capability - used to identify organic and polymeric materials, using infrared light to scan test samples and observe chemical properties
  • Electrochemical impedance spectroscopy - used for the characterisation of electrochemical systems and to investigate mechanisms in electro-deposition, electro-dissolution, corrosion studies and the study of biosensors
  • Surface Profiling – 3D micro coordinate and surface roughness measurement using contact and non-contact methods
  • Surface energy – drop shape analyser for measuring surface free energy
  • Electrokinetic analyser - automated surface zeta potential analysis of solids
  • Thermal analysis
    • Differential scanning calorimetry (DSC) - rapid technique that measures the heat flow associated with material transitions as a function of temperature and time  
    • Dynamic mechanical analysis (DMA) - a versatile technique used for characterising time, temperature and frequency dependent mechanical behaviour of a materials  
    • Thermo mechanical analysis (TMA) - used for measuring dimensional changes in a material as a function of time, temperature and the applied force

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Work with us

Our research and measurement solutions support innovation and product development. We work with companies to deliver business advantage and commercial success.
Contact our Customer Services team on +44 20 8943 7070