Overview

Failure analysis is the process of identifying, and typically attempting to mitigate, the root cause of a failure. In the electronics industry, failure analysis typically involves isolating the failure to a location on a printed circuit board assembly (PCBA) before collecting more detailed data to investigate which component or board location is functioning improperly.

Approaches and Techniques

The typical approach to a failure analysis of an electronic system is to locate the failure and collect data that will explain the failure's root cause and potentially illuminate mitigation strategies. A wide variety of methodologies exist to gather data about failure location, root cause, and mitigation.

Failure Isolation

PCBA failures most often manifest as either short circuits or open circuits. A short circuit is an unwanted electrical connection. An open circuit is a break in an expected electrical connection.

Electrical testing is typically the first step in any PCBA failure analysis. Electrical continuity testing can be used to isolate the failure location on PCBA that is not functioning correctly. This typically involves probing the circuit with a multimeter to iteratively measure resistance across components and conductive PCB traces until an anomalous short or open circuit is detected. Ideally, this will point to an individual component, solder joint, or PCB trace. Once the failure site is identified, more detailed failure analysis can begin.

Non-Destructive Failure Analysis Techniques

When the failure has been located, the next step in the failure analysis of an electronic system is to gather as much relevant data as possible without damaging the specimen. Standard non-destructive failure analysis techniques for electronics include:

• Visual Inspection/Optical Microscopy
• X-Ray Microscopy (2-D and 3-D)
• Electrical Characterization
• Acoustic Microscopy
• Thermal Imaging
• Fourier-transform infrared spectroscopy (FTIR)
• Scanning Electron Microscopy/Energy-dispersive X-ray spectroscopy(SEM/EDS)
• Superconducting Quantum Interference Device (SQUID) Microscopy

Destructive Failure Analysis Techniques

After all non-destructive options are exhausted, electronic failure analysis often requires further data acquisition utilizing destructive techniques. Typical destructive approaches include:

• Cross Sectional Analysis
• Ion chromatography
• Acid Decapsulation
• Wire Bond Pull/Shear Testing
• Component Deconstruction (De-soldering, de-lidding, etc.)
• Mechanical Testing (Shock, drop, and vibration)
• Environmental Testing (Thermal Cycling and Temperature Humidity Bias Testing)

Resources

The expert engineers and reliability professionals at DfR Solutions are thought leaders in electronics reliability. We’ve compiled a wide-range knowledge base on failure analysis. Click on the resources below to access whitepapers, webinars, presentations, and more.