Method of assessing reliability of electronics assemblies under drilling vibration conditions

A method for assessing reliability of an electronic component under downhole vibration conditions, comprising:

• mounting one or more electronic components on a printed circuit board to form a test vehicle;
• measuring a natural vibration frequency of the test vehicle;
• choosing a test vibration frequency range that includes the natural vibration frequency of the test vehicle;
• determining an overstress limit of the test vehicle, wherein the overstress limit has a power spectral density (PSD) value of 0.6 G2/Hz;
• determining a step stress profile for testing the test vehicle, wherein the step stress has a maximum value lower than the overstress limit of the test vehicle;
• testing the test vehicle according to the step stress profile until one or more of the plurality of electronic components on the test vehicle fails;
• measuring an electrical resistance of the failed electronic component without a vibration load;
• when the electrical resistance of the failed electronic component remains large, cross-sectioning the failed electronic component;
• and
• examining the cross-sectioned electronic component to identify a failure mode,
• wherein testing the test vehicle according to the step stress profile comprises applying to the test vehicle a stress of PSD value ranging from 0.1 G2/Hz to 0.3 G2/Hz.