Ground Allocation of Multi Tier Hardware Warranty Liabilities
Ground allocation distributes warranty liability across hardware tiers based on integration depth, physical root cause, and explicit contract caps.
JEDEC Thermal Cycling
Meaning
Standardized reliability test that subjects electronic assemblies to repeated transitions between temperature extremes. Jedec thermal cycling identifies weaknesses in solder joints and material interfaces by using the different expansion rates of components. This test is a requirement for qualifying parts for automotive and industrial applications.
Profile Definition
Dwell times at the hot and cold peaks allow the assembly to reach thermal equilibrium. The rate of change between these peaks is controlled to prevent thermal shock, which is a different failure mode. A typical cycle might run from minus forty to one hundred and twenty five degrees Celsius.
Engineers adjust the number of cycles based on the intended service life of the final product.
Solder Fatigue
Repeated expansion and contraction work the metal of the solder balls. Small cracks form over hundreds of cycles and eventually lead to an open circuit. Jedec thermal cycling accelerates this process so that a lifetime of use can be simulated in a few weeks.
Package Integrity
Delamination between the silicon die and the plastic molding is a common failure discovered during this test. The stress of the cycling can also cause the printed circuit board to warp or vias to crack. Tracking these failures allows manufacturers to improve the mechanical design of the package.