- A combination of parts joined together to perform a specific function.
- Burn-in is usually applied during production at the end item level only and consists of an operational period for a specified number of hours with a specified failure-free period. The operational conditions and environmental stresses in most cases attempt to simulate field conditions and therefore usually are the same as the test conditions used for demonstrating reliability. Burn-in is normally performed on 100 percent of the items in each production lot.
- The level of stress (thermal or mechanical) which an item is able to achieve or endure without damage or significant reduction of its overall usable life.
Environmental Stress -
Environmental stress screening of a product is a process Screening which involves the application of one or more specific types of environmental stresses for the purpose of precipitating to hard failure, latent, intermittent, or incipient defects or flaws which would cause product failure in the use environment. The stress may be applied in combination or in sequence on an accelerated basis but within product design capabilities.
- The fundamental physical or chemical process responsible for a failure; the causative agents of a failure, including circumstances during design, manufacture or use that may lead to a failure. Hermeticity The ability of a sealed item to remain impervious to outside contaminants.
- Level of assembly; the highest indenture level is a system, the lowest is apart.
Infant Mortality -
Failures that occur early in the life of the unit.
The reduction in severity of response, force, or motion to input stimulus.
- An inherent or induced weakness, not detectable by ordinary means, which will either be precipitated to early failure under ESS conditions or eventually fail in the intended-use environment.
- A self-contained collection of chassis-mounted components and/or printed wiring assemblies within one package which performs a specific function or group of functions, and which is removable as a single package from an operating system.
Any identifiable item within the product which can be removed or repaired (e.g., discrete semiconductor, resistor, integrated circuit, connector); used interchangeably with piece part, component part, and device.
- Usually refers to all microcircuits and semiconductors at receiving inspection being tested to specification and environmental requirements.
- An inherent or induced weakness which can be detected by inspection, functional test, or other defined means without the need for stress screens.
- The process of transforming a latent (undetected) defect Defects into a patent (detected) defect through the application of stress screening.
- An assembly containing a group of interconnected Assembly components mounted on a circuit card. Comparable terminology includes printed circuit board and printed circuit assembly.
Generally, a measure of the capability of a screen to Effectiveness precipitate latent defects to failure; sometimes used specifically to mean screening strength.
Screening Strength The probability that a specific screen will precipitate a latent defect to failure, given that a latent defect susceptible to the screen is present.
A group of units interconnected or assembled to perform an overall function.
- The ratio of output response to input motion.
A group of modules interconnected or assembled to perform a specific function with a system.