TABLE OF CONTENTS Stress screening is a manufacturing process in which the simulated environmental stresses are used to screen out those failures that would otherwise occur in the field. A basic premise of stress screening is that under specific screening stresses applied over time, the failure rates of defectives are accelerated from that which would occur under normal field operating stress conditions. All assembled hardware consists of many paths along which a stress might be transmitted. The selected of screening parameters and methods of stress application must be suited to the stress transmission characteristics of the hardware's design. The stress should be closely tailored to he equipment's design capability, to provide an effective screen without damaging good components.
A tailored screen requires that specific parameters of the equipment being screened be reviewed such that the defects are detected and removed without incurring undue damage to the equipment. Therefore, the tailoring process should be based on the following premises:
Good hardware should not be damaged, or have its useful service life compromised.
The method of stress application must be such that critical hardware components are indeed stressed as expected.
The primary emphasis in tailoring should be on the latent defect type to be precipitated, hardware design capability and program needs.
It is important to have confidence that the stress transmitted to the hardware will not exceed the design limits and the hardware will indeed behave in the expected manner after screening. The only way to...
