Continuing advances in electronics state-of-the-art
plus increased emphasis on reliability and early development testing have
increased the potential for providing a basically sound and inherently
reliable design. As this potential has increased, so has the complexity and
density of contemporary equipment packaging. This complexity amplifies the
ever-present problems of detecting and correcting latent manufacturing
defects. Equipment malfunction. after many hours of field operation, has often
been attributable to something as simple as a wire which was improperly
soldered. The occurrence of such a failure when equipment is installed on
ship, shore, or in aircraft incurs high maintenance costs and results in low
operational readiness rates.
The ability to detect simple anomalies through even
the most intense visual inspection and bench checkout has become a thing of
the past because of the complexity of current equipment. Effective
manufacturing screens for the purpose of stimulating latent defects, whether
or not such screens resemble expected mission environments, have become an
absolute necessity. The manned space program of the 1960's evolved what
continues to be the most cost-effective manufacturing screens: temperature
cycling and random vibration. The Naval Material Command is striving to
replace current and ineffective temperature cycling and low-level sinusoidal
vibration with more stringent temperature cycling and random vibration in
manufacturing screens such as burn-in and acceptance testing.
This report outlines, primarily for Navy contractors,
an adapted and effective manufacturing screening program consisting of
temperature cycling and random vibration. With the recognition that test
facility cost has been a major obstacle to the use of random vibration, a
technical report, which describes in detail a proven means to generate random
vibration at low cost, is included as an appendix. Together, temperature
cycling and random vibration provide a most effective means of decreasing
corporate costs and increasing fleet readiness.
W.J. WILLOUGHBY, Jr.
Deputy Chief of Naval
Material
Reliability, Maintainability
& Quality
Assurance
