Accession Number : ADA307538

Title :   Tropical Service Life of Electronic Parts and Materials.

Descriptive Note : Final rept. 1 Jun 65-31 May 66,

Corporate Author : MELPAR FALLS CHURCH VA

Personal Author(s) : Dennison, B. H. ; Morrow, W. B.

PDF Url : ADA307538

Report Date : OCT 1966

Pagination or Media Count : 217

Abstract : During the contract year a degree of correlation between the field and laboratory stress environments, as reflected through changes in component characteristics was accomplished. Since the correlation studies are as yet incomplete, detailed information will be provided in future reports. The specified MIL-STD-2O2O Method 106B 20-cycle temperature and humidity stress environment was found to yield correlation with certain jungle exposed components. From the 6-l8-64 Phase I groups, these were composition resistors, carbon film resistors, wire wound resistors, Mylar capacitors, and mica capacitors. From the 9-2l-65 Phase II component groups, correlation was observed for the cermet variable resistor on a failure only basis. The variable ceramic capacitor has exhibited failure in the field environment, but not in the laboratory environment. None of the remaining exhibited a failure mechanism and field data are considered premature at present for a correlation analysis based upon degradation. One very significant indication of both field and laboratory stressing is that correlation will be based primarily upon degradation rather than failure. The specified laboratory test does not in any way provide the stress and corrosion effects of the airborne salt and dust present at the tropical seashore exposure site. It is the conduction of this surface that has yielded data which do not faithfully represent the performance of certain high impedance components.

Descriptors :   *LIFE EXPECTANCY(SERVICE LIFE), *ELECTRONIC EQUIPMENT, *ENVIRONMENTAL TESTS, LABORATORY TESTS, CORROSION, DEGRADATION, EXPOSURE(GENERAL), DUST, CORRELATION, POLYMERIC FILMS, JUNGLES, TROPICAL REGIONS, SALTS, ELECTRICAL IMPEDANCE, THERMAL CYCLING TESTS, HUMIDITY, CERMETS, FILM RESISTORS, CERAMIC CAPACITORS, MICA CAPACITORS, VARIABLE CAPACITORS, CARBON RESISTORS, POLYETHYLENE TEREPHTHALATE, VARIABLE RESISTORS, SALT SPRAY TESTS.

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE