STRESS ANALYSIS OF ENCAPSULATION MATERIALS FOR WELDED MODULES,
Abstract
A strain-gauge load transducer, simulating an axial-leaded discrete component, was developed and fabricated by DAC to measure the magnitude and direction of axial stresses exerted by an encapsulating material. The epoxy encapsulation materials exhibited residual compressive stresses due to the initial cure of resin. Thermal cycling substantially increased these compressive stresses at the lowest temperatures. Tensile stresses were recorded during the elevated temperature phase of the test. Compressive stresses were produced as the cycle was completed forming a closed hysteresis loop, characteristic of these materials, on the stress vs. temperature curve. Within a typical cordwood welded module with component density levels of 10-30 percent, the stress levels were reduced by increasing levels of component loading. The low-density, microballoon-filled Stycast 1090/11 epoxy material exhibited significantly lower, more uniform tensile and compressive stresses than the medium-density, mineral-filled Hysol 4215/3561 (9709466, Type I) epoxy material within this same test configuration. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1966
- Accession Number
- AD0628833
Entities
People
- M. H. Smith
Organizations
- Douglas