Dielectric breakdown of MXB-71 phenolic and Sylgard 184/GMB silicone at high temperature

Technical Report · Fri Jul 01 00:00:00 EDT 1983

OSTI ID:5999618

Johnson, Jr, R T; Beeson, P M

High temperature electrical breakdown characteristics have been determined for MXB-71 phenolic and Sylgard 184/GMB silicone in air and nitrogen environments. The phenolic material is used for electronic case housings whereas the silicone is an encapsulant. The experiments were performed with constant electric fields (values ranging from 3 x 10/sup 3/ to 2.5 x 10/sup 4/ V/cm) applied to the samples while the temperature was increased at a rate of 10/sup 0/C/minute. The sample current until breakdown was determined. Results showed that breakdown occurred between 470 to 725/sup 0/C, and was principally dependent upon the material conductivity at time breakdown and the electric field. The breakdown temperature decreased with increasing electric field and decreased in an oxygen-containing environment. Materials postcured at 580 to 600/sup 0/C prior to electrical testing exhibited considerably lower breakdown temperatures at higher electric fields. Results suggest that breakdown occurred via thermal runaway.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5999618
• Report Number(s): SAND-83-1244; ON: DE83016768
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
PLASTICS
BREAKDOWN
RESINS
SILICONES
AIR
HIGH TEMPERATURE
NITROGEN
ELEMENTS
FLUIDS
GASES
MATERIALS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLYMERS
SILOXANES
SYNTHETIC MATERIALS
360404* - Materials- Polymers & Plastics- Physical Properties- (-1987)