A cure shrinkage model for analyzing the stresses and strains in encapsulated assemblies
- Sandia National Labs., Albuquerque, NM (United States)
- Pittsburgh Univ., PA (United States). Dept. of Materials Science and Engineering
Electrical component assemblies are encapsulated to provide delicate parts with voltage isolation and protection against damage caused by shock, vibration, and harsh atmospheric environments. During cure, thermosetting resins shrink and harden simultaneously. If the natural deformation of the resin is constrained by adhesion to the mold or to relatively stiff embedded components, cure shrinkage stresses are generated in the encapsulant. Subsequent cooling or thermal cycling produces additional stresses that are caused by the mismatches in thermal strains among the materials in the encapsulated assembly. Although cure shrinkage stresses frequently are neglected because they are considerably smaller than thermal stresses, cure shrinkage stresses can cause delamination or fractures in the encapsulant, since the partially cured resin is not as tough as the fully cured material. Cracks generated during cure can compromise performance (e. g., permit dielectric breakdown), degrade a component`s protection, and grow under subsequent thermal cycling producing residual stresses that differ from those found in uncracked assemblies. 3 refs., 11 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 10102853
- Report Number(s):
- SAND-91-1829C; CONF-920452-2; ON: DE92002926
- Resource Relation:
- Conference: American Society of Mechanical Engineers/Japan Society of Mechanical Engineers (ASME/JSME) joint conference on electronic packaging,San Jose, CA (United States),9-12 Apr 1992; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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