DocumentCode :
2504322
Title :
Numerical analysis of adhesive shrinkage due to thermal cycling
Author :
Guo, Shu ; Chen, Buo ; Park, Taigyoo ; Dillard, David A.
Author_Institution :
Dept. of Eng. Sci. & Mech., Virginia Polytech. Inst. & State Univ., Blacksburg, VA, USA
fYear :
1998
fDate :
28-30 Sep 1998
Firstpage :
365
Abstract :
Summary form only given. For bonded joints containing certain types of adhesives, residual stresses may become more tensile following exposure to cyclic temperature conditions. The more tensile state increases the likelihood of debonding. Significant shrinkage 15% or more of some adhesives has been observed following such debonding if the joint continues to be exposed to thermal cycles. The effect of thermal cycling on the stress state and deformation following debonding in such adhesive materials was investigated using finite element analysis. Viscoelastic materials were found to continue shrinking under cyclic thermal conditions when friction exists between adhesive and substrate. The work explored the effects of coefficient of friction, thermal cycling profile, and viscoelastic properties of the adhesive. Due to problems encountered in our attempts at 3D analyses, 2D geometries of two different types were investigated in this study. Fixed substrates were used in the first geometry type, but loss of contact between adhesive and substrate was seen. For the second case, the adherends were moved at the end of each thermal cycle to maintain contact between adhesive and substrate. The results of the numerical work indicate that viscoelasticity, constraints, and friction are the three requirements for the anomalous shrinkage of the adhesive under thermal cycling
Keywords :
adhesives; deformation; finite element analysis; friction; internal stresses; packaging; shrinkage; stress analysis; thermal analysis; thermal stresses; viscoelasticity; 2D geometries; adherends; adhesive debonding; adhesive materials; adhesive shrinkage; adhesive-substrate contact; adhesive-substrate friction; adhesives; anomalous shrinkage; bonded joints; coefficient of friction; constraints; cyclic temperature conditions; cyclic thermal conditions; debonding; deformation; finite element analysis; fixed substrates; friction; numerical analysis; residual stresses; shrinkage; stress state; tensile state; tensile stresses; thermal cycle; thermal cycles; thermal cycling; thermal cycling profile; viscoelastic materials; viscoelastic properties; viscoelasticity; Bonding; Elasticity; Friction; Geometry; Numerical analysis; Residual stresses; Temperature; Tensile stress; Thermal stresses; Viscosity;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Adhesive Joining and Coating Technology in Electronics Manufacturing, 1998. Proceedings of 3rd international Conference on
Conference_Location :
Binghamton, NY
Print_ISBN :
0-7803-4934-2
Type :
conf
DOI :
10.1109/ADHES.1998.742057
Filename :
742057
Link To Document :
بازگشت