Reliability of epoxy molding compounds used in plastic packages of integrated circuit (IC) devices depends to a great extent on the level of thermal stresses. These are due primarily to the thermal expansion (contraction) mismatch of the epoxy and the silicon materials. In this analysis we assess the effect of silica fillers on the level of thermal stresses. We conclude that thermal stresses in the compound can indeed be reduced by the application of appropriate fillers. We found that the filler volume concentration does not have to be larger than 30 percent to keep the thermal stresses at a sufficiently low level. This number is close to the filler volume concentration of 30–40 percent in commercially available molding compounds. The obtained results and recommendations can be helpful in the analysis of stresses in, and physical design of, plastic packages.

Issue Section:
Technical Papers
Keywords:
silicon compounds, filled polymers, moulding, thermal stresses, integrated circuit packaging, plastic packaging, integrated circuit reliability, thermal expansion, compressive strength, elastic moduli, thermoelasticity
Topics:
Composite materials, Epoxy adhesives, Epoxy resins, Fillers (Materials), Molding, Particulate matter, Thermal expansion, Elastic moduli, Thermal stresses, Shear modulus, Stress, Bulk modulus, Poisson ratio, Thermoelasticity
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Copyright © 2001
 by ASME
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