The peeling stress near the free edge of a bimaterial beam under uniform temperature change creates a moment which causes both layers to have identical curvatures at the interface. A new formula from beam theory is given for this Peeling Moment. A beam with a negative Peeling Moment resists delamination at the free edge. A physical explanation for the moment is developed; the sign of the Peeling Moment is also the determinant of the location of the equivalent centroid of the bimaterial beam. This provides a valuable new rule for designing resistance to thermomechanical delamination of a bimaterial structure.

Issue Section:
Technical Papers
Keywords:
microassembling, delamination, integrated circuit packaging
Topics:
Delamination, Stress, Temperature, Design
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Copyright © 2004
 by ASME
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