Cs. Desai et al., THERMOMECHANICAL ANALYSIS IN ELECTRONIC PACKAGING WITH UNIFIED CONSTITUTIVE MODEL FOR MATERIALS AND JOINTS, IEEE transactions on components, packaging, and manufacturing technology. Part B, Advanced packaging, 21(1), 1998, pp. 87-97
A unified constitutive modeling approach based on the disturbed state
concept (DSC) provides improved characterization of thermomechanical r
esponse of joining (solders), ceramics and printed wire board (PWB) ma
terials in electronic packaging, Various versions in the DSC approach
are calibrated and validated with respect to laboratory test data, and
are implemented in a nonlinear finite element (FE) procedure, The hie
rarchical nature of this procedure permits the user to choose a consti
tutive model, simple (elastic) to sophisticated (elastoviscoplastic wi
th disturbance), depending upon the material and need, The FE is used
to analyze thermomechanical behavior of two typical problems: 1) leadl
ess ceramic chip carrier (LCCC) package; 2) solder ball connect (SEC)
package, The FE results under cyclic thermal loading are compared with
experimental data for the two packages, and with a previous FE analys
is for the SEC package, In conjunction with the idea of critical distu
rbance at which thermal fatigue failure can occur, the analyzes allow
identification of cycles to failure, N-f, and evaluation of reliabilit
y of the package, In the case of the SEC package, the analysis permits
an evaluation of ball spacing on the thermomechanical behavior, The D
SC approach can provide an integrated and improved procedure compared
to available models for elastic, plastic, creep strains, and microcrac
king leading to degradation of strength and fatigue failure for a wide
range of problems in electronic packaging under thermomechanical load
ing.