A New Method for Measuring Adhesion Strength of IC Molding Compounds.

Evaluating IC-package interface delamination by considering moisture-induced molding-compound swelling

“…1 [6]. We perform three-point bending tests using two-layer end-notched flexure (ENF) specimens composed of a molding compound and adherend.…”

“…Delamination is supposed to start propagating when the sum 1521-3331/99$10.00 © 1999 IEEE of the stresses reaches a critical stress. On the other hand, sum of the stresses reaches the critical stress with a smaller load, because the shear stress due to bending acts in the direction which increases the residual stress Therefore, the true adhesion strength (critical shear stress) can be estimated by arithmetically averaging the apparent strength (shear stresses) due to bending alone, and These stress fields near the precrack tip caused by the critical bending loads and are expressed in terms of the stress intensity factor of the interface crack [8], [10] as and These apparent stress intensity factors can be calculated by a finite element method or by beam theory [6]. We can obtain the "true" adhesion strength which is not affected by residual stress, by calculating the average of and Adhesion strength was measured using two kinds of epoxy molding compounds and two kinds of lead frame materials (alloy 42 and copper) .…”

“…7 and 8. A half of the difference between and equals the stress intensity factor due to residual stress [6]. Fig.…”

“…We previously developed a new adhesion test method for obtaining "true" adhesion strength which is not affected by residual stress [6], and we also developed an evaluation approach that can predict interface delamination in dry IC packages [9]. The purpose of the present study is to extend this approach to the quantitative prediction of interface delamination in moisture-absorbed IC packages.…”

Investigation of delamination control in plastic package

“…5, which could not be included in the simulation. (End Notch Flexure) ENF [13], (Compact Tensile Shear) CTS [14] and (Double cantilever beam) DCB are the usual methods for the interfacial fracture toughness. The interfacial fracture toughness experiment should be carried out with the consideration of different moisture concentration at the crack initiation, while determining the degradation induced by temperature and moisture.…”