A New Method for Measuring Adhesion Strength of IC Molding Compounds

Abstract

Adhesion strength evaluation of molding compounds is a critical issue in structural design and material selection for IC plastic packages. However, since conventional adhesion tests can only give apparent adhesion strengths, which include the effect of residual stress, their results cannot be used for design purposes. This paper proposes a new strength evaluation method which can experimentally separate residual stress from adhesion strength. In this method, three-point bending tests of ENF specimens are performed in both directions. Residual stress is then cancelled by simply averaging the apparent strengths for both directions. The method’s validity is verified by experiments and stress analyses of specimens composed of an IC molding compound and Alloy 42 lead frame material. Adhesion strength is expressed in terms of the stress intensity factor of the interface crack. It is confirmed that constant strengths can be obtained independently of specimen dimensions.

Evaluation of dynamic fracture toughness of a bonded bi-material interface subject to high-strain-rate shearing using digital image correlation

“…[32]. Nishimura et al [50] reported that the values of the stress intensity factor for different interfaces in the case of mode II fracture were 1.2 MPa･m 1/2 . These values were obtained upon conducting the bending test from the resin section of the test piece, to which the IC sealing resin and the lead frame material (Fe-42Ni) were bonded.…”

Preparation of Intumescent Fire Protective Coating for Fire Rated Timber Door

“…Two cylindrical steel rods were then tested using the Instron Micro Tester-Universal Testing machine manufactured by Instron in Norwood, MA, USA with a constant rate of 1 mm/min continually drawn apart in tensile mode until the coating samples on the cylindrical steel rods tore apart. The adhesion strength of the coating sample in MPa is calculated based on the following Equation (1) [21]: (1) where, adhesion strength MPa ; maximum load at rupture N ; adhered area mm .…”

Interface Cracking of Plastic Electronic Package under Temperature and Humidity Environment

“…Hauck et al [10] determined the interface fracture property with mixed mode phase angle from 0° to 90° by employing CTS (Compact Tension Shear) specimen. Nishimura et al [11] determined the interface fracture property with ENF (End-Notch Flexure) specimen to exclude the impact of residual stress of thermal expansion, hygro-swelling and curing shrinkage. The mixed mode phase angle of ENF is about 80° [12].…”