Effect of Bonding Force on the Conducting Particle With Different Sizes

Abstract

Finite element analysis was used to model the transient heat transfer problem and the mechanical influence of the conducting particle in the anisotropic conductive adhesive (ACF). Three-dimensional (3D) brick element was performed for the transient heat transfer analysis, and the result was found that heat was transferred and spread from the die to the ACF and its conducting particle very quickly; in around 0.5 sec the ACF can reach the bonding temperature of 220°C. For the mechanical stress analysis of the conducting particle, the degree of the deformation was increased as the bonding force increased. The conducting particle was subjected to the larger stress level as the smaller of the particle size. The stress concentration was located at the edge area and diminished at the center area. It was also found that the cracks were found at the four corners of the conducting particles which was due to the highest stress level subjected on that location. Moreover, if only considering the plastic particle, the stress level was concentrated at the center area and vanished at the edge area.

An experimental methodology for the study of co‐planarity variation effects in anisotropic conductive adhesive assemblies

“…A commercial ACA, Sony FP1508E, which is a pre‐formed film material, was used to assemble the bare chips onto the flex substrates. Sony FP1508E is a product specifically developed for fine pitch chip‐on‐flex packaging and has previously been shown to be effective for assembly of these type of assemblies (Tan et al , 2004; Dou et al , 2003; Yeung et al , 2003). It also incorporates an adhesion promoter which improves its resistance to subsequent lead‐free reflow process conditions, e.g.…”

“…Bonding force, bonding temperature and bonding time are the main controllable process parameters in an ACA assembly process. The bonding force affects the compression of the adhesive layer, therefore determining the particle deformation degree and, consequently, the contact area between the particles and the component pads (Dou et al , 2003; Yeung et al , 2003; Määttänen, 2003; Kim et al , 2007; Chen et al , 2006). Moreover, determining the optimum bonding force is important to achieving a reliable assembly, because the deformation of the conducting particles affects the reliability of the ACA joints (Chan and Luk, 2002a, b).…”

Reliability of Anisotropic Conductive Adhesive Joints in Electronic Packaging Applications

“…This is because the concentration and deformation of particles within the material vary at different locations, and hence may result in low reliability of the assemblies. In order to understand the effect of the conductive particles on the reliability of the assemblies using anisotropic conductive adhesives, some investigations have been done [39,60,[125][126][127][128][129].…”

The Effect of Co-planarity Variation on Anisotropic Conductive Adhesive Assemblies

“…The bonding force affects the compression of the adhesive layer, therefore determining the particle deformation degree, and consequently the contact area between the particles and the component pads [3][4][5]. Moreover, determining the optimum bonding force is important to achieving a reliable assembly, because the deformation of the conducting particles affects the reliability of the ACA joints [6,7].…”