Performance of a Novel Anisotropic Conductive Adhesive under Thermal and Temperature/Humidity Aging Conditions

The electronics industry, in recent years, has been focusing primarily on product miniaturization and lead-free assembly. The need to eliminate lead-based materials as a means of interconnection has renewed the industry's interest in exploring other means of assembling surface mount devices reliably, especially using conductive adhesives.

This paper will discuss the performance characteristics and preliminary research findings pertaining to a novel anisotropic conductive adhesive (ACA) for electronics packaging applications. The novel ACA uses a magnetic field to align the conductive particles in the Z-axis direction, during curing, thereby eliminating the need for pressure. The formation of conductive columns within the adhesive matrix, during cure, provides a very high insulation resistance between adjacent conductors and also eliminates the need for precise printing or dispensing of adhesives onto individual fine pitch pads. The novel ACA can also be mass cured, eliminating the need for sequential component assembly.

The novel ACA's IV characteristics and contact resistance performance under thermal and temperature-humidity aging will be discussed in detail. In addition, preliminary findings pertaining to the adhesives performance under thermal shock conditions (-55 to 125ºC, 20 minute cycles) will be discussed.