Anisotropic Conductive Adhesives (ACAs) have
been used in fine pitch electronics packaging for over
a decade and provide a high density and low temperature
bonding method in a range of niche applications.
The principal objective of this paper is to provide significant
insights into the basic conductive characteristics
of ACAs based on a review of previously reported
scientific research, and to identify the current
challenges and future prospects for this technology.
In order to provide a concise, structured overview of
this topic, many detailed conductive models, mathematical
solutions and research methodologies are presented
based on the reviewed literature. These models
can partially explain the conductive mechanisms of an
ACA particle, but make a number of important sirnplifying
assumptions. However, one model was developed
and can be used to explain the conductive mechanism
of an ACA particle more successfully. In conclusion,
existing computational models, mathematical models
and physical models have been used to estimate the
resistance of an ACA particle and the particle contact
area, and therefore constriction resistance, for a given
degree of particle deformation, thereby almost achieving
a model for the whole resistance of an ACA joint.
The paper will close by identifying other research challenges
remaining for this important electronics interconnection
technology
