The project aimed to develop a world-leading manufacturing process for continuous production of anisotropic conductive films (ACF) for electronics and biomedical applications. The innovation relies on a patented technology by CondAlign AS in which an electric field is applied to a liquid polymer mixture containing nano/microparticles. The electric field induces electric dipoles in the particles, causing the particles to be aligned into chains. The particles are locked into their aligned position when the polymer is cured, creating a unique conductive film.
In the initial phase of the project we focused on modelling, manufacturing polymer samples with aligned and non-aligned particle and establishing characterization techniques.
We performed electromagnetic modelling of particles dispersion. We investigated the impact of particles shapes (spherical, parallelepipedal) on the absorption of electromagnetic energy.
We also studied the correlation between parameters at the microscopic scale (physical contact between particles, particle shape and material, viscosity) and parameters at the macroscopic scale (macroscopic conductivity and geometrical arrangement of the particle). To that aim we manufactured polymer samples with aligned and non-aligned particles and established characterization methods. Characterization methods, based on Scanning Electron Microscopy, conductivity and optical microscopy have been established and used to study the samples at the two scales.
Macroscopic quantities related to conductivities and degree of alignment of particles (correlated to the spatial organization of the particles) were quantified by resistivity measurement and by image analysis. Microscopic quantities related to physical behaviour of single particles and chain, e.g. mechanical contact or non-contact between individual particles and conductivity of single particle chain were quantified by analysis of SEM images. We discovered high correlations between microscopic and macroscopic quantities. Based on these results, we design an experiment to study more systematically which process parameters have the most influence on the ACF conductivity. There are many ways to create experimental designs, in AniConFilm we have used "optimal design of experiment" which is a collection of mathematical algorithms that find combinations of variables (cross-testing) for which one can safely say which variables influence the end result, but with as few as possible so that the experiment is as simple and cost effective as possible. Based on this experiment, we established a model that express the conductivity as function of parameters like particles diameter, film thickness and particle concentration.
In the final part of the project, we have developed and transferred an optical imaging set-up on the Roll to Roll process of CondAlign. We have demonstrated that Inline tests successfully compared ACF films during production. The optical differentiation system enables comparing aligned and non-aligned samples without stopping the process line which increased the process continuity for long stretches of samples. Furthermore, the optical system can also differentiate the degree of alignment within the same sample which can be used as a quality test for continuous film production.
I dette prosjektet har vi oppnåd en bedre forståelse av produksjon process til Anisotropisk ledende filmer ved hjelp av
ny utviklede off-line karakterisering metoder samt effektivt planlegging av eksperiment.
Det optisk systemet installert på R2R prosess til CondAlign AS gjør at man kan kontinuerlig inspisere opplinjering av partiklene i Anisotropic Conductive Film (ACF) i sanntid. Dette gjør at man kan detektere feil i opplinjeringsprosessen uten å stoppe prosesslinjen.
Dette øker prosesskontinuiteten for lange strekninger av prøver. Videre kan det optiske systemet også differensiere graden av opplinjering i den samme prøven noe som kan brukes som en kvalitetstest for kontinuerlig filmproduksjon.
Dette fører til fremstilling av anisotropisk ledende filmer med dokumentert høy kvalitet for bl.a. elektronikk og biomedisinske applikasjoner.
The planned innovation is to develop a world-leading manufacturing process for continuous production of unique anisotropic conductive films (ACF) for electronics and biomedical applications. The innovation is based on a patent technology where an electric field is applied to a liquid polymer mixture containing nano/microparticles which induces an electronic dipole in dispersed particles, causing the particles to be aligned into chains. The particles are locked into their aligned position when the polymer is cured, creating a unique conductive film. The chains form permanent pathways through the material, which opens for many potential applications including ECG electrodes and anisotropic conductive films for electronics applications.
-CondAlign AS has developed a patented technology whereby an electric field is used to structure and align particles in a polymer mixture.
-Technical Univ. Iasi has expertise in modeling and testing kinetics of suspended nanoparticles under electromagnetic fields
-All Green SRL domain of expertise lies in the production of nanostructured composites with predefined electromagnetic properties.
-SINTEF Digital has expertise in development of optical system for inline process control and
After modeling, development and optimization of conductive films prototypes, a pilot demonstration line equipped with an inline process control system for nondestructive measurement of product quality will be developed. It will be used to demonstrate production of anisotropic conductive film at a scale large enough to allow building a business, expand and make profit out of it.
The project address needs for low cost and new types of ECG electrodes using conductive pressure sensitive adhesive (PSA) as the contact medium to skin and the electronic industry where there is needs for better ACF for application in production of displays and thermal interface materials, used to transport heat away from critical components.