He J.Y.,Norwegian University of Science and Technology |
Nagao S.,Norwegian University of Science and Technology |
Kristiansen H.,Conpart AS |
Zhang Z.L.,Norwegian University of Science and Technology
Express Polymer Letters | Year: 2012
Mechanical failure of monodisperse Ni/Au coated acrylic particles has been investigated by individual compression tests using nanoindentation-based technique equipped with a flat diamond punch. We have found that both fracture property and morphology of particles depend on the compression loading rate. The breaking strain of the metal coating decreases with increasing loading rate, while the breaking stress increases. Two obvious fracture patterns with cracking in meridian or latitude direction are identified according to the loading rate, and attributed respectively to tension- or bendingdominated deformation of the coating. The findings reported here give a significant guiding to the manufacture design of metal coated polymer particles for Anisotropic Conductive Adhesive (ACA) packaging. © BME-PT.
Halaciuga I.,Clarkson University |
Njagi J.I.,Clarkson University |
Redford K.,Conpart AS |
Goia D.V.,Clarkson University
Journal of Colloid and Interface Science | Year: 2012
Anisotropic conductive adhesives (ACAs) are widely used as interconnect materials in the manufacturing of LCD screens. To be integrated in a broader range of applications, several technical and economical issues still need to be addressed. Encapsulating the polymer particles within continuous, compact, and adhering metallic conductive shells is one of these challenges. This work describes a method for depositing nickel layers with different thickness (30-120. nm) onto monosized polymer particles. The novelty of the approach consists in modifying the surface of polymer particles with linear polymeric amines. We show that by increasing amine chain length the structure and adhesion of deposited nickel shell are significantly improved. The effect of key parameters of the electroless Ni plating are discussed and illustrated. © 2012 Elsevier Inc.
Nguyen H.-V.,Buskerud and Vestfold University College |
Andreassen E.,Buskerud and Vestfold University College |
Andreassen E.,Sintef |
Kristiansen H.,Conpart AS |
And 3 more authors.
Materials and Design | Year: 2013
Novel isotropic conductive adhesives (ICAs) filled with metal-coated polymer spheres have been introduced in order to improve the mechanical reliability compared to conventional silver-filled ICAs. The topic of this study is the rheology of an epoxy filled with monodisperse polymer spheres with or without Ag coating. In trials with uncoated spheres, the viscosity increases with increasing sphere fraction, while the sphere diameter (6 vs. 30μm) only has a minor effect. With 45. vol% of spheres (giving an ICA with adequate electrical properties), the Ag coating on the spheres has a large effect on the rheology of the adhesive paste. Compared to the epoxy with uncoated spheres, the epoxy with Ag-coated spheres exhibits higher viscosity, higher storage and loss moduli, and a higher ratio of storage modulus to loss modulus (about 10. times). Furthermore, the viscosity of the epoxy with coated spheres increases with time in oscillatory measurements with low to intermediate frequencies. With hardener added to the epoxy containing Ag-coated spheres, the viscosity increase at room temperature is small within the first three hours. In curing trials, the viscosity development is different for unfilled and sphere-filled epoxies. The rheological properties of the ICA with 45. vol% Ag-coated spheres were found to be suitable for stencil/screen printing and dispensing processes. © 2012 Elsevier Ltd.
Conpart AS | Date: 2013-05-29
An isotropic conductive adhesive having silver coated polymer beads within an adhesive matrix and a method of forming an isotropic conductive adhesive are disclosed. The mean average diameter of the polymer cores of the beads is less than 30 m, and the silver coating comprises interlinked silver deposits grown from dispersed nucleation sites scattered across the surface of the beads.
Conpart As | Date: 2011-10-28
A heat-treated polymer particle comprising an addition polymer core particle which has had swollen and polymerised therein a blend of an aromatic alcohol with an aldehyde or a blend of an aromatic amine or urea with an aldehyde and which has been subsequently heat treated, e.g. to a temperature of at least 150 C.