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.
Agency: European Commission | Branch: FP7 | Program: CP-IP | Phase: NMP.2013.1.4-2 | Award Amount: 12.85M | Year: 2013
The thermal properties of nanostructured materials are of fundamental importance to modern technology, but at present reproducible metrological definitions, tools and methods do not exist. This is because the mechanisms of heat transport at the nanoscale are entirely different to those at the macro scale. The project will place nanothermal metrology on a solid basis by an integrated physics-based experimental and modelling effort to: Define a common terminology for nanothermal measurement Realise standard materials and devices for measurement and calibration of nanothermal measurements Develop new instruments and methods for traceable nanothermal measurement Develop calibrated and validated thermal models covering the range from atomic to macro-scale Apply these tools to selected representative industrial problems Assess the tools for suitability for adoption as potential standards of measurement including their traceability and reproducibility The objectives will be achieved by a team comprising physicists, materials scientists, modellers, instrumentalists, microscopists, industrial partners (including SMEs and OEMs) and National Measurement Institutes. The outputs of QUANTIHEAT will be embodied in highly characterised reference samples, calibration systems, measurement tools, numerical modelling tools, reference measurements and documented procedures. The availability of calibrated numerical modelling tools will facilitate the rapid digital thermal design of new nanosystems without the need for extensive prototyping. Their validation against experiment over all length scales will provide a solid basis for the deployment of new nanostructured materials, devices and structures having optimised performance without the need for excessively conservative design. Standardization is a key driver of industrial and scientific progress: QUANTIHEAT is expected to constitute a de-facto standard for a key area of physical measurement at the nanoscale worldwide.
Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: NMP.2012.2.1-1 | Award Amount: 4.56M | Year: 2013
Tomorrows micro-electronic devices will have to show more functionality and performance at smaller form factor, lower cost and lower energy consumption in order to be competitive on this multi-billion dollar market. Advanced system integration is thus inevitable, a trend bound to joining dissimilar materials with new packaging technologies. These processes must enable lower thermal resistances and higher interconnect density and device reliability under thermomechanical loading. Hyperconnect addresses these challenges by a radically new material joining process. The objective is to demonstrate superior electrical, thermal and thermomechanical performance and to combine design and technology with the support of simulation and testing. The central new idea comprises a sequential joint forming process, using self-assembly of nanoparticles, polymers and filler composite materials exploiting capillary action and chemical surface functionalisation: In other words, the formed joint reaches its outstanding properties by the very processing of the materials. This contrast to existing technology demands own understanding of the joint formation, joint property creation and the joint reliability. Therefore advanced experimental characterization and simulation techniques will accompany the material and technology development, in particular involving physics-of-failure-based lifetime modelling. Finally, the joint performance will be validated on four different demonstrators of industrial significance. To tackle these challenging issues the consortium pools the required interdisciplinary excellence, by uniting nine partners from industry, SMEs and academia of five European countries. Its members are convinced that these new developments will outperform commercially available solutions by one order of magnitude and will radiate out also to other fields in electronic packaging.
Ibm, Conpart AS, Intrinsiq Materials and Jerzy Haber Institute Of Catalysis And Surface Chemistry | Date: 2015-10-12
A bridging arrangement includes a first and a second surface defining a gap therebetween. At least one surface of the first and second surface has an anisotropic energy landscape. A plurality of particles defines a path between the first and second surface bridging the gap.
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.
Conpart As | Date: 2013-07-12
A conductive adhesive, such as an anisotropic conductive adhesive, comprising a population of conductive particles and a population of signal particles in an adhesive; wherein both the conductive particle population and the signal particle population have an average particle diameter of <200 m with a coefficient of variance of <10%; wherein the signal particles are arranged to provide an indication when they are deformed to a pre-determined height; and wherein the conductive particles are arranged such that they will not fail, e.g. crack or fracture, when deformed to a height larger than or equal to the pre-determined height at which the signal particles are arranged to provide the indication.
Conpart As | Date: 2013-12-13
A method of applying a conductive adhesive comprising: using a conductive adhesive 18 made up of conductive beads 12 in an adhesive matrix 8, the conductive beads comprising a polymer core and a conductive coating and having a maximum dimension of 100 m or less; and depositing droplets of the adhesive 18 on a substrate via a nozzle 20.
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.
Conpart As | Date: 2011-10-28
A process for the preparation of an activated polymer particle comprising contacting a polymer particle with at least one polyamine, wherein said polyamine has three or more amino groups, to form a surface treated polymer particle; and applying a catalyst to the surface treated polymer particle to form an activated polymer particle.