Lithography is the most commonly used method for the selective metallisation of non-conductive surfaces in the manufacture of electronic devices such as printed circuit boards and antennae. However, when used in subtractive mode, lithography results in the generation of large amounts of organic solvent and metal containing waste and requires high initial capital investment. For these reasons, additive methods of selective metallisation are being widely investigated. In this work, a novel additive approach of Selective Metallisation using a Magnetic Field (SMMF) was studied. This method uses a magnetic catalyst to initiate the electroless plating process. Magnetic catalyst particles composed of magnetite-silicon dioxide-silver were synthesised by a wet-chemical procedure. Their composition was analysed by scanning electron microscopy and energy dispersive X-ray spectroscopy and the phase formation was confirmed by X-ray diffractometry. Catalytic activity towards formaldehyde oxidation and the magnetic properties of particles were confirmed by cyclic voltammetry and vibrating sample magnetometry, respectively. The results showed that the particles can be used as a catalyst for electroless copper plating and are attracted by the magnetic field. The pattern of deposition of the magnetic catalyst is defined by the magnetic field. Two different configurations of magnet and substrate were used to deposit the catalyst dispersion onto the substrate surface. In both cases, the particles were attracted by the magnetic field and deposited exclusively where the magnetic field was applied. Subsequent electroless copper plating also only occurred at these areas. Parallel lines of electroless copper were obtained. The effect of the magnetic field on magnetic catalyst deposition and subsequent electroless plating was studied and key process-specific defects were identified.
Bibliographical noteNOTICE: this is the author’s version of a work that was accepted for publication in Electrochimica Acta. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Electrochimica Acta, 389, (2021) DOI: 10.1016/j.electacta.2021.138763
© 2021, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
FunderThe authors want to acknowledge Coventry University, which sponsored the present research and also COST MP1407 which sponsored the collaboration with Autonomous University of Barcelona Universitat Autònoma de Barcelona. Partial financial support by the European Research Council (SPIN-PORICS 2014-Consolidator Grant, Agreement N° 648454), the Catalan Government (2017-SGR-292) and the Spanish Government (MAT2017-86357-C3-1-R) is also acknowledged.
- Catalyst particles
- Copper plating
- Electroless deposition
- Magnetic particles
- Selective metallisation
ASJC Scopus subject areas
- Chemical Engineering(all)