AbstractSelective metallisation of non-conductive materials is a manufacturing process which is often used in the electronics industry to create printed circuit boards, radio-frequency identification tags, solar panels and other devices. Selective metallisation is often achieved by a combination of blanket metal deposition and photolithography processes. However, photolithography is an expensive and time-consuming process which generates hazardous waste. A range of methods of selective metal deposition are currently being developed in order to replace the photolithography process.
In the present work, a novel approach of selective electroless copper deposition was investigated. Electroless deposition of copper onto non-conductive material requires prior catalyst deposition. The concept of this research was to apply a gradient magnetic field during catalyst deposition and attract the catalyst exclusively to areas of maximum magnetic field strength, meaning subsequent electroless plating should also occur only at these areas. This approach requires the catalyst for electroless plating to be magnetic. Therefore, this research project focussed on the following areas:
• Synthesis of magnetic catalyst Fe3O4-Ag composite nanoparticles by a range of procedures and characterisation of their size, composition, crystal structure, magnetic properties and catalytic activity;
• The fabrication of the magnetic template and simulation of the magnetic field distribution across the substrate surface;
• Deposition of the magnetic catalyst onto the non-conductive substrate via gradient magnetic field application and characterisation of the catalyst in solution and on the substrate surface after deposition;
• Selective electroless copper plating onto the surface of the non-conductive substrates that were selectively catalysed by the novel magnetic catalyst and characterisation of the coatings.
Selectively deposited copper lines with a width of 400 μm were obtained using this novel approach of selective metallisation. This research project proves that selective electroless copper deposition can be achieved by gradient magnetic field application.
|Date of Award||Apr 2020|
|Supervisor||John Graves (Supervisor), Alex Pedcenko (Supervisor) & Andrew Cobley (Supervisor)|