Susonence – a new multi-partner project developing advanced sonochemical processes to reduce chemical usage and decrease waste in the PCB and metal finishing industries

Circuit World

ISSN: 0305-6120

Article publication date: 3 February 2012



Goosey, M. (2012), "Susonence – a new multi-partner project developing advanced sonochemical processes to reduce chemical usage and decrease waste in the PCB and metal finishing industries", Circuit World, Vol. 38 No. 1.



Emerald Group Publishing Limited

Copyright © 2012, Emerald Group Publishing Limited

Susonence – a new multi-partner project developing advanced sonochemical processes to reduce chemical usage and decrease waste in the PCB and metal finishing industries

Article Type: Industry news From: Circuit World, Volume 38, Issue 1

A new European multi-partner development project has recently commenced to introduce more efficient and cleaner production into the printed circuit board (PCB) and metal finishing industries. The project will employ sonochemical processes that decrease hazardous chemical usage and minimise the amounts of waste generated. Energy consumption will also be reduced by the use of new processes that operate at lower temperatures for shorter times.

The three-year project is known as Susonence, an abbreviation of Sustainable Ultrasonically Enhanced Chemical Processes, and it is being supported via the European Commission’s CIP Eco-innovation scheme for “First Application and Market Replication Projects”. Susonence has seven partners from across Europe, including three UK-based organisations, namely C-Tech Innovation Ltd, Env-Aqua Solutions Ltd and Coalesce Solutions Ltd The other partners are Pragoboard s.r.o. from the Czech Republic, Protection des Metaux S.A.S. (Promet) and International Project Management, Plating and Materials from France and EIPC Services B.V. from The Netherlands. Together, these organisations represent a broad cross-section of the requisite industry supply chains and several of them have already worked together on other projects.

The key aims of the Susonence project are to implement ultrasonically enhanced surface modification processes for removing surface layers, etching, and texturing a variety of widely used substrates (metallic, polymer, and ceramic) with greatly decreased chemical consumption that will enable a step change in competitiveness within the surface finishing and PCB manufacturing sectors, whilst significantly decreasing environmental impact. Susonence is a first application project bridging the gap between research and the marketplace and will take an already demonstrated new technology, via the design and scale-up of the ultrasound treatment systems, towards successful, economically viable industrial processes for both of the PCB target sectors.

A major part of the project will be to optimise solution chemistries based on dilute water-based formulations specifically developed for each application, i.e. the aim is the replacement of existing corrosive and/or toxic chemical formulations, which often operate at high temperatures. One target process will be the conventional high-temperature permanganate-based desmear operation, which uses both solvents and strong oxidising agents. Another target process will be the chromic acid surface treatment stage used for texturing the surfaces of polymers such as ABS prior to metal plating. This reduction in the use and concentration of hazardous chemicals will lead to more sustainable and environmentally friendly processes that will additionally offer significantly reduced waste treatment costs due to the use of less hazardous chemicals. The new ultrasonic technology will also offer decreased energy consumption via reductions in the operating temperatures of the target processes and the time taken to complete a specific chemical treatment stage.

The project will achieve these aims by the implementation of advanced sonochemical systems scaled up for industrial application, with four main areas of innovation. The first is the realisation of the potential for achieving surface modification treatment of a wide range of substrates through the application of acoustic cavitation, while at the same time greatly reducing the chemical content of surface pickling and etching solutions. The second is a novel concept of formulating cleaning/etching/pre-treatment solutions specifically for use with ultrasound. Third, this project will also optimize and incorporate an innovative and novel method of applying ultrasound for surface modification through the use of optimised ultrasonic frequencies and transducers. The fourth innovation is the design and scale-up of optimised surface treatment processing equipment integrating these novel ultrasonic probes/transducers and control systems whose design is tailored to specific substrate configurations.

The Susonence project aims to implement the first industrial scale plants incorporating the new ultrasonically enhanced process technology within the project partners’ facilities in the metal finishing (Promet) and PCB (Pragoboard) manufacturing sectors. Key factors that will encourage the adoption and uptake of the developed technology are the increasing costs of raw materials, energy, and treatment of waste and ultimately the disposal of waste from site, which are all projected to continue to rise inexorably due to a combination of legislative demands in the instance of waste and escalating world demand, primarily from Eastern manufacturing areas.

As a result, there is clearly defined competitive need, and an opportunity, to achieve significant cost benefits in the reduction of direct manufacturing overheads in these strategically important sectors of European industry. The major outputs from the project will be five industrial scale units matched to the needs of the targeted sector manufacturing plants. These plants will then be used to collect detailed field trial data that will enable the true performance benefits to be accurately determined and further iterative improvements to be made to the equipment and processes. Based on the construction and operational data generated, other key objectives will be to undertake techno-economic modelling and a life cycle assessment to determine the overall environmental impact and benefits compared to traditional processes. These benefits are expected to include:

  • reduced use of toxic/hazardous chemicals;

  • waste minimisation/diversion from landfill;

  • reduced energy consumption; and

  • reduced water consumption.

and the operation of each of the five pieces of equipment in true industrial manufacturing environment with a range of processes will enable them to be fully assessed and demonstrated.

The Susonence project is thus aiming to help the European PCB fabrication and metal finishing industries by developing new processes that are more efficient than conventional processes through the use of advanced ultrasonic technology. Subsequent uptake of the technology industry is expected to provide environmental, economic and societal sustainability benefits by virtue of the reductions in hazardous chemicals used and associated cost savings, cost benefits from reduced energy, waste treatment and waste generation/disposal as a manufacturing overhead reduction and greater competitiveness for the targeted manufacturing sectors within Europe.

The new processes will also enable European companies in the PCB and metal finishing sectors, and their customers, to produce more competitive products via both increased process and assembly yields and to provide higher levels of quality in finished products. Further information about the Susonence project is available from a dedicated web site:, and there will also be a wide range of publications and dissemination activities throughout the life of the project.

Martin GooseySeptember 2011

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