CitationDownload as .RIS
Emerald Group Publishing Limited
Copyright © 2012, Emerald Group Publishing Limited
Article Type: Editorial From: Circuit World, Volume 38, Issue 1
Welcome to the first issue of Circuit World Volume 38, which has five papers covering a wide range of subject matter that I hope you will find of interest. The issue begins with a paper from Joe Fjelstad of Verdant Technologies that covers the current state of development of 3D interconnects. The reasons for employing 3D interconnects are both many and varied, but are typically focussed on the need to enhance functionality while shrinking dimensions in order to meet the ever-present demands for better cost and performance in each new generation of products. Interconnection technologies that can truly utilise 3D will play an increasingly important role in the future in enabling these demands to be met. The paper presents details of 3D solutions that have been used over the last 50 years to make interconnections from chip to system and it also includes some details of what may be expected to appear in the future.
Sustainability, environmental compliance and reductions in energy consumption are key themes that are increasingly impacting manufacturing processes used in the electronics industry and particularly the printed circuit board (PCB) sector. In the second paper, by Andrew J. Cobley and Veronica Saez, attention has been paid to the possibility of developing more efficient plating processes that use less energy. Electroless nickel plating is an important process that is used in both PCB and broader electronics manufacturing, and it typically requires temperatures of up to 95°C to give a suitable metal-deposition rate. Such high temperatures are becoming an increasing concern because of the rising price of energy, which represents an ever-growing proportion of overall production costs. There is thus a growing demand to reduce the operating temperatures of chemical processes via the introduction of new technology. The potential beneficial effects of ultrasonic irradiation upon electroless plating processes have previously been reported and it is known, for example, that sonication can increase plating rates and produce changes to the chemical and physical properties of the deposited coatings. This paper details the results of a study into the potential for reducing the operating temperatures of electroless nickel baths by introducing ultrasound to the process.
Continuing with the themes of sustainability and reducing costs in the PCB industry, there is also an increasing need to recover valuable metals, rather than consign them to waste. In the third paper of the issue, Martin Goosey and Rod Kellner present the results of an interesting and novel study into a new approach to metal recovery from waste produced in the PCB manufacturing process. The work reported details the use of a waste product from the seafood industry in a method for recovering copper as metal from effluent produced during the chemical processing of PCBs. The process described provides a potential new use for by-products that are typically treated as waste and enables the recovery of valuable metals, thereby offering a range of both sustainability benefits and the opportunity to recover metal that would otherwise be lost.
Although there are many types of solderable finishes available to fabricators, nickel-gold is often the preferred choice for many PCBs and it still represents, by value, the largest proportion of all solderable finishes currently used. However, it has long been associated with reliability issues, such as “black pad” that can cause significant problems in service. Paper four of this issue outlines work undertaken, and progress to date, on the multi-partner “ASPIS” project, a European Commission-supported collaboration to develop new materials, processes and tools that will enable the traditional reliability issues associated with nickel-gold finishes to be either avoided or, at the very least, detected prognostically before assembled circuit boards enter service.
Finally, the paper by Olivia M. Flaherty, Xiaoyun Cui, Divya Rajamohan, David Hutt, Chris Denning, Paul P. Conway, Andrew A. West covers an interesting biomedical application of circuitry, where the authors describe the formation of conductors and interconnections in multi-electrode arrays (MEAs) used in electrophysiological recording systems. The authors detail a novel manufacturing process for a biochip with an MEA that is specifically designed for use in characterising cardioactive substances and they demonstrate a novel proposed solution prototype structure.
As always, I am pleased to receive your comments and feedback about the journal and its content and I can be contacted by e-mail at: email@example.com