Emeritus Professor David Allen is spotlighted for his upcoming presentation on the “Strengthening the Weakest Links in the PCM Process Chain: #4 – Factors Affecting Photoresist Adhesion” at our Spring 2020 International Technical Conference.
Strong adhesion of a photoresists stencil to a metal surface is essential for production of quality parts fabricated by the PCM process. Photoresist adhesion is affected by many variables and good adhesion is only achieved by strict control of the processes involved in the PCM process chain leading to the formation of the photoresist stencil, especially metal cleaning, chemical and physical surface preparations, photoresist composition, photoresist processing and chemical etching. Clean stripping of the photoresist stencil after etching is also affected by the nature of the photoresist adhesion.
The various ways in which photoresist adhesion can be increased are discussed together with the process recommendations. However, a quantitative figure of merit to describe adhesion strength is difficult to achieve although several qualitative adhesion tests have been proposed in the past to measure adhesion strength. These various tests are appraised for fitness of purpose.
Emeritus Professor David Allen started his career as a chemist (BSc, 1968) and moved into photochemistry research (PhD, 1972) while studying at Cardiff University. Following post-doctoral research at Warwick University and imaging technology development in industry, David joined Cranfield University in 1976. He was appointed a Technical Liaison Member to the Photo Chemical Machining Institute (PCMI) in 1981 and is currently on the Board of Directors of PCMI responsible for education.
David became Professor of Microengineering at Cranfield University in 1998 and was elected as a Fellow of The International Academy for Production Engineering (CIRP) in 2006.
David has published:
- Two PCM books: “The Principles and Practice of Photochemical Machining and Photoetching” (1986) and “Photochemical Machining and Photoelectroforming” (2015, reprinted 2016, 2017 and 2019);
- Five book chapters on non-conventional machining and contributed the chapter on ‘Etching’ to the online CIRP Encyclopedia of Production Engineering;
- Seven confidential industrial PCM consortium reports;
- 198 journal and conference papers and was awarded the higher doctoral degree of DSc from Cranfield University in 2013 for his thesis entitled “Contributions to Photochemical Machining and Photoelectroforming”.
David retired from academia in 2011 and he now carries out consultancy and staff training in PCM companies across the world. He has worked with 21 different companies over the past 8 years.
David will be speaking at the PCMI Spring International Technical Conference in Germany this May. For more information, visit our registration page.