TY  - JOUR
T1  - Novel method for plasma etching of printed circuit boards as alternative for fluorocarbon gases
A1  - Kintzel, Wolfram
A1  - Schmid, Marvin
A1  - Rentschler, Achim
A1  - Eisenlohr, Jorg
A1  - Bucher, Volker
Y1  - 2023///
KW  - Printed circuit board
KW  - plasma etching
KW  - fluorocarbon
KW  - PCB
KW  - HFC
KW  - PTFE.
JF  - International Journal of Plasma Environmental Science and Technology
VL  - 17
IS  - 2
SP  - e02002
EP  - e02002
DO  - https://doi.org/10.34343/ijpest.2023.17.e02002
UR  - http://ijpest.com/Contents/17/2/e02002.html
N2  - This paper describes a novel method for plasma etching of printed circuit boards (PCBs), replacing climate-damaging perfluorinated Hydrocarbons (HFCs) such as tetrafluoromethane (CF4). In our alternative process, reactive fluorine would be generated from an inert precursor like commercial PTFE (polytetrafluoroethylene) by means of low-pressure oxygen plasmas. The released fluorine would further be applied to PCB as etchant. Excess fluorine could be chemically absorbed and re-used as recycled precursor later in order to gain a process free of fluorine emissions. Diverse tests were carried out in a lab-scale RF plasma device. We considered different precursor types and examined the plasma composition by means of real-time mass spectrometry. We also determined etch rates on epoxy resin samples by means of mass loss measurements. Process gas composition, precursor type and plasma power were varied, including comparative tests applying state-of-the-art CF4-O2-plasma. The efficiency of the etching process was proven. The environmental impact of the novel method was discussed and evaluated regarding PTFE production and greenhouse gas emissions.
ER  -