Binder, C. (2015). Inkjet printing of organic polymers for semiconductor applications [Diploma Thesis, Technische Universität Wien]. reposiTUm. http://hdl.handle.net/20.500.12708/78875
Inkjet printing as patterning technology has been investigated in the past decade and gained raising interest in various industrial and scientific applications as an attractive printing method. Inkjet printers offer the benefits of digitally controlled ejection and precise deposition of small quantities of various liquids with high speeds and low costs. Among all the advantages inkjet printing enables the coverage of the outer edge of a wafer including bevel and rim, which is unfeasible with common technologies such as spin-coating. The goal of this works was to investigate alternative inkjettable polyimide materials, which function as protective layer to avoid metal deposition and 'flitter' formation during an electroless metal deposition process. In order to find a reliable material commercially available inks as well as materials, which has to be adapted for inkjet application were investigated to ascertain that the purchased inks gave the best printing results. The modified inks however featured poor drop formations, low layer thicknesses and primarily unacceptable print pattern dimension. Additionally the solvent NMP partly dissolved the print heads, which made these ink types unemployable for inkjet printing. The purchased inks with more proper ink formulations revealed a good drop formation, the required layer thicknesses and excellent dimension stability of the print. The sought coverage of the bevel and rim was obtained in all cases. 'Flitter' formation occurred only at the end of print segments and was related to insufficient overlap of print files. Even though this provided three possible inks, only one featured easy monitoring of the print on various substrates thanks to its colour.