This research project has demonstrated that with carefully selected processes it is possible to fabricate tools for injection moulding of both diffractive and refractive optical components. The fabrication procedure is based on an aluminium disc on which selected optical components (gratings and lenses) in glass are mounted. Using physical vapour deposition (PVD) a thin conducting layer of gold is deposited on the entire surface. On this substrate 50 ìm of nickel and 3000 ìm of copper is deposited using electroforming processes. Various types of mechanical machining is then performed while the delicate optical surfaces are buried/sealed in the metal sandwich. The aluminium is then dissolved in warm sodium hydroxide and the glass components are carefully removed. Finally, glue residue is dissolved and the thin gold layer selectively etched. The finished tool insert is then placed in the injection-moulding machine, and used to replicate the original glass components in polymer (PMMA, PC or COC). AFM measurements of the replication quality of a diffractive grating were used for most of the evaluation, both other components on the test tools were examined as well. The results of the project are an optimised electrochemical procedure for the fabrication of accurate electroformed tools and a number of important findings regarding the conditions for the injection moulding process required for exact replication.
|Title of host publication||2nd VDE World Micro-technologies Congress|
|Publication status||Published - 2003|
|Event||2nd VDE World Microtechnologies Congress - Munich, Germany|
Duration: 13 Oct 2005 → 15 Oct 2005
Conference number: 2
|Conference||2nd VDE World Microtechnologies Congress|
|Period||13/10/2005 → 15/10/2005|