12 May Manufacturing functionalized 3D thin glass
The Fraunhofer Institute for Production Technology IPT has developed a process chain for manufacturing functionalized 3D thin glass in a research project with partners. The combination of ultrashort-pulse laser structuring followed by forming is intended to reduce energy demand and CO₂ emissions compared with conventional processes while eliminating the need for chemical etching.
Laser structuring instead of chemical etching
Thin glass with micro- and nanostructures is used in applications including electronics, sensor technology, semiconductor manufacturing and the automotive industry. Surface structures provide functions such as anti-reflection, anti-fingerprint properties, wetting control and haptic feedback.
Until now, structuring has often been carried out using chemical etching processes or replication with molding tools. While chemical methods depend on etchants such as hydrofluoric acid, thermal replication requires high temperatures and long process times.
In the EffF3D – Efficient Functionalization of 3D-Formed Thin Glass project, the research team first structured flat glass blanks using an ultrashort-pulse laser with pulse durations below ten picoseconds. The low heat input enables optically and haptically effective micro- and nanostructures to be produced while processing the material gently.
To increase throughput, the researchers investigated different beam guidance concepts, including polygon scanners with rotating mirror facets. This enabled large-area anti-glare, anti-reflective and anti-fingerprint structures to be produced.
Non-isothermal forming reduces cycle times
The structured glass blanks were then transformed into three-dimensional geometries by hot forming. In addition to isothermal processes, Fraunhofer IPT particularly investigated a non-isothermal process approach in which heating, forming and cooling are separated from one another. This made it possible to achieve cycle times of less than 100 seconds per component.
As microstructures change during forming, the project team also developed a simulation-based compensation method. This allows expected structural distortions to be taken into account before laser processing.
Life cycle assessment examines CO₂ footprint
As part of a life cycle assessment, the project partners analyzed the developed process chains in terms of energy and material use. The combination of USP laser structuring and non-isothermal forming proved particularly CO₂-efficient, as both processes can be operated entirely electrically.
Partners and funding
In addition to Fraunhofer IPT as coordinator, the project partners include Saint-Gobain Sekurit Deutschland, Flabeg Automotive Germany, ModuleWorks, LPKF SolarQuipment and Vitrum Technologies. The research project EffF3D – Efficient Functionalisation of 3D-Formed Thin Glass was funded by the German Federal Ministry for Economic Affairs and Energy (BMWE) as part of the Federal Government’s 7th Energy Research Programme.
Image caption: USP lasers structure glass blanks with picosecond pulses – precisely, with almost no thermal impact, and with micro- and nanostructures that are both visible and tactile. Image: Fraunhofer IPT
Source: www.ipt.fraunhofer.de