German laser system integrator 4JET Technologies has developed a new process solution for precision cutting of glass, the PearlCut. The process uses ultrafast laser pulses and a unique beam shaping solution for a controlled crack propagation in brittle materials.
The first potential applications include free shape cutting of thin glass parts for mobile electronics and display substrates and cover glasses, yet the process is also suitable to separate thicker glasses for other applications. Processable glass types include soda lime and chemically strengthened glass with any ion-exchange depth. Additional brittle transparent materials such as sapphire can also be processed.
The new laser solution works non-ablative and kerf-free. As a result, no dust is created during the cutting process and the cut edges have a smoothness of Ra <2µm. By minimizing edge defects, parts that were separated with the PearlCut process require very little to no edge finishing.
The standard process setup allows to cut strengthened glass up to 1mm thickness in one pass with speeds in the range of 400mm/s for straight lines and 100mm/s for radii. A smart phone cover glass including a notch can be cut within less than 5 seconds.
The PearlCut process recombines several well known phenomena to induce micro modifications of laser radiation in glass by use of an ultrafast laser and a proprietary beam shaping solution.
4JET offers the new process in a very compact system platform that allows to process one mothersheet up to Gen 4.5 or two mothersheets of up to Gen 3. Loading is performed manually, by conveyors or cassette loaders. The system maps and corrects the panel position by CCD cameras. Part accuracy is better +/- 20µm.
The ability to control the crack propagation is mission critical for achieving repeatable results along the entire edge including corners. To enable this a path-synchronized process reduces the speed when cutting a corner radius and accelerates to full speed when performing straight cuts.
The PearlCut technology completes 4JET´s portfolio of micromachining solutions for glass, photovoltaics and electronics. The company has already installed numerous laser glass drilling systems for display- and solar-glass.