High precision, state-of-the-art glass cutting technology based on Coherent SmartCleave ultra-short pulsed lasers delivers the results needed for the most demanding applications.
Glass is literally everywhere around us, known and used by mankind for more than 5000 years. So it is easy to overlook that it is a unique material with a very useful combination of physical properties. The most obvious of these, and one of the most valuable, is that it is transparent. Glass is also mechanically strong and relatively scratch resistant. In addition, it does not react with most chemicals - even many strong acids. And neither liquids nor gases pass through it. Glass is biocompatible, which means that sterilized glass can be safely implanted into the human body. For these and other reasons, the use of glass has expanded far beyond the architectural and automotive windows we are all familiar with into increasingly sophisticated products. It is already widely used in medical devices, life science instruments, semiconductor tools and consumer electronics. In the latter area, it is used for display screens in phones, laptops, tablets and televisions.
Old glass cutting methods can't do it
In many of these modern technology applications, there is a constant push to make products ever more sophisticated, but also physically smaller and lighter. When it comes to using glass, this usually means the need for thinner pieces, often with curved edges or cutouts. An example that everyone is familiar with with its cut-outs may be mobile phone displays and wearable electronics.
However, this requirement presents a challenge. That's because traditional glass cutting methods - such as good old-fashioned mechanical carbide tool cutting or waterjet cutting - can't easily work with really thin glass or create different kinds of features - especially thin curves. At least not within the required cost and production time constraints. Even the usual laser glass cutting methods cannot cut some shapes in a way that makes the whole production process cost sensible.
Older glass cutting methods create very small cracks and residual stresses in the glass. This makes the glass much more susceptible to breakage during subsequent handling and use. In fact, it turns out that when glass breaks, the crack almost always starts at the outer edge, even if the force is applied to it in the middle. Also, most glass cutting processes usually produce small chips and fragments, and the cutting edge is not necessarily perfectly perpendicular to the glass surface. Because of all this, various additional steps may be necessary, such as grinding or polishing the cut surface. For the manufacturer, any additional processing steps required after cutting represent an increase in production time and costs. In addition, they can have a negative impact on the environment if they generate contaminants that are difficult to dispose of or require large amounts of water for cleaning.
SmartCleave accelerates precision laser cutting of glass
A new precision cutting method called "filamentation" has been developed specifically to meet the growing need for precise, stress-free and debris-free cutting of thin glass. Filamentation requires an Ultra ShortPulseLaser (USP) because only this can generate the very high peak power on which the technique is based. In filamentation, the USP laser focuses into the interior of the glass and creates a series of microscopic cavities (or filaments) that can be up to several millimetres deep. To create a continuous cut, the laser beam moves against the glass in the desired shape and creates a series of very closely spaced cavities in the glass. Depending on the thickness and type of glass, the finished part is then either mechanically separated directly along the cut or can be separated by heating. Filamentation enables high-speed cutting of curves and inserts (without tapering) in glass thicknesses from 0.05 mm to 10 mm. Glass filamentation also works on chemically strengthened glass, which is widely used in touchscreen displays.
Coherent has developed its own form of filament cutting called SmartCleave. This method specifically uses the unique features of our HyperRapidUSP series lasers . One of these is the so-called "burst mode", where the laser emits a rapid series of pulses. This achieves a finer heating profile than a chain of pulses with the same total energy but delivered over a longer period of time. The advantage of SmartCleave technology is that the cutting speed is up to twice as fast. It also produces smoother and straighter holes than other filament cutting methods. In addition, SmartCleave technology leaves the cutting edge free of micro-cracks, chips and debris. All of this improves production throughput and reduces costs by eliminating post-processing steps. In addition, the result is a mechanically stronger finished glass part.
The use of glass in high-tech products will clearly continue, as nothing else compares. And SmartCleave cutting enables glass parts to be produced with the precision that these new demanding applications require. Read more about the SmartCleave system for cutting glass, sapphire, ceramics and composite materials.
Source: Coherent.com
