“Being nominated for the German Future Prize is a great honor,” says Dr.-Ing. E.h. Peter Leibinger, head of the TRUMPF Laser Technology/Electronics Division. “We’re very happy that the German President is honoring the entrepreneurial daring we showed over many years in driving this highly complex research topic of the ultrashort pulse laser to industrial maturity.”
There is more
The promise of ultrashort pulsed lasers
In recent years, ultrashort pulsed lasers have evolved from being a prestige object in research to an industrial tool. They have become a standard feature in three-shift manufacturing of smartphones, computer chips and solar energy systems. The latest applications range from the drilling and cutting of brittle, hard materials such as glass, ceramics and sapphire to the cutting of silicon wafers, the drilling of PCBs and the cutting of thin polyimide films.
Read more on the technology, applications and promise of ultrashort pulsed lasers in our Special
Industrial beam sources
Nanosecond lasers for fast ablation over a large area
- Fast ablation over a large area – for example of impurities or functional coatings prior to the joining process for welded or adhesive joints
- Targeted ablation of layers in the complex layered structure of photovoltaic modules
- P1, P2 and P3 patterning of photovoltaic modules
Picosecond lasers for the highest micro-level quality and cost efficiency
- Precise cutting of silicon wafers with no need for post-processing
- Precise cutting and drilling of brittle materials such as glass and ceramics
- Burr-free cutting of heat-sensitive materials, such as Nitinol for stents, with no need for post-processing
- Drilling of PCBs
- Ablation of layers at the nanometer scale
TRUMPF is the world’s largest manufacturer of lasers for industrial production. Ultrashort pulse lasers used for the micro-processing of all kinds of different materials – from glass smartphone covers to medical implants and injection valves – are an important and fast-growing market. The fact that the ultrashort pulse laser has such a broad application here – while still being only on the threshold of its full potential – is primarily the achievement of joint research and development work by TRUMPF, Bosch and the University of Jena.
“The route taken by the ultrashort pulse laser is a perfect example of the German research model,” explains Dr. Peter Leibinger. “Universities do the basic research, companies develop the results in accordance with market requirements, and the value-added remains in Germany.” Dr. Jens König from Bosch, Dr. Dirk Sutter from TRUMPF, Professor Dr. Stefan Nolte from the University of Jena and Fraunhofer IOF were thus all nominated for the German Future Prize, which is awarded by the German President.
Innovation without limits
The most important technical innovations in history were a means to an end – they were tools. “They have changed the course of technological history far more than individual products,” says Dr. Peter Leibinger. “Because tools determine what can be produced in the first place, as well as in what quantities, and at what price. The ultrashort pulse laser is that kind of tool.” Long celebrated in theory by the experts, the ultrashort pulse laser – thanks to TRUMPF and Bosch – is now showing what it can actually do in factories, and how it is changing the face of industrial mass production.
Back in 1999, the two companies joined forces in a development venture. The University of Jena supplied the theoretical models and the basic experiments. Bosch developed the industrial process, while TRUMPF realized the requirements placed on an industry-suitable beam source. During the project the partners registered a total of 51 patent families, and relied on a type of laser that was different from all the others: the disk laser. Today they have made the average output of ultrashort pulse lasers more than ten times as powerful – essential for the throughput rates required by industry.
Mass-produced small miracles
“Today’s production of high-precision structural components forces our brain to tune out all its everyday notions of what the word ‘duration’ means,” says nominated TRUMPF expert Dr. Dirk Sutter. “Because with the ultrashort pulse laser, production has entered the unimaginable realms of the temporally tiny. ‘Ultrashort’ here means a pulse lasting only picoseconds (10-¹² seconds).” While a ray of light needs around one second to get from the Earth to the Moon, within one picosecond it only travels a distance of 0.3 millimeters. Concentration of laser radiation into such brief time periods leads to enormous peaks in performance.
Hundreds of thousands of these tiny laser flashes are generated every second, and this sequence of pulses has a further effect. When material is under fire at picosecond intervals it has no time to melt, instead it actually sublimates. Skillful selection of pulse duration, pulse energy, cycle rate and the right focus heats up the material so quickly and powerfully that it breaks off and vaporizes without melting – and can then be simply sucked away using a stream of air. This enables ablation in the very finest ranges of just a few millionths of a millimeter (i.e. nanometers) – without any burr formation from residual melt, or any heat transfer to the material that would impair its quality. In production, this is referred to as “cold processing”; the process transfers no heat, and leaves no residue behind.
Contribution toward gasoline saving
Until only a few years ago, this small miracle only occurred in research chambers at universities, under laboratory conditions. Today Bosch is mass-producing structural components in their millions with the ultrashort pulse laser for sectors such as the automotive industry. One example is a direct injection valve for gasoline: Here, the ultrashort pulse laser drills geometrically complex injection holes with smooth walls. This distributes the gasoline more efficiently in the combustion chamber, contributing toward fuel savings of up to 20 percent. Thanks to the new production process this optimization can also be achieved in engines with medium, smalls and ultra-small displacements. The advantages of direct injection – less consumption and fewer emissions – are therefore available for all vehicle classes now.
Ultrashort pulse lasers are also suitable for the high-precision machining of almost all materials, including ceramics, sapphire, carbon fiber, plastics or glass. A second example from practice: cover screens on smartphones, which have to be extremely thin and very hard at the same time. If they are cut out using diamond saws or other methods, microscopic cracks often appear in the glass. With the ultrashort pulse laser this danger can be avoided – which is why it has developed into the tool of choice for the world’s largest manufacturers.
There are also the minimal invasive processes used in medical technology – in the production of stents, for example, which are used to keep blood vessels open. To prevent them from damaging the vessels and to stop any blood clots from forming, stents have to be absolutely burr-free. Today, they are made from nitinol, for instance, a shape-memory alloy. With the fusion cutting method used so far, stents had to be deburred. Now, with the ultrashort pulse laser, stents can be produced without the need for refinishing work – and this also makes them far cheaper. Clinical studies are currently being carried out on bioresorbable coronary stents made from polymer, which dissolves in the body after a certain time period. The production of stents like these is only possible with ultrashort pulse lasers.
A finger on the pulse of the times
These three examples alone demonstrate how industry is making use of the ultrashort pulse laser. TRUMPF has standardized the laser sources and is now supplying them to industry. The manufacturers certainly have their finger on the ultrashort pulse of the times: Sectors such as the automotive industry, semiconductor production, industrial technology, medical technology, the photovoltaic sector and the electronics industry are all developing applications for ultrashort pulse lasers. By the end of 2013, Bosch will have delivered 30 million components fabricated using ultrashort pulse technology to its customers worldwide. By the year 2020 the number of picosecond lasers in use at Bosch is expected to have more than tripled.
TRUMPF is the world leader with regard to the average power, modulation capability and pulse stability of this laser. “Apart from the disk laser technology, what is unique here above all is the safe and precise control technology. The patented double control loop monitors every single picosecond pulse and keeps the power and the pulse energy at exactly the level required, independent of external influences”, explains Dr. Dirk Sutter. This is done by means of an external modulator which decouples the pulse build-up from the power control, so it always delivers precisely the power and pulse energy needed – while beam quality and pulse duration remain constant.
With this development TRUMPF offers an extremely robust laser concept, specially designed to make it ideal for operation in today’s three-shift production. No need to sacrifice quality for economic efficiency here: With average outputs of over 150 watts, the TRUMPF picosecond lasers are among the fastest and most powerful in the world.