Laser surface treatments

Present situation worldwide and in Switzerland

The term “surface treatment” covers a multitude of processes that alter the properties of a material or texture its surface to apply markings. Surface treatment is typically carried out using laser beam sources with medium output power. These lasers operate in continuous wave mode, in pulsed mode (micro- resp. nanosecond pulses) or in ultrashort pulse mode (pico- resp. femtosecond pulses). In the past five years, the development of laser beam sources with high output power resp. with ultrashort femtosecond pulses, combined with the availability of associated optical components, beam steering systems and sensors, has enabled new processes as well as improved quality and reduced processing times for existing processes. These past years, photonics has been the decisive enabler for the successful industrialisation of many innovative products. In 2017, the global market for laser beam sources used for surface treatment was worth roughly 2 billion USD, which amounts to around 20% of the total laser market.

Surface treatment plays a role in almost all sectors, e.g. car manufacturing, battery technology, screens and displays, electronics, communication, aerospace technology, medical technology, food, security systems, watchmaking and jewellery, consumer electronics and defence technology. Key drivers in the field of surface treatment are:

• the need for new production processes with high energy and power density
• rising requirements in terms of surfaces’ functionality or resistance to wear due to increases in productivity
• the need for traceability of parts and products along the entire process and logistics chain using codes or text
• new regulations in the fields of aviation and space technology, medical technology and other sectors imposing highly resistant labelling along the entire process chain

New surface treatment processes include crystallisation processes to produce OLED or LCD displays, the detachment of flexible displays from substrate materials, or tempered glass processing. Laser markings with conventional nanosecond lasers tend to trigger structural changes in high-grade steels, with the risk of corrosion. The use of ultrashort pulsed lasers has enabled a technological leap and highly corrosion-resistant markings. The short timescale in which a pico- or femtosecond laser pulse interacts with a material makes it possible to create unusual surface structures, e.g. enhancing absorption or emission properties, or providing catalytic support to electrochemical processes. Significant progress in the coating of various materials with sub-nanometer precision enables the production of new compounds and coatings. In combination with optically active materials and special waveguide structures, it is possible to produce smart and active optical components, sensors or switches. Appropriate 53 micro-texturing enables the use of innovative joining techniques, for example to achieve specific thermal or tribological properties.

Megatrends such as digitalisation, globalisation, individualisation and security will lead to rising requirements regarding the traceability of components, products and parts along the entire process and logistics chain. Further trends such as connectivity, mobility and neo-ecology mean that surface texturing of metals, semiconductors and polymers, layer ablation and display production processes will gain ground. In the field of electric mobility, thousands of lasers will be used to strip wires for the production of electric motors.

Implications for Switzerland

The Swiss photonics market, which comprises laser beam sources and systems as well as optical components, coatings and sensors, is worth around 4 billion CHF, of which roughly 400 million CHF are generated by surface treatment lasers and laser systems. This market segment displays average annual growth of 8% and has an export rate of more than 90%. According to experts, over the next ten years the share of photonic components in all products developed and produced by Switzerland’s MEM industry (mechanical and electrical engineering) will increase from currently 40% to over 60%. These figures highlight the major role played by Swiss industry in the global photonics market. Photonics’ share of GDP is significant and set to grow further. In order to retain a leading position in the field of surface treatment, next to basic research Swiss institutions of higher education must increase their focus on enabling technologies such as photonics. Almost all of roughly 20 Swiss academic research institutes in photonics have therefore joined the National Thematic Network (NTN) “Swissphotonics”. Their research activities are underpinned by educational courses at bachelor, master and doctoral level. Specialised photonics degree courses have now been on offer for four years.