Laser cutting and laser fine cutting are applied for different kinds of materials where complex contours demand precise, fast and force-free processing. Lasers create narrow kerfs and thus achieve high-precision cuts. This method does not show any distortion and in many cases post-processing is not necessary as the component is subject to only little heat input and can mostly be cut dross-free. Almost all kinds of metals can be laser cut: mild steel, stainless steel and aluminum are the most common applications. Other laser cut parts are made from wood, plastics, glass and ceramics. Compared to alternative techniques like die cutting, laser cutting is cost-efficient already for small-batch production. The big benefit of laser cutting is the localized laser energy input providing small focal diameters, small kerf widths, high feed rate and minimal heat input.
The laser beam welding is mainly used for joining components that needs to be joined with high welding speeds, thin and small weld seams and low thermal distortion. The high welding speeds with an excellent automatic operation and the possibility to control the quality online during the process makes the laser welding a common joining method in the modern industrial production. The application range covers finest welding of non-porous seams in medical technology to precision spot welding in electronics or the jewelry industry, to deposit welding in tool and mold-making and welding complete car bodies in automobile construction. However, new and efficient production processes are often not possible without the advantages of laser technology. Thus, diverse sheet thicknesses and qualities are turned into tailored blanks by welding and resistance spot welding is replaced by laser seams.
Marking and Engraving
Durable Markings with High Contrast
The laser virtually marks all metals and plastics and various other materials with high contrast and without adding any undesirable substance. In most cases the typical physical effect of the laser marker induces a color change within the material so there is no surface modification by corrugations or burrs. Different marking methods and laser sources (solid state and CO2) are used to achieve the best results on every type of material.
Flexible and On-the-fly
Independent of material and marking method, laser marking offers almost unlimited possibilities in terms of marking contents and shape. The flexible, software-controlled process allows individualized marking contents as well as on-the-fly marking of moving work pieces.
High flexibility and high speeds are the big benefits of laser technology when it comes to drilling of blind and through holes. As with cutting, there are two different laser processes for micro drilling: fusion drilling with pulsed lasers and external gas support, and vaporization-induced melt ejection as realized with q-switched solid-state lasers, for instance. Choosing the appropriate wavelength and power density of the laser beam, practically all solid materials (metals, semiconductors, plastics, ceramics, diamonds) can be laser drilled.
Precise, local ablation of thin layers of material is finding its way into many different areas of industrial production. Depending on the material a suited laser is employed. Wavelength and pulse width are crucial factors. For plastics, the most commonly used CO2 lasers or frequency converted solid-state lasers are used. Metals and semiconductors are processed with q-switched solid-state lasers in fundamental wavelength.
Excimer lasers can be used to shape a wide range of materials including polymers, metals, glass, ceramics and even diamonds. The direct-write approach using CAD/CAM software for laser machining in the dimensions of microns allows almost any shape to be generated on a surface.
The combination of compact excimer lasers and precision motion systems, video imaging and CAD/CAM software allows precision machining on scale-sizes in the 1 to 100 micron range.
Raster scanning on the work surface is one means of producing such three-dimensional structures. This technique forms the part by removing the material layer by layer.
Ceramic processing applications for lasers have increased since the development of several new industrial lasers. Lasers are now used to scribe, drill and profile, as well as for selective material removal and marking/serializing applications. They are also used to process fired substrates such as alumina (AL2O3 ), aluminum nitride (AIN) and beryllium oxide (BeO), and unfired (green) substrates.
Laser Brazing and Soldering
When it comes to soldering, one generally speaks of a substance-to-substance bond. Soldering involves melting an additional material that has a considerably lower melting temperature than the material to be joined by using laser light. The material of the parts themselves is not melted, like it is the case in the laser welding process. The soldering process is characterized by the use of a fill metal (solder) which is melted to fill the bonding gap and which acts as a wetting agent in the soldering process.
Copper-zinc (brass) or tin alloys, for instance, are used as a solder material. The solder material is added as a wire during the process, but can also be applied as a soldering paste.
It can be differentiated between brazing with melting temperatures > 450°C and soldering with temperatures < 450°C. The brazing process requires higher laser powers and is mainly used within the automotive industry, for example for the joining of sheet metal blanks of automotive body parts, whereas soldering is often used within the semiconductor or electronic industry.
Glass Cutting and Scribing
Laser cutting and scribing of display glass and functional foils are important processes for the Flat Panel Display industry. The contact-free laser processes enable the trend towards thinner glass and advanced material mixes.
Lasers, especially high-frequency excited, fast modulating CO2 lasers with extraordinary power stability, are especially suited for perforating paper or plastic foils. Usually, web material is processed at winder systems at high speeds of up to 700 m/min. With laser perforating hole diameters ranging from 50 – 400 microns can be achieved.