Job coating – perfection from A to Z

Wohlrab‘s most commonly supplied technical coatings are PVD* or PECVD* based and can be found e.g. in EMC and ESD protection, reflective layers or anti-glare coatings. Miscellaneous special coatings are also available for optics, sensors and medical technology.

*PVD = physical vapour deposition
*PECVD = plasma-enhanced chemical vapour deposition

Thermal evaporation is a thin-film deposition method, where a pure metal material is evaporated into vapour particles. These in turn condense back into a solid state when reaching the target substrate surface. Typical source materials are e.g. aluminium, copper or gold but depending on the application in question material combinations like Cu/NiCr, Cu/Sn can also be applied.

Sputtering is a process where particles are ejected from a solid target material due to collisions with high-energy argon ions (in a plasma) and condense onto a target substrate, forming a thin layer. Copper and stainless steel alloys are typical target materials.

Anti-glare layers on display panes improve readability enormously. In the meantime, they are also standard on optical sensors or other optical components (e.g. collimators).

Wohlrab‘s reflective coatings are tailor made to their specific application with various base materials (e.g. Al, Ag, Au) and can be enhanced with additional protective layers (e.g. dielectric layers as a corrosion inhibitor). Moreover, the reflectivity across specific wavelength ranges can be increased (protected aluminium, protected silver and enhanced aluminium). Typical application for high reflectivity coatings:

• High-tech deflector mirrors for sensors, lasers and optics
• Automotive head lights and interior lighting
• High-tech reflectors for general lighting applications

Semi transparent layers are used in automotive interior applications where a chrome-like appearance is desired under daylight but illumination at night is required. This can be achieved with a nanometer thin reflective layer (e.g. Aluminium based), and sealed with an appropriate protective layer.

Transparent Easy-To-Clean coatings provide anti-adhesion properties to surfaces. Their water and grease repellent characteristics prevent dirt and micro organisms from sticking and therefore make cleaning less arduous.

• Contact angle > 100°
• For bulk coatings in a drum or in an individual process
• Suitable for high gloss surfaces

Protection against electrostatic discharge is vital in all fields of the electronics industry. Wohlrab provides transparent, conductive layers (e.g. ITO / Indium-Tin-Oxide) and thin metal layers ranging from 150…1500 Å.

Wohlrab supplies all-over coatings on films (> 5 µm) using various materials for sensor applications (e.g. gas detectors) and structured coatings of PVDF films (> 5 µm) for electronic applications (bonding), e.g. in infrared or ultrasonic sensors.

Parylene based layers are only a few µm thin and act as a highly efficient diffusion barrier, providing corrosion protection. Its biocompatibility is also favourable for medical applications.

For more than ten years we have been developing innovative solutions for our customers in the medical industry, e.g. for hearing aids and other medical devices like OR lamps. Our long standing expertise in the development and production of these highly sophisticated coatings and a holistic understanding of the entire process chain allow us to meet even the strictest medical standards.

Our portfolio of biocompatible surface treatments covers technical coatings (masked EMC gold evaporation), decorative two-colour automated robotic painting, 6-colour pad printing, laser engraving and Easy-to-Clean nano coatings.

Take advantage of our extensive experience in this field!