Medical devices

For more than 20 years we have been successfully using our coating know-how in the medical device market. Our core competence lies in the integration of sapphire windows into optical medical analysis devices (hermetic packaging), for example for endoscopy. We produce among others solderable coatings and sterilization-resistant optical filters for camera systems.

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Antireflective coatings

The main disadvantage of sapphire crystal is its very high refractive index (1.77). This causes a high reflection of the incident light, greater than approx. 15% (approx. 7.5% per side).

The anti-reflective layers applied on one or both sides of the lens or sapphire window reduce this reflection in order to avoid the formation of ghost images and to maximize the intensity of the light signal transmitted through the endoscope.

Anti-reflective coatings are applied to both sapphire and mineral crystals. Blösch SA's portfolio is based on 5 anti-reflective layers used in the field of medical devices:

DLC coatings

Blösch has a great know-how in the metallization of complex geometric parts, also with a structuring operation if necessary. Whether your parts are made of sapphire, ceramic material or metal, we offer 2 families of DLC coatings:

  • decorative hard coatings with Blaktop® (deep black) and Anthratop® (dark grey / anthracite)
  • a decorative and functional hard layer, DLC Move® (dark grey / anthracite).


The main difference between these 2 families of DLC layers is their field of application: link

Antis-reflective coating

AR VIS Coating

  • Anti-reflection in the visible range
  • Possibility to optimize the design for different angles of incidence
  • Applicable on 1 and 2 sides, or in combination with a more resistant anti-reflective coating.

AR VIS-NIR Coating

  • Anti-reflection in the visible and near infrared range
  • Possibility to optimize the design for different angles of incidence
  • Applicable on 1 and 2 sides, or in combination with another anti-reflective coating

Autoclavable AR coating

  • Anti-reflective with excellent chemical and mechanical resistance
  • Coating resistant to >10'000 autoclave cycles
  • Spectral range and angle of incidence of the adjustable anti-reflection coating
  • Applicable on 1 and 2 sides, or in combination with another anti-reflective coating

UV-protective coating

  • For the protection UV photosensitive structures
  • Applicable on 1 and 2 sides, can be combined with an anti-reflective coating

Insulating coating

  •  Transparent and hermetic layer for encapsulating moisture-sensitive structures
  • Also provides excellent scratch resistance
  • All our anti-reflective coatings are compatible with the deposition of solderable coatings


Solderable coating for Gold or Tin brazing

In order to achieve high quality assemblies, our unique technology combining PVD and galvanic deposition allows you to deposit multilayers for gold, tin or copper soldering. The structure of our PVD multilayer gives us the possibility to include "anti-diffusion" layers allowing the assembly of various materials by brazing (e. g. sapphire, ceramic, steel).

This technology is commonly used to assemble the last sapphire lens at the end of a rigid endoscope by low temperature brazing. The assembly is guaranteed to be helium-tight, autoclavable and meets the requirements of the regulations in force in the medical field.

Solderable coating for nickel-free brazing

In order to achieve high quality assemblies in highly corrosive environments or for allergenic reasons, a Nickel-free weldable layer is available.

Mirror coating

Blösch benefits from metallic PVD coating technology that allows the deposition of thin layers with high reflectivity. Several mirror layer variants with or without masking, on geometries with different bending radii are available depending on your application.

Black Chromium Coating

Blösch has extensive experience in the deposition of black coatings based on chromium or carbon. These thin layers are opaque and can be applied to all types of glass.

For medical imaging applications, a layer of black chromium deposited around the sapphire lens improves optical contrast and image quality.

This type of layer combines perfectly with solderable coatings.

Conductive coatings

It is possible to place an ultrathin electrode with or without masking on electrical insulating glass or ceramic part. Blösch offers you our know-how in the deposition of conductive coatings of different types.

  • Transparent ITO layer for electromagnetic protection
  • Au or Pd layer for high temperature application
  • Au layer on radiofrequency cauterization ceramic