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Hermetic LIDS with Windows

Materion developed its unique VISI-LID™ covers for customers who require a hermetic packaging lid with a window for their photonic package. A wide range of technologies such as MEMS, LIDAR, CCD chips, photodiodes, laser diodes and many others employ hermetic lids that must transmit electromagnetic radiation.


Visi-Lid hermetic lids allow for mixing and matching various optical windows onto a range of housings. It offers an anti-reflective (AR) coated window soldered onto an etched Kovar frame for seam seal or solder seal attachment onto the hermetic packaging. Advantages include:

  • Window substrates can be glass, sapphire, germanium, silicon and other materials
  • Compatible windows customized for visible, infrared or ultraviolet transmission
  • Anti-reflective coatings or filter coatings designed for specific transmission requirements
  • Variety of solder alloys & preforms available to tack-weld onto the frame of Visi-Lid™, simplifying assembly onto detector housing
  • Precise Visi-Lid hermetic lid housing with attached selectively metallized, AR-coated window that is leakproof for high performance hermetic sealing
  • For smaller, lower cost hermetic packaging lids, a solder frame can be tack weld directly onto the metallized window, known as the Visi-Cap™ option. Visi-Caps™ do not have a Kovar frame. See below for typical assembly.

Visi Cap diagram 

Typical Visi-Cap Assembly


An optical assembly passes light at specified wavelengths. To obtain the desired level of transmittance for the package window depends on selecting the right combination of quality material, surface finish and Anti-Reflective coating.

Visi-Lid Wave Length Diagram

These assemblies can hermetically seal various device packages. In simplest form, a Visi Cap™ cover assembly consists of an AR coated + metallized window, with a solder frame tack welded onto the metallized area on the window. More complex Visi-Lid™ assemblies feature a metallized window sealed into a plated Kovar frame. The Kovar frame can have a thin flange at the perimeter suitable for seam seal welding, or the Kovar frame can have a solder frame tack welded onto it.


Materion is an industry-leader in durable hermetic lids and microelectronic packaging. Materion offers these benefits:

  • In-house custom design and manufacturing capabilities
  • Extensive knowledge of solder sealing systems and assembly
  • Engineering support from initial design through final assembly

When it comes to lids, Materion has you covered! Contact our engineering team to assist with your optical hermetic lid or any microelectronic packaging needs.