Heraeus Black Quartz (HBQ®) –
a revolutionary hybrid material

HBQ® Black Quartz

Heraeus Black Quartz (HBQ®) is a unique black opaque quartz glass composite that benefits from high purity and other properties of our advanced white opaque (OM®) and clear fused (HSQ®) quartz solutions. HBQ® offers smart answers to individual problems, and new answers to old material challenges. Convince yourself and step into a new world of possibilities with Heraeus Black Quartz. To learn more follow the links below.

High Optical Absorption

Over 95% absorption is achieved in a wide range of wavelengths from UV through VIS to MWIR in as little as 3mm of thickness. Over 80% absorption is achieved already at a thickness of just 1mm.

High Emissivity

Values for emissivity close to a black body emitter are achieved at elevated temperatures. Over a wide range of wavelength the emissivity is between 80% and 90%. Between 2.6µm and 2.7µm reaching 95%. HBQ® represents a new option as black body emitter.

Thermal Conductivity

Despite the high emissivity, HBQ® offers a very low thermal conductivity, defined by the SiO2 nature of the material. The thermal conductivity is as low as 1.5 W/mK. This offers unique application benefits, e.g. in semiconductor process chambers, adding a degree of freedom in thermal management, where heat dissipation is an issue.

Chemical Purity

The total level of impurities in HBQ® is <50 ppm, resulting in a bulk purity of >99.995%. Even for the most sensitive leading-edge semiconductor applications HBQ® is a qualified and viable material solution. HBQ® is free of carbon and problem metals like Iron, Titanium, Tungsten, Chrome or Nickel.

Mechanical Machining

Compared to the alternative black ceramic materials like SiC or AlN, HBQ® is faster and more economical when comparing machining time and tool wear. This gives HBQ® the opportunity to significantly reduce your total cost of ownership.

Chemical Inertness

Analogous to clear fused quartz material HBQ® is inert to most chemical acids and solvents. For example no reaction is seen with HCl, HNO3 or gases like Cl2, H2 or O2. In almost any atmosphere HBQ® can be used at temperatures up to 1300°C safely and reliably.

HBQ® can be used in several applications. Please find below some examples.

Further applications:

  • Thermal homogenization of process environment
  • Blocking of radiation from certain process environments
  • Heating element covers, shielding plates, pedestal plates, dummy wafers, wafer holders, etc.


HBQ® is available as a full body ingot material in solid round format. We currently offer round ingot with a maximum outer diameter (OD) up to 720mm. Ingot height can be up to 60mm.


Heraeus can provide HBQ® in square or rectangular ingots. The current maximum dimension of a square is 500mm x 500mm (length x width) while Rectangular blocks can have a current maximum dimension of 900mm x 300mm (length x width). Block height can be up to 60mm on both square and rectangular ingots.


HBQ® is also available as a ring, which can be tailored to custom dimensions for maximum material efficiency in ring or cylinder applications. Current maximum outer diameter (OD) is 800mm while inner diameter is flexible. Height up to 250mm is possible for HBQ® rings.

General properties

Unit HBQ®
Density g/cm3 2.19
Porosity % <0.5
Pore Size µm <10

Electrical properties

Unit HBQ®
Resistivity (20°C) Ω∙m >1015
Resistivity (1200°C) Ω∙m >1000
Type Insulator
Dielectric constant (εr) @ 13,56 MHz 3.82

Mechanical properties

Unit HBQ®
Tensile strength MPa 50
Flexural strength MPa 84
Compressive strength MPa >1000
Young modulus GPa 54

Thermal properties

Unit HBQ®
Thermal expansion (20-200°C) K-1 0,57 x 10-6
Thermal conductivity (20°C) W∙m-1∙K-1 1.49
Max. working temperature °C 1160 °C (long)
1300 °C (short)
Emissivity @ 1000°C % 80-90