Cellular Fused Quartz: LD80™

LD80 is a unique, high purity opaque fused quartz material containing microscopic bubbles that are engineered to a specific size and quantity. This novel grade retains many of the desirable properties of conventional fused quartz. At the same time, LD80 provides superior performance where heat transfer needs to be minimized or where the transmission of radio-frequency energy needs to be maximized. In addition to its unique properties, such as its reduced dielectric properties, LD80 can be molded into useful net and near-net shapes. Subsequently, it is an optimal grade for applications where thermal management is critical, such as in semiconductor processing chambers. Microwave & RF transparency, ideal window material.

LD80 is being manufactured under patents granted and pending.

Download the full LD80 technical data brochure


  • LD80 is a semiconductor grade of fused quartz that is 99.998 SiO2
  • The density of the material is 1.76 g/cm3 , (80% of theoretical density).
  • The average bubble diameter in LD80 is less than 20 μm
  • The bubbles in LD80 are closed cells. Subsequently, the material is impermeable to gases and liquids, even after the surfaces have been machined.
  • Just like conventional fused quartz, LD80 is chemically inert, can be used at temperatures up to 1200° C and has tremendous thermal shock resistance.
  • LD80 reduces the transmittance of infrared heat by 85%, as compared to conventional opaque fused quartz.
  • Thermal conductivity is reduced by 40% when using LD80, as compared to conventional opaque fused quartz.
  • LD80 has reduced dielectric properties
  • Microwave & RF transparency
  • Ideal window material
  • LD80 can be welded to any other fused quartz grades (clear or opaque), using conventional techniques.
  • LD80 surfaces can be fire polished flat and smooth, as opposed to the irregular, "orange-peel" surfaces found after fire polishing the surfaces of conventional opaque fused quartz.
  • A diffusion tube furnace is an example of a LD80 application:
    • LD80 is near-net shaped, then finished ground into a flange;
    • The LD80 flange is welded on to a clear fused quartz tube;
    • The LD80 surfaces are fire polished to a smooth finish;
    • Because of its superior thermal management properties, the LD80 flange prevents deterioration of the polymer o-ring.
    • Also, because of its smooth surface, the LD80 flange forms a tight seal against the o-ring.

Custom sizes are available. FAX or e-mail us your specifications today and allow us to help reduce your operating cost.                



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