NEXCERA®(Optical mirrors)

NEXCERA® is a material with thermal expansion similar to that of low thermal expansion glass as well as high stiffness. It is primarily used for mirrors such as in semiconductor manufacturing equipment, 3D-CMM equipment and telescopes.

Advantages

  • ●Thermal expansion coefficient similar to low expansion glass
  • ●Able to be machined to precise mirror finishes
  • ●Extremely high stability (thermal, aging)
  • ●Light weight, high stiffness
  • ●Self-diffusion bonding enables bonding without a binding agent

  1. Thin ribbed structure
    (Rib thickness: 3mm)
  2. Lid bonding (self-diffusing bond) + precision mirror finish

  3. Box structure (mirror)
    340mm dia. x 70mm

  4. Flatness 36 nm < λ/10

  5. Roughness：
    Ra 0.36 nm, PV 32 nm

Bonding technology: Self-diffusion bonding

  • ・This method binds by structural element diffusion by heating while treating with ceramics set in direct contact.
  • ・It is possible to bond without a binding agent.

  1. Thin ribbed structure
    (Rib thickness: 3mm)
  2. Lid bonding

  3. Box structure
    340mm dia. x 70mm

  4. Photograph of bond cross-section

NEXCERA® thermal stability

  • ●Heat cycle
    (RT ⇒ －20℃ (11h) ⇒ ＋60℃ (11h) ⇒ RT) x 4 times
  • ●Sample
    NEXCERA®(N117B) mirror/thin rib bonded structure


Sample size: 340mm dia.


  1. Before heat cycle: Flatness: 0.058μm

  2. After heat cycle: Flatness: 0.060μm

The changes in flatness before and after the heat cycle are within the tolerance of the equipment.
Also, the shape profile has not changed significantly.

The hysteresis of the heat cycle is extremely low.

See the NEXCERA® characteristics

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