technical ceramic solutions


Pyrolytic Boron Nitride Crucible

PBN is with 99.99% purity and a grade of hexagonal boron nitride. It is produced by the chemical vapour deposition process to create its solid body and all the boron nitride crystals grow parallel to the surface on which the vapour is deposited. The CVD process gives this pyrolytic boron nitride an almost perfect layered structure, which leads to anisotropic thermal conductivity, making it an ideal material to make crucibles for crystal growing.

Main Features
1. The colour of PBN is between ivory and orange-brown, nontoxic, imporosity, easy processing.
2. The purity is up to 99.99%, surface densification, good gas barrier properties.
3. The strength increases as the temperature rises and peaked at 2200℃.
4. Acid, alkali, salt, and organic reagent resistance. Meanwhile, it does not react with the majority of molten-metal and semiconductor material.
5. Excellent thermal shock resistance, excellent thermal conductivity, low thermal expansion coefficient.
6. High resistance, high dielectric strength, low dielectric constant, low dissipation factor, excellent microwave and infrared ray ability
7. It’s with anisotropy in mechanics, heat, and electricity.


Property Unit Value
Lattice constant μm a: 2.504 x 10^-10   c: 6.692 x 10^-10
Density g/cm3 2.10-2.15 (PBN Crucible); 2.15-2.19 (PBN Plates)
Micro hardness (Knoop)(ab side) N/mm2 691.88
Resistivity Ω*cm 3.11 x 10^11
Tensile strength N/mm2 153.86
Bending strength ⊥C N/mm2 243.63
⊥C N/mm2 197.76
Elastic modulus N/mm2 235690
Thermal conductivity W/m*k “a” direction  “c” direction
200℃ W/m*k 60           2.60
900℃ W/m*k 43.7          2.8
Dielectric strength (at room temperature) KV/mm 56

Main Applications
* Crystal growth (VGF, LEC Crucible)
* Molecular Beam Epitaxy (MBE) Crucible
* Polycrystalline Synthesis Boat
* OLED and MBE Effusion Cell
* MOCVD Heater
* PBN Infrared Window
* Traveling Wave Tube (TWT) (PBN Support Rod)
* High temperature, vacuum equipment insulator