Pyrolytic Boron Nitride (PBN) is an anisotropic, high-temperature ceramic which exhibits a unique combination of high electrical resistance and good thermal conductivity. This non-toxic, non-porous compound is exceptionally pure by virtue of the synthesis process (high temperature/low pressure chemical vapor deposition). It can be deposited or easily machined into a limitless number of shapes, including
- Crucibles
- Boats
- Tubes
- Bottles
- Machined plate products
- Coatings on graphite
PBN's directional thermal conductivity provides excellent "heat spreading" capability for improved temperature uniformity. The combination of high strength, good thermal conductivity, and a low coefficient of thermal expansion makes the material extremely resistant to thermal shock. PBN has found wide acceptance in the semiconductor, electronics, metallurgical, thin film, and pharmaceutical industries.
PBN Coatings
PBN has become the material of choice for compound semiconductor crystal growth and wafer processing. PBN coatings also seal and protect graphite from very corrosive atmospheres including most molten metals, all acids, and hot ammonia. PBN is an electrical insulator which exhibits a high degree of anisotropy, e.g. good thermal conductor parallel ("ab") to substrate and thermal insulator through thickness ("c").
12 Reasons why PBN Belongs on Your Next Job
- Non-toxic
- High purity
- Low density
- Chemically inert
- Non-porous
- One of the highest dielectric strengths known
- Good thermal conductivity
- Tensile strength increases with temperature
- Excellent thermal shock resistance
- High oxidation resistance
- Negligible outgassing
- Advantageous anisotropy (electrical, mechanical, and thermal)
Typical Properties (R.T.)
|
Apparent Density (gm/cc)
|
1.95-2.22
|
Tensile Strength (MPa, psi)
|
40, 6000
|
Flexural Strength (MPa, psi)
|
80, 12000
|
Thermal Conductivity (W/m°C)
|
“ab” 60
“c” 2
|
CTE (mm/mm/°C (1000°C) “ab”)
|
2x10-6
|
Resistivity (ohm-cc)
|
1015
|
Dielectric Strength (D.C. volts/mmc)
|
2x1015
|
Dielectric Constant
|
“ab” 5.2
“c” 3.4
|
Total Metallic Impurities (ppm)
|
<10
|
Outgassing
|
>Negligible
|
Maximum Suggested Use (°C)
|
2,500
|