PBN - Pyrolytic Boron Nitride Heaters

Momentive Performance Materials' heaters and electrostatic chucks(e-chucks) combine the unique electrical, chemical, and thermal properties of PBN, a dielectric material, and pyrolytic graphite (PG), an electrical conductor, to produce a truly advanced system. These non-brittle refractory materials owe their exceptional purity to the high-temperature chemical vapor deposition (CVD) production method. The high thermal conductivity and anisotropy of both materials result in excellent thermal uniformity.Design VersatilityMomentive's heaters and e-chucks use PBN as the dielectric and PG as the conductor. For flatness, a graphite coreis typically added. PBN and PG can be deposited in various shaped 3-D parts. Tailored power distributions and multiple zones can be designed into the conductor patterns. For chucks, dielectric layers can be doped for a JR effect.Key Features & Typical BenefitsPower densities over 50 watts/cm2Tailored thermal gradients and heatfluxChuck force up to 100 gm/cm2Low thermal resistance with the waferLow heat capacity of 1.2 Joule/gm-°Cto 700°CPBN dielectric strength of 200,000 V/mmPBN dielectric constant of 3.41Light weightHeaters and electrostatic chucks: thermally engineered solutionsThermal responseA potential advantage of Momentive's technology is the use of low thermal mass, shock resistant materials, capable of high power densities.Ramp rates for heating and cooling have been demonstrated as high as 600°C/ minute for PBN plate based heaters, while conventional sintered ceramics are limited to around 15°C/minute.E-chuck performanceThe dielectric materials used in Momentive's heaters and e-chucks can offer several advantages> 0.03 watts/cm2-K heat transfer coefficientBack side gas not requiredFast heating and cooling without thermal shockPBN Plate Heater1Full power to 700°C, Cool to 400°C.800 700 600 500 400 300 200 10000:00 1:002:00 3:00 4:00 Time (mm:ss) E-Chuck Heat Transfer Coefficient1 0.035 0.03 0.025 0.02 0.015 0.010 Broad operating temperature range 0.005No metal contaminationControlled doping for JR chucksStable dielectric for high temperature chuckingTypical ResultsHigh temperature capability: over 1500°CFast cycle times: ramp rates up to 600°C/minThermal uniformity (< 1%), tunable multiple zonesLong life: shock resistant materialsHeated JR and coulombic e-chucks