What is hBN?
Hexagonal Boron Nitride (hBN)
Aurexene Materials hBN is a family of thermally conductive, electrically insulating platelet powders for thermal fillers and TIMs, epoxy molding compounds, underfills, encapsulants, and HBM package heat paths.
Technical owner: Aurexene Materials Engineering Team · Last updated: 2026-07-26
What It Is Not
- hBN is hexagonal boron nitride, not cubic boron nitride and not an electrically conductive carbon analogue of graphite.
- A standard hBN powder grade is not a ready-to-use liquid coolant; liquid-loop hBN nanofluids are separately formulated and qualified dispersions.
When Not to Use It
- Do not use hBN when the material must form an electrically conductive pathway or when high ceramic loading and platelet orientation cannot be accommodated.
Intrinsic Screening Summary
- Identity screen
- BN; Platelet
Application Fit
Material Identity & Specification Status
hBN Powder Grade Lineup
Compare particle-size and surface-area families first, then confirm resin compatibility, viscosity, packing, and directional heat flow in the final formulation.
| Grade | Grade role | D50 (µm) | BET (m²/g) | BN (%) | Primary selection fit |
|---|---|---|---|---|---|
| kBN-C30 | Coarse platelet | 30.4 | 1.1 | 99.1 | High-fill gap filler, pad precursor and thermoplastic loading trials. |
| kBN-C18 | Coarse/fine platelet | 18.2 | 2.1 | 99.2 | General TIM, thermal pad, potting and EMC filler blend trials. |
| kBN-M10 | Medium platelet | 10.2 | 3.2 | 99.1 | First-choice starter grade for broad TIM and EMC screening. |
| kBN-M7 | Medium/fine platelet | 7.1 | 6.1 | 99.2 | Thermal coatings, smooth potting compounds and medium-viscosity adhesive systems. |
| kBN-F5 | Fine platelet | 5.1 | 8.8 | 99.0 | Cosmetic soft-focus and fine lubricant/release coating trials; conditional blend use only for TIM/EMC. |
| kBN-F2 | Fine 2 µm platelet | 2.0 | 15.2 | 99.0 | Specialty fine coating and interface R&D; not a standard TIM or EMC filler grade. |
| kBN-UF | Ultra-fine submicron platelet | <1.0 | >30 | >99.0 | Submicron and nano-oriented formulation trials requiring D50 below 1 µm. |
Powder Chemistry and Density
Use chemistry and packing values to compare powder handling and loading behavior. kBN-UF is the submicron option for programs that require D50 below 1.0 µm.
| Grade | B2O3 (%) | Oxygen (%) | Carbon (%) | D90 (µm) | Loose density (g/cm3) | Tap density (g/cm3) |
|---|---|---|---|---|---|---|
| kBN-C30 | <0.12 | 0.22 | <0.08 | 63.0 | 0.78 | 1.00 |
| kBN-C18 | <0.11 | 0.31 | <0.08 | 42.5 | 0.79 | 1.01 |
| kBN-M10 | <0.10 | 0.39 | <0.09 | 24.0 | 0.82 | 1.04 |
| kBN-M7 | <0.11 | 0.52 | <0.09 | 17.5 | 0.51 | 0.72 |
| kBN-F5 | <0.10 | 0.96 | <0.10 | 12.2 | 0.42 | 0.62 |
| kBN-F2 | <0.25 | 1.18 | <0.10 | 5.0 | 0.36 | 0.54 |
| kBN-UF | <0.30 | <1.0 | <0.20 | Not specified | Not specified | Not specified |
Compare Material Routes
Material Evidence
Technical Guides
| Technical Guide | Summary |
|---|---|
| Bond-Line Thickness, Contact Pressure, and Surface Roughness in Thermal Interfaces | An assembly-level method for separating bulk-layer resistance from two contact interfaces while controlling bond-line thickness, pressure, surface topography, coverage, aging, and mechanical retention. |
| Controlling Voids and Porosity in Thermal Adhesives, Encapsulants, Pads, and Composites | A defect-control method that distinguishes air, moisture, volatiles, wetting, cure, delivery, and assembly causes, then verifies void location and finished thermal-interface response. |
| Hybrid hBN, AlN, and Insulating-Filler Networks for Higher Thermal Transport | Hybrid Hexagonal Boron Nitride (hBN), AlN, and Insulating-Filler Networks for Higher Thermal Transport — a method-conditioned engineering guide for Thermally Conductive & Electrically Insulating Polymers covering structure-function behavior at the material, interface, and finished-system boundary, process limits, validation, and qualification boundaries. |
FAQ
Why does hBN work for thermal conductivity and heat dissipation?
Hexagonal BN provides a platelet heat-conduction route through a host while remaining electrically insulating; interface resistance, orientation, loading, and dispersion determine the result.
Is hBN used for electrical insulation or thermal conductivity?
Both properties are the reason it is selected: hBN can move heat without creating the electrically conductive carbon network associated with carbon fillers.
What must be validated before using hBN for thermal conductivity?
Validate particle distribution, wetting, platelet orientation, thermal interface resistance, loading, viscosity, polymer compatibility, and thermal cycling in the final host.
How does hBN fit epoxy molding compounds and semiconductor packaging?
hBN can serve as an electrically insulating ceramic filler in thermally conductive epoxy molding compounds, underfills, encapsulants, prepregs, and TIM layers. The finished package still requires thermal, dielectric, moisture, cure, adhesion, CTE, and warpage qualification.
Can hBN be used in HBM liquid-cooling systems?
Distinguish the role. hBN is relevant in solid package heat paths that move heat from HBM toward a liquid-cooled cold plate. Experimental hBN-water nanofluids have also been studied in computer cooling loops, but they are separate formulations requiring fluid stability, pumping, clogging or erosion, dielectric, and materials-compatibility qualification.
Documents & Inquiry
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Technical Data Sheet
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Safety Data Sheet
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Grade, Sample & Qualification Support
The Aurexene Materials Engineering Team can review the required form, host system, formulation or process, target, sample quantity, volume and timeline, and the grade-specific evidence needed before qualification.
Review Lab Capabilities for sample evaluation and qualification support, or Production Capabilities for scale-up, quality, documentation, and supply support.
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