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DIASEMI™ Nanocrystalline Diamond (NCD) Film

May5, 2026

DIASEMI™ Nanocrystalline Diamond (NCD) Film

High Thermal Conductivity with Engineered Mechanical Compliance


Product Overview

DIASEMI™ Nanocrystalline Diamond (NCD) films redefine the conventional perception of diamond as a purely rigid material. At the nanoscale, diamond exhibits size-dependent mechanical behavior, transitioning into a surface-dominated, elastically compliant structure while retaining its exceptional thermal properties.

Leveraging this phenomenon, DIASEMI NCD films deliver a unique combination of:

  • Ultra-high thermal conductivity

  • Enhanced elastic compliance

  • Superior interface reliability

These properties make NCD an enabling material for next-generation high-power electronics, photonics, and advanced packaging systems.


Key Value Proposition

“High thermal conductivity meets mechanical compliance.”

Unlike bulk diamond, DIASEMI NCD films provide strain-tolerant thermal spreading, addressing critical challenges in heterogeneous integration and high heat flux devices.


Technical Advantages

1. Size-Dependent Elasticity (Core Differentiator)

  • Nanocrystalline structure introduces:

    • High surface atom fraction

    • Reduced bond stiffness at grain boundaries

  • Results in:

    • ~30% reduction in effective stiffness (vs. bulk diamond)

    • Increased elastic strain tolerance

 Enables stress buffering at material interfaces


2. Exceptional Thermal Conductivity

  • Thermal conductivity: 800 – 1800 W/m·K (film dependent)

  • Efficient phonon transport across nanograins

  • Maintains superior heat spreading vs. Cu, Al, and SiC


3. Interface Stress Mitigation

NCD films act as a compliant thermal layer:

  • Reduces CTE mismatch stress:

    • Diamond / Si

    • Diamond / GaN

    • Diamond / Cu

  • Improves:

    • Adhesion strength

    • Thermal cycling reliability

    • Device lifetime


4. Scalable Thin Film Integration

  • Deposition method: MPCVD / CVD

  • Wafer-scale uniformity

  • Compatible with:

    • Semiconductor back-end processes

    • Advanced packaging platforms


Typical Properties

PropertyValue RangeNotes
Grain size4 – 100 nmTunable (NCD / UNCD regimes)
Thermal conductivity800 – 1800 W/m·KProcess dependent
Young’s modulus600 – 900 GPaLower than bulk (~1050 GPa)
Elastic strain limit↑ vs. bulk diamondEnhanced recoverability
Surface roughness (Ra)< 10 nmAfter polishing
Thickness0.5 – 500 μmCustomizable

Mechanism Illustration (Conceptual)

Bulk Diamond:

  • Fully coordinated sp³ lattice

  • Maximum stiffness

  • Brittle under stress concentration

DIASEMI NCD Film:

  • Core–shell grain structure

  • Surface/grain boundary dominated

  • Reduced bond stiffness + structural relaxation

 Result:
Elastic, strain-tolerant diamond network


Applications

Semiconductor Thermal Management

  • GaN HEMT heat spreaders

  • SiC power modules

  • Advanced CPU / GPU cooling

Photonics & Laser Systems

  • High-power laser diode submounts

  • Optical window thermal stabilization

Heterogeneous Integration

  • Diamond-on-Si platforms

  • 3D integration thermal layers

  • Chiplet packaging

RF & Microwave Devices

  • High-frequency high-power modules

  • Microwave windows


Why DIASEMI NCD?

Conventional DiamondDIASEMI NCD
Ultra-stiff, brittleElastic, strain-tolerant
Interface cracking riskStress-buffering layer
Limited integration flexibilityProcess-compatible thin films

Customization Options

  • Grain size engineering (UNCD → NCD → MCD)

  • Thickness control (sub-micron to bulk-like)

  • Surface finishing (optical grade available)

  • Doping options (e.g., boron-doped for conductivity)


Summary

DIASEMI™ Nanocrystalline Diamond films introduce a new materials paradigm:

Diamond is no longer just the stiffest material — it is now an engineered, compliant, high-performance thermal platform.

By combining extreme thermal conductivity with nanoscale-enabled elasticity, DIASEMI enables reliable operation in the most demanding thermal and mechanical environments.