Polycrystalline diamond (PCD) belongs to wide band gap materials group. It has properties similar to single crystal diamonds (SCD), including exceptional thermal conductivity, high electron mobility, and high power capacity. These properties make it an excellent materials in improving the reliability and enhancing the power density while reducing the size of the power devices. The main differences between PCD and SCD are that PCD has slightly lower thermal conductivity compared with SCD; however, it is more commonly used in industry due to the lower cost and availability in large size. It is used in various applications, including heat spreader, cutting tool, epitaxy substrate, and power electronics. For example, researchers at University of Bath grow epitaxial GaN films on a polycrystalline diamond wafer for high power application resulting in a promising solution for heat dissipation problem.

Specification:

Size	Customized
Thickness	0.1 ~ 0.5mm
Thickness Tolerance	± 5%
Bulk Resistivity	10¹²ohm.cm
Surface Resistivity	10¹⁰ ohm.cm
Thermal Conductivity	1000 ~ 2200W/m.K
Thermal Diffusivity at 300K	> 8.3cm²S^-1/ > 10cm²S^-1
Surface Finish	Single Side Polished / Double Side Polished
Polished Side Surface Roughness	Ra < 1nm / Ra < 0.5nm (Customizable upon request)
Unpolished Side Surface Roughness	Ra < 50nm
TTV	< 15μm
Bow	< 30μm
Quantity	1 piece

*The figure is for reference only. The actual product may look different due to configuration difference.

References:

1. Wafer-sized polycrystalline diamond photodetector planar arrays for solar-blind imaging. Journal of Materials Chemistry C (2022).

2. Diamond FET using high-quality polycrystalline diamond with f T of 45 GHz and f max of 120 GHz. IEEE Electron Device Letters 27, no. 7 (2006): 570-572.

3. Diamond as the heat spreader for the thermal dissipation of GaN-based electronic devices. Functional Diamond 1, no. 1 (2022): 174-188.

4. Growth of GaN epitaxial films on polycrystalline diamond by metal-organic vapor phase epitaxy. Journal of Physics D: Applied Physics 50, no. 16 (2017): 165103.