As electronic products continue to move toward higher integration and smaller form factors, thermal management has become one of the most important engineering constraints. Diamond thermal composites are attracting growing attention because they offer excellent heat transport and can be engineered across a wide range of matrices and structures.
Researchers have explored many ways to improve the thermal conductivity of these materials, including highly conductive metal matrices, larger diamond particles, higher diamond loading, and better interfacial design. Even so, phonon scattering at the diamond/matrix interface still limits real-world performance, which is why low-loading, high-efficiency design remains a major goal.
Compared with other inorganic non-metal thermal composites such as boron nitride, aluminum nitride, alumina, and silicon carbide, diamond-based systems typically deliver the highest thermal conductivity. They also offer excellent chemical stability, although brittleness and interface control still need to be managed carefully.
Main preparation routes
1. Blending: the most straightforward route, suitable when process simplicity and material flexibility are priorities, though higher filler loading is usually required.
2. Template construction: builds an oriented three-dimensional conduction network and can deliver strong performance at lower filler content, but the process is more complex.
3. Electrodeposition: useful when precise structural control is required, especially in metal-based systems.
4. Sintering: a mature route for dense bulk materials, though high temperatures and dispersion control remain important constraints.
5. Magnetron sputtering: strong for interfacial coating design thanks to good thickness control and film uniformity, but equipment cost is relatively high.
6. Chemical vapor deposition (CVD): ideal for high-purity diamond coatings and can be combined with template or three-dimensional network design.
Comparison summary
| Method | Strength | Limitation | Performance trend |
| Blending | Simple processing and flexible material choice | Interface quality and orientation are hard to control | Usually needs higher filler loading |
| Template construction | Creates oriented pathways and high-quality interfaces | Process complexity is relatively high | Can achieve high conductivity at lower filler content |
| Electrodeposition | Low-temperature route with strong structural control | Deposition rate and adhesion can limit scale-up | Well suited to coated systems and metal matrices |
| Sintering | Flexible shaping and mature process base | High temperature and high energy demand | Supports stable bulk performance with dense structures |
| Magnetron sputtering | Uniform coating and precise thickness control | Higher equipment complexity and cost | Strong for interface engineering |
| CVD | High purity and excellent coating quality | Equipment cost and throughput remain challenging | Delivers strong thermal stability and coating integrity |
Going forward, progress will depend on better interface design, more efficient three-dimensional heat pathways, and preparation routes that balance conductivity, reliability, and manufacturing cost.
