High‐Throughput Screening Enables Ultrathin and High Thermal Conductivity All‐Carbon Graphene Foam Thermal Interface Materials

Why It Matters

The material provides a scalable, high‑temperature TIM solution that mitigates thermal bottlenecks as chip power density rises, enabling thinner, more efficient cooling stacks and improved system reliability.

Key Takeaways

• PMMA microsphere templating creates interconnected graphene network
• Thermal diffusivity reaches 608 mm²/s in‑plane, 51.8 mm²/s through‑plane
• Contact resistance drops to 0.104 K·cm²/W at 40 psi
• Bond line thickness thins to 29 µm, cutting pad size
• Stable operation up to 300 °C surpasses polymer TIM limits

Pulse Analysis

The relentless rise in power density of modern processors has turned thermal management into a primary design constraint. Conventional thermal interface materials (TIMs) based on polymer matrices struggle to dissipate heat efficiently, especially beyond 230 °C, and their in‑plane conductivity is limited. Graphene, with its exceptional intrinsic thermal conductivity, offers a promising alternative, yet integrating it into a mechanically robust, ultrathin form factor has remained elusive. The new all‑carbon graphene foam addresses these gaps by delivering both high in‑plane and through‑plane heat transport while remaining chemically stable at elevated temperatures.

The researchers employed poly(methyl methacrylate) (PMMA) microspheres as sacrificial templates, enabling a high‑throughput screening workflow guided by finite‑element simulations. During pyrolysis, the PMMA decomposes, releasing CO that cleans oxygen‑functional groups from graphene oxide and generates a porous carbon scaffold. This process establishes continuous thermal pathways in both directions and creates an acidic environment that promotes epoxy ring‑opening, further bonding the graphene network. The resulting foam exhibits through‑plane diffusivity of 51.8 mm²/s, in‑plane diffusivity of 608.6 mm²/s, contact resistance of 0.104 K·cm²/W at 40 psi, and a bond‑line thickness of just 29 µm.

Such performance opens the door for ultrathin, high‑temperature TIMs in power electronics, automotive power modules, and data‑center servers where operating temperatures can exceed 250 °C. By shaving microns off the bond line and delivering a 16 °C temperature reduction versus commercial pads, system designers can achieve higher power envelopes without redesigning cooling hardware. The scalable templating approach also suggests that other carbon‑based architectures could be mass‑produced, accelerating the shift toward all‑carbon thermal solutions across the semiconductor supply chain.