Objectives of the Smartherm project

The objective of SMARTHERM project is to build up a pilot production line for high-performance thermal interface materials (TIMs) based on functionalized carbon nanotubes (CNTs) .

We are aiming to demonstrate the pilot production of the vertically aligned CNT based TIMs with high through-put at industrial scale to meet the requirement on thermal management for future high-packaging-density microsystems.

Thermal interface materials are used as bonding materials when heat must be transferred through an interface. An interface resistance arises from the lack of intimate contact between two surfaces with given roughness. Thermal interface materials exhibit mechanical compliance and a high thermal conductivity in order to reduce this resistance. They however still represent a thermally resistive point in the path dedicated to the evacuation of the heat from where it is produced (the device or component) to the location where it is dissipated (the heat sink).

High performance TIMs decrease the temperature in the device, result in higher reliability, higher power handling or lower thermal architectures costs.

Carbon nanotubes are carbon based nanostructures in the form of a tube about 10,000 times thinner that a human hair. They attract interest since the discovery of their outstanding properties. These nanostructures indeed exhibit a very peculiar set of thermomechanical performances (among others); they are extremely resistant but flexible and exhibit an extremely high thermal conductivity.

Growth processes allow the formation of dense mats in which CNTs are grown aligned perpendicular to the substrate. This spontaneous organization results in a thermal interface in which CNTs are aligned in the direction of the heat flow. VACNT TIMs form an array of dense nano-channels through which the heat is very efficiently transferred between the two surfaces.

The challenge of bringing this TIM to market is addressed by a complementary consortium gathering the competencies needed to achieve this goal.

• High quality carbon nanotubes on large area substrates, for high quality, high throughput synthesis of materials.
• Organic and composite material engineering, to develop the implementation process of these CNTs in thermal interfaces.
• Cutting edge thermal characterization methods, to assess CNT quality (quality control) and perform testing of the thermal interfaces at the preproduction stage (definition and assessment of the pilot line), and in the final devices (non-destructive testing)
• Microelectronic implementation know-how and production means, to ensure the development of specific process guaranteeing performance and reliability of the thermal architectures.