Graphite is a carbon-based mineral with extreme properties. It is the most stable form of carbon under standard operating conditions with high thermal stability and electrical and thermal conductivity. These natural properties make graphite an ideal solution for managing extreme heat in many different formats.
Graphite thermal heat spreaders are ideally suited for thermal spreading and shielding applications in minimal dimensional space with very high in-plane thermal conductivity in an ultra-lightweight format. Graphite heat spreaders are available in two principle formats: exfoliated flake natural graphite and pyrolytic graphite. Exfoliated flake natural graphite is mined as graphite ore, processed and calendared to varying thicknesses with a thermal conductivity performance range of 300 W/mK to 600 W/mK and a thickness range from 0.04mm to >1mm. Pyrolitic graphite is derived from a carbonized polymer and calendared to extraordinarily thin sheets. Thermal conductivity is very high, ranging between 1000 W/mK to >1500 W/mK with thickness down to 0.017mm.
These ultra high performing thermal management solutions are ideal for:
- Lowering the temperature of hot components, decreasing the overall power consumption of a device
- Shielding sensitive components from hot spots, increasing device lifetime
- Evenly distributing surface temperature of a device, controlling touch temperature and improving the user experience
- Shielding sensitive components, like OLED displays, from hot spots and overheating, improving the performance and longevity of consumer devices.
Graphite sheet thermal spreaders offer 10X the thermal conductivity of stainless steel and as much as 5X that of copper. It is anisotropic, meaning it is much more thermally conductive in-plane than through-plane, as well as flexible. With it's lightweight and compact format, it is ideally suited for demanding heat management in tightly controlled spaces like mobile phones, tablets, wearable devices, displays, consumer electronics, medical electronics, lighting and generally devices with space constraints and high thermal needs. Flexible graphite sheet is a challenging material to work with - it is relatively soft and flakey - which makes it difficult to manufacture and design into end products with cleanliness requirements or expectations. Boyd Corporation is an expert converter of the brittle material with decades of experience in high tolerance, high volume manufacturing technologies customized for this specialty solution. Add in our ability to design end configurations that exploit the excellent performance of the material while containing and controlling its flakey, brittle nature in an end configuration that is optimized for final assembly efficiency and ease of handling, Boyd is the foremost expert in designing flexible graphite sheet thermal solutions from both synthetic and natural graphite sheet materials.
Aavid’s patented k-Core® technology utilizes encapsulated graphite that enables high performance cooling for aerospace, military, and commercial applications. Annealed Pyrolytic Graphite is inserted within an encapsulating structure that can be fabricated with a number of thermally conductive materials such as aluminum or copper alloys, ceramics, or composites depending on application requirements. This results in a light weight, highly conductive heat spreader that allows engineers to tailor the coefficients of thermal expansion (CTE) as needed. Due to its flexibility in materials and construction, k-Core® technology can easily replace traditional solid metal conductors or heat spreaders to substantially improve heat transfer and cooling.
Because of its low mass, k-Core® technology is used in aerospace satellites, avionics, and military aircraft such as the F-35, F-22 and F-16 fighter planes. k-Core® Technology thermal management products also cool high power density electronic packaging, power electronics and other applications requiring high-performance heat transfer.
The k-Core® Product Line
•Patented encapsulated Annealed Pyrolytic Graphite technology that has three times the conductivity of copper with the mass of aluminum
•Annealed Pyroloytic Graphite provides a high conduction path
•Encapsulant sets the CTE and structural properties
•Encapsulant material is selected to satisfy requirements
•Drop-in replacement for conventional conduction solutions
Graphite Flexible Sheet
•Suited for thermal spreading and shielding applications
•High in-plane thermal conductivity 300 W/mK to >1500 W/mK
•Minimum graphite thickness 0.017mm
•Minimum aggregate thickness with adhesive and protective film 0.0275mm
•Natural and synthetic options
•5X the thermal conductivity of copper
•Very high thermal diffusivity