A unique consortium has been formed between industry-leading companies and academic institutes to introduce Graphene into advanced printed circuit boards.
Graphene is a phenomenal 2D material made out of carbon hexagons. Despite its monoatomic thickness, it is extremely strong and has better electrical conductivity than that of metals. This attractive material can be deposited on copper, which is the metal of choice for PCBs, by chemical vapor deposition using methane as a precursor. Graphene/Cu stacks can then be integrated into standard PCB processing to form advanced circuits. Due to its 2D structure and high charge mobility, Graphene improves the circuit performance at high frequency, which is relevant for both RF systems - such as airborne and automotive radars, as well as for high-speed digital circuits used for 5G communication.
Another exceptional property of Graphene is its thermal conductivity, which is 5 times higher than that of copper. This property enables significant improvements in heat dissipation, which is critical for an analog high-power devices such as amplifiers and transmitters. Graphene can be included in circuits not only as a layer – Graphene platelets can be mixed into hole-filling epoxy pastes thus improving the heat conduction of non-plated vias. A fine balance is needed in this case between Graphene and epoxy since a high percentage of the Graphene in the mix results in an electrically-conductive paste.
The challenge in working with Graphene is finding a way to include the material on Cu layers without harming its chemical nature by standard processing. As an example, Graphene is not resistant to strong oxidizing agents, such as those critical for surface preparation before drill-hole coating. Exposed Graphene can contaminate electrodeposition baths with carbon or lose its desired properties due to mechanical damage from handling.
So far researchers have managed to drill, press, and plate holes in Graphene-including circuits, which makes the next phase of Graphene patterning look promising. This work is done in close collaboration with Prof. Doron Naveh (Bar Ilan University), Prof. Oren Regev, and Prof. Gennady Ziskind (both from Ben-Gurion University).
Publisher: PCB Directory