Electromagnetic crosstalk isolation with transferred vertically aligned carbon nanotube arrays through thermocompression bonding

As electronic devices become smaller, more powerful, and operate at higher frequencies, electromagnetic compatibility (EMC) is becoming an ever-greater challenge due to the board real estate required for their proper operation. Thus, this paper presents a solution to augment existing electromagnetic (EM) isolation solutions to increase their effectiveness and reduce their required board real estate. Carbon nanotubes (CNTs) have long been touted as a promising, electrically conductive, high aspect ratio material for use in electronics. However, their widespread use has been limited due to the harsh environments needed for their growth. This paper describes the application of an improved vertically aligned carbon nanotube (VACNT) transfer technique that circumvents this limitation. The process of transferring a carbon nanotube fence wall (CNTFW) on existing grounded via-fence structures via thermocompression bonding augments the EM isolation capability of the CNTFW using the metal coating used for the thermocompression bond, along with a post-process metal epoxy coating. The combination of augmentations possible on a transferred CNTFW structure enables an electromagnetic crosstalk isolation improvement of up to 16 dB in the frequency range from 0 to 50 GHz. The integration of such a technology allows for further downscaling of electromagnetic isolation solutions in electronic devices.