Thermally Conductive Boron Nitride Nanosheet Composite Paper as a Flexible Printed Circuit Board

Abstract

The development of portable and wearable electronic devices has substantially increased the demand for printed circuit boards with high thermal conductivity, optimal mechanical flexibility, electrical insulativity, and minimal high-frequency transmission loss. Herein, we demonstrate the fabrication of a thermally conductive, flexible composite paper, for electronic and microwave devices, based on hexagonal boron nitride nanosheets, poly­(vinyl alcohol) (PVA), and fiberglass mesh (FGM). The prepared composite paper exhibits in-plane thermal conductivity of 22.51 W/(m·K), and the FGM induced high mechanical strength of 27.92 MPa. The transmission loss, of the grounded coplanar waveguide lines, was 0.10 dB/mm at 7.0 GHz, and shows negligible variation while bending, indicating the high flexibility of the circuit board. These results demonstrate potential application of BN-based composite paper in flexible electronic devices.

Hexagonal Boron Nitride/Microfibril Cellulose/Poly(vinyl alcohol) Ternary Composite Film with Thermal Conductivity and Flexibility

“…A coupling agent [7,8] is commonly used to modify the surface of h-BN to improve its compatibility with the resin matrix. This is a complex process [9,10,11] that has been used to give h-BN a certain directivity, which improves the thermal conductivity of the material. Currently, the goal is to apply more environmentally-friendly surface treatment agents and develop easier preparation methods.…”

Advances in Studies of Boron Nitride Nanosheets and Nanocomposites for Thermal Transport and Related Applications

“…The observed TD values of the films were monotonically higher at higher BNNs loadings, and the performance was at the upper end of the levels attained by similarly fabricated PVA and other polymer nanocomposite films with BNNs from various other exfoliation methods. [137,138,[145][146][147][148][149][150][151] There have also been efforts on enhancing the in-plane thermal transport performance of polymer/BNNs nanocomposite films. [148,152,153] For example, BNNs in polyvinylidene fluoride (PVDF), PVA, and epoxy resin were aligned via electrospinning fabrication, vertical folding, and post-fabrication hot-pressing, resulting in clearly observable increases in TC values.…”

“…A major use of BNNs is in polymeric nanocomposites for thermal transport properties and others that take advantage of the mechanical and chemically stable characteristics. The focus here is on the former, [7,13–25,33,95,102,112,133,135–138,142–266] and those who are interested in the latter are referred to other reviews …”

Research on X‐Ray Inspection of Basin Insulators and Wireless Image Sensing Technology

“…Wireless sensor network low-power technology has been in a very important position in the research of wireless sensor network technology along with the development of wireless sensor network systems. At present, wireless sensor network lowpower technology has been deeply researched at home and abroad, most of which are researching and optimizing the protocol stack technology [13]. For example, the S-MAC protocol is a contention-based MAC layer protocol for sensor networks that focuses on three aspects, namely, periodic listening and sleep, conflict and crosstalk avoidance, and long message delivery, to reduce the energy consumption of the system while supporting good scalability and conflict avoidance, but its use of adaptive listening and periodic sleep leads to reduced system throughput and increased latency [14].…”