Large‐scale plasma grafts voltage stabilizer on hexagonal boron nitride for improving electrical insulation and thermal conductivity of epoxy composite

Abstract

Better electrical insulation and thermal management are both urgently required in integrated power semiconductors. Electrical insulation epoxy encapsulation suffers from poor heat conduction, which has increasingly become a bottleneck of power semiconductors integration. Although incorporating high thermal conductivity ceramics, such as hexagonal boron nitride (hBN), aluminium nitride etc. into epoxy promotes the thermal conductivity, the eco‐friendly scalable fabrication of these composites with sufficient electrical breakdown strength remains a formidable challenge. Suitable voltage stabilizers are known to provide additional benefits to breakdown strength. Herein, a high‐throughput approach combining plasma with roll‐to‐roll was developed. The voltage stabilizer (acetophenone) was grafted on interfaces between hBN and epoxy matrix through plasma. The high‐energy electrons are consumed by the grafted interface, which leads to the significant suppression of partial discharge in Epoxy/hBN. Meanwhile, interfacial phonon scattering is repaired by grafting. Therefore, the epoxy composite concurrently exhibits improved breakdown strength (by 27.4%) and thermal conductivity (by 142.9%) at about 11.9 wt.% filler content, outperforming the pure epoxy. Consequently, a promising modification strategy for mass production is provided for the encapsulation materials in various high‐power‐density semiconductor devices.

Superior Surface-Insulated Polymers with Low Leakage Current Enabled by Tailored Coatings Deposited with Colliding Plasma Jets

“…The Schottky barrier height of the copper–polymer interface can be obtained according to the electron affinity. To compare the electron affinity of PTFE, PI, epoxy, TiO 2 , SiO 2 , and SiO 2 /TiO 2 composites in the work, the corresponding infinite molecular chain and crystal model were established based on previous work, ,, and density functional theory simulation was carried out through CASTEP. Geometric optimization and final energy calculation were performed using the generalized gradient approximation (GGA) with Perdew–Burke–Ernzerhof (PBE) for the exchange-correlation function.…”

“…During the surface charge measurement, the temperature and relative humidity were kept at 296 K and 40%, respectively. Isothermal surface potential decay (ISPD) was conducted for gas side surface charge injection measurement (as shown in Figure S4), and its principle is the same as our previous work . Specific test settings are described in the Supporting Information.…”

“…Isothermal surface potential decay (ISPD) was conducted for gas side surface charge injection measurement (as shown in Figure S4), and its principle is the same as our previous work. 26 Specific test settings are described in the Supporting Information.…”

Modulating sparks in a pulse train for repetitive and energy efficient plasma generation

“…Compared with arc discharges, active species can produce more energy efficiently through the rich non-equilibrium chemical processes in spark plasma. The unique features of spark discharge plasma have attracted increasing attention from the community of ignition and combustion [2][3][4][5], flow control [6,7], surface treatment [8][9][10], energy conversion [11][12][13], high-voltage switch design [14,15], laser ignition [16,17], and material engineering [18,19].…”

A novel high‐voltage solid‐state switch based on the SiC MOSFET series and its overcurrent protection

“…Pulse power technology has developed rapidly, and its application fields have been continuously expanding and widely applied in biomedicine [1][2][3][4][5], plasma material processing [6][7][8], high-power power supplies [9], accelerator [10], and other fields [11][12][13]. As one of the core devices of pulsed power systems, switching devices have received much attention.…”