High Voltage Electrical Properties of Epoxy / h-BN Microcomposites

• Published in: 2018 IEEE 2nd International Conference on Dielectrics (ICD) pp. 1 - 5
• Main Authors: DESMARS, Loriane, GALY, Jocelyne, BACHELLERIE, Damien, CRISTIANO-TASSI, Antonella, HALLER, Servane, PRUVOST, Sebastien
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01-07-2018
• Subjects: AC breakdown strength; Conductivity; DC conductivity; Dielectrics; Electric breakdown; Electric fields; electrical conduction mechanisms; Electrodes; epoxy composites; hexagonal boron nitride; High-voltage techniques; Thermal conductivity
• DOI: 10.1109/ICD.2018.8514777

Two high voltage properties - DC conductivity and AC breakdown strength - of epoxy composites filled with 30 wt% of micron sized hexagonal boron nitride (h-BN) are discussed in comparison to neat epoxy. The influence of h-BN upon the field dependence of DC conductivity has been studied up to 18 kV/mm. The addition of h-BN does not lead to a modification of limiting conduction mechanisms: the J-V characteristics show an ohmic behavior at low fields and a space charge limited current (SCLC) at higher fields for both neat epoxy and composite. However, the addition of 30 wt% h-BN reduces the overall electrical conductivity and increases the threshold voltage between ohmic and SCLC regions, leading to a significant modification of electrical conductivity within the field range compared to neat epoxy. AC breakdown strength is enhanced for epoxy-h-BN composites while generally speaking the addition of micro fillers in an epoxy matrix tends to decrease it.