TY - JOUR
T1 - Nano-enabled metal oxide varistors
AU - Tan, Daniel Qi
AU - Younsi, Karim
AU - Zhou, Yingneng
AU - Irwin, Patricia
AU - Cao, Yang
N1 - Funding Information:
The authors would like to thank Bob Radtke of GE License for his financial support to this work. Consulting work of Manu Haddad from Cardiff University and assistant work of Baojun Chu from Penn State University are greatly acknowledged.
PY - 2009/8
Y1 - 2009/8
N2 - Zinc oxide based metal oxide varistors (MOV) are widely used electrical surge protection components. The design of modern high power, high-density electronic systems necessitate the need for smaller footprint, higher current density and higher nonlinearity MOVs. Such requirements can no longer be satisfied by commercially available MOVs due to their limited voltage capability, high leakage current and mechanical cracking related reliability issues, most of which are associated with the presence of defects and coarse granularity and lack of uniformity in their microstructures. New formulations and processes have been developed to overcome such limitations. This work has developed nano-enabled MOV compositions that can be sintered at relatively lower temperatures than typical commercial MOVs, but with largely improved I-V characteristics due to refined and uniform sub-micron structures. These nano-enabled MOVs show not only high breakdown strength (1.5 kV/mm) with low leakage current, but also a large nonlinear alpha coefficient > 50 at high fields, a measure of the speed of the transition from the insulating to conducting state and the effectiveness of over-voltage protection. A > 10x increase in breakdown strength compared to commercial MOVs, along with much higher nonlinearity, will enable MOV miniaturization, high voltage surge protection, and open up new areas of application.
AB - Zinc oxide based metal oxide varistors (MOV) are widely used electrical surge protection components. The design of modern high power, high-density electronic systems necessitate the need for smaller footprint, higher current density and higher nonlinearity MOVs. Such requirements can no longer be satisfied by commercially available MOVs due to their limited voltage capability, high leakage current and mechanical cracking related reliability issues, most of which are associated with the presence of defects and coarse granularity and lack of uniformity in their microstructures. New formulations and processes have been developed to overcome such limitations. This work has developed nano-enabled MOV compositions that can be sintered at relatively lower temperatures than typical commercial MOVs, but with largely improved I-V characteristics due to refined and uniform sub-micron structures. These nano-enabled MOVs show not only high breakdown strength (1.5 kV/mm) with low leakage current, but also a large nonlinear alpha coefficient > 50 at high fields, a measure of the speed of the transition from the insulating to conducting state and the effectiveness of over-voltage protection. A > 10x increase in breakdown strength compared to commercial MOVs, along with much higher nonlinearity, will enable MOV miniaturization, high voltage surge protection, and open up new areas of application.
KW - Metal oxide varistor, ZnO, Nano, breakdown voltage, sintering, surge protection, grain boundary, I-V characteristics.
UR - http://www.scopus.com/inward/record.url?scp=70249149752&partnerID=8YFLogxK
U2 - 10.1109/TDEI.2009.5211836
DO - 10.1109/TDEI.2009.5211836
M3 - 文章
AN - SCOPUS:70249149752
SN - 1070-9878
VL - 16
SP - 934
EP - 939
JO - IEEE Transactions on Dielectrics and Electrical Insulation
JF - IEEE Transactions on Dielectrics and Electrical Insulation
IS - 4
M1 - 5211836
ER -