TY - GEN
T1 - High frequency characteristics of nanocomposite thin film "Supercapacitors" and their suitability for embedded decoupling
AU - Raj, P. Markondeya
AU - Balaraman, Devarajan
AU - Govind, Vinu
AU - Wan, Lixi
AU - Abothu, Robin
AU - Gerhardt, Rosario
AU - Bhattacharya, Swapan
AU - Swaminathan, Madhavan
AU - Tummala, Rao
PY - 2004
Y1 - 2004
N2 - Embedded decoupling capacitor problem has been pursued by several groups and industry around the world over the past decade. Currently popular ceramic-polymer composites can only provide limited capacitance, typically within 10 nF/cm 2. With the reliability and processing constraints imposed, the capacitance density would be much lower. Newer capacitor concepts such as supercapacitors can overcome the limitations of existing polymer based capacitors and are now being considered by some groups. These concepts rely on nanostructured electrodes for high surface area per unit volume resulting in ultrahigh capacitance densities and unconventional polarization mechanisms such as electrical double layer and interfacial polarization. Supercapacitive structures lead to ultrahigh capacitance densities of the order of 100s of microfarads. However, manufacturers report that the properties are unstable at high frequencies, typically even at 10s of MHz. To adapt these structures for mid-to-high-frequency decoupling, it is hence essential to systematically characterize the high frequency dielectric properties of the thin nanocomposite films and nanostructured electrodes. This work reports complete electrical characterization of a part of such system, carbon black-epoxy nanocomposites. The high-frequency properties of the cured films were evaluated with a multiline calibration technique by measuring s-parameters of transmission lines fabricated on the top of the dielectrics. Though the nanostructured carbon black epoxy composites showed high dielectric constant of 1000 at low frequencies, the high frequency (0.5-4.5 GHz) dielectric constant was found to be only up to 10X that of the base polymer matrix. The measured dielectric constant at GHz frequencies increased from 15-30 when the filler content was increased from 3.8 % to 6.5 %, with excessive leakage currents. Based on these measurements, conduction and polarization relaxation mechanisms will be assessed and the suitability of the thin film supercapacitors for high-frequency decoupling applications will be discussed.
AB - Embedded decoupling capacitor problem has been pursued by several groups and industry around the world over the past decade. Currently popular ceramic-polymer composites can only provide limited capacitance, typically within 10 nF/cm 2. With the reliability and processing constraints imposed, the capacitance density would be much lower. Newer capacitor concepts such as supercapacitors can overcome the limitations of existing polymer based capacitors and are now being considered by some groups. These concepts rely on nanostructured electrodes for high surface area per unit volume resulting in ultrahigh capacitance densities and unconventional polarization mechanisms such as electrical double layer and interfacial polarization. Supercapacitive structures lead to ultrahigh capacitance densities of the order of 100s of microfarads. However, manufacturers report that the properties are unstable at high frequencies, typically even at 10s of MHz. To adapt these structures for mid-to-high-frequency decoupling, it is hence essential to systematically characterize the high frequency dielectric properties of the thin nanocomposite films and nanostructured electrodes. This work reports complete electrical characterization of a part of such system, carbon black-epoxy nanocomposites. The high-frequency properties of the cured films were evaluated with a multiline calibration technique by measuring s-parameters of transmission lines fabricated on the top of the dielectrics. Though the nanostructured carbon black epoxy composites showed high dielectric constant of 1000 at low frequencies, the high frequency (0.5-4.5 GHz) dielectric constant was found to be only up to 10X that of the base polymer matrix. The measured dielectric constant at GHz frequencies increased from 15-30 when the filler content was increased from 3.8 % to 6.5 %, with excessive leakage currents. Based on these measurements, conduction and polarization relaxation mechanisms will be assessed and the suitability of the thin film supercapacitors for high-frequency decoupling applications will be discussed.
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M3 - Conference contribution
AN - SCOPUS:28544450825
SN - 0780388216
SN - 9780780388215
T3 - Proceedings of 6th Electronics Packaging Technology Conference, EPTC 2004
SP - 154
EP - 161
BT - Proceedings of 6th Electronics Packaging Technology Conference, EPTC 2004
A2 - Toh, K.C.
A2 - Mui, Y.C.
A2 - How, J.
A2 - Pang, J.H.L.
T2 - 6th Electronics Packaging Technology Conference, EPTC 2004
Y2 - 8 December 2005 through 10 December 2005
ER -