Volume Electrical Resistivity

Retaining a high electrical volume resistivity in the presence of moisture is one of the most important properties of moulding powder resin systems which are used for the encapsulation of electronic components. 

Electrical and Chemical. Oven aging at ISO C for 26 days had no effect on the electrical volume resistivities of either FVF or EVA films. Both maintained 10 J2-cm (see Table IV). The plFVB increased from 10 il-cm to 10 J2-cm in four days due to the evolution of plasticizer and absorbed water. Both plasticizer and absorbed water in plFVB cause its low initial volume resisitivity. Low volume resistivity material used in a photovoltaic panel can cause electrical current leakage (1.). BAgMMA decreased from 10 n-cm to 10 5 in 10 days. 

To obtain the lowest electrical volume resistivities (in the 10 to 10 ohm-cm range) and the lowest contact resistances, polymer resins must be highly Ailed with 70-80% by weight (25-30% by volume) of metal particles and must be thoroughly cured. Silver and silver alloys are the most widely used fillers but, in specific applications, other metal fillers including gold, copper, nickel, and even carbon are used. Carbon-filled polymers are often used to dissipate static electricity or to protect from electromagnetic interference (EMI). 

Figure 7.8 Electrical volume resistivity and agglomerate area ratio as a function of the SME for polyamide 6 composites containing 5 wt% NanocyF NC7000 (adapted from Krause et al. ).

Figure 7.9 Electrical volume resistivity and agglomerate area ratio Ap as a function of SME for PC composites filled with 1 wt% Baytubes C150HP prepared at different processing conditions (adapted from Kasaliwal et aV).

PC matrix viscosity at 100 rad s, 280 °C ( without CNTs) (Pas) SME input (kWh kg- ) CNT length X value (nm) Electrical volume resistivity (Q cm) Agglomerate area ratio (%)... 

Electr. volume resistance Plastics 10 -10 K with metal powder 1 Qcm... 

The mechanical and electrical properties of acrylates are similar to those for many other polymer types. Tensile strengths range from approximately 1,300 psi to 4,500 psi and shear strengths of PCB lap samples range from 424 to 566 psi. Aluminum-to-aluminum lap-shear strengths are reported at approximately 3,000 psi. Electrical volume resistivities under room ambient conditions ranged from 1 x ohm-cm to 1.4 x 10 ohm-cm. dielectric constants from 3.15 to 3.43 at 10 MHz and dissipation factors... 

Electrical volume resistivity of PP and PP/MWCNT nanocomposites. (Reprinted from Seo, M.K. and Park, S.J., Chem. Phys. Lett., 395,44,2004.)... 

Max. continuous temperature of use Coefficient of linear thermal expansion Thermal conductivity Oxygen Index Electrical volume resistivity... 

Max. continuous temperature of use Coefficient of linear thermal expansion Thermal conductivity Oxygen Index Electrical volume resistivity Processing Mold shrinkage Drying temperature Drying time Mold temperature Melt temperature Dimensional stability Trade names Elf Atochem Kynar 460 Solvay Solef 1000 series... 

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