Conductive Compounds

UV-2507 is a 100% solids, UV curable screen printable material which has outstanding adhesion to print treated polyester films, conductive inks and copper used in flexible circuits and membrane switches. High strength, toughness and outstanding flexibility make this material an excellent candidate for screen printed dielectric layers in membrane switch crossover and tail areas. Cured UV-2507 will withstand extreme thermal shock cycling, from +150°C to well below -50°C and maintains its electrical integrity over a wide temperature and frequency range. UV-2507 can be cured with UV light in seconds, allowing for high speed production. UV-2507 is compatible with AG-800 silver filled conductive ink; EP-600, EP-900 and EP-1000 silver epoxies and UV-3010 encapsulant

TYPICAL PROPERTIES (Uncured Liquid)

Appearance: Clear or coloured Thixotropic Liquid
Viscosity, Brookfield RVT @ 25°C #5, 10 rpm: 13,000 cps
Weight per Gallon @ 25°C: 9.5 1bs
Specific Gravity @ 25°C: 1.14
Flash Point, PMCC: >212°F (100°C)
Shelf Life @ 25°C: 6 Months

TYPICAL CURED PROPERTIES

MECHANICAL PROPERTIES

Shrinkage on Cure (Volumetric): 3%
Tensile Strength: 1,700 psi
% Elongation: 15%
Tg by DMA (Dynamic Mechanical Analysis): 47°C

ELECTRICAL PROPERTIES

Volume Resistivity @ 25°C: 1.2 x 10 14 ohm-cm
Surface Resistivity @ 25°C: 5.0 x 10 15 ohm/Square
Dissipation Factor 60 Hz, @ 25°C: 0.027
Dielectric Constant @ 25°C: 3.62

APPLICATION METHODS:

UV-2507 can be applied by screen printing using stainless steel or monofilament polyester screens from 305 to 390 mesh, with emulsion thicknesses from .001" to .003". For thicker coatings, use smaller mesh sizes and thicker emulsions. A polyurethane squeegee with a shore 'A' durometer between 60 and 70 is recommended. Other conventional methods of application include dip, roll or knife over roll coating, curtain coating or die application. The excellent pot life and UV cure mechanism allow for the heating of the material to precisely control viscosity for consistent application weights.

When using this material as a screen printed dielectric for membrane switches and other additive circuits, it is essential to make sure that pinholes and contamination in the cured material do not allow shorting between conductive paths. It is recommended that two layers of UV-2507 be applied in order to assure that any pinholes or defects are eliminated. After screening the first layer of UV-2507, it should not be cured completely in order to allow for optimal chemical bonding between the two layers when the second layer of UV-2507 is screened. After screening and curing two layers of UV-2507 on a test substrate, perform a cross hatch/tape adhesion test. If you find that the two layers of dielectric are separating from each other, then the UV lamp density needs to be reduced for curing the first layer or the line speed needs to be increased for curing the first layer so that it is slightly undercured. Before screening the second layer of UV-2507, be sure to reset the line speed and lamp density to allow for complete curing.

METHOD OF CURE:

UV-2507 must be exposed to ultraviolet light of the proper wavelength to activate the curing mechanism. This can be done with any ultraviolet light source which puts out wavelengths of <380 nanometers. The most common commercial light source is the medium pressure mercury vapour (MPMV lamps), electrode or microwave activated arc, with or without spectral enhancement (doped). Cure can also be accomplished with xenon or carbon arc lamp sources, UV lasers or electron beam sources. These sources are available in increasing arc lengths and varying intensities for specific applications from a large number of manufacturers.

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NOTE: Although the above properties are accurate to the best of our knowledge Conductive Compounds Inc makes no guarantees for customer specifications established in applications where this product is used. Customer assumes responsibility for determining fitness of use in their particular application.