Conductive Compounds

UV-3201
UV Curable Screen Printable
Dielectric Coating

UV-3201 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. UV-3201 is designed for high temperature applications up to 130°C. High strength and toughness also make this material an excellent candidate for encapsulating electronic components or providing environmental protection to sensitive components. Cured UV-3201 will withstand extreme thermal shock cycling, from +200°C to well below -50°C, and maintains its electrical integrity over a wide temperature and frequency range. UV-3201 can be cured with UV light in seconds, allowing for high speed production.

TYPICAL PROPERTIES (Uncured Liquid) Appearance Clear or Colored Thixotropic Liquid
Viscosity, Brookfield RVT @ 25°C
#7, 2.5 rpm 22,400 cps
#7, 10 rpm 12,400 cps
#7, 100 rpm 8,320 cps
Weight Per Gallon @ 25°C 9.7 lbs.
Specific Gravity @ 25°C 1.17
Flash Point, PMCC >212°F (100°C)
Shelf Life @ 25°C 2 Years

TYPICAL CURED PROPERTIES

Mechanical Properties Shrinkage On Cure (Volumetric) 4.5%
Tensile Strength 2,100 psi
% Elongation 17%
TG by DMA (Dynamic Mechanical Analysis) 53°C
Electrical Properties Volume Resistivity @ 25°C 1.2 x 1014-cm
Surface Resistivity @ 25°C 5.0 x 1015/Square
Dissipation Factor, 60 MHZ, @ 25°C 0.027
Dielectric Constant @ 25°C 3.62

APPLICATION METHODS:

UV-3201 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 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 materials do not allow shorting between conductive paths. It is recommended that two layers of UV-3201 be applied in order to assure that any pinholes or defects are eliminated. After screening the first later of UV-3201, it should not be cured completely in order to allow for optimal chemical bonding between the two layers when the second layer of UV-3201 is screened. After screening and curing two layers of UV-3201 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-3201, be sure to reset the line speed and lamp density to allow for complete curing.

METHOD OF CURE:

UV-3201 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 vapor (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 typical 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.