Conductive Compounds

EP-900
Silver Filled Electrically Conductive
Two Part Component Epoxy Adhesive

EP-900 is a unique, one part electrically conductive epoxy adhesive used for component attachment, termination and other applications in hybrid circuits, membrane switches and other electromechanical assemblies. The rheology of EP-900 make it an ideal material for screen or stencil printing. EP-900 exhibits excellent adhesion to most metal and plastic substrates and has excellent temperature resistance and toughness. EP-900 is available in pre-weighed and sealed plastic pouches, open containers or plastic syringes. For dot dispense processes, EP-1000 single component or EP-600 two component adhesives are recommended.

TYPICAL PROPERTIES

Appearance: Thixotropic Silver Coloured Paste
Viscosity (Room Temperature): 75,000 to 100,000 cps
Shelf Life (Ambient Temperature): 30 Days in unopened container
Hegman Gage: <100 µ
Volume Resistivity (ref ASTM D-257): <5.0 x 10 -4 ohm-cm
Coefficient of Thermal Expansion:
Below Tg 6.0 x 10 -5 in/in/°C
Above Tg 1.5 x 10 -4 in/in/°C
Thermal Conductivity: 11 BTU in/ft² hr °F
Glass Transition Temperature (TMA): 110°C (Fully Cured)
Operating Temperature Range: -55°C to +175°C Continuous Intermittent at higher temperatures when fully cured.

Curing Schedule (Time at Temperature)/ 90% Cure/Complete Cure
120°C/ 5 minutes/ 15 minutes
140°C/ 3 minutes/ 5 to 7 minutes

At 90% cure, the assembly can generally be handled carefully without the danger of damaging the adhesive bond. EP-900 will not continue to cure at room temperature once heat is removed. Cure times above are intended as guidelines and are dependent on the actual glue line being held at the given temperature.

APPLICATION GUIDELINES

For screening, a monofilament polyester (157 to 200 mesh) or a stainless steel (165 to 270 mesh) screen is recommended, with emulsion thickness between .001" and .003". A polyurethane squeegee with a Shore 'A' durometer between 60 and 70 is recommended. Stencil thickness of .001" to .003" are recommended.

In general, a more open screen with thicker emulsions, or a thicker stencil will give a larger pad of adhesive for bonding devices. However, thinner emulsions and stencils provide thinner pads that are less susceptible to wicking and shorting out during high temperature curing - especially with smaller surface mounted devices. EP-900 can be thinned with solvent. Contact us for samples of non-toxic, non flammable solvent appropriate for thinning.

Because EP-900 has a shelf life of 30 days at room temperature, the rheological properties allow for accurate and repeatable pad geometries over long production runs. While the viscosity of the mixed material will change gradually over the 30 day storage window, most application equipment can easily compensate for the rheological changes to accuragely maintain pad configuration.

PACKAGING

EP-900 is available in pre-weighed open containers, plastic pouches and EFD type syringes. There is no minimum purchase quantity with the open container packaging option. Contact us for more information about plastic pouch or EFD type syringe packaging configurations.

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The above guidelines are intended to provide a starting point for evaluation. Conductive Compounds Inc recognises that each customer's manufacturing process is unique and we can customise the rheology and curing properties of EP-900 to conform more closely to your process parameters. Call us to discuss your application in more detail.

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.