Master Bond Launches EP3UF-1 Underfill Epoxy with Dielectric Constant of 4.5

Press Release Summary:

The EP3UF-1 Thermally Conductive Underfill Epoxy is offered in 10 cc syringes and 30 cc syringes. The product features viscosity of 5,000-15,000 cps, compressive strength of 18,000-20,000 psi and tensile modulus of 450,000-500,000 psi. The compound exhibits thermal conductivity and resistance of 1.30-1.44 W/(m•K) and 5-7 x 10-6 K•m²/W respectively. The epoxy cures in 20-30 minutes at 250°F, or in 10-15 minutes at 300°F and is suitable for underfill and bonding applications.

Original Press Release:

Low Viscosity, Thermally Conductive Underfill Epoxy

Master Bond EP3UF-1 is a new single component epoxy that is not premixed and frozen. Due to its low viscosity of 5,000-15,000 cps, this heat curable thixotropic compound is ideal for underfill and many bonding applications. EP3UF-1 delivers high bond strength and dimensional stability with a compressive strength of 18,000-20,000 psi and a tensile modulus of 450,000-500,000 psi.

EP3UF-1 has a thermal conductivity of 9-10 BTU•in/ft²•hr•°F [1.30-1.44 W/(m•K)], making it an effective thermal interface material. It contains a special filler with a small particle size. This allows it to be applied in bond lines as thin as 10-15 microns imparting a low thermal resistance of 5-7 x 10-6 K•m²/W. It offers superior electrical insulation with a low dielectric constant of 4.5 at 60 Hz as well as a high dielectric strength of 450 volts/mil (for 1/8” thick test specimen), both measured at 75°F.

As a single component system, EP3UF-1 is more convenient to handle, apply and store than typical two component adhesive systems. It has an unlimited working life at room temperature and cures in 20-30 minutes at 250°F, or in 10-15 minutes at 300°F. EP3UF-1 is available for use in 10 cc syringes and 30 cc syringes, which are compatible with automated dispensing systems.

Master Bond Adhesives for Electronic Applications

Well suited for underfill applications, Master Bond EP3UF-1 is a one part, low viscosity epoxy adhesive that cures rapidly at elevated temperatures. It offers thermal conductivity, electrical insulation and dimensional stability. Read more about Master Bond’s adhesives for electronics packaging and assembly at or contact Tech Support. Phone: +1-201-343-8983 Fax: +1-201-343-2132 Email:

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James Brenner, Marketing Manager
Tel: +1-201-343-8983
Fax: +1-201-343-2132

154 Hobart Street 
Hackensack, NJ 07601-3922

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