Master Bond EP42HT-3AO is a two component, moderate viscosity epoxy system with good flow properties. It is ideal for small to moderate size encapsulating, potting and casting applications. It is also effective in bonding fragile components requiring a low coefficient of thermal expansion. EP42HT-3AO is designed to optimize heat dissipation properties, improve the quality and reliability of electronic devices subjected to thermo-mechanical stresses.

This compound combines a low CTE of 13-16x10^-6 in/in/°C with a high glass transition temperature (T_g) of 140-150°C. It has a thermal conductivity of 11-12 BTU•in/ft^²•hr•°F [1.59-1.73 W/(m•K)]. It also exhibits low shrinkage upon curing, dimensional stability, and excellent structural strength. EP42HT-3AO is a reliable electrical insulator with a volume resistivity of >10¹⁴ ohm-cm. This system is serviceable from -100°F to +400°F.

This 100 percent reactive epoxy formulation has a non-critical 100 to 40 mix ratio by weight and a working life of 60 to 90 minutes after mixing for a 100 gram batch at 75°F. It has a recommended cure schedule of overnight at room temperature, followed by tow to three hours at 150°F to 200°F. EP42HT-3AO is available for use in ounce, ½ pint, pint, quart and gallon kit containers. Specialty packaging options in the form of pre-mixed and frozen syringes are also available. The specialty packaging allows for automated dispensing. The color of Part A is white and Part B is off-white.