Adhesives for the Assembly of Electronic Devices

Silver filled electrically conductive, for die attach and general bonding. Low volume resistivity and high temperature resistance. Superior bond strength. Thermally conductive. Thixotropic paste, consistency. Available in syringes that are compatible with various types of automatic dispensers or manual dispensing. Serviceable from -80°F to +400°F.

Master Bond EP112 is an ultra-low-viscosity, electrically insulating, two-component epoxy system ideal for various applications. This two-part case study series presents two use cases for EP112 for microelectronics fabrication processes when used to bond a silicon wafer to a glass substrate.

The rise of electric vehicles and driver aids along with the proliferation of electronic sensors and safety features point towards continued growth in automotive electronics. Due to their lightweight, functional properties, adhesives, encapsulants and coatings will be of increased importance for use in structural bonding, as well as in non-structural applications for electronic, optical and mechanical components in electric vehicle manufacturing. Read more about the properties, uses and future developments of these compounds as they pertain to the automotive industry.

Graphite filled epoxy that cures at 80°C. Good electrical and thermal conductivity. Passes NASA low outgassing certification. Can be used for bonding, sealing, coating. Service temperature range is -50°C to +175°C

Epoxy resins are widely used as insulation material in electrical and electronic applications. They are employed as adhesives, sealants, coatings, impregnants, moldings and potting compounds to produce void-free insulation around components. The selection of a specific epoxy formulation for a given application requires not only an understanding of desirable dielectric properties, but also many other characteristics such as physical and mechanical strength, chemical resistance, operating temperature range and thermal cycling, dimensional stability and resistance to shock and vibration.Epoxy resins for electrical and electronic applications can be divided into two general categories: epoxies with amine type curing agents and those coupled with anhydride curing systems. Epoxy resin systems that contain amine are most frequently employed as adhesives, sealants, impregnants and coatings. Anhydride epoxy compounds are primarily employed for encapsulation and potting purposes, especially for applications which have high temperature demands or large volume usage.The high speed offered by UV curable epoxy formulations has increased their popularity in high performance bonding, sealing and coating applications. Master Bond offers UV curable compounds that can cure at ambient temperatures, in the presence of oxygen, in less than one minute.The chart below summarizes some of the most important characteristics in evaluating the electrical performance of epoxies:Dielectric Properties of Epoxy Insulation MaterialsPropertyDescriptionVolume ResistivityThe measurement of the ability of an insulating material to resist the passage of electric current through the thickness of a solid specimen under specified conditions. A typical unfilled epoxy has a volume resistivity of >1010 ohm-cm at 25°C.Surface ResistivityThe measurement of the ability of an insulating material to resist the passage of electrical current along the surface of a solid specimen under specified conditioning. A typical unfilled epoxy has a surface resistivity of >1010 ohm-cm at 25°C.Dielectric ConstantThe measurement of the strength of a given specimen at a specified thickness and is expressed in volts/mil. Dielectric strength decreases with specimen thickness. Typical values for epoxy specimen 0.125 inches thick are in the 420–480 volts/mil range.Arc ResistanceThe measurement of the resistance to a specified high voltage, low current arc conditions in terms of seconds to insulator breakdown. Values for typical epoxies are in the 100–300 second range.Dissipation FactorThe measurement of the energy lost to the dielectric material in an alternating field.ASTM test methods are generally used for measuring these values. The table below lists the various properties and the corresponding test used for measurement.Electrical/Electronic Test Methods for Epoxy ResinsPropertyTest MethodVolume ResistivityASTM D257Surface ResistivityASTM D257Dielectric ConstantASTM D150Dielectric StrengthASTM D149Arc ResistanceASTM D495Dissipation FactorASTM D150All of the properties listed, are affected to some degree by temperature and the addition of inorganic fillers such as silica, alumina and glass. For this reason, designers tend to use the highest values for volume and surface resistivity, dielectric strength and arc resistance, and the lowest values for dielectric constant and dissipation factor.Master Bond offers epoxy compounds for every type of electrical insulation application. They include both amine and anhydride curing compositions as well as an innovative line of UV curing products. The product line includes compounds for service from cryogenic temperatures to as high as 600°F including NASA low outgassing certified systems. Two particularly noteworthy Master Bond products are EP30-2, an optically clear, low viscosity epoxy system with a volume resistivity as high as 1016 ohm-cm which meets NASA’s stringent low outgassing requirements for aerospace use, and EP112, a very low viscosity cycloaliphatic epoxy system with superior arc resistance for use up to 500°F. Master Bond’s technical support team would be glad to recommend a product that meets your particular application’s requirements.