LORD EX-5640

Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other

LORD EX-5640

Main features

  • Controlled Non-Slump Flow
  • Electronics Structural Bonding
  • Thermal and Dielectric Data

Product Description

LORD EX-5640 Adhesive is a semi-thixotropic, two-component structural epoxy system for bonding supported metal, plastic and ceramic materials in electronic applications. LORD EX-5640 A resin mixes with EX-5640 B hardener at 4:1 by weight, creating a red adhesive with controlled flow and surface wetting without dripping or slumping. Typical gel time is 20 to 45 minutes at 25 deg C or 10 minutes at 65 deg C, and full strength develops after 24 hours at 25 deg C. The cured system has thermal, electrical and dielectric characteristics relevant to electronic applications.

Key features

  • Controlled semi-thixotropic flow: Wets supported metal, plastic and ceramic surfaces without dripping or slumping during application.
  • Electronics structural bonding: The two-component epoxy system is used for structural bonding in supported electronic applications.
  • Thermal and electrical properties: Cured-system properties include thermal conductivity, CTE, volume resistivity and dielectric performance.

Applications

Applications include structural bonding of supported metal, plastic and ceramic materials in electronic assemblies.

Technical Specifications

General Properties
Color
The color
Off-White Liquid (resin), Red Liquid (hardener), Red Liquid (mixed)
Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume. For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
1.1 (resin), 1.08 (hardener)
Physical Properties
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow. Viscosity is commonly measured in centiPoise (cP). One cP is defined as the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP. A product like honey would have a much higher viscosity -around 10,000 cPs- compared to water. As a result, honey would flow much slower out of a tipped glass than water would. The viscosity of a material can be decreased with an increase in temperature in order to better suit an application
18500 @ 77°F (25°C) (resin), 6250 @ 77°F (25°C) (hardener) mPa.s
Electrical Properties
Dielectric Strength
Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material. Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property. As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow.
17.7 kV/mm
Volume Resistivity
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
1 x 10^14 @ 77°F (25°C) Ohms⋅cm
Thermal Properties
Thermal Conductivity
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance. Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
0.21 W/m.K

Additional Information

Technical properties

As-supplied / before-processing properties

Typical values are identified for LORD EX-5640 A resin, B hardener or mixed material.

PropertyValueUnitMethod / condition
Component appearanceOff-white liquid; red liquid-Typical; EX-5640 A resin; EX-5640 B hardener
A-resin viscosity18,500cPTypical at 25 deg C; spindle 7 at 50 rpm
B-hardener viscosity6250cPTypical at 25 deg C; spindle 6 at 50 rpm
Component specific gravity1.1; 1.08-Typical; EX-5640 A resin; EX-5640 B hardener
Mix ratio4:1parts by weightEX-5640 A resin to EX-5640 B hardener
Gel time20 to 45minutesTypical; mixed material at 25 deg C
Gel time10minutesTypical; mixed material at 65 deg C
Shelf life1yearEach component; original unopened container at 25 deg C
Technical properties

After-processing / final-state properties

Typical bulk properties apply to cured LORD EX-5640 under the stated test conditions.

PropertyValueUnitMethod / condition
Thermal conductivity0.21W/m-KTypical; cured material
Coefficient of linear thermal expansion51ppm/deg CTypical; cured material; TMA
Hardness85Shore DTypical; cured 24 hours at 25 deg C
Volume resistivity1 x 10^14ohm-cmTypical; cured material at 25 deg C
Dielectric strength17.7 (450)kV/mm (V/mil)Typical; cured material
Dielectric constant4.2-Typical; cured material at 100 kHz
Dissipation factor0.035-Typical; cured material at 100 kHz

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