Kovar®* is a nickel-cobalt ferrous alloy used by semiconductor, telecommunications, optical, aerospace, military/defense and aerospace companies in high tech applications. Its thermal expansion coefficient is similar to borosilicate glass, having low expansion characteristics even during thermal cycling in many critical assemblies. Additionally it offers superior machinability, thermal conductivity, fatigue strength and a high melting point. Its specific gravity is around 8.36. Usages include:
- Hybrid packages
- Power tools
- Microwave tools
Kovar® is available in bars, rods, sheets, coils, plates and in other forms.
Consideration for Bonding Kovar®--Low Thermal Impedance
Key compounds used for bonding Kovar® are Master Bond Supreme 10AOHT-LO, EP37-3FLFAO and EP30AOHT. Single part, no-mix Supreme 10AOHT has outstanding shear and peel strength properties. NASA low outgassing approved, this smooth thixotropic paste cures in 45 to 60 minutes at 250 - 300°F. It is serviceable from 4K to +400°F. Highly flexible, two component epoxy EP37-3FLFAO has excellent flowability. This thermally conductive, electrically insulative compound resists rigorous thermal cycling and can withstand cryogenic temperatures. Dimensionally stable, chemically inert EP30AOHT cures at ambient temperatures. It features a low thermal expansion coefficient, high compressive strength and superior electrical insulation characteristics.