Kovar (ASTM F15) – Precision Thermal Expansion for Hermetic Sealing
Kovar is a controlled-expansion nickel–iron–cobalt alloy specifically engineered to match the thermal expansion of borosilicate glass and ceramics. Advanced Hermetic Solutions integrates Kovar into high-reliability applications demanding long-term vacuum integrity and mechanical strength.
Material Properties
- Chemical Composition: Fe (balance), Ni 29%, Co 17%, Mn 0.3%, Si 0.2%, C 0.02%
- Density: 8.36 g/cm³
- Melting Point: 1,450°C (2,642°F)
- Curie Temperature: 435°C (815°F)
- Thermal Conductivity: 17 W/m·K
- CTE (25–200°C): 5.5 × 10⁻⁶ /K
- Electrical Resistivity: 49 µΩ·cm
- Modulus of Elasticity: 138 GPa
- Tensile Strength: 517 MPa
- Yield Strength: 345 MPa
- Elongation: 30%
- Hardness (Rockwell B): 68
Applications in Hermetic Engineering
Glass-to-Metal Seals
Provides unmatched stability when sealing with borosilicate glass, ensuring long-term vacuum performance in aerospace, electronics, and medical assemblies.
Electronic Headers & Packages
Widely used in transistor headers, TO cans, ceramic IC packages, and hybrid modules requiring dimensional stability and hermetic reliability.
Optoelectronic & Sensor Devices
Ensures thermal expansion matching in laser housings, fiber optic feedthroughs, and sensor windows under thermal cycling.
Vacuum and RF Feedthroughs
Kovar brazed to ceramic insulators is a standard in feedthroughs for RF/microwave and vacuum applications.
Battery & Power Assemblies
Used in sealed lithium battery headers and other power devices requiring leak-proof, stable performance across cycles.
Medical Implant Packaging
Supports hermetically sealed electronics in life-sustaining devices where performance and bio-barrier protection are non-negotiable.
Leverage Kovar in Your Hermetic Component Design
Advanced Hermetic Solutions provides Kovar machining, brazing, and sealing integration services for demanding electronic and optical assemblies. Contact us for application guidance, prototyping, and high-volume production support.
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