What is Ceramic-to-Metal Brazing?
Ceramic-to-metal brazing is a highly specialized joining technique that forms strong, vacuum-tight seals between non-metallic ceramics and metallic components. It is a foundational process for fabricating high-reliability packages and assemblies in aerospace, medical, semiconductor, and defense sectors.
Process Overview
Ceramic-to-metal brazing utilizes a specially formulated filler alloy that melts below the base materials' temperature, allowing the metal and ceramic parts to be permanently joined without melting either substrate. The process begins with metallization—applying a thin conductive layer to the ceramic—followed by nickel plating and precise furnace brazing under high vacuum or controlled atmosphere. This creates an exceptionally durable and hermetic interface suitable for harsh operating environments.
Key Process Steps
- Titanium and Niobium Sputtering (Optional): Applied to enhance biocompatibility in medical-grade assemblies, creating inert and stable surfaces.
- Metallization of Ceramic: A refractory coating (e.g., molybdenum-manganese or tungsten) is sintered onto ceramic substrates to allow alloy adhesion.
- Nickel Plating: Provides a wettable and oxidation-resistant surface for the braze alloy to adhere reliably.
- Brazing Assembly: Parts are joined with braze alloy preforms and heated under vacuum to form a robust bond via capillary flow.
- Cooling & Post-Braze Inspection: Controlled cooling and non-destructive inspection ensure hermeticity and structural performance.
Common Materials Utilized
Ceramic Substrates
- Alumina (Al₂O₃)
- Zirconium Oxide (ZrO₂)
- Ruby
- ATZ (Alumina Toughened Zirconia)
- ZTA (Zirconia Toughened Alumina)
- Sapphire
- Aluminum Nitride (AlN)
Metal Components
- Kovar
- Stainless Steel
- Titanium
- Niobium / Molybdenum
- Platinum-Iridium
- Pure Platinum
Brazing Alloys
- Silver-Copper (Ag-Cu)
- Gold-Nickel (Au-Ni)
- Titanium-Based Active Brazes
- Pure Gold (Au)
- Pure Silver (Ag)
Core Benefits
- Reliable hermetic seals for extreme environments
- High strength and thermal stability under load
- Electrical insulation with corrosion resistance
- Supports miniaturization and custom designs
- Medical and aerospace-grade material compatibility
Typical Applications
- Aerospace & Defense: Feedthroughs, sensors, vacuum-sealed connectors
- Medical Devices: Implantable housings, imaging and diagnostic components
- Semiconductors: Vacuum assemblies, RF packages, optical windows
- Energy Sector: Pressure seals, nuclear instrumentation, oil field devices
Why Partner with Advanced Hermetic Solutions?
At Advanced Hermetic Solutions, we fuse engineering expertise with state-of-the-art vacuum brazing to deliver precision ceramic-to-metal components for critical applications. Our solutions are trusted across defense, aerospace, medical, and high-tech markets for their unmatched reliability and technical integrity.