Metallized ceramic components for New Energy HVDC Contactors: Material Properties, Metallization Processes, and OEM Manufacturing

The metallized ceramic components for new energy HVDC contactors utilizes 95%–99% alumina ceramic as the insulating substrate, achieving a reliable connection between the ceramic and metal terminals through Mo-Mn metallization, high-temperature sintering, and brazing processes. This component features a dielectric strength exceeding 15 kV/mm, insulation resistance greater than 1000 MΩ, and mechanical strength ranging from 200 to 500 MPa; it is primarily used in HVDC contactors for new energy vehicles, energy storage systems, photovoltaic inverters, and high-voltage power equipment, ensuring electrical isolation and stable circuit interruption in high-voltage, high-current environments.

 

 

Power battery systems for new energy vehicles are transitioning from 400V to 800V high-voltage platforms, while voltage levels in energy storage systems and the DC side of photovoltaic systems are also steadily increasing. HVDC contactors must maintain stable insulation under conditions of high voltage, high current, and frequent switching, while simultaneously withstanding mechanical shock from contact actuation and thermal shock from electric arcs.

 

As critical insulating structural components of HVDC contactors, metallized ceramic bodies consist primarily of a ceramic substrate and localized metallized layers. The ceramic section provides high insulation performance and mechanical support, while the metallized areas facilitate the connection of copper terminals, electrodes, or contact assemblies, thereby enabling reliable electrical connectivity for the ceramic material.

 

In practical structural design, ceramic bodies are typically configured as blocks, cylinders, or complex shapes, customized to suit the contactor's internal arc-extinguishing chamber, terminal layout, and mounting method. Some designs incorporate positioning holes, grooves, and reinforcing structures to enhance assembly precision and mechanical reliability.

 

Their primary functions include:

 

• Providing stable insulation and isolation between moving and stationary contacts to prevent high-voltage breakdown.
• Offering mechanical support for internal contact assemblies to ensure long-term operational stability.
• Facilitating reliable connections between the ceramic and metal components-such as copper or stainless steel-via the metallized layers.
• Maintaining dimensional stability in environments characterized by high temperatures, electric arcs, and vibration.

 

 

The ceramic components of HVDC contactors demand high material performance, requiring a balance of insulation, electrical, mechanical, and thermal stability properties. Currently, 95% alumina (95% Al₂O₃) is the most widely used material in the new energy vehicle and energy storage sectors.

 

Alumina ceramics offer high dielectric strength, high mechanical strength, and excellent heat resistance. Increasing the alumina content further enhances the material's density, insulation performance, and resistance to mechanical damage.

 

Silicon nitride (Si₃N₄) ceramics are also used in certain high-performance applications due to their superior thermal shock resistance and wear resistance; however, their adoption in HVDC contactors remains relatively limited due to higher manufacturing costs and stringent requirements for metallization compatibility.

 

For high-voltage systems in new energy vehicles, ceramic bodies typically need to meet the following engineering specifications:

 

These parameters ensure that the ceramic body maintains stable performance under conditions of voltage fluctuation, temperature cycling, and mechanical vibration.

 

 

Ceramic materials cannot directly form reliable bonds with metals such as copper, nickel, or steel; therefore, a metallization process is required to establish a conductive bonding layer on the ceramic surface.

 

The Mo-Mn metallization process is commonly used for the ceramic bodies of HVDC contactors. This process involves printing a molybdenum-manganese (Mo-Mn) paste onto the alumina ceramic surface and firing it at high temperatures to form a metallized layer, followed by nickel plating to enhance subsequent brazing performance.

 

The typical manufacturing process includes:

 

Ceramic powder mixing → Precision forming → High-temperature sintering → Surface grinding → Mo-Mn metallization → Nickel plating → Vacuum brazing → Dimensional inspection.

 

Among these steps, high-temperature sintering determines the density and strength of the ceramic substrate, while the thickness and adhesion strength of the metallized layer determine the reliability of the bond between the ceramic and the metal.

When joining ceramics to metals, it is essential to manage the matching of coefficients of thermal expansion; otherwise, temperature fluctuations can generate residual stresses, leading to ceramic cracking or the delamination of the metal layer.

 

High-strength joints between ceramics and copper terminals can be achieved using silver-copper brazing, active brazing, or vacuum brazing processes, while simultaneously maintaining low contact resistance and stable electrical conductivity.

 

 

For HVDC contactor ceramic bodies, customers in the new energy sector focus not only on material properties but also on mass production consistency and quality traceability.

 

Product quality is controlled during the manufacturing process through dimensional inspection, electrical performance testing, and reliability verification.

 

Key inspection items include:

 

 

For new energy vehicle projects, we can provide IATF 16949 quality management system documentation, PPAP Level 3 data, material reports, and process control records upon customer request.

 

 

New Energy Vehicle High-Voltage Systems

 

In new energy vehicles, metallized ceramic components are primarily used in:

 

• Main positive and negative HVDC contactors for traction battery packs
• Pre-charge contactors
• High-voltage Power Distribution Units (PDUs)
• High-voltage control modules for fast-charging systems

 

During vehicle operation, these ceramic components must withstand vibration, thermal cycling (exposure to high and low temperatures), and the thermal impact of arcing caused by frequent switching.

 

Energy Storage Systems (ESS)

 

In large-scale energy storage power stations and commercial/industrial energy storage units, HVDC contactors manage the connections between battery clusters, the Power Conversion System (PCS), and the grid.

 

Metallized ceramic body provide a stable insulating environment, ensuring the safe operation of energy storage systems throughout charge-discharge cycles.

 

PV Inverters and DC Protection Equipment

 

The high-voltage DC side of photovoltaic (PV) systems operates in outdoor environments over long periods, requiring components that are resistant to heat, humidity, and environmental aging.

 

Metallized ceramic components are used in:

 

• PV inverters
• DC combiner boxes
• High-voltage protection modules

 

 

Xiamen Apollo Stamping Welding Technology Co., Ltd. specializes in the manufacturing of precision components for new energy vehicles, energy storage, and power electronics. The company provides OEM services for HVDC contactor ceramic bodies, metallized ceramic assemblies, and related precision connectors.

 

Manufacturing capabilities include:

 

• Precision forming of alumina ceramic bodies
• High-temperature sintering
• Mo-Mn metallization
• Ceramic-to-metal vacuum brazing
• Precision dimensional inspection
• Mass production quality control

 

For projects within the Tier 1 and Tier 2 supply chains of the new energy vehicle industry, the company supports DFM design reviews, sample development, PPAP Level 3 documentation submission, and long-term mass production delivery.

 

For custom requirements regarding HVDC contactor ceramic bodies, high-voltage fuse ceramic tubes, or alumina ceramic assemblies, please provide product drawings, material specifications, and annual volume estimates for engineering evaluation.

 

Obtain OEM engineering evaluation for ceramic bodies