Brazing Silver Contacts To Copper Bars
Products Description
In low- and medium-voltage electrical systems, Brazing Silver Contacts to Copper Bars not only conducts current but also directly affects the equipment's breaking capacity, temperature rise control, and service life. Silver Contact Brazed Assemblies achieve an optimal balance between conductivity and arc resistance by metallurgically bonding silver-based alloy contacts to a highly conductive copper substrate, making them particularly suitable for applications with frequent operation or large load fluctuations.
Compared to mechanical pressing or simple welding, brazing creates a continuous and dense metallic bonding layer at the contact interface, significantly reducing contact resistance and improving structural stability.
Application Scenarios: Enhancing the Performance of Medium and Low Voltage Electrical Appliances
Moulded Case Circuit Breakers (MCCBs) and Universal Circuit Breakers (ACBs)
Serving as core current-carrying actuators for transient short-circuit protection.
AC Contactors
Maintaining the integrity of the Resistance Projection Welding Silver Contact working surfaces during tens of thousands of opening and closing cycles.
Industrial Disconnect Switches
Reducing busbar temperature rise under high current loads through excellent thermal dispersion performance for Copper Spot Welding Silver Contact.
Rail Transit Control
Meeting stringent automotive-grade electrical requirements for vibration and shock resistance.
Technical Features: Four Core Capabilities Provided by Brazing
| Ultra-Low and Constant Contact Resistance | Because the brazed layer is a continuous intermetallic compound + solid solution, its volume resistivity is only about 15-20% higher than that of pure copper, and it does not change over time. In contrast, the contact resistance of riveted components gradually increases due to vibration and thermal cycling. For circuit breakers, this translates to lower temperature rise and higher rated current margin. |
| Withstands Electrodynamic Repulsion of Short-Circuit Current | When a circuit breaker interrupts a short-circuit current, a huge electrodynamic repulsion is generated between the moving/stationary contacts, and the Resistive Welding Silver Contact may bounce. Brazed joints can withstand impact accelerations of up to tens of g without delamination-because the brazing filler metal layer has formed a metallurgical bond with the substrate, rather than a physical interlocking. |
| Resistance to Arc Thermal Shock | The temperature at the centre of an electric arc can reach thousands of degrees Celsius, and heat is rapidly conducted to the AC Resistance Welding Silver Contact. The melting point of the brazed interface (typically >600℃) is much higher than the softening temperature of the riveted interface, and it contains no organic or low-melting-point fillers. Our components showed no cracking or melting migration in the brazed layer after 200 ultimate breaking tests. |
| Supports High Current Continuous Flow | For contactors with a rated current of 250A or higher, the copper strip itself may experience a high temperature rise. The brazed joint, by eliminating Electric Resistance Spot Welding Silver Contact thermal resistance, becomes a "low-temperature zone" in the entire conductive circuit, preventing heat concentration and premature contact oxidation. |
Design Advantages: Details Built for Reliability and Manufacturability
Contact Bottom Storage Channel Design
We design micro-annular grooves or radial grooves on the bottom surface of the Silver and Copper Welding Button Contact. During brazing, the molten brazing filler metal flows into the grooves, forming a double safety mechanism of mechanical locking and metallurgical bonding, while preventing filler metal overflow and contamination of the working surface.
Positioning Features on the Copper Strip
Bosses or Countersunk Holes: Shallow bosses (0.1~0.2mm high) or recesses are pre-fabricated on the copper strip, automatically centering the contacts after placement, reducing tooling dependence.
Flow Guides: V-shaped grooves are machined along the edge of the brazing area to guide excess filler metal to non-functional areas, preventing it from flowing onto the contact working surface.
Multi-layer Contact Design
For double-break contactors, we can simultaneously braze two silver contacts at both ends of the same copper strip. A special fixture ensures that the symmetry of the contacts at both ends relative to the center line is ≤0.05mm, significantly simplifying overall assembly and debugging.
Anti-silver migration edge: Leave a 0.3~0.5mm copper protrusion at the junction of the Silver to Copper Brazing to prevent silver from migrating along the surface at high temperatures, which would shorten the creepage path.
contact us
If you are looking for a Silver and Copper Welding Button Contact component solution that can operate stably for a long time in real-world conditions and can be deeply integrated with design optimization, our engineering team can provide more feasible customized support for your project.
Hot Tags: brazing silver contacts to copper bars, China brazing silver contacts to copper bars manufacturers, suppliers, factory, Welding Electrical Silver Contact Tip Assembly, Contact Joining Brazing, Brazed Silver Contacts, Projection Welding Silver Contact, contact brazing assembly, Silver To Copper Brazing
You Might Also Like
Send Inquiry