Vacuum Brazing for EV Battery Cooling Plates

Electric vehicles generate a significant amount of heat during operation. To keep battery packs safe and performing at their best, manufacturers rely on aluminum cooling plates, components that circulate coolant directly against the battery cells to regulate temperature.

The way these cooling plates are assembled matters enormously. Two aluminum sheets are bonded together to form sealed internal coolant channels, and the quality of that bond determines whether the plate lasts the lifetime of the vehicle or fails prematurely.

Vacuum brazing is the joining process the industry trusts to get this right.

How it works

The two aluminum plate halves are assembled with a braze filler alloy placed at the joint. They are then loaded into a vacuum furnace, where the chamber is evacuated of all air and heated to approximately 600°C. At this temperature, the filler melts and flows into the joint by capillary action, creating a strong, fully sealed bond once cooled.

No flux. No oxidation. No contamination of the coolant circuit. Just a clean, reliable joint.

Fig: Aluminum Colling Plates

Why vacuum brazing is the right choice

1. Leak-free joints that hold up under pressure and thousands of thermal cycles

2. No flux residues that could corrode aluminum or contaminate coolant over time

3. Full braze penetration for consistent thermal conductivity across the plate

4. Handles complex channel designs without distorting thin aluminum walls

5. Repeatable results batch after batch, essential for automotive production volumes

The Furnace Is Everything

Even the best process design fails without the right equipment. A vacuum brazing furnace must maintain stable deep vacuum, deliver uniform temperature across the entire load (within ±5°C), and provide precise control over heating and cooling rates to avoid warping thin plate sections.

This is where Normantherm vacuum furnaces make the difference. Designed for demanding production environments, our furnaces deliver the temperature uniformity, vacuum integrity, and process control that EV component manufacturers require, with full cycle traceability to meet automotive quality standards.

Ready to optimize your cooling plate production? Contact Normantherm to speak with our process experts.