Gantry Laser Welding Machine for AI Server Liquid Cold Plates: Leak-Tight Copper & Aluminum Sealing

The Thermal Bottleneck Behind AI Servers

As GPU racks move from 400 W to 700 W and beyond per accelerator, air cooling has reached its physical limit. Liquid cold plates are now the standard thermal interface for AI servers, data-center racks, and high-density energy-storage systems. The cold plate itself, however, is only as good as its seal: a leak of a few microliters per minute is enough to destroy a server tray, and a single pinhole in a 2,000 mm copper seam can fail an entire helium leak test.

This project documents how a gantry laser welding production line replaced TIG welding for extra-long copper and aluminum cold plate seams, combining zero-deformation welding with helium-leak-tight airtightness.

Customer Challenge

The customer manufactures thermal modules for AI server racks and large-capacity energy-storage liquid cooling systems. Their existing TIG process struggled with four problems:

• Extra-long continuous seams — cold plates for AI servers run from 1,200 mm to 2,400 mm, with microchannel walls as thin as 0.5 mm.
• Heat distortion — TIG heat input bowed thin plates by 3–5 mm, closing microchannels and forcing a post-weld machining step.
• Leak-test failures — intermittent porosity along the seam caused helium leak test rejects, especially on copper-to-aluminum joints.
• Throughput ceiling — TIG sealing ran at roughly 0.4 m/min, making the welding station the bottleneck of the whole line.

Solution: Gantry Laser Welding Production Line

Hailei Laser configured a gantry-type galvanometer laser welding system around the cold plate envelope instead of forcing the plate through a fixed machine. The long-stroke gantry carries a high-precision wobble welding head over the fixture, with an optional second station so one plate welds while the next is loaded.

The system uses a 1064 nm fiber laser with a 0.6 mm fiber core and up to four output channels, water-cooled and powered by 380 V ±10% / 50 Hz. CCD visual monitoring provides 0.1 mm positioning and closed-loop quality control, and the recipe for each cold plate model is stored and recalled by model number.

Verified Process Configuration

Production Results

The table compares the original TIG process with the gantry laser line on the same cold plate family. Laser figures are the validated capability of the delivered configuration; customer acceptance data should be attached to the final report.

Project Gallery

All photographs below show the same HL-ZJ-3000W gantry machine.

Why a Gantry Architecture Wins on Cold Plates

• Motion is separated from the workpiece. The plate stays clamped and flat; only the lightweight head moves, so long seams do not accumulate positioning error.
• Heat input is an order of magnitude lower than TIG. Narrow welds with a small heat-affected zone keep microchannel geometry intact.
• Wobble welding stabilizes copper. Beam oscillation widens the keyhole and suppresses the porosity that pure copper normally produces at 1064 nm.
• Optional dual station doubles uptime. Loading happens outside the welding cycle.

“The cold plate is a pressure vessel with microchannels. If the seam moves, the channel closes; if the seam leaks, the server dies. Laser welding lets us control both at once.”

Scope of Supply and Next Step

The line is delivered as a complete production cell: gantry frame, 3000 W fiber laser, wobble welding head, CCD vision, dual-station fixture, chiller, and PLC with model recipes. Minimum order quantity is one unit, delivery is 5–8 working days for standard configurations, and equipment is packed in strong wooden cases with CE and CCC certification.

For AI server cold plates, EV battery trays, and energy-storage liquid cooling modules, send us your plate drawing, material stack-up, and leak-test specification. Our engineers will return a welding recipe and fixture layout sized to your longest seam.