Can Laser Processing Equipment Meet Demanding Hermetic Welding Requirements?

Hermetic (airtight) welding is critical in medical implants, aerospace sensors, and battery enclosures—where even a tiny leak can lead to product failure. Many engineers wonder if laser processing equipment can reliably achieve the required leak-tightness, often specified at 1×10⁻⁸ to 1×10⁻⁹ Pa·m³/s.

Why Laser Welding Is Well-Suited

Laser welding offers precise energy control and a narrow heat-affected zone, which minimizes distortion and micro-cracking—common causes of leaks in traditional welding. When properly configured, it produces fully fused, continuous seams with minimal porosity or spatter, both essential for gas-tight integrity.

For example, stainless steel or titanium housings used in pacemakers are routinely laser-welded to meet MIL-STD or ISO 13485 hermeticity standards. The key is consistent penetration and clean joint fit-up.

Critical Factors for Success

Joint Design & Fit-Up: Gap must be ≤0.1 mm. Even small misalignment can create micro-channels. Precision fixtures or seam-tracking vision systems help maintain alignment.

Shielding Gas Purity: Use ≥99.999% argon with trailing shields to protect the cooling weld bead—oxidation can compromise seal quality.

Process Stability: Power fluctuations or focus drift during welding can cause incomplete fusion. Closed-loop power monitoring and thermal management in the laser processing equipment are essential.

Material Cleanliness: Oils, oxides, or residues outgas during welding and form pores. Parts must be cleaned before welding.

Validation Is Non-Negotiable

Don’t assume hermeticity—verify it. Perform helium leak testing on sample welds under conditions matching your production run. Ask your equipment supplier for test reports on similar applications.

In short, yes—laser processing equipment can meet stringent hermetic welding requirements, but only when the entire process (design, material prep, parameters, and validation) is tightly controlled. It’s not just about the laser; it’s about the system.