Blogs

+91-8217848475, +91-9353104574
Facebook-f Instagram Linkedin-in Twitter
Menu
Let's Talk

Solving the copper challenge – New wavelengths for high-reflectivity metals

by: adminblogPosted on:
Blue laser welding of copper battery busbars

Synopsis

In the rapidly expanding electric vehicle (EV) and renewable energy sectors, copper and brass have become the building blocks of efficiency. However, their high thermal conductivity and extreme reflectivity to standard infrared (IR) light have long made them a “nightmare” for laser engineers. This blog explores the technical breakthrough of alternative wavelengths—specifically Blue and Green laser technology—and how they are solving the “back-reflection” problem. We compare the absorption rates of standard IR lasers (5%) with Blue lasers (over 65%), demonstrating how shorter wavelengths enable stable, spatter-free welding of battery tabs and motor windings. We also detail advanced beam-delivery techniques like Adjustable Ring Modes (ARM) and wobble optics that protect sensitive hardware from damage. Discover how Dynotech’s innovative laser solutions are turning the copper challenge into a high-yield opportunity for India’s next-generation electrical and automotive manufacturers.

Table of Contents

The Copper Paradox: Essential but Elusive

Copper is the lifeblood of the modern electrical world, but welding it is one of the most difficult tasks in industrial manufacturing. The Copper Paradox: Essential but Elusive  Its ability to conduct electricity and heat also makes it a “mirror” to most industrial lasers.

Why Standard IR Lasers Struggle with Copper

Why Standard IR Lasers Struggle with Copper  Traditional near-infrared (IR) fiber lasers, which operate at a wavelength of approximately 1,070nm, only achieve about 5% absorption in solid copper. The rest of the energy is reflected away, leading to unstable welds and high spatter.

Back-Reflection: The Invisible Threat to Laser Hardware

Back-Reflection: The Invisible Threat to Laser Hardware  is the most dangerous consequence of this reflectivity. If the laser light bounces directly back into the delivery fiber or the resonator, it can cause catastrophic damage to the sensitive optics and internal components. To compensate, operators often have to “brute force” the weld with excessive power, which increases the risk of “blowouts” and poor joint quality.

Wavelength Innovation: The Rise of Blue and Green Lasers

Wavelength Innovation: The Rise of Blue and Green Lasers  has fundamentally changed the rules.

Blue Lasers (450nm): Superior Absorption for Thin Foils

Blue Lasers (450nm): Superior Absorption for Thin Foils  By moving to the blue spectrum, absorption rates jump to over 65%. This allows for stable “heat conduction” welding where the metal melts smoothly without the violent instability of IR lasers. This is a game-changer for welding delicate battery busbars and thin foil stacks.

Green Lasers (532nm): Precision for Heat-Sensitive Components

Green Lasers (532nm): Precision for Heat-Sensitive Components  offer a middle ground with roughly 40% absorption, providing high-precision “keyhole” welds that are deeper and faster than those achievable with blue diodes, making them perfect for motor hairpin welding.

Protecting Your Investment: Advanced Beam Management

Protecting Your Investment: Advanced Beam Management  involves more than just a different color of light.

Adjustable Ring Modes (ARM) and Dual-Wavelength Systems

Adjustable Ring Modes (ARM) and Dual-Wavelength Systems  Modern systems now use “hybrid” beams, where a center IR spot is surrounded by a ring of laser energy. This ring pre-heats the copper, significantly increasing its absorption before the main welding beam hits, resulting in a much more stable and repeatable process.

Wobble Optics: Stabilizing the Molten Pool

Wobble Optics: Stabilizing the Molten Pool  by oscillating the beam in a circular or “infinity” pattern, we can stir the molten metal and allow gases to escape. This eliminates the porosity (internal bubbles) that often weakens electrical connections.

Why Dynotech? Leading the Electrical Revolution in India

Why Dynotech? Leading the Electrical Revolution in India  With 30+ years of experience, Dynotech is at the forefront of solving the copper challenge for India’s EV and power sectors. We provide the 100% innovative technology required to weld high-reflectivity metals with zero risk to your hardware. From blue-assisted IR systems to high-power green lasers, we help you achieve the low-resistance, high-strength connections that will power India’s sustainable future.

FAQs

Copper reflects about 95% of near-infrared (IR) light in its solid state. This makes it difficult for the laser to start the melting process. Additionally, once it does melt, the absorption increases suddenly, often causing a “blowout” or excessive spatter.

Blue lasers (450nm) are absorbed by copper 13 times more effectively than IR lasers. Because the energy is actually absorbed by the material rather than being reflected, there is significantly less “back-reflected” light to damage the laser’s sensitive internal optics.

Wobble optics use high-speed mirrors to oscillate the laser beam in a specific pattern (like a circle) as it moves. This “stirs” the molten pool, keeping it open longer and allowing trapped gases to escape, which eliminates the holes (porosity) often found in copper welds.

Yes. Laser technology is excellent for joining dissimilar metals. Blue lasers are particularly effective for copper-to-aluminum joints in EV batteries because they offer the precise heat control needed to minimize brittle “intermetallic” layers that can weaken the joint.

Not necessarily. Because Blue and Green lasers are absorbed so efficiently, they often require much less power (Wattage) to achieve the same result as an IR laser. This reduces the heat input on the part and lowers the overall electricity consumption of the machine.