Precision Laser Material Processing: The Definitive Guide

In modern manufacturing, where demands for miniaturization, complexity and efficiency are constantly increasing, precision laser material processing has emerged as an indispensable technology. From the intricate life-saving patterns of a medical stent to the billions of microscopic connections in a semiconductor chip, lasers provide the accuracy and speed required to fabricate the technologies that define our world. At the heart of this transformative capability is the precise control of motion—the ability to guide a powerful beam of light with sub-micron accuracy to cut, drill, weld and texture virtually any material.

Aerotech, Inc. is a global leader and expert partner in the high-precision motion control and automation systems that make these advanced applications possible. Our solutions are engineered to solve the toughest precision challenges, enabling manufacturers in the semiconductor, electronics, medical device and photonics industries to push the boundaries of what is possible. This guide serves as a central resource for understanding the fundamentals of laser material processing, the critical role of motion control and how Aerotech’s technologies empower you to achieve unparalleled results.

What is laser material processing?

Laser material processing refers to the use of a focused beam of high-intensity light (a laser) to alter the properties or shape of a material. The laser acts as a highly controllable energy source that can be used for a vast range of applications, including cutting, welding, drilling and surface modification. Because the laser beam can be focused to a very small spot size, it can deliver extremely high power densities—far exceeding traditional heat sources like an electric arc. This intense, localized energy allows for the precise removal or modification of material with minimal impact on the surrounding area, a key advantage for fabricating small, delicate or complex components.

The flexibility of laser processing is one of its core strengths; by manipulating parameters such as power, spot size, and interaction time, a single laser system can perform a multitude of tasks on nearly any known material, from metals and plastics to ceramics and composites.

What is the meaning of laser processing?

The meaning of laser processing lies in its ability to use light as a non-contact tool for high-precision manufacturing. Unlike mechanical tools that physically touch and exert force on a workpiece, a laser beam alters the material through the absorption of optical energy. This fundamental difference has profound implications:

• No Tool Wear: Since there is no physical tool, there are no issues with tool wear, breakage or the need for replacement, leading to more consistent and reliable processing over time.
• Minimal Mechanical Stress: The non-contact nature means that minimal mechanical stress is imparted on the workpiece, making it ideal for processing fragile or thin materials without causing distortion or damage.
• High Flexibility: The process is software-driven. Complex shapes and patterns can be created simply by changing the instructions sent to the motion control system that directs the beam. This allows for rapid prototyping, low-volume manufacturing of custom parts and quick changeovers between different jobs.

Essentially, the meaning of laser processing is the harnessing of light’s unique properties to achieve manufacturing outcomes with a level of precision, flexibility and control that is often unattainable with conventional methods.

How does laser processing work?

Laser processing works on the principle of converting light energy into thermal energy to modify a material. The process begins with generating a laser beam, which is a highly concentrated stream of monochromatic (single wavelength) and coherent (in-phase) light. This beam is then guided by a series of optics, such as mirrors and lenses, and focused onto a very small spot on the surface of the workpiece.

The interaction is governed by the material’s properties—primarily its ability to absorb the specific wavelength of the laser—and the laser’s power density. When the laser energy is absorbed, the material heats up rapidly. Depending on the intensity and duration of the exposure, this heating can lead to several outcomes:

• Heating: For processes like transformation hardening, the material is heated to a specific temperature to change its microstructure without melting it.
• Melting: For welding, the material is heated to its melting point and then allowed to cool and solidify, fusing it together.
• Vaporization: For cutting and drilling, the power density is so high that the material is rapidly heated past its melting point to its vaporization temperature, effectively removing the material to create a cut (kerf) or a hole.

In all these cases, a motion system—either moving the workpiece under a fixed beam or steering the beam over a stationary workpiece—is fundamental for creating the desired feature or path. The precise, synchronized control of this motion dictates the geometry, accuracy, and quality of the finished part.

What type of laser is used in laser beam machining?

The type of laser used in laser beam machining is selected based on the specific material and application requirements, primarily driven by the material’s absorption characteristics at different wavelengths. A common question is how many types of laser exist for industrial use, and the choice depends heavily on the material properties and the specific process requirements, including wavelength absorption, required power density, pulse characteristics, and beam quality. Key types include:

• Gas Lasers (e.g., CO₂ Lasers): Operating at a long wavelength (typically 10.6µm), CO₂ lasers are powerful and versatile, making them a workhorse for cutting, welding and surface treatment of non-metals, organic materials and thick-section metals.
• Solid-State Lasers (e.g., Nd:YAG, Yb:YAG): These lasers, including traditional rod-based lasers, disc lasers and fiber lasers, operate at shorter wavelengths (around 1µm). This wavelength is better absorbed by metals, making the lasers highly effective for cutting, drilling and welding metals with high precision and speed. Their high beam quality also allows for very fine focusing.
• Fiber Lasers: A type of solid-state laser where the gain medium is an optical fiber, fiber lasers have become dominant in many metal processing applications. They offer excellent beam quality, high efficiency and robustness, enabling faster cutting and welding speeds compared to other laser types.
• Excimer Lasers: These lasers produce ultraviolet (UV) light, which is ideal for “cold” ablation processes where material is removed via photochemical bond-breaking rather than thermal heating. This makes them suitable for machining polymers and delicate electronic components with minimal thermal damage.
• Ultrafast Lasers (Picosecond and Femtosecond): These lasers deliver energy in extremely short pulses. This enables “cold” ablation on virtually any material, creating exceptionally clean, precise features with almost no heat-affected zone (HAZ), which is critical for medical device manufacturing and semiconductor micromachining.

The selection often comes down to matching the laser’s wavelength to the material for optimal energy absorption and the pulse characteristics to the desired interaction mechanism. 

What is the laser drilling process?

The laser drilling process uses a focused laser beam to create holes in a material by rapidly melting and vaporizing it. The intense energy of the laser beam heats the material at the target point, and the resulting vapor pressure – often combined with an assist gas jet – expels the molten and vaporized material, leaving a hole. This process is extremely fast and can create holes with diameters ranging from several millimeters down to a few micrometers.

There are several methods used in laser drilling:

• Percussion Drilling: This is the simplest method, where single or multiple laser pulses are fired at a stationary spot to create the hole. It is very fast but can result in a tapered hole and a “recast” layer of melted material on the sidewalls.
• Trepanning: For larger or more precise holes, the laser beam is moved in a circular path to cut the hole’s perimeter. This gives greater control over the hole’s diameter, roundness and edge quality.
• Helical Trepanning: This advanced technique involves moving the beam in a spiral path to machine the hole progressively deeper. It offers the highest precision for hole shape, taper and wall quality but is generally a slower process.

Laser drilling is critical in industries like aerospace for creating cooling holes in turbine blades and in electronics for drilling microscopic vias in circuit boards. Success depends on precise control of laser parameters (pulse energy, duration) and motion, whether it’s the high-speed circular motion for trepanning or the rapid point-to-point positioning for drilling dense arrays of holes.

What are the advantages of laser material processing?

Laser material processing offers numerous advantages over traditional mechanical and chemical methods, making it a preferred choice for high-value and high-precision manufacturing. The key benefits stem from its non-contact nature and the highly controllable properties of the laser beam itself.

• High Precision and Quality: Lasers can be focused to incredibly small spot sizes, enabling the creation of micro-scale features with exceptional accuracy and repeatability. The localized energy input minimizes the heat-affected zone (HAZ), reducing thermal distortion and improving the quality of the finished part.
• Flexibility and Speed: As a software-driven process, laser systems can be quickly reprogrammed to produce different parts or patterns without needing to change physical tools. When combined with high-speed motion systems like galvanometer scanners, lasers can achieve very high throughput for applications like marking, engraving and drilling. High-acceleration stages also reduce non-processing time, boosting overall productivity.
• Material Versatility: The high power density of a focused laser beam can be used to process almost any material, including hard metals, brittle ceramics, soft polymers and composites. By selecting the appropriate laser type and parameters, the process can be tuned for optimal interaction with a specific material.
• Non-Contact Processing: Because the laser is a light-based tool, there is no mechanical force exerted on the workpiece and no tool wear. This is ideal for processing delicate, brittle or thin materials and without causing distortion or damage.
• Automation-Friendly: The process is inherently well-suited for automation. The combination of precise motion control, in-process sensing and computer control allows for fully automated, “lights-out” manufacturing, improving consistency and reducing labor costs.

What are the applications of lasers in material processing?

The applications of laser in material processing are vast and span nearly every major manufacturing sector, driven by the technology’s unique combination of precision, speed and flexibility. Key applications enabled by precision motion include:

• Semiconductor Advanced Packaging: Lasers are critical for next-generation packaging technologies. Applications include high-precision laser dicing of wafers, drilling of through silicon vias (TSVs) and through glass vias (TGVs) for 3D interconnects, laser annealing and marking of individual chips. Aerotech’s control features like Position Synchronized Output (PSO) are vital for handling the unique challenges of high-density TGV drilling.
• Electronics Manufacturing: In high-volume electronics, lasers are used for PCB depaneling (singulation), micro-drilling of vias for high-density interconnect (HDI) boards, cutting of flexible circuits and solder mask ablation. The emphasis is on speed, accuracy and process control to maximize yield.
• Medical Device Manufacturing: Laser processing’s precision and cleanliness meet the medical industry’s stringent requirements. Major applications include laser cutting of stents, catheter drilling and skiving, welding of hermetic enclosures for implants and permanent marking of surgical tools for traceability.
• Photonics Chip Packaging and Assembly: The assembly of photonic integrated circuits (PICs) demands exceptional precision. Lasers are used for optical fiber alignment and welding, waveguide fabrication and other highly precise micromachining tasks where synchronized motion is critical.
• Ultrafast Laser Micromachining: This is a broad category of applications that leverages ultrafast (picosecond or femtosecond) lasers for “cold” ablation. It is used for high-precision drilling, cutting and milling of nearly any material, including brittle materials like glass and ceramics, with minimal thermal damage. This is the enabling technology for high-demand applications like stress-free glass cutting and high-aspect-ratio TGV drilling.

What is the most common laser material processing application?

Determining which is the most common laser material processing application can be challenging as the market is diverse and constantly evolving; however, laser cutting is arguably one of the most prevalent and mature applications based on widespread industrial adoption and volume.

Laser cutting systems are found in job shops and large-scale manufacturing facilities globally, used to profile cut sheet metal for everything from automotive parts to electronic enclosures. Beyond metals, lasers are used extensively for cutting plastics, wood, textiles and composites. 

Cutting is the most ubiquitous use case for laser processing, followed closely by laser welding and laser marking. Laser welding is a cornerstone of the automotive industry for applications like tailored blank welding and body-in-white assembly, while laser marking is used universally for part identification, branding and traceability across all sectors. While applications like microdrilling are extremely high volume in terms of features created (e.g., billions of vias), the number of systems dedicated to cutting and marking is vast.

What is the laser processing of materials?

The laser processing of materials is a discipline of manufacturing engineering that applies the principles of laser physics and optics to modify materials for industrial purposes. It encompasses a wide spectrum of techniques that can be broadly categorized by the nature of the laser-material interaction:

• Material Removal Processes: This is the largest category and includes laser cutting, drilling and ablation (micromachining). In these processes, the laser energy is high enough to melt and vaporize the material, which is then ejected to create a cut, hole or finely machined feature.
• Joining Processes: This category is dominated by laser welding, where the laser melts the edges of two or more components that fuse together upon cooling. It can also include laser soldering and brazing.
• Surface Modification Processes: These processes alter the surface properties of a material without removing it entirely. This includes laser transformation hardening to increase surface durability, laser surface melting and alloying to create novel surface compositions, and laser cladding to deposit a protective or functional layer.
• Additive Processes: This includes rapid prototyping techniques like selective laser sintering (SLS) and direct metal deposition (DMD), where a laser is used to selectively fuse powder or melt wire to build a part layer by layer.

At its core, the laser processing of materials is about using a precisely controlled beam of light as a thermal or photochemical tool to achieve manufacturing goals that often cannot be met using conventional methods.

How do lasers cut through materials?

Lasers cut through materials by delivering a highly concentrated beam of energy to a small spot, causing the material in that spot to rapidly melt and/or vaporize. This process, controlled with a high degree of precision, is typically assisted by a coaxial gas jet that helps eject the molten and vaporized material from the cut zone, known as the kerf.

The mechanism involves a few key steps:

• Energy Absorption: The laser beam is focused on the material’s surface. The material must absorb the laser’s energy at its specific wavelength for heating to occur. Surface coatings can be used to enhance absorption on reflective materials.
• Rapid Heating and Phase Change: The absorbed energy causes a very rapid temperature rise. The material quickly reaches its melting point and then its boiling point. The process creates a “cut front” of molten material.
• Material Ejection: A high-pressure assist gas (such as oxygen, nitrogen or argon) is directed into the kerf through a nozzle concentric with the laser beam. This gas flow has two primary functions.
  • It physically blows the molten and vaporized material out of the bottom of the cut, clearing the path for the beam to penetrate deeper.
  • In the case of cutting reactive materials like steel with an oxygen assist gas, the gas can create an exothermic reaction, contributing additional energy to the process and increasing cutting speed. For non-reactive cutting, an inert gas like nitrogen is used to prevent oxidation and produce a clean, high-quality edge.
• Relative Motion: To create a continuous cut, a motion system moves the laser beam relative to the workpiece, tracing the desired cutting path. The traverse speed is a critical parameter that must be carefully balanced with laser power and material thickness to achieve a clean cut without excessive thermal damage.

By precisely controlling these factors, lasers can achieve high-quality, narrow cuts with a minimal heat-affected zone in a vast array of materials.

Contact our team to learn how Aerotech’s precision motion systems can elevate your laser material processing capabilities.