Today, the evolution of technology within the laser industry continues at a rapid pace, with output parameters (e.g., energy, pulse duration, wavelength) that enable lasers to open new applications every year and frequently replace conventional machining processes in every market segment.

New Approaches to Micromachining

A key advancement is the solid-state femtosecond laser in which the laser’s pulse duration is measured in a few hundred femtoseconds, so fast there is no time for heat build-up in the surrounding material. This cold-ablation process breaks the molecular bonds of the material, effectively removing material with sharp edges to create smooth walls with no burr or slag. To appreciate how fast a femtosecond is, consider that in one femtosecond, light travels only 300 nanometers—a distance comparable to the size of a virus. A femtosecond is to 1 second as 1 second is to 30 million years. 

Moreover, these laser sources align with sustainable practices by replacing traditional chemical etching and mechanical (consumable) techniques for micro-machining and model texturization. This transition to laser technology not only minimizes environmental impact but also enhances production efficiency. The use of femtosecond lasers eliminates the need for physical tools such as EDM electrodes, which in turn, significantly reduces maintenance costs and downtime. 

The integration of an industrial femtosecond laser into a five-axis CNC machine tool offers these multiple advantages in high precision manufacturing, including micro-mold production.

The New Era of Micro-Machining

Achieving precise and intricate details in micro-manufacturing while maintaining efficiency has always been a significant challenge. 

In the following examples, a laser ablation tool, equipped with a femtosecond laser source and CAD/CAM software, was used, facilitating a fully digital workflow from design to machining, allowing for seamless design changes. This specific laser can be configured for three-axis machining, common for micro-molds, or in a five-axis configuration to accurately machine highly contoured surfaces. A touch-probe and integrated camera enable accurate positioning of the mold cavity or insert.

Traditional methods often rely on electrodes and additional processing operations, which are time-consuming, costly, and prone to manufacturing errors. With direct laser machining as an alternative to EDM, there is no need to machine electrodes. The time savings is substantial and allows manufacturers to respond faster to their clients’ design changes. A design engineer’s micro-mold design change can be readily uploaded into the system’s software for rapid machining of the modified design. Faster turnaround time for prototypes and design changes is a competitive advantage for contract manufacturers. 

The example of the micro-mold in Figure 1 demonstrates the advantages provided by this cutting-edge technology.

Laser machining using a three-axis scan head typically results in a wall taper of seven to 10 degrees. Today’s software modules make it possible to laser machine straight walls to effortlessly tackle highly demanding 3D shapes, achieve total taper control from negative to zero and positive, and meet the sharpest edge radius requirements. Combining this with femtosecond laser technology ensures a homogeneous surface finish and shape continuity, effectively eliminating the need for any post-processing work.

In the example presented in Figure 2, a 10x10x10-mm tungsten carbide blank is laser machined utilizing the straight-wall software feature. An edge radius of 7.0 μm and flatness of <5.0 μm is achieved with direct laser machining, as measured by an optical coordinate measuring machine. In other examples, an edge radius of <2.0 μm has been demonstrated in the same material.

Conclusion

Advances in laser technology for industrial high-reliability femtosecond laser sources, and the continued evolution of software strategies in three- and five-axis high precision CAD/CAM machining tools, are delivering high accuracy and increased speed for machining molds and final part production in the medical market. The potential to eliminate other machining steps, such as EDM electrodes, results in a lean manufacturing process that is both efficient and precise, overcoming the limitations of traditional manufacturing methods and ensuring complete accuracy on the most demanding shapes.

Jérôme Durand is a marketing professional with a strong background in B2B environments, having held various roles in trade marketing, product management, and digital strategy across the Europe, Middle East, and Africa region. Since 2024, he has been serving as the product marketing manager for the laser portfolio at UNITED MACHINING. Durand is currently based in Geneva, Switzerland.

Mark Keirstead has worked in various roles within the laser industry, including R&D, product management, marketing, and international sales management across Asia and Latin America. He holds 22 U.S. patents for development of solid-state laser technologies. Keirstead is currently the North America sales manager for UNITED MACHINING’s Advanced Solutions Group. He is based in Silicon Valley, Calif.