Laser Micromachining: 5 Things to Know About this Precision Manufacturing Technology

Recent advancements in laser technology have resulted in machines capable of high precision micromachining: cutting, drilling, joining, and texturing. Because laser micromachining (or laser micro machining)  is a remote (non-contact) photonic processing technique, it is beginning to replace the more traditional machining methods commonly used to create small drill-holes, narrow pockets, slots and intricately shaped features in parts across many industries including microelectronics, semiconductors, medical and aerospace. The following are answers to the top 5 questions we get asked about this technology.

1. What is Laser Micromachining?

Laser Micromachining is a tightly controlled material removal process in which a laser beam is used to reshape a material (e.g. cut, drill, texture). For years, these processes have been achieved using mechanical milling, chemical etching and EDM. But as parts get progressively smaller with every passing year, the need for improved processing techniques that can produce smaller features with fewer defects has increased. Lasers meet that requirement.

2. What industries rely on Laser Micro Machining?

The extreme level of precision achieved using lasers for micromachining makes them ideal for applications such as:

• Cutting and drilling ceramic semiconductor wafers
• Etching next generation solar cells
• Cutting lithium ion battery foils
• Machining fuel injector nozzles in the automotive industry
• Drilling fine holes into advanced, lightweight space-grade alloys in aerospace applications
• Countless sensitive, precision medical device processing techniques. The laser micromachining market is growing fastest in the medical device sector, where minimally invasive surgical techniques and drug delivery capabilities are driving the need for smaller and more precise components. Features like ports, slots, and grooves must be precisely machined with tolerances as low as +/- 2.5 µm. There is little room for defects or imperfections. Laser beams can be focused to extremely small diameters, and, since they are pure light, there is no chance for broken or worn tools to leave burrs on the parts.

3. What types of lasers are used for Laser Micromachining?

One of the most exciting advancements in laser technology in recent years has been the refinement of the ultrashort pulse (USP) laser, which emits extremely short pulses that may be only a few hundred femtoseconds in duration. This timescale is shorter than electron relaxation times and the subsequent transition of photon energy into thermal energy (heat). This allows for localized near-athermal ablation in the laser-material interaction region (within the area of the focused laser beam), resulting in highly repeatable features with ablation resolution as small as +/- 1 µm and excellent finish quality – no burrs, no dross, and dramatically reduced heat-affected zones. USP lasers can be used to process metals, polymers, ceramics, and glass.

Note that the laser source is THE key component in a laser micromachining system. Laser integrators should carefully test and vet all laser options to ensure that the best laser is selected for any particular application.

4. What are the critical components and design features in a Laser Micro Machining system?

In addition to the right laser source (see #3 above), critical components and features include:

• Class I enclosure with fume extraction, light curtains, and proximity sensors for operator safety
• Vibration dampeners to stabilize and isolate the processing zone
• Carefully selected optics and optomechanics to deliver the beam to the work piece
• High precision motion with machine vision to move the work piece precisely and repeatably
• Integrated robotic arms, tube loaders, and conveyors to safely handle parts to support high volume automated production
• Ergonomic and intuitive user interfaces/controls
• Built-in monitoring and data logging for rapid, efficient troubleshooting
• Easy access to machine subsystems to facilitate efficient maintenance

5. How should a system integrator position itself to provide high quality industrial Laser Micromachining solutions?

Laser system integrators and machine builders should design laser micromachining systems with the laser process foremost in mind. Put simply, these system integrators and machine builders must be as dedicated to their customers’ projects and product lines as they are to their own. This means drawing on a combination of hands-on and academic experience to optimize the customer’s process and then build a machine that satisfies complex requirements.

Conclusion

The medical device, aerospace, semiconductor and displays, and energy and renewables industries already rely on laser micromachining for many of the smallest and most delicate processes. Every day, new applications are developed that further showcase the unique capabilities of laser micromachining.