Micro-Nano Processing: Femtosecond Laser vs. Picosecond Laser – How to Choose Tool?
In high-precision fields such as microelectronic manufacturing, medical device R...
MONO | 2025-11
NEWS CENTER
As mentioned earlier, the precision machining of grooves is the "lifeline" for pressure relief disc manufacturing. However, traditional groove machining technologies have long been plagued by insurmountable bottlenecks, resulting in low qualification rates of high-precision pressure relief discs and limited applicable scenarios. The emergence of femtosecond laser technology, with its characteristics of "ultra-short pulses and ultra-low thermal impact", has completely reshaped the landscape of precision manufacturing for pressure relief discs.
Before the application of femtosecond laser technology, groove machining for pressure relief discs mainly relied on two methods: mechanical stamping and chemical etching, both of which had unavoidable defects:
• Mechanical stamping: Grooves are formed by applying pressure to the diaphragm using a mold. This method has extremely poor depth uniformity (errors often exceed 5μm), and mechanical stress generated during stamping causes diaphragm deformation, resulting in a batch qualification rate of less than 60%.
• Chemical etching: Grooves are formed by corroding the diaphragm with chemical reagents. Although this method improves uniformity, chemical reagents cause corrosive damage to the diaphragm surface. Additionally, heat generated during etching leads to "recast layers" (layers of material re-solidified after melting) at the diaphragm edges, which seriously affects the stability of burst pressure. This makes it completely unsuitable for high-precision scenarios such as aerospace.
These limitations have long left high-precision pressure relief discs for high-temperature and high-pressure scenarios trapped in a dilemma of "high demand, low productivity, and poor qualification rates"—until the intervention of femtosecond laser technology.
The core advantages of femtosecond lasers stem from their "ultra-short pulse width" (1 femtosecond = 10⁻¹⁵ seconds, equivalent to the time it takes for light to travel 0.3 microns in a vacuum) and "ultra-high peak power". This enables "direct material sublimation" during machining, fundamentally addressing the pain points of traditional machining:
1. Non-thermal damage processing: The ultra-short pulse allows laser energy to act on the material surface in an instant. Before heat can diffuse to the surrounding area, the material has already sublimated, completely avoiding melting and recast layers. The groove edges are as smooth as a mirror, with no residual thermal stress.
2. Extreme machining precision: It can achieve sub-micron (0.1μm level) control of material removal. The tolerance of groove depth and width can be stably controlled within ≤1μm, meeting the strict burst pressure requirements of the aerospace industry.
3. Unparalleled repeatability: Laser pulse parameters (energy, frequency, scanning speed) can be precisely adjusted, and the consistency error of batch machining is less than 0.3μm, significantly increasing the qualification rate to over 99%.
4. Broad material adaptability: Femtosecond lasers can accurately etch not only metal diaphragms such as stainless steel and nickel but also brittle graphite diaphragms. No tool replacement is required, making it suitable for working conditions in different industries.
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(Under a microscope, a clear contrast is visible: Grooves machined by traditional nanosecond/picosecond lasers have obvious recast layers at the edges, while those machined by femtosecond lasers show no signs of damage.)
The manufacturing of high-performance pressure relief discs requires not only advanced femtosecond laser light sources but also the coordinated optimization of "light source + equipment + process". As a provider of femtosecond laser extreme manufacturing technology and equipment, MONO has launched a targeted solution that perfectly addresses the core challenges of groove machining for pressure relief discs:
To meet the core requirement of groove depth precision, MONO adopts a "layered iterative removal" process: The target groove depth (e.g., 70μm) is divided into dozens to hundreds of machining layers, with only sub-micron (0.1-0.5μm) material thickness removed per layer. By precisely optimizing the matching relationship between "laser energy density + number of scanning layers", the final depth precision is controlled within ≤0.5μm. For example, for circular and cross-shaped grooves with a depth of 70μm, the actual machining depth deviation can be stably controlled within ≤1μm, fundamentally ensuring that the burst pressure is completely consistent with the design value.
MONO's ML-Etch femtosecond laser microstructuring and etching equipment is equipped with an industrial-grade femtosecond laser light source and a built-in dynamic focus compensation algorithm. During the layered scanning process, the equipment real-time detects the diaphragm surface height and automatically adjusts the laser focus position, ensuring the focus always acts accurately on the surface to be machined. This avoids machining deviations caused by minor diaphragm deformation. Meanwhile, the non-contact machining method completely eliminates stress damage from mechanical stamping, allowing the machined grooves to withstand higher-frequency repeated pressure fluctuations.
For intersecting grooves commonly used in pressure relief discs (such as cross-shaped grooves and star-shaped grooves), traditional machining often leads to depth over-tolerance due to repeated ablation in the intersecting areas. MONO optimizes the laser scanning path through an intelligent path planning algorithm to avoid over-machining in intersecting areas, enabling precise etching of cross-shaped grooves, concentric circular grooves, and customized complex patterns. This not only supports the rapid implementation of small-batch customized designs in the aerospace industry but also meets the mass production needs of large-diameter diaphragms in the chemical industry.
In industries with extremely high safety and precision requirements—such as petrochemicals and aerospace—femtosecond laser technology is redefining the manufacturing standards of pressure relief discs. MONO's "equipment + process + customized service" model not only breaks through the technical bottlenecks of traditional machining but also makes the industrial mass production of high-precision pressure relief discs possible.
If you need to learn more about femtosecond laser machining cases, conduct process verification, or consult sample testing, please feel free to contact us.
