Precision Micro Laser Cutting Technology

I. Core Working Principle of Precision Micro Laser Cutting

1. Thermal Ablation (Nanosecond / Ultraviolet Fiber Laser) Photon energy is converted into thermal energy to locally melt and vaporize materials, with auxiliary gas (N₂/O₂/Ar) blowing away molten slag. Thermal conduction exists, generating heat-affected zone (HAZ), melted edges and oxide layers.
2. Ultrafast Cold Ablation (Picosecond / Femtosecond Ultrashort Pulse) The pulse width is shorter than the molecular thermal diffusion time. Materials are directly stripped at atomic/molecular levels through multiphoton ionization and Coulomb explosion, with no time for heat outward diffusion. The heat-affected zone approaches zero; no melting, carbonization or microcracks occur, realizing genuine “cold processing”.

II. Comparison of Mainstream Laser Light Sources (Core Basis for Model Selection)

• Nanosecond: A hot cutting blade with melted edges after processing
• Picosecond: An extremely sharp cold blade with slight extrusion effect
• Femtosecond: Heat-free optical cutting edge; no thermal deformation of materials during cutting

III. Core Technical Advantages (vs. Mechanical Micro-Cutting & Wire EDM)

1. Ultra-High Dimensional Accuracy Minimum light spot reaches 3 μm; micro grooves, micro holes and sharp corners of special shapes can be formed in one pass with stable tolerance of ±1 μm. It can fabricate complex miniature patterns unachievable by traditional cutting tools (micro gears, spiral micro slits, micron filter meshes).
2. Non-Contact & Stress-Free Processing No tool extrusion or cutting force. Ultra-thin foils (0.005 mm metal / PI film), glass, silicon wafers and other brittle materials stay free of deformation and cracking.
3. Controllable Edge Quality Surface roughness Ra ≤0.2 μm for femtosecond processed cross-sections, burr-free, no recast layer or carbonization. Post-polishing and deburring procedures are eliminated for most working conditions.
4. Excellent Material Compatibility Applicable to metals, hard-brittle dielectric materials, polymer thin films and composite materials; femtosecond laser can fabricate internal microstructures inside transparent materials (glass, sapphire).
5. Flexible Digital Processing CAD drawings can be imported directly without mold manufacturing or tool replacement. Fast switching between various miniature parts, suitable for R&D sampling and small & medium batch production.
6. Narrow Kerf & Material Saving Kerf width is only several microns, drastically reducing material loss compared with mechanical milling, with prominent advantages for precious metal processing.

IV. Processable Material Categories

1. Metals & Alloys (Common for Sheet Metal & Precision Machining)

2. Hard-Brittle Inorganic Materials

3. Polymer Thin Films / Medical Soft Materials

4. Composite & Special Materials

V. Typical Industrial Applications

1. Medical Devices (Femtosecond Laser as Mainstream)

2. Semiconductor & Electronic Manufacturing

3. Optics & Precision Instruments

4. New Energy & Aerospace

5. Alternative to Precision Sheet Metal / Micro Stamping

VI. Key Process Parameters & Quality Control Points

1. Light Spot Size: Determines minimum feature size; femtosecond laser can focus to 3~5 μm
2. Pulse Repetition Frequency & Single Pulse Energy: Control ablation depth and heat accumulation
3. Scanning Speed & Path: Reduce speed at sharp corners to avoid over-burning; uniform speed for thin sheets to prevent deformation
4. Auxiliary Gas: N₂ delivers bright oxidation-free cutting surfaces; O₂ improves metal cutting efficiency; Ar is adopted for highly active alloys
5. Motion Platform: Linear motor positioning with ±0.5 μm repeat positioning accuracy to guarantee batch consistency
6. Thickness Limit: Conventional micro-cutting fits plates of 0.003~3 mm; layered scanning is required for thick microstructures

VII. Technical Limitations & Application Boundaries

1. Low Efficiency for Thick Workpieces Processing efficiency for parts thicker than 3 mm is inferior to large-format fiber laser. Micro-cutting is mainly targeted at ultra-thin miniature components.
2. High Equipment Cost for Ultrafast Lasers The investment cost of femtosecond equipment is 3~8 times that of nanosecond laser. Nanosecond ultraviolet laser is preferred for mass production with low precision requirements.
3. High-Reflectivity Metals (Pure Copper, Pure Aluminum) Wavelength and energy parameters need optimization; reflected laser may damage optical lenses easily.
4. Taper on Deep Through Holes Micro holes processed by nanosecond laser carry slight taper. It is acceptable for workpieces without vertical wall requirements; picosecond or femtosecond laser is mandatory for high-precision micro holes.

VIII. Industry Development Trends

1. Mass Production of High-Power Ultrafast Lasers Improve processing speed of picosecond and femtosecond lasers, reduce unit processing cost, and gradually replace nanosecond laser in high-end markets
2. Integrated Composite Microfabrication All-in-one machine integrating cutting, micro-hole drilling and micro-etching to complete multiple procedures of miniature parts in one station
3. Composite Light Sources with Infrared / Dual Wavelength Compatible with both metals and transparent brittle materials; single equipment covers multiple workpiece categories
4. Closed-Loop In-Line Visual Inspection Real-time dimensional measurement during processing with automatic laser trajectory compensation to greatly boost product yield
5. Popularization of Low-Cost Industrial Femtosecond Lasers Miniaturized equipment penetrates precision sheet metal factories and small & medium-sized medical component manufacturers