Zero-Taper Microholes: Precision Drilling for High-End Components by MONO

As femtosecond lasers gain popularity in precision manufacturing, their "cold processing" characteristics—no heat-affected zone (HAZ) and sub-micron level precision—have become the core technology for industries such as automotive, medical, and semiconductor to overcome challenges in high-end component processing. However, the inherent Gaussian energy distribution of femtosecond laser beams inevitably leads to a "top-wide, bottom-narrow" taper in microholes during traditional vertical drilling.  

This seemingly minor taper has become a major barrier to performance upgrades of high-end components. Leveraging its profound expertise in ultrafast laser processes, Mono has broken this physical limitation to achieve zero-taper (vertical) microhole drilling, opening up new possibilities for precision component manufacturing.

I. Why Is "Zero-Taper" So Critical?

A "zero-taper hole" refers to a hole where the sidewall is perfectly perpendicular to the surface, with identical inlet and outlet diameters.  

As a precise channel for fluid or gas transmission, the taper of the hole directly affects fluid flow characteristics such as velocity, pressure, and reaction efficiency. In the following critical applications, zero-taper is a rigid requirement:  

• Automotive Industry: In the fuel injectors of GDI (Gasoline Direct Injection) engines, zero-taper holes ensure uniform and stable fuel atomization, enabling more complete combustion, improved engine efficiency, and reduced emissions.  

• Medical Devices: In microfluidic chips, drug delivery devices, or implantable sensors, vertical hole walls are the foundation for accurate metering of liquid samples and flow rate control—taper would cause dosage inaccuracies.  

• Semiconductor Testing: Probe Cards are core components for chip testing, with tens of thousands of microholes for mounting test probes. Zero-taper ensures probe perpendicularity and contact stability, guaranteeing accurate and reliable test results.  

• High-End Textiles: The shape and perpendicularity of microholes in spinnerets for special fibers directly determine the cross-sectional morphology and final performance of fibers. Zero-taper is a prerequisite for manufacturing high-performance fibers with specific functions (e.g., moisture absorption, conductivity). 

II. MONO’s Femtosecond Laser Drilling: Solving the Taper Challenge

To achieve zero-taper, it is first essential to understand the root cause of taper. During femtosecond laser drilling, energy is most concentrated at the focal point; as depth increases, beam divergence and absorption/scattering of energy by ablated products cause the hole diameter to gradually decrease along the depth direction.  

High-quality drilling requires more than just a femtosecond laser. Mono Technology’s femtosecond laser solution integrates advanced optics, precision mechanics, and intelligent algorithms to realize dynamic and accurate control of beam posture, breaking through the barriers to high-quality processing of non-tapered straight holes.  

How Processing Technology Impacts Microhole Quality

Advanced Beam Control Technology: ML-VOTEX femtosecond laser precision processing center adopts a 5-axis linkage system, enabling high-speed rotation and tilting of the laser beam during processing. By precisely controlling the laser beam’s incident angle, the system "trims" the hole wall from the side to actively compensate for the natural taper caused by Gaussian beams.  

Adaptive Parameter Strategy: Developed for different materials and hole depths, this strategy gradually reduces the scanning diameter with processing depth and real-time matches the optimal laser power, ensuring consistent hole diameter throughout the hole and achieving near-zero taper (taper angle < 0.5°).  

Multispectral Confocal Ranging + 3D Visual Modeling: These technologies construct a micron-level digital twin of the workpiece, dynamically compensating for clamping errors and material deformation to ensure zero-taper processing accuracy on complex surfaces (e.g., catheters, special-shaped nozzles).  

III. Technical Advantages: Redefining the Standard for Precision Drilling

Mono Technology’s zero-taper drilling technology has been validated in numerous demanding application scenarios, redefining the standards for precision drilling in terms of accuracy, efficiency, material adaptability, and batch stability.  

1. Extreme Precision: Breaking Through Tolerance and Surface Finish Limits

Semiconductor: Microhole arrays on probe boards, with ±1μm positioning accuracy, high perpendicularity, and excellent roundness & surface finish.

• Medical Devices: Tantalum metal microhole arrays, with inlet (left) and outlet (right) diameters of only 25μm ± 1μm and a taper angle < 0.5°.  

2. Extreme Structures: High Aspect Ratios and High-Density Arrays

Aerospace: 3,500 non-tapered microhole arrays on curved filter screens, with high consistency, no recast layer, and surface roughness Ra ≤ 0.4μm.  

Aerospace: Non-tapered microhole arrays on tungsten sheets, with an aspect ratio of 10:1 and high roundness. 

3. Versatile Material Adaptability: From High-Melting-Point Metals to Hard-Brittle Ceramics

• Semiconductor: 50 microholes drilled in ceramics, with an aspect ratio of 10:1 and high roundness.  

• Medical Devices: Zero-taper microhole processing on PI (Polyimide) catheters, with no burrs.  

4. Customizable Shapes: From Perfect Circles to Complex Special Shapes

Textile Industry: Processing of special-shaped holes in spinnerets, with zero-taper, clear contours, and one-step forming.  

IV. Femtosecond Laser Solutions

In micro-nano manufacturing, precision is an eternal pursuit. Achieving high-quality "zero-taper" microholes requires more than just a femtosecond laser—it demands a complete solution that can control the beam, optimize processes, and stably replicate results.  

We provide customers with end-to-end services covering technical solutions, equipment selection, and process training. Whether your challenge involves materials, hole diameters, or shapes, Mono Technology’s expert team is ready to collaborate with you to turn the infinite possibilities of design into precise reality.