Laser-Etched Glass Recesses With Controlled Opening Angles

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Solution Overview

Problem

Existing methods for creating recesses or openings in transparent materials, such as glass, face limitations in achieving precise control over opening angles and diameters due to isotropic etching and inability to produce structures with large aspect ratios, leading to undesirable expansions and microcracks.

Innovation Solution

The method involves using electromagnetic radiation, specifically laser beams with phase modulation and varying pulse energy, to create modifications with different characteristics along the beam axis, allowing for inhomogeneous etching rates and targeted control of recess formation, including the use of etching resist to concentrate etching on specific areas, enabling the creation of recesses with varying angles and diameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If isotropic etching is used to create recesses in transparent materials, then the etching process is simple and uniform, but the opening angles and diameters cannot be precisely controlled and structures with large aspect ratios cannot be produced

Engineering Contradiction:
Improvecontrol over opening angles and diametersVSAvoidetching process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating modifications with different characteristics at different positions along the beam axis. The laser beam is focused at different depths to create modified zones with varying etching rates, allowing precise control of opening angles and diameters at different locations within the recess, while maintaining a relatively simple overall etching process.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If laser beam is focused to create cylindrical modification zone, then the opening diameter remains constant, but the ability to create varied opening angles and controlled widening is limited

Engineering Contradiction:
Improvecontrol over recess shape and opening angleVSAvoidflexibility in recess geometry
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent employs dynamics by dynamically adjusting the focus position of the laser beam along the beam axis during the modification process. This allows the creation of modification zones with different characteristics at different depths, enabling versatile recess geometries including conical widenings, cylindrical sections, and controlled opening angles, while maintaining precise control over the final recess shape.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for precise and adjustable creation of recesses with controlled opening angles and diameters, reducing unwanted expansions and microcracks, and enabling the production of components with optimized removal performance and accuracy, suitable for applications like microfluidics and nozzle plates.

Implementation Method 1

the material is selectively modified along a beam axis by means of electromagnetic radiation, in particular a laser

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

the recesses are subsequently produced by an etching process, wherein different etching rates occur in a modified and in the unmodified areas

Methodology Applied
Scientific EffectChemical etching:

Data Source

PatentEP3592500B1Process for manufacturing a recess in a material by means of electromagnetic radiation and subsequent etching process
Publication Date: 2023.10.11 LPKF LASER & ELECTRONICS AG
  • EP3592500B1 patent drawingFigure 1
  • EP3592500B1 patent drawingFigure 2
  • EP3592500B1 patent drawingFigure 3a~3c

AI summary

The invention relates to a method for producing at least one opening (1) in a transparent or transmissive glass substrate (2), the glass substrate (2) being selectively modified along a beam axis (s) by means of electromagnetic radiation, particularly a laser. By providing the modifications in the glass substrate (2) along the beam axis (s) by means of the electromagnetic radiation with different characteristics, for example by means of different pulse energy, the etching process in the glass substrate (2) is carried out non-homogeneously at different etching rates. This allows the possibility of forming the opening (1) created by the etching treatment in the transparent or transmissive material in a targeted and selective manner as a result of different characteristics of the modifications, and for example, varying the cone angle (α, β) of the opening (1).