Structured Glass Etching with Laser-Defined Tapered Walls

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Solution Overview

Problem

Existing methods for structuring glass elements using ultrashort pulse lasers require extensive process control and precise adjustments, making them complex and difficult to implement effectively.

Innovation Solution

A method involving a pulsed laser beam is directed onto a glass element to create filament-shaped flaws that are then widened by an etching medium, forming walls or holes with adjustable taper angles, eliminating the need for precise process control by adjusting the position and intensity distribution of the focus line.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If oblique laser pulses are directed onto the glass element surface to create tilted filaments, then the filament-shaped flaws extend at an angle to the surfaces, but extensive process control is required to adjust and monitor laser parameters and workpiece positioning precisely

Engineering Contradiction:
Improvefilament orientation angleVSAvoidprocess control complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

Instead of directing the laser beam at an oblique angle to create tilted filaments, the patent inverts the approach by directing the laser beam perpendicularly to the surface while tilting the focusing optics. This produces the same tilted filament geometry without requiring complex oblique beam positioning and monitoring systems

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent replaces the mechanical/positional control system (precise workpiece positioning and oblique beam alignment) with an optical solution (tilted focusing optics). This substitution eliminates the need for extensive process control while achieving the desired filament orientation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If special focusing optics are provided to compensate for astigmatic deformation, then the beam profile is corrected, but the device complexity increases

Engineering Contradiction:
Improvebeam profile accuracyVSAvoidoptical system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of using complex special focusing optics to correct astigmatic deformation, the patent inverts the approach by intentionally introducing astigmatism through a simple cylindrical lens. This controlled astigmatism directly produces the desired tilted filament pattern without requiring complex correction optics

Inventive Principle:
Principle #13The other way round (Inversion)

3Manufacturing precision

If multiple process parameters are adjusted and monitored precisely, then the filament geometry is controlled accurately, but the ease of operation decreases

Engineering Contradiction:
Improvefilament geometry controlVSAvoidprocess simplicity
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent employs a self-service mechanism where the cylindrical lens automatically generates the tilted filament pattern through its inherent astigmatic property. The geometry of the filaments is self-determined by the lens orientation and focal length, eliminating the need for manual adjustment and monitoring of multiple process parameters

Inventive Principle:
Principle #25Self-service

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 method simplifies the process of creating structured glass elements with blind holes or channels, allowing for precise control over geometry and taper angles without requiring complex optical devices, suitable for applications like interposers and printed circuits.

Implementation Method 1

several spaced apart filaments are produced along an intended separation line, exploiting a nonlinear effect of selffocusing

Methodology Applied
Scientific EffectSelf-focusing:

Implementation Method 2

The filament-shaped flaw is produced with a laser beam that is concentrated by means of a focusing optics to form a focus line in the glass element

Methodology Applied
Scientific EffectFocusing: Focusing

Implementation Method 3

The glass element is exposed to an etching medium or an etching bath which removes glass by etching, so that the filament-shaped flaw widens to form a wall

Methodology Applied
Scientific EffectEtching:

Data Source

PatentEP4011846A1Method of structuring a glass element and structured glass element produced thereby
Publication Date: 2022.06.15 SCHOTT AG
  • EP4011846A1 patent drawingFigure 1~2
  • EP4011846A1 patent drawingFigure 3~4
  • EP4011846A1 patent drawingFigure 5~6b

AI summary

The invention relates to a method of structuring a glass element (1), wherein - a pulsed laser beam (5) of an ultrashort pulse laser (7) is directed onto the glass element (1), wherein - the glass element (1) is transparent for the laser beam (5) and wherein - at least one filament-shaped flaw (9) is produced in the glass element (1), the filament-shaped flaw (9) extending transversely to the side faces (14, 15) of the glass element (1), the filament-shaped flaw (9) being produced with a laser beam (5) that is concentrated by means of a focusing optics (70) to form a focus line (8) in the glass element (1), wherein the intensity of the laser beam (5) within the focus line (8) is sufficient to produce the filament-shaped flaw (9), and wherein - the focus line (8) is adjusted so that the filament shaped flaw (9) ends within the glass element (1), and wherein - the glass element (1) is exposed to an etching bath (81) which removes glass by etching, so that - the filament-shaped flaw (9) widens to form a wall (6) extending between the opposite side faces (14, 15) of the glass element (1), the wall (6) having a boundary line (12) that is tapered at the vertex (16, 17, 18, 19) between the wall (6) and an adjacent side face (14, 15), with a taper angle (94) with respect to the perpendicular (13) of the side face (14, 15), - the taper angle (94) being adjusted by at least one of the position and intensity distribution of the focus line (8). A further aspect of the invention relates to glass elements (1) produced or producible with a method according to the invention.