Glass Microstructures With Etched Overhangs and Contoured Capping

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Solution Overview

Problem

Current methods for producing microstructures in glass substrates are limited in creating complex, three-dimensional structures with arbitrary contours and topography, and do not effectively utilize the glass substrate's properties for applications like sensors and electrical contacts.

Innovation Solution

A method involving laser-induced modifications and anisotropic etching to create mutually opposing recesses, followed by applying a resistant cover layer on one surface, allowing further etching to create overhang structures that can be used as an etching resist and for material removal, enabling the production of glass substrates with arbitrary contours and topography suitable for complex electrical microstructures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional etching methods are used to create microstructures in glass substrates, then simple recesses can be produced, but complex three-dimensional structures with overhangs and arbitrary contours cannot be achieved

Engineering Contradiction:
Improvemicrostructure complexityVSAvoidmanufacturing capability
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent applies a cover layer to the glass substrate surface before etching. This preliminary action creates a protective mask that defines the desired microstructure pattern, enabling complex three-dimensional shapes with overhangs to be formed through subsequent selective etching processes without requiring complex manufacturing equipment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cover layer acts as an intermediary between the etching process and the glass substrate. It protects specific areas from etching while allowing precise material removal in exposed regions, enabling the creation of complex microstructures that would otherwise be impossible to manufacture with conventional direct etching methods

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the entire glass substrate surface is utilized for microstructures, then manufacturing efficiency is improved, but electrical contacts and sensor applications are compromised

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidapplication flexibility
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent creates microstructures with varying local properties by selectively applying the cover layer and etching process. Different regions of the glass substrate can have different microstructure densities, depths, and patterns, allowing areas optimized for manufacturing efficiency while preserving regions suitable for electrical contacts and sensor applications

Inventive Principle:
Principle #3Local quality

3Length of stationary object

If deep recesses are created through the glass substrate, then through-holes and deep structures are achieved, but material removal and substrate thinning occur

Engineering Contradiction:
Improverecess depthVSAvoidmaterial removal
Core Design Contradiction:
Length of stationary objectVSLoss of substance

Solution Approach 1:

The cover layer is applied beforehand to protect areas where material should be retained. During the etching process, this preliminary protective action ensures that deep recesses are created only in exposed regions, minimizing unnecessary material removal while achieving the required recess depths for through-holes and deep structures

Inventive Principle:
Principle #10Preliminary action

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

Enables the creation of glass substrates with overhang structures that serve as separating surfaces and can be used for electrical contacts, sensors, and other applications, with adjustable shape and size, and can reduce material thickness for optimal use in microsystem technology.

Implementation Method 1

modifications are first introduced into at least one outer surface by means of laser radiation and, due to the laser action during the modification, a chemical conversion of the substrate material occurs

Methodology Applied
Scientific EffectLaser-induced chemical transformation: Laser

Implementation Method 2

The laser's action results in no or only very minimal material removal from the substrate's surface. The laser energy input can thus be limited to a few pulses or a single pulse

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

the microstructures are produced by an etching process by means of anisotropic material removal through a plurality of, in particular at least partially conical, recesses

Methodology Applied
Scientific EffectAnisotropic etching:

Data Source

PatentEP3966157B1Method for producing microstructures in a glass substrate
Publication Date: 2024.03.20 LPKF LASER & ELECTRONICS AG
  • EP3966157B1 patent drawingFigure 1~2
  • EP3966157B1 patent drawingFigure 3~4
  • EP3966157B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for producing microstructures in a glass substrate (1), wherein firstly laser modifications are introduced into the glass substrate (1) in both outer surfaces (2, 3). Etching the glass substrate (1) that has been treated in this way gives rise to a multiplicity of conical cutouts (5) in the glass substrate (1) on account of anisotropic material removal. As soon as the cutouts (5) of the desired size have been produced, the etching process is interrupted and a capping layer (6) that is resistant to the etching attack is applied to the upper, first outer surface (2), said capping layer thus matching the contour of the cutouts (5). Afterward, the glass substrate (1) that has been coated in this way is etched further, further material removal occurring in the cutout (5) at the second outer surface (3) facing away from the capping layer (6), while the first outer surface (2), which is protected by the capping layer (6) as etching resist, is maintained unchanged. The progressive material removal results in a deepening (T) of the cutout (5) until the latter has finally reached a rear side (7) of the capping layer (6), and the etching process is ended. As a result, the capping layer (6) bridging the cutouts (5) acquires, according to the invention, a three-dimensionally contoured constitution which is usable for diverse application purposes.