Multi-Layer Laser Drilling with Layer-Specific Pulse Control

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Solution Overview

Problem

Standard laser drilling methods often result in cracks at the interfaces of multiple-layer components due to differences in material properties, which is a challenge that existing technologies have not effectively addressed.

Innovation Solution

The method involves controlling laser pulses by setting different frequencies, pulse durations, and pulse shapes for each layer to minimize or eliminate cracking, with the laser emitting device generating pulses with varying characteristics to drill through each material layer optimally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard laser drilling methods are used on multi-layer components, then drilling efficiency is maintained, but cracks form at the interfaces between different material layers

Engineering Contradiction:
Improvecrack-free drillingVSAvoiddrilling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The laser drilling process is segmented into multiple stages with different pulse parameters. The method divides the drilling process into: (1) pre-drilling stage with lower energy pulses to create an initial hole without excessive heating, (2) main drilling stage with higher energy pulses to complete penetration, and (3) cooling stage with reduced energy pulses to prevent crack formation at material interfaces. This segmentation allows optimization of each stage to balance productivity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs periodic laser pulsing with varying parameters throughout the drilling process. Instead of continuous or uniform pulsing, the system periodically adjusts pulse duration, energy, and frequency based on the drilling depth and material layer being penetrated. This periodic variation in action parameters enables effective drilling while preventing thermal accumulation that causes interface cracking.

Inventive Principle:
Principle #19Periodic action

2Manufacturing precision

If uniform laser pulses are applied to all layers, then process simplicity is maintained, but material-specific optimal drilling cannot be achieved

Engineering Contradiction:
Improvelayer-specific drilling qualityVSAvoidpulse control system
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The laser pulse parameters are made dynamic rather than static. The control system continuously adjusts pulse duration, energy level, and frequency based on real-time feedback and pre-programmed sequences corresponding to different material layers. This dynamic adaptation enables precise control for each layer's specific material properties while using a single laser device, managing complexity through software control rather than hardware complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention systematically changes key laser parameters including pulse duration (from milliseconds to microseconds), pulse energy, and repetition frequency according to the specific material layer being drilled. Each material layer has optimized parameter sets that maximize drilling quality while minimizing thermal damage. This parameter change strategy achieves high manufacturing precision through controlled variation rather than complex device architecture.

Inventive Principle:
Principle #35Parameter changes

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 effectively minimizes or eliminates cracks at the interfaces between different material layers, ensuring precise and crack-free drilling through components with multiple layers.

Implementation Method 1

drilling is performed by means of a laser emitting device

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

generating at least one first layer pulse with a first pulse duration and a first pulse shape defining a varying energy level over time for drilling through a first layer

Methodology Applied
Scientific EffectThermal ablation: Ablation

Data Source

PatentEP3072628B2Laser drilling through multi-layer components using pulse in the millisecond range and having varying energy over time
Publication Date: 2022.07.20 PRATT & WHITNEY CANADA CORP
  • EP3072628B2 patent drawingFigure 1~2
  • EP3072628B2 patent drawingFigure 3A
  • EP3072628B2 patent drawingFigure 3B

AI summary

There is described herein a method OF and system for drilling holes in components (300) having multiple layers of materials using a laser emitting device (302) in combination with a control unit (304), by controlling the laser pulses in such a way that cracks at the interfaces between the various materials are minimized or eliminated.