Laser Hole Drilling Sequence With Ventilation for Fragile Substrates

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Solution Overview

Problem

Challenges arise in high-precision laser machining of substrates such as crystalline silicon (c-Si) wafers and polymer-based build-up films due to localized heating, poor drilling efficiency, and debris interference, which compromise precision and quality, especially when processing thin and fragile materials at high speeds.

Innovation Solution

A method and apparatus for laser machining that involves controlled laser beam movements in specific directions relative to fluid flow, with each hole drilled iteratively and multiple times, using a ventilation system to manage debris, and ensuring angles between laser beam movements and fluid flow directions meet certain criteria to avoid interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high laser energies are used for high-speed processing, then productivity is improved, but manufacturing precision deteriorates due to localized heating and melting

Engineering Contradiction:
Improveprocessing speedVSAvoiddrilling precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The laser beam is applied in periodic pulses rather than continuous exposure. The patent specifies that the laser beam is directed onto the area to be subjected to the laser beam in a predetermined sequence multiple times, with intervals between exposures allowing heat dissipation and preventing localized melting while maintaining high processing speed

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

A ventilation system is activated before laser exposure to establish a controlled fluid flow environment. The system blows fluid onto the substrate surface prior to and during laser machining to preemptively manage heat and debris, preventing damage before it occurs

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If laser machining is performed on thin and fragile substrates, then manufacturing cost is reduced, but reliability deteriorates due to substrate damage or breakage

Engineering Contradiction:
Improvemanufacturing costVSAvoidsubstrate integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The ventilation system provides protective cushioning by directing fluid flow onto the substrate surface before and during laser exposure. This fluid layer acts as a protective medium that absorbs excess heat and captures debris, preventing direct damage to the thin and fragile substrate while allowing cost-effective processing

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent employs a controlled fluid environment (inert atmosphere) during laser machining to protect the substrate from thermal damage and contamination. The fluid flow creates a protective environment that prevents substrate breakage while maintaining manufacturing efficiency

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Productivity

If continuous laser exposure is used for drilling, then productivity is improved, but manufacturing precision deteriorates due to debris generation and heat accumulation

Engineering Contradiction:
Improvedrilling efficiencyVSAvoidprocessing accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The laser exposure is implemented as periodic pulsed action rather than continuous exposure. The beam is directed multiple times in a predetermined sequence with intervals between exposures, allowing debris removal and heat dissipation while maintaining drilling efficiency

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

A ventilation system using fluid flow (pneumatic/hydraulic action) is employed to remove debris generated during laser drilling. The system blows fluid onto the processing area to clear away particles that would otherwise interfere with processing accuracy, enabling continuous high-productivity operation

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 enhances precision and quality by minimizing localized heating and debris impact, allowing high-speed, uniform hole formation with improved uniformity and reduced damage to substrates.

Implementation Method 1

A laser beam is directed onto a set of areas on a substrate to be subjected to the laser beam in a predetermined sequence so that material is removed from the areas

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

A ventilation system is provided which is configured to blow a fluid onto a surface of the substrate

Methodology Applied
Scientific EffectFluid flow: Convection

Data Source

PatentEP4304804B1Apparatus and method for laser machining of a substrate
Publication Date: 2025.06.25 APPLIED MATERIALS ITALIA SRL
  • EP4304804B1 patent drawingFigure 1~2
  • EP4304804B1 patent drawingFigure 3~4
  • EP4304804B1 patent drawingFigure 5~6

AI summary

An apparatus for hole drilling in a substrate is provided. The apparatus includes a laser system configured to apply a laser beam onto the substrate for removing material from a set of areas on the substrate by directing the laser beam onto predefined positions corresponding to the set of areas on the substrate in a sequence. The apparatus includes a ventilation system configured to produce a fluid flow along one or more sides of the substrate. The apparatus controls the laser beam such that the laser beam is sequentially positioned according to a first laser beam movement direction and a second laser beam movement direction.