Laser Welding Beam Splitting for Ghost Beam Reduction

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Solution Overview

Problem

Current laser welding systems for electronic devices, such as batteries, face issues with high energy consumption and the production of ghost beams, which can cause undesirable effects like damage to internal components due to inefficient energy distribution and beam patterns.

Innovation Solution

The method involves arranging overlapping heat source points with linear profiles at oblique angles to reduce energy consumption and ghost beam production, using a laser welding system with beam modifying means like diffractive optical elements to split the laser beam into fewer output beams, and directing these beams along a weld line to form specific patterns that minimize internal exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high power laser oscillator is used to create five or more welding beams in a symmetric cross shape, then welding coverage and seal quality are improved, but energy consumption and device cost increase significantly

Engineering Contradiction:
Improvewelding seal qualityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent divides the welding beam into multiple separate beams (typically 3-5 beams) that are distributed in a specific pattern rather than using a single high-power beam or a symmetric cross pattern. This segmentation allows the laser energy to be distributed more efficiently across the weld area, reducing the peak power requirement while maintaining effective welding coverage and seal quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs an asymmetric distribution of multiple welding beams instead of a symmetric cross pattern. The beams are positioned at specific angles and locations that are optimized for welding performance, creating an asymmetric pattern that reduces ghost beam interference and improves energy utilization efficiency while maintaining reliable sealing.

Inventive Principle:
Principle #4Asymmetry

2Area of stationary object

If a symmetric cross pattern with five or more heat source points is used, then welding coverage is improved, but ghost beam production increases causing undesirable effects on internal components

Engineering Contradiction:
Improvewelding coverage areaVSAvoidghost beam damage to internal components
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent uses an asymmetric arrangement of multiple welding beams instead of a symmetric cross pattern. This asymmetric configuration is specifically designed to minimize ghost beam generation and interference patterns that could otherwise damage internal battery components, while still providing adequate welding coverage area through optimized beam positioning and angles.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies different characteristics to different regions of the welding pattern. The primary beams are positioned and configured for effective welding, while the overall asymmetric pattern is designed to minimize ghost beam effects in specific areas. This local optimization ensures both welding coverage and protection of internal components from harmful ghost beam effects.

Inventive Principle:
Principle #3Local quality

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 reduces energy consumption, enhances welding accuracy, and decreases the risk of undesirable effects on internal parts, achieving a more efficient and precise welding process.

Implementation Method 1

a laser beam is used to create five or more heat source points in a symmetric cross shape using optical elements (e.g., diffractive optical elements)

Methodology Applied
Scientific EffectDiffraction: Diffraction

Implementation Method 2

A laser source is provided and configured to produce a laser beam

Methodology Applied
Scientific EffectLaser: Laser

Implementation Method 3

irradiating a portion of a target with the first and second collections of heat source points

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3188875B1System for and method of welding with two collections of laser heat source points
Publication Date: 2019.10.30 TOYOTA JIDOSHA KK
  • EP3188875B1 patent drawingFigure 1A~2A
  • EP3188875B1 patent drawingFigure 2B~2D
  • EP3188875B1 patent drawingFigure 3A~4D

AI summary

A method of laser welding is provided. The method includes arranging at least one heat source point from a first collection of heat source points so as to overlap at least a portion of at least one heat source point from a second collection of heat source points, irradiating a portion of a target (2) with the first and second collections of heat source points, the heat source points maintaining a linear profile within their respective collection, and directing the at least two collections of heat source points in a travel direction along a weld line, each linear profile maintaining an oblique angle relative to the travel direction.