Multi-Head Ultrasonic Bonding Timing for Accurate Multi-Position Joining

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Solution Overview

Problem

Conventional multi-position ultrasonic bonding methods for solar cell substrates face bonding failures due to overlapping ultrasonic vibrations, leading to inaccurate bonding at multiple positions.

Innovation Solution

An ultrasonic bonding method using multiple ultrasonic bonding head units with a head unit moving mechanism and position detection units, where each unit operates independently to ensure non-overlapping ultrasonic vibration times, allowing precise control of bonding heights and contact timings to prevent wave motion interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple ultrasonic bonding head units operate simultaneously at multiple bonding positions, then productivity is improved, but wave motion interference causes bonding failure and manufacturing precision deteriorates

Engineering Contradiction:
Improvebonding speedVSAvoidbonding accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The control unit determines ultrasonic vibration start times for each bonding head unit in advance, calculating timing that prevents wave motion overlap. This preliminary timing coordination allows multiple heads to operate simultaneously without interference, maintaining both high productivity and bonding precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the operation timing of each ultrasonic bonding head unit based on its position and the wave motion characteristics of other units. By making timing dynamic rather than uniform, the system enables simultaneous operation without wave interference, resolving the contradiction between multi-position productivity and bonding accuracy.

Inventive Principle:
Principle #15Dynamics

2Reliability

If ultrasonic vibration operation time is extended to ensure proper bonding, then bonding reliability is improved, but production takt time increases and productivity decreases

Engineering Contradiction:
Improvebonding reliabilityVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system uses periodic ultrasonic vibration operations with precisely controlled durations and intervals. By optimizing the periodic timing of each bonding head unit to prevent wave overlap, the system achieves reliable bonding in shorter time periods, improving both bonding reliability and production efficiency simultaneously.

Inventive Principle:
Principle #19Periodic 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

This approach enables efficient and accurate ultrasonic bonding on multiple positions by preventing wave motion interference, ensuring high accuracy and reliability in the bonding process.

Implementation Method 1

an ultrasonic bonding process to apply ultrasonic waves while applying pressure to the electrode wire disposed on the substrate

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentEP3730243B1Method of ultrasonic bonding
Publication Date: 2022.04.27 TOSHIBA MITSUBISHI ELECTRIC IND SYST CORP
  • EP3730243B1 patent drawingFigure 1
  • EP3730243B1 patent drawingFigure 2
  • EP3730243B1 patent drawingFigure 3~4

AI summary

An object of the present invention is to provide an ultrasonic bonding method capable of performing ultrasonic bonding efficiently and accurately on a plurality of bonding positions of a bonding target. Then, in the ultrasonic bonding method as the present invention, in step S2, three ultrasonic bonding head units (61 to 63) are disposed above the bonding target. At this time, initial heights h1 to h3 in the three ultrasonic bonding head units (61 to 63) are set to different heights from each other. Thereafter, in step S4, a batch multiple lowering operation by a lifting-lowering servomotor (2X) and ultrasonic vibration operations by the three ultrasonic bonding head units (61 to 63) are executed. At this time, a lowering speed V6 of the batch multiple lowering operation, an operation time T6 (min) of the ultrasonic vibration operation, and an adjustment gap length Δg among the initial heights h1 to h3 are set to satisfy {T6 < Δg/V6}.