Electrowetting Display Fluid Dispensing Uniformity

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Solution Overview

Problem

The existing methods for fabricating electrowetting displays face challenges in achieving uniformity and efficiency in dispensing fluids onto substrates, leading to higher costs and lower yields in the manufacturing process.

Innovation Solution

A double-slit fluid dispenser is used to dispense a first fluid, such as opaque oil, and a second fluid, like an electrolyte solution, onto a substrate with a wetting strip that improves fill uniformity by pushing back the second fluid relative to the first fluid, ensuring uniform distribution across the display elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional fluid dispensing methods are used, then the manufacturing process is simpler, but the uniformity of fluid distribution across display elements deteriorates

Engineering Contradiction:
Improveuniformity of fluid distributionVSAvoidcomplexity of dispensing apparatus
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The fluid dispensing apparatus is segmented into multiple independent dispensing nozzles arranged in an array, with each nozzle targeting specific display elements. This segmentation enables precise control of fluid distribution across different regions of the substrate, achieving uniformity through distributed dispensing points rather than a single source.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dispensing system provides local quality control by enabling different fluid volumes, viscosities, or dispensing parameters to be applied to different regions of the substrate. Each dispensing nozzle can be independently controlled to accommodate variations in display element requirements across the substrate surface, ensuring optimal fluid distribution uniformity.

Inventive Principle:
Principle #3Local quality

2Productivity

If manual or sequential fluid dispensing is used, then the equipment is simpler, but the manufacturing productivity deteriorates

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidcomplexity of dispensing system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

Multiple fluid dispensing functions are merged into a single integrated apparatus that can dispense different fluids simultaneously through multiple nozzles. This consolidation enables batch processing of multiple display elements in parallel, dramatically improving manufacturing productivity compared to sequential manual dispensing while maintaining controlled complexity through functional integration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The dispensing apparatus is designed with multi-functionality to handle different types of fluids (e.g., electrowetting fluid, encapsulant, adhesive) using the same basic platform. The system can be configured with different nozzle types and dispensing parameters to accommodate various fluid viscosities and application requirements, enhancing productivity by eliminating the need for separate dispensing equipment for each fluid type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 the uniformity of the first fluid in the display elements, leading to improved manufacturing efficiency and reduced costs by ensuring consistent fill of the display devices.

Implementation Method 1

A number of display elements and a wetting strip are formed on the substrate. A wettability between the first fluid and the wetting strip is different from a wettability between the second fluid and the wetting strip.

Methodology Applied
Scientific EffectCapillary pressure: Capillary Pressure

Data Source

PatentEP3161542B1Methods and apparatuses for fabricating electrowetting displays
Publication Date: 2020.10.28 AMAZON TECH INC
  • EP3161542B1 patent drawingFigure 1~2
  • EP3161542B1 patent drawingFigure 3~4
  • EP3161542B1 patent drawingFigure 5~6

AI summary

An apparatus for fabricating electronic displays comprises a glass substrate that includes pixel arrays formed on the glass substrate. Individual pixels of the pixel arrays include pixel walls to retain a first fluid, such as oil. The pixel arrays may include an edge seal to retain a second fluid, such as an electrolyte solution, that overlays the pixel walls and the first fluid. The glass substrate also includes a hydrophobic strip formed on the glass substrate. A wettability between the first fluid and the hydrophobic strip is different from a wettability between the second fluid and the hydrophobic strip.