Liquid Ejecting Head Electrode Density Uniformity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing liquid ejecting heads face issues with non-uniform electrode densities in the mounting region, leading to adhesion failures and heat distribution biases, which affect the adhesive strength and film formation during the manufacturing process.

Innovation Solution

The introduction of third electrodes that do not contribute to liquid ejection, arranged between adjacent second electrodes in the mounting region, helps to uniformize electrode densities by maintaining equal pitches across different regions, thereby reducing the difference in adhesive coating and heat distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrodes are arranged to correspond to each piezoelectric element in the mounting region, then electrical connection is achieved, but electrode density becomes non-uniform causing adhesion failure and heat distribution bias

Engineering Contradiction:

Improveadhesion strengthVSAvoidelectrode density uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by differentiating electrode arrangements into two distinct regions: a first region where electrodes correspond to piezoelectric elements for electrical connection, and a second region where dummy electrodes are added specifically to achieve uniform density. This localized differentiation allows the mounting region to simultaneously satisfy electrical connectivity requirements and uniform heat distribution requirements.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Dummy electrodes serve as an intermediary element that does not perform electrical connection functions but fulfills the structural role of maintaining uniform electrode density. These intermediary electrodes mediate between the functional requirement of electrical connection and the manufacturing requirement of uniform heat distribution, allowing both to coexist.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If electrodes are arranged with varying densities to match piezoelectric element positions, then electrical connection is optimized, but adhesive coating becomes non-uniform leading to adhesion failure

Engineering Contradiction:

Improveelectrical connection efficiencyVSAvoidadhesion strength

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent differentiates the mounting region into two local zones with different electrode configurations: the first region maintains variable electrode density for optimized electrical connection to piezoelectric elements, while the second region introduces dummy electrodes to create uniform density for consistent adhesive coating. This local quality differentiation resolves the conflict between electrical connection efficiency and adhesion reliability.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If heating is applied during manufacturing, then components are formed, but non-uniform heat distribution occurs due to varying electrode densities causing characteristic non-uniformity

Engineering Contradiction:

Improvecomponent formationVSAvoidcharacteristic uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Dummy electrodes act as thermal intermediaries that do not perform electrical functions but provide uniform heat distribution during manufacturing processes. By introducing these intermediary elements in the second region, the patent ensures uniform heat conduction across the mounting region, preventing characteristic non-uniformity while maintaining ease of component formation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent achieves homogeneity in heat distribution by ensuring uniform electrode density across the entire mounting region through the addition of dummy electrodes. This homogeneous arrangement ensures that heat is distributed evenly during manufacturing processes, eliminating the non-uniformity that would otherwise occur due to variable electrode densities.

Inventive Principle:

Principle #33Homogeneity

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 configuration enhances adhesive strength and prevents film formation failures by ensuring uniform electrode density and heat distribution, improving the overall performance and reliability of the liquid ejecting head.

Implementation Method 1

a plurality of piezoelectric elements that are arranged in two rows of a first row and a second row

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9840076B2Liquid ejecting head and liquid ejecting apparatus

Publication Date: 2017.12.12 SEIKO EPSON CORP

AI summary

A liquid ejecting head includes driving elements and electrodes each extending a second direction for ejecting liquid of pressure chambers through nozzles. The driving elements are classified into a first element group and a second element group. The electrodes are arranged along a first direction intersecting the second direction and are classified into a first electrode group electrically connected to the first element group, a second electrode group electrically connected to the second element group and a third electrode group not contribute to the ejecting liquid.