Fluid Ejection Die With Feed Holes

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Solution Overview

Problem

Existing fluid ejection devices face challenges in reducing the width and thickness of substrates while maintaining or increasing nozzle density, due to limitations from longitudinal fluid feed slots that affect structural integrity and integration complexity, and fluidic cross-talk issues that arise with closer proximity of drop generators.

Innovation Solution

A molded fluid ejection device design featuring a narrow 'sliver' die with fluidic fan-out through molded channels at the back surface, eliminating the need for a costly manifold integration and using pillar structures to mitigate cross-talk and clogging, allowing for closer placement of drop generators and increased nozzle density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If longitudinal fluid feed slots are used to supply fluid through the substrate, then fluid delivery is enabled, but the structural integrity of the substrate deteriorates

Engineering Contradiction:
Improvefluid deliveryVSAvoidstructural integrity of substrate
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The patent divides the continuous longitudinal fluid feed slot into multiple discrete fluid feed holes arranged in an array. This segmentation allows fluid to be delivered to multiple drop generators simultaneously while maintaining the structural integrity of the substrate between the holes, resolving the contradiction between fluid delivery and structural strength.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If longitudinal fluid feed slots are used in the substrate, then fluid can reach drop generators, but the die width and thickness cannot be reduced

Engineering Contradiction:
Improvefluid supply to drop generatorsVSAvoiddie size
Core Design Contradiction:
Quantity of substanceVSVolume of moving object

Solution Approach 1:

The patent transitions from using longitudinal fluid feed slots that extend through the length of the substrate to using an array of fluid feed holes that traverse the substrate thickness in a transverse direction. This dimensional change allows for a more compact die design with reduced width and thickness while maintaining effective fluid supply to all drop generators through the array configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If drop generators are placed closer together to increase nozzle density, then higher resolution is achieved, but fluidic cross-talk increases

Engineering Contradiction:
Improvenozzle densityVSAvoidfluidic cross-talk
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent uses individually addressed fluid feed holes for each drop generator, creating isolated fluid delivery pathways. This segmentation prevents fluidic cross-talk between adjacent drop generators even when they are placed in close proximity, enabling high nozzle density without the harmful effects of fluid interference between neighboring elements.

Inventive Principle:
Principle #1Segmentation

4Volume of moving object

If the substrate is made thinner to reduce die size, then smaller die dimensions are achieved, but structural stability deteriorates

Engineering Contradiction:
Improvedie thicknessVSAvoidmechanical stability
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent successfully implements a thin substrate design where the substrate thickness is reduced to minimize die size while maintaining adequate mechanical stability. The array configuration of fluid feed holes and the overall structural design allow the thin substrate to function effectively without compromising mechanical stability, achieving both miniaturization and stability.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3233500B1Fluid ejection device with fluid feed holes
Publication Date: 2021.12.01 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP3233500B1 patent drawingFigure 1
  • EP3233500B1 patent drawingFigure 2
  • EP3233500B1 patent drawingFigure 3

AI summary

A fluid ejection die has a substrate through which an array of fluid feed holes is formed. The fluid feed holes are separated by ribs. Each fluid feed hole is to guide fluid to an array of drop generators.