Printhead Conductor Traces Across Slots

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Solution Overview

Problem

The challenge in printing devices is to maintain high resolution and operational speed while minimizing the printhead size, which is hindered by the need for increased power and redundancy in fluid ejection elements, and the complexity of routing conductor traces across the slot can lead to bubble formation and reduced printing quality.

Innovation Solution

A printhead circuit design with conductor traces routed across a slot, utilizing a thinfilm bridge and scalable slot configuration to minimize circuitry and prevent bubble formation, using materials like gallium arsenide and silicon for structural support, and forming openings in the thinfilm bridge to promote fluid flow and reduce heat accumulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductor traces are routed across the slot to connect circuitry on both sides, then electrical connectivity is achieved, but bubble formation occurs that reduces printing quality

Engineering Contradiction:
Improveelectrical connectivityVSAvoidbubble formation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The slot is divided into multiple segments with conductor traces routed through defined paths. The slot configuration is segmented to allow conductor traces to pass through without creating large continuous openings that would trap bubbles, thereby maintaining electrical connectivity while reducing bubble formation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A thin film bridge structure serves as an intermediary element that supports the conductor traces across the slot. This bridge provides a controlled pathway for electrical connectivity while its thin structure allows any trapped bubbles to escape, mediating between the need for conductor routing and bubble prevention

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the printhead size is minimized to improve resolution, then higher image resolution is achieved, but space for circuitry is reduced

Engineering Contradiction:
Improveimage resolutionVSAvoidsubstrate size
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

Circuitry is arranged in a three-dimensional configuration utilizing vertical space and layered structures. Conductor traces are routed in multiple layers and dimensions rather than only on the substrate surface, effectively increasing the available circuitry space without increasing the footprint area, thus maintaining small printhead size while accommodating necessary circuitry

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

Solution Approach 2:

Circuit elements are nested within each other and arranged in compact configurations. Multiple conductor traces are routed through shared pathways and the circuitry is integrated into the substrate structure, maximizing the use of available space within the minimized substrate area

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If more fluid ejection elements are added to increase power and redundancy, then operational reliability is improved, but printhead complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidcircuitry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conductor trace routing structure serves multiple functions simultaneously: it provides electrical connectivity, acts as a mechanical support framework, and defines the slot geometry. This multi-functionality reduces the need for separate redundant circuitry elements, maintaining reliability while reducing overall device complexity

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

Solution Approach 2:

Multiple circuitry functions are merged into integrated structures. The conductor traces are combined with the slot structure and substrate, creating unified elements that perform multiple roles. This integration reduces the number of discrete components needed, simplifying the device while maintaining operational reliability

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2828086B1Printheads with conductor traces across slots
Publication Date: 2019.09.11 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2828086B1 patent drawingFigure 1A~1B
  • EP2828086B1 patent drawingFigure 2
  • EP2828086B1 patent drawingFigure 3

AI summary

The present disclosure describes a printhead circuit, devices, and methods of forming the printhead circuit. An example of a printhead circuit includes a substrate including a slot having a first, a second, and a third dimension in the substrate, circuitry on a first side and a second side of the slot, and a number of conductor traces routed across the slot along substantially a same geometrical plane as the circuitry on the first side and the second side of the slot.