Micro-Structural Fluid Ejector Contact Detection by Edge Imaging

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Solution Overview

Problem

Existing contact printing methods for forming conductive lines on substrates face challenges in maintaining alignment precision over large distances and accurately detecting contact and fault conditions in fluid flow from micro-structural fluid ejectors.

Innovation Solution

A method involving a micro-structural fluid ejector with a tapering portion, an imaging system, and a print head positioning system to detect contact, adjust contact, and detect fault conditions by capturing digital images, pre-processing them to detect edges, and analyzing the images to determine the presence of fluid on the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If contact printing method is used to form conductive lines, then line width precision is improved (1 μm to 10 μm), but alignment precision deteriorates over large distances (requires 0.0001° parallelism)

Engineering Contradiction:

Improveline width precisionVSAvoidalignment precision

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent implements active feedback control by continuously monitoring the vertical displacement of the print head using a laser displacement sensor and adjusting the print head position in real-time to maintain constant distance from the substrate. This feedback mechanism compensates for substrate topography variations and maintains alignment precision over large printing areas without requiring extreme initial parallelism.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent transitions from a static print head position to a dynamic positioning system that actively adjusts the print head height during operation. The print head is mounted on a motorized positioning stage that can dynamically compensate for alignment errors, enabling precise printing over large areas while reducing the stringency of initial parallelism requirements.

Inventive Principle:

Principle #15Dynamics

2Ease of manufacture

If capillary tube contact printing is implemented, then conductive line formation is achieved, but contact detection and fault detection capabilities are insufficient

Engineering Contradiction:

Improveconductive line formationVSAvoidcontact detection and fault detection

Core Design Contradiction:

Ease of manufactureVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces an intermediary optical detection system that uses a laser displacement sensor to indirectly measure the contact status between the capillary tube and substrate. This intermediary measurement method provides precise contact detection without requiring direct mechanical contact sensing, enabling reliable fault detection while maintaining the simplicity of capillary tube printing.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 method enables precise control of the contact between the micro-structural fluid ejector and the substrate, improving alignment precision and effectively detecting fault conditions in fluid flow, thereby enhancing the reliability and accuracy of conductive line formation.

Implementation Method 1

capturing a digital image of the tapering portion and its surroundings

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

applying pressure to a fluid in the micro-structural fluid ejector

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentUS12202279B2Methods of detecting and adjusting contact of a micro-structural fluid ejector to a substrate and method of detecting a fault condition in fluid flow from a micro-structural fluid ejector onto a substrate

Publication Date: 2025.01.21 XTPL SA

AI summary

Methods are disclosed relating to the operation of a micro-structural fluid ejector in a fluid printing apparatus. The methods include providing an imaging system, capturing a digital image of the micro-structural fluid ejector and its surroundings, and pre-processing the digital image to detect edges. A method of detecting contact of a micro-structural fluid ejector to a substrate includes repeatedly lowering the print head and measuring the length of a detected edge until the currently measured length is determined to be longer than a previously measured length. A method of adjusting contact of a micro-structural fluid ejector to a substrate includes calculating a bending coefficient A of the micro-structural fluid ejector and lowering the print head toward the substrate if the bending coefficient A is less than a minimum threshold value Amin, raising the print head away from the substrate if the bending coefficient A is greater than a maximum threshold value Amax, and making no change to the vertical displacement of the print head if the bending coefficient A is in the range of Amin to Amax. A method of detecting a fault condition in fluid flow from a micro-structural fluid ejector onto a substrate includes analyzing the digital image to determine whether edges are present in a region of interest where fluid dispensed from the micro-structural fluid ejector should be present.