Inkjet Film Pattern Formation via Contact Angle Control

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Solution Overview

Problem

In semiconductor device manufacturing, the inkjet method for forming thin film patterns faces challenges in achieving reliable wiring formation due to residual conductivity traces on the bank surfaces, leading to potential short-circuits and reduced reliability of fine wiring.

Innovation Solution

A method is developed where the functional liquid is placed under conditions with a difference in advancing and receding contact angles of 10 degrees or more, and a receding contact angle of 13 degrees or more with the bank surface, ensuring the liquid is poured into the pattern formation region without residue on the bank, using a bank formed from photosensitive polysilazane or polysiloxane materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a functional liquid is discharged into a wiring formation region partitioned by a bank with fine width, then fine wiring can be formed to meet higher circuit density demands, but residual conductivity traces remain on the bank surface causing short-circuits and reduced reliability

Engineering Contradiction:

Improvewiring finenessVSAvoidwiring reliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the contact angle between the functional liquid and bank surface to be 40 degrees or more, and controlling the liquid's viscosity and surface tension to ensure complete pouring into the wiring formation region without residual traces on the bank, thereby preventing short-circuits while forming fine wiring

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies preliminary action by performing lyophobic treatment on the bank surface before discharging the functional liquid, creating a repelling effect that directs the liquid completely into the wiring formation region and prevents any residue from remaining on the bank surface

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the difference in contact angle between bank and substrate is increased to 40 degrees or more, then droplets reliably spread in wet state in the wiring formation region, but landing traces remain on the bank causing conductivity residues and potential short-circuits

Engineering Contradiction:

Improveliquid placement precisionVSAvoidconductivity residue

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies parameter changes by optimizing the contact angle to 40 degrees or more while also controlling the liquid's viscosity and surface tension parameters, ensuring that the liquid pours completely into the wiring formation region without leaving conductive residues on the bank surface

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potential harm of liquid spreading on the bank into a benefit by using the controlled spreading to ensure complete filling of the wiring formation region, while the lyophobic treatment ensures that once poured, the liquid does not leave residues on the bank

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 prevents residual conductivity traces on the bank, reducing the risk of short-circuits and enhances the reliability of the formed film patterns, allowing for precise and reliable fine wiring formation.

Implementation Method 1

the functional liquid is placed under conditions that a difference between an advancing contact angle and a receding contact angle of the functional liquid with a top surface of the bank is 10 degrees or more and that the receding contact angle is 13 degrees or more

Methodology Applied

Scientific EffectContact angle control: Wetting

Data Source

PatentUS7771246B2Method of forming film pattern, film pattern, device, electro optic device, and electronic apparatus

Publication Date: 2010.08.10 SEIKO EPSON CORP

AI summary

A method of forming a film pattern by placing a functional liquid on a substrate, comprises:forming a bank on the substrate, wherein the bank corresponds to a region for forming the film pattern;placing the functional liquid in the region for forming the film pattern partitioned by the bank; andcuring the functional liquid to form the film pattern;wherein the functional liquid is placed under conditions that a difference between an advancing contact angle and a receding contact angle of the functional liquid with a top surface of the bank is 10 degrees or more and that the receding contact angle is 13 degrees or more.