Flexible Film Imprint Lithography for Large Area Patterning

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Solution Overview

Problem

Current nano-imprinting processes face challenges in transferring fine features below 100 nm on flexible substrates without distortion or fracture, particularly in achieving accurate pattern overlay and minimizing in-plane film distortion, which limits their viability for commercial applications.

Innovation Solution

The implementation of an imprint lithography system that uses a flexible film substrate and a flat substrate with a template, where the flexible substrate is translated between rollers with controlled motion and UV curing, allowing for precise patterning and feature transfer through the use of a fluid dispense system and energy source, while also employing protective film rollers and electrostatic discharge devices to manage substrate tension and particle contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional imprint lithography is used to transfer fine features on flexible substrates, then pattern transfer can be achieved, but distortion and fracture of fine features occur

Engineering Contradiction:
Improvepattern transfer accuracyVSAvoidfeature integrity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies dynamics by enabling independent motion control of the flexible substrate and template during the imprinting process. The flexible substrate can be tilted and skewed independently relative to the template, allowing dynamic adjustment of their relative positions and orientations. This dynamic capability enables the system to accommodate substrate curvature and maintain optimal contact between the template and substrate during pattern transfer, preventing distortion and fracture of fine features.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs parameter changes by adjusting multiple motion parameters including tilt angles, skew angles, and relative positions of the flexible substrate and template. By changing these parameters dynamically during the imprinting process, the system can optimize the contact between the template and substrate surfaces, ensuring accurate pattern transfer while maintaining feature integrity on the flexible substrate.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the flexible substrate is translated between rollers with controlled motion, then pattern overlay accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvepattern overlay accuracyVSAvoidmotion control system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by designing motion control systems that perform multiple functions. The same motion control mechanisms used to translate the flexible substrate between rollers also provide tilt and skew adjustments, alignment, and positioning. This multi-functional approach reduces the need for separate dedicated systems for each function, thereby managing device complexity while maintaining high pattern overlay accuracy.

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

Solution Approach 2:

The patent employs feedback mechanisms to monitor and adjust the motion parameters of the flexible substrate and template in real-time. By using sensors to detect positions, orientations, and contact conditions, the system can automatically adjust motion parameters to maintain optimal pattern transfer conditions. This feedback-based control reduces the complexity of manual operation and improves pattern overlay accuracy consistently.

Inventive Principle:
Principle #23Feedback

3Productivity

If UV curing is applied during translation, then polymerizable material solidifies efficiently, but energy consumption increases

Engineering Contradiction:
Improvecuring efficiencyVSAvoidUV energy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies continuity of useful action by integrating UV curing with the continuous translation and imprinting process. Instead of separate batch curing steps, the UV light source operates continuously during the translation and pattern transfer process, maintaining constant curing activity. This continuous operation ensures that polymerizable material solidifies efficiently as patterns are formed, maximizing productivity while managing energy consumption through sustained useful action rather than intermittent processing.

Inventive Principle:
Principle #20Continuity of useful action

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 enables efficient and accurate transfer of fine features onto flexible substrates, reducing distortion and fracture, and allows for the use of flexible substrates in commercial nano-imprinting applications by maintaining pattern integrity and minimizing contamination.

Implementation Method 1

An energy source (e.g. UV source) is positioned between the imprint/separation rollers and adjacent the backside surface of the flexible film substrate. The energy source provides curing energy to solidify polymerizable material positioned between the flexible film substrate and the flat substrate as the two substrates translate between the imprint/separation rollers.

Methodology Applied
Scientific EffectUV curing: Photopolymerisation

Implementation Method 2

electrostatic discharge devices (e.g.) are positioned proximate the first and second protective film rollers. These electrostatic discharge devices further are configured to remove electrostatic charge from the front surface of the flexible film substrate as the protective film is overlayed onto or retracted from the flexible film substrate, which aids in protecting against particle contamination of the substrate.

Methodology Applied
Scientific EffectElectrostatic discharge: Electrostatic Discharge

Data Source

PatentEP2823356B1Large area imprint lithography
Publication Date: 2018.05.23 MOLECULAR IMPRINTS INC
  • EP2823356B1 patent drawingFigure 1~2
  • EP2823356B1 patent drawingFigure 3~4
  • EP2823356B1 patent drawingFigure 5

AI summary

Methods and systems are provided for patterning polymerizable material dispensed on flexible substrates or flat substrates using imprint lithography techniques. Template replication methods and systems are also presented where patterns from a master are transferred to flexible substrates to form flexible film templates. Such flexible film templates are then used to pattern large area flat substrates. Contact between the imprint template and substrate can be initiated and propagated by relative translation between the template and the substrate.