Thick Photoresist Film with Controlled Absorbance for Precise Patterns

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Solution Overview

Problem

Conventional photoresist films struggle to form high-precision patterns with poor photoresist profiles and accuracy in etching or electroplating processes due to their inability to maintain stability and depth-to-width ratios required by complex electronic components.

Innovation Solution

A photoresist film with specific absorbance ratios (A405 nm/T ≤ 0.006 and A436 nm/T ≤ 0.005) and thickness (60 μm to 600 μm) is developed, comprising alkali-soluble polymers, ethylenically unsaturated compounds, and photopolymerization initiators, optionally with protective films, to enhance pattern precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional photoresist film is used, then the film can be applied in standard processes, but the photoresist profile is poor and footing is obvious resulting in low manufacturing precision

Engineering Contradiction:
Improvephotoresist pattern precisionVSAvoidphotoresist profile stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the photoresist film by incorporating specific compounds (bifunctional acrylic acid-based compounds, carboxyl-containing polymers, and particular photopolymerization initiators) to achieve optimal absorbance characteristics. This compositional parameter change enables the thick film to maintain excellent photoresist profiles and minimal footing during etching and electroplating processes, directly resolving the precision-reliability contradiction.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite photoresist system by combining multiple functional components: alkali-soluble polymers for etch resistance, bifunctional acrylic acid-based compounds for controlled absorbance, and photopolymerization initiators for pattern formation. This composite material approach allows the thick photoresist film to simultaneously achieve high manufacturing precision and reliable profile stability throughout the fabrication process.

Inventive Principle:
Principle #40Composite materials

2Length of stationary object

If thick photoresist film is used to meet depth-to-width ratio requirements, then the film can cover complex electronic components, but the photoresist pattern accuracy deteriorates with poor profiles and footings

Engineering Contradiction:
Improvephotoresist film thicknessVSAvoidphotoresist pattern accuracy
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

The patent achieves the breakthrough of using thick photoresist films (superior to conventional thicknesses) by fundamentally changing the film's optical and chemical parameters. The specific absorbance characteristics (A405nm and A436nm values) and compositional parameters enable the thick film to maintain excellent pattern accuracy, proving that increased thickness no longer sacrifices precision when proper material parameters are established.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If conventional photoresist film composition is used, then the formulation is simple and easy to manufacture, but the etching and electroplating accuracy is poor

Engineering Contradiction:
Improvephotoresist film formulation simplicityVSAvoidetching and electroplating accuracy
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent establishes specific parameter ranges for key components to balance manufacturability with precision. By defining quantitative guidelines for bifunctional acrylic acid-based compounds, carboxyl-containing polymers, and photopolymerization initiators, the patent enables manufacturers to produce high-precision photoresist films through controlled parameter selection rather than complex multi-step formulations, maintaining ease of manufacture while achieving superior etching and electroplating accuracy.

Inventive Principle:
Principle #35Parameter changes

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

The film achieves high-accuracy etching and electroplating by maintaining precise photoresist profiles, suitable for 2.5D and 3D integrated circuits, with improved operability and resistance to deformation.

Implementation Method 1

the photoresist film comprises: (A) an alkali-soluble polymer; (B) a component of ethylenically unsaturated compound(s); and (C) a photopolymerization initiator

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

when the photoresist film is characterized by ultraviolet-visible spectroscopy, the photoresist film has an absorbance A405 nm at 405 nm and an absorbance A436 nm at 436 nm

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS12416860B2Photoresist film and application thereof
Publication Date: 2025.09.16 CHANG CHUN PLASTICS CO LTD

AI summary

A photoresist film and application thereof are provided. The photoresist film has a thickness T with a unit of μm, and when the photoresist film is characterized by ultraviolet-visible spectroscopy, the photoresist film has an absorbance A405 nm at 405 nm and an absorbance A436 nm at 436 nm, wherein 0<A405 nm/T≤0.006 and 0<A436 nm/T≤0.005, and the thickness T is 60 μm to 600 μm.