Photosensitive Resin Composition for Low-Temperature Curing

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Solution Overview

Problem

Existing photosensitive resin compositions for printed circuit boards require high temperatures for curing, are not environmentally friendly due to the use of toxic solvents, and struggle with precision alignment and filling fine circuit patterns, while also lacking the necessary properties like solder heat resistance and chemical resistance.

Innovation Solution

A photosensitive resin composition comprising polyamic acid, a photopolymerizable compound, and a photoinitiator, which can be developed with an alkaline aqueous solution and cured at relatively low temperatures, forming a robust interpenetrating polymer network that provides excellent heat resistance, bending resistance, and chemical resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If polyimide-based photosensitive resin composition is used to achieve heat resistance and bending resistance, then thermal stability is improved, but developing process becomes difficult and high temperature curing (350°C) is required which causes copper circuit oxidation

Engineering Contradiction:

Improvecuring temperatureVSAvoidcopper circuit oxidation

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using polyamic acid instead of polyimide, and incorporating specific photopolymerizable compounds (acrylate, vinyl ether, vinyl ester groups) to enable low-temperature curing at 150-250°C while maintaining heat resistance properties, thus avoiding copper circuit oxidation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite photosensitive resin composition by combining polyamic acid with multiple photopolymerizable compounds (acrylate, vinyl ether, vinyl ester) and photoinitiators, achieving both low-temperature curability and high heat resistance that prevents copper oxidation

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If conventional photosensitive resin composition is used to achieve good developing properties, then developing ease is improved, but environmental stability deteriorates due to use of flammable organic solvents and toxic solvents

Engineering Contradiction:

Improvedeveloping easeVSAvoidtoxic solvent emission

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent changes the solvent system from flammable organic solvents to an alkaline aqueous solution as the developing medium, eliminating toxic solvent emissions while maintaining good developing properties through the specific polyamic acid composition that provides alkaline solubility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive and hazardous organic solvents with a simple, non-toxic alkaline aqueous solution (such as sodium hydroxide or potassium hydroxide solution), making the process more environmentally friendly and cost-effective

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Temperature

If polyamic acid is used as precursor to achieve low temperature curing, then curing temperature is reduced, but film formation ability deteriorates

Engineering Contradiction:

Improvecuring temperatureVSAvoidfilm formation ability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent combines polyamic acid with photopolymerizable compounds containing acrylate, vinyl ether, and vinyl ester groups to create a composite system that maintains film formation ability at low temperatures through the synergistic effects of multiple functional groups

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent introduces different photopolymerizable functional groups (acrylate for crosslinking, vinyl ether for adhesion, vinyl ester for flexibility) at specific locations within the resin composition to ensure uniform film formation while enabling low-temperature curing

Inventive Principle:

Principle #3Local quality

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 composition allows for precise pattern formation and improved environmental stability, enabling the creation of high-quality cover films and circuit protection films for printed circuit boards with enhanced properties such as solder heat resistance and chemical resistance without the need for high-temperature curing or toxic solvents.

Implementation Method 1

a photopolymerizable compound having at least one polymerizable ethylenic unsaturated bond in its molecule; and (C) a photoinitiator

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS8354219B2Photosensitive resin composition and dry film comprising the same

Publication Date: 2013.01.15 LG CHEM LTD

AI summary

The present invention relates to a photosensitive resin composition which is developable with an alkaline aqueous solution and does not need a high temperature for curing and the like, and has all the properties suitable for use in a cover film of a printed circuit board or a laminated body for a semiconductor, and a dry film comprising the same. The photosensitive resin composition comprises (A) a polyamic acid comprising a polymer of at least one diamine compound and at least one acid dianhydride; (B) a photopolymerizable compound having at least one polymerizable ethylenic unsaturated bond in its molecule; and (C) a photoinitiator.