Aqueous Solid Photoresist Remover for Electronics
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Solution Overview
Problem
Current methods for removing photoresist and residue from electronic device substrates during manufacturing are inefficient, often requiring organic solvents that pose safety risks, generate hazardous waste, and require extensive tooling and processing steps, while also struggling with foam generation and selectivity to avoid damaging sensitive metals and substrates.
Innovation Solution
Aqueous-based, solid-form chemical compositions comprising inhibitors, alkaline agents, and surfactants that dissolve in DI water to effectively remove photoresist and residue without altering existing tooling, reducing foam production, and extending bath life, thus providing a safer, more cost-effective, and environmentally friendly solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If organic solvents are used to remove photoresist and residue, then removal effectiveness is improved, but safety risks and hazardous waste generation increase
Solution Approach 1:
The patent changes the chemical composition parameters by replacing organic solvents with aqueous-based formulations containing specific alkaline agents (sodium hydroxide, potassium hydroxide, ammonium hydroxide), inhibitors (catechol, hydroquinone, ascorbic acid), and surfactants. This parameter change maintains photoresist removal effectiveness while eliminating the safety risks and hazardous waste associated with organic solvents.
Solution Approach 2:
The patent uses composite material formulations combining multiple components: alkaline agents for photoresist dissolution, inhibitors for metal protection, and surfactants for residue removal. This composite approach achieves comprehensive cleaning performance previously requiring organic solvents, while using safer aqueous-based materials.
2Productivity
If conventional stripping compositions are used, then photoresist removal is achieved, but foam generation increases and selectivity to protect metals decreases
Solution Approach 1:
The patent applies local quality by assigning specific functions to different components: alkaline agents target photoresist removal, inhibitors locally protect metal surfaces from corrosion, and surfactants manage foam generation. This differentiated approach allows effective photoresist removal while protecting metals and controlling foam through specialized additives.
Solution Approach 2:
The patent introduces inhibitors as intermediary substances that mediate between the alkaline stripping agents and metal surfaces. These inhibitors (catechol, hydroquinone, ascorbic acid) form protective complexes on metal surfaces, preventing direct contact and damage from the alkaline photoresist remover, thus enabling selective action.
3Ease of manufacture
If existing tooling is used without modification, then manufacturing continuity is maintained, but processing efficiency and safety are compromised
Solution Approach 1:
The patent creates a universal stripping composition that works with existing tooling while providing multiple functions: photoresist removal, residue cleaning, metal protection, and foam control. The aqueous-based formulation can be used in conventional dip, spray, or spin tools without modification, achieving both ease of manufacture and improved manufacturing efficiency.
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 compositions enable rapid and effective removal of photoresist and residue while protecting metals, reducing waste, and increasing bath life, allowing for continuous processing without the need for new tooling or special equipment, thereby improving manufacturing efficiency and safety.
Implementation Method 1
aqueous-based compositions and the manner they remove amorphous and thermoset polymers from electronic devices
Implementation Method 2
compositions that comprise metal-safe and solids-borne materials
Implementation Method 3
without effect to the adjacent metals, dielectric, or underlying substrate
Data Source
AI summary
Compositions and methods useful for the removal of organic substances from substrates, for example, electronic device substrates, are provided. A method is presented which uses a minimum amount of solid form concentrate that is diluted into water, introduced into a manufacturing tool and heated, applied to said substrate for a sufficient time to allow penetration and removal of an organic substance, and immediately rinsed with water to achieve complete removal. These compositions and methods are particularly suitable for removing and completely dissolving photoresists of the positive variety most commonly used in the manufacture of a flat panel display (FPD) and other electronic substrates.