Acidic Defluxing Composition for Miniaturized Electronic Assemblies
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Solution Overview
Problem
Current methods for cleaning solder flux residues from electronic assemblies are inefficient, particularly in miniaturized components, and often fail to meet environmental and safety standards, with existing products being either alkaline or neutral, which are not effective for a wide range of fluxes and can be harmful.
Innovation Solution
A defluxing composition comprising a C6-C15 glycol ether as the main solvent and a phosphoric acid ester as an acidic additive, which is highly effective in both aqueous and anhydrous methods, capable of cleaning a wide range of flux residues and materials, while being environmentally friendly and safe for personnel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional alkaline or neutral defluxing products are used, then they are safe for personnel and environmentally friendly, but they are not effective for removing a wide range of flux residues, particularly in miniaturized components
Solution Approach 1:
The patent changes the pH parameter of the cleaning composition from conventional alkaline or neutral to acidic (pH 2-5), and specifically incorporates phosphoric acid ester as the active cleaning agent. This parameter change enables effective removal of diverse flux residues while maintaining environmental compatibility and personnel safety
Solution Approach 2:
The patent creates a composite cleaning composition by combining phosphoric acid ester with specific solvents (C6-C15 glycol ethers, fluorinated solvents, or chlorinated solvents) in defined concentration ranges. This composite formulation achieves synergistic effects that improve cleaning effectiveness across different flux types while controlling environmental and safety impacts
2Productivity
If miniaturization of electronic assemblies is pursued to achieve higher performance and more functionalities, then component density increases, but flux retention areas become substantial and difficult to access, reducing cleaning effectiveness
Solution Approach 1:
The patent formulates the cleaning composition with phosphoric acid ester at specific concentrations (0.1-20% for aqueous methods, 1-5% for solvent methods) optimized to penetrate and act in difficult-to-access interstitial spaces under miniaturized components, ensuring effective flux removal in localized retention areas
Solution Approach 2:
The patent creates a universal cleaning composition that effectively handles flux residues across all miniaturized component types (capacitors, diodes, quartz, MEMs, μBGAs, flip chips, LEDs) and various flux formulations (water-soluble, solvent-soluble, no-clean), making the solution adaptable to diverse cleaning challenges in miniaturized assemblies
3Adaptability or versatility
If various cleaning methods (solvent, aqueous immersion, spray) are selected based on component compatibility and production rate, then specific cleaning needs are met, but the process complexity increases and environmental regulations become more difficult to comply with
Solution Approach 1:
The patent develops a universal phosphoric acid ester-based composition that can be applied across multiple cleaning methods (aqueous immersion, solvent immersion, spray methods, vapor phase) and is compatible with various component materials (metals, polymers, ceramics). This reduces process complexity by eliminating the need for method-specific formulations while maintaining adaptability to different cleaning requirements
Solution Approach 2:
The patent optimizes the composition parameters (phosphoric acid ester concentration, solvent type and ratio) to achieve effective cleaning across different methods and materials, simplifying the overall process by providing a single versatile formulation that adapts to various application conditions rather than requiring multiple specialized formulations
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 demonstrates high cleaning effectiveness across various flux types and assembly materials, reducing environmental impact and meeting health and safety standards, with improved rinsability and reduced foam formation, allowing for efficient cleaning in complex miniaturized electronic assemblies.
Implementation Method 1
an additive which imparts an acidic nature to said composition
Implementation Method 2
from 20% to 99.5% by weight of a main solvent consisting of at least one C6-C15 glycol ether
Data Source
AI summary
The invention relates to a composition intended for the cleaning of contaminants and flux residues on electronic assemblies, particularly solder cream residue. Said composition comprises:from 20% to 99.5% by weight of a main solvent consisting of at least a C6-C15 glycol ether, and optionally a secondary solvent,from 0.5% to 20% by weight of a selected acid additive which is a phosphoric acid ester. The invention also relates to a defluxing product incorporating said composition, as well as to the defluxing methods using these products