Water-Based OSP Formulation for Low-Temperature Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Water-based organic solderability preservatives face challenges in low-temperature stability due to crystallization of imidazole compounds, which affects the formation and durability of protection coatings on electrode terminals, and existing solutions compromise either stability or coating performance.
Innovation Solution
A water-based organic solderability preservative formulation including an imidazole compound, organic acid, complex coating formation aid, and a specific organic solvent with high solubility and boiling point, such as tripropylene glycol monomethyl ether, improves low-temperature stability while maintaining coating formation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an organic solvent is added to improve low-temperature stability, then the solubility of imidazole compound improves, but the formation performance of protection coating deteriorates
Solution Approach 1:
The patent changes the chemical structure parameters of the imidazole compound by introducing specific substituents (alkyl groups with 1-10 carbon atoms at positions 1 and 2, and alkyl groups with 1-4 carbon atoms at position 5) to improve low-temperature stability while maintaining coating formation performance. This structural modification allows the compound to remain soluble at low temperatures without compromising its ability to form protective coatings.
Solution Approach 2:
The patent creates a composite formulation by combining the modified imidazole compound with specific organic acids (having 1-4 carbon atoms) and water in defined proportions. This composite approach synergistically improves low-temperature stability while maintaining effective protection coating formation, overcoming the limitations of using单一 imidazole compounds or simple organic solvents.
2Reliability
If gold plating is applied to prevent oxidation, then the oxidation resistance improves, but the production cost increases
Solution Approach 1:
The patent replaces expensive noble metal (gold) plating with a cost-effective organic solderability preservative formulation based on modified imidazole compounds. This preservative forms a protective coating that prevents oxidation during distribution and storage, providing an economical alternative to gold plating while maintaining adequate protection performance.
Solution Approach 2:
The patent introduces an organic solderability preservative as an intermediary substance between the electrode terminal surface and the oxidizing environment. This preservative layer acts as a protective barrier that prevents direct contact between oxygen and the metal surface, substituting the protective function previously provided only by gold plating.
3Quantity of substance
If imidazole compound is used in water-based preservative, then the cost reduces, but crystallization occurs at low temperature
Solution Approach 1:
The patent modifies the physical and chemical parameters of the imidazole compound by introducing specific alkyl substituents that enhance solubility and prevent crystallization at low temperatures. The combination of alkyl groups at positions 1, 2, and 5 with specific carbon chain lengths adjusts the molecular structure to maintain liquid state and solubility in water-based formulations under refrigerated storage conditions.
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 formulation achieves excellent low-temperature stability and coating performance, preventing oxidation and ensuring effective protection of electrode terminals without the need for costly noble metals like gold.
Implementation Method 1
the imidazole compound in the water-based organic solderability preservative is not or poorly soluble to water, the water-based organic solderability preservative is usually dissolved in water with an assistance of an organic acid such as acetic acid
Implementation Method 2
a problem of crystallization of an imidazole compound contained in the water-based organic solderability preservative when the water-based organic solderability preservative is stored at a low temperature (e.g. 5 degrees C. or less)
Implementation Method 3
the surface of the electrode terminal is likely to be oxidized during distribution and/or storage of the printed circuit boards
Data Source
AI summary
A water-based organic solderability preservative includes (A) an imidazole compound, (B) an organic acid, (C) a complex coating formation aid, (D) an organic solvent and (E) water. The component (D) (organic solvent) has a solubility to water of 10 g/100 g or more at 20 degrees C. and a boiling temperature in a range from 100 degrees C. to 300 degrees C.