Halogen-Free Solder Composition for Wettability and Viscosity Stability

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Solution Overview

Problem

Halogen-free or non-halogen solder compositions typically lack sufficient wettability and viscosity stability, and compositions using amine activators instead of halogen activators fail to achieve both favorable wettability and viscosity stability.

Innovation Solution

A solder composition comprising a flux composition with rosin resin, an organic acid activator such as 3-hydroxy-2-naphthoic acid, an imidazoline compound with a phenyl group, and an antioxidant like hindered phenol compounds, which together enhance wettability and viscosity stability without using halogen activators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a halogen-free or non-halogen solder composition is used, then environmental safety is improved, but wettability deteriorates

Engineering Contradiction:
Improveenvironmental safetyVSAvoidwettability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the flux composition by using organic acid activators (succinic acid, glutaric acid) instead of halogen activators, and by adding imidazoline compounds with phenyl groups. This parameter change maintains wettability while achieving halogen-free composition for environmental safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite flux composition containing multiple components: rosin resin, organic acid activators, imidazoline compounds with phenyl groups, and antioxidants. This composite material approach combines the benefits of each component to achieve both environmental safety and satisfactory wettability.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If a halogen-free or non-halogen solder composition is used, then environmental safety is improved, but viscosity stability deteriorates

Engineering Contradiction:
Improveenvironmental safetyVSAvoidviscosity stability
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical composition parameters by introducing imidazoline compounds with phenyl groups and specific organic acid activators, which stabilize the viscosity of the solder paste while maintaining halogen-free status for environmental safety.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The imidazoline compounds with phenyl groups act as intermediary substances that mediate between the rosin resin and organic acid activators, providing viscosity stability to the flux composition while allowing the use of environmentally safe halogen-free materials.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If an amine activator is used instead of a halogen activator, then environmental safety is improved, but both wettability and viscosity stability deteriorate

Engineering Contradiction:
Improveenvironmental safetyVSAvoidwettability and viscosity stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the activator type from amine to organic acid (succinic acid, glutaric acid), and additionally introduces imidazoline compounds with phenyl groups. This dual parameter change resolves the deficiencies of amine activators, achieving both environmental safety and satisfactory wettability and viscosity stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the single amine activator with a composite activation system consisting of organic acid activators combined with imidazoline compounds containing phenyl groups. This composite material approach provides the multiple functions needed to achieve environmental safety, wettability, and viscosity stability simultaneously.

Inventive Principle:
Principle #40Composite materials

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 solder composition achieves excellent wettability and viscosity stability, comparable to halogen-containing compositions, while being halogen-free or non-halogen, making it suitable for electronic substrates and printed circuit boards.

Implementation Method 1

a halogen-free or non-halogen solder composition typically does not have sufficient wettability of solder

Methodology Applied
Scientific EffectWettability: Wetting

Implementation Method 2

a solder composition containing an amine activator instead of a halogen activator does not achieve both favorable wettability and viscosity stability

Methodology Applied
Scientific EffectViscosity stability:

Implementation Method 3

the (D) component contains at least one selected from the group consisting of a hindered phenol compound, 3,3′-thiodipropionic acid didodecyl, and 1,2,3-benzotriazole

Methodology Applied
Scientific EffectOxidation resistance: Oxidation

Data Source

PatentUS11780035B2Solder composition and electronic substrate
Publication Date: 2023.10.10 TAMURA KK

AI summary

A solder composition of the invention contains: a flux composition containing (A) a rosin resin, (B) an activator, (C) an imidazoline compound having a phenyl group, and (D) an antioxidant; and (E) solder powder, in which the (B) component contains (B1) an organic acid, the (B1) component contains at least one selected from the group consisting of (B11) 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, and 1,4-dihydroxy-2-naphthoic acid, and the (C) component is at least one selected from the group consisting of 2-phenylimidazoline and 2-benzylimidazoline.