PR Pulse Copper Plating Solution for Uniform Via and Through-Hole Filling

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Solution Overview

Problem

Conventional copper plating solutions fail to achieve uniform film thickness and excellent physical properties when used in PR pulse electrolysis, especially in substrates with densely packed through-holes and vias, due to non-uniform current distribution and the presence of nitrogen-based compounds that inhibit electrodeposition.

Innovation Solution

A copper plating solution for PR pulse electrolysis comprising a copper (II) ion, a polyvalent metal ion (such as iron (II) ion), and an unsaturated fatty acid, which together form a uniform copper film by controlling current distribution and suppressing copper dissolution, without using tertiary or quaternary amine compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional copper plating solutions are used in PR pulse electrolysis, then the plating process can be performed, but the film thickness is non-uniform and physical properties are poor

Engineering Contradiction:
Improvefilm thickness uniformityVSAvoidfilm physical properties
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the plating solution by replacing nitrogen-based compounds with unsaturated fatty acids and polyvalent metal ions. This parameter change resolves the contradiction by enabling uniform film thickness deposition while improving film physical properties through the specific chemical interactions of the new additive system.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts and removes nitrogen-based compounds from the plating solution formulation. By taking out these harmful additives that cause non-uniform deposition and poor film properties, the invention achieves both uniform film thickness and improved physical properties through the remaining copper sulfate, unsaturated fatty acid, and polyvalent metal ion system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If nitrogen-based compounds are used as additives, then electrodeposition can be enhanced, but film ductility is degraded

Engineering Contradiction:
Improveelectrodeposition efficiencyVSAvoidfilm ductility
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent converts the harmful effect of nitrogen-based compounds into a benefit by replacing them with unsaturated fatty acids and polyvalent metal ions that provide similar electrodeposition enhancement while improving film ductility. The new additive system maintains productivity while eliminating the harmful effect on film properties.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical composition parameters by substituting nitrogen-based additives with unsaturated fatty acids and polyvalent metal ions. This parameter change maintains electrodeposition efficiency while improving film ductility, resolving the contradiction between productivity and film strength.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If PR pulse electrolysis is used for via filling and through-hole filling, then filling performance is improved, but current distribution becomes non-uniform

Engineering Contradiction:
Improvefilling performanceVSAvoidcurrent distribution uniformity
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent introduces unsaturated fatty acids and polyvalent metal ions as intermediary substances that mediate the current distribution during PR pulse electrolysis. These intermediaries facilitate uniform current distribution across the substrate surface while maintaining the enhanced filling performance of the pulse electrolysis process.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical parameters of the plating solution to include unsaturated fatty acids and polyvalent metal ions, which modify the electrochemical reactions and current distribution patterns. This parameter change enables uniform current distribution while maintaining superior via filling and through-hole filling performance.

Inventive Principle:
Principle #35Parameter changes

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 solution enables the formation of a copper film with uniform surface thickness and excellent physical properties, improving via filling and through-hole filling performance, while avoiding the need for nitrogen-based additives that degrade film ductility.

Implementation Method 1

allowing a PR pulse current to pass through the acidic copper plating solution to perform electrolytic copper plating by using an object to be plated as a cathode

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

the polyvalent metal ion and the unsaturated fatty acid exert their effects when low current is applied. In the dense TH portion, sacrificial oxidation of the polyvalent metal ion becomes effective

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentUS20250215597A1Copper plating solution for PR pulse electrolysis and copper plating method by means of PR pulse electrolysis
Publication Date: 2025.07.03 OKUNO CHEM IND CO LTD

AI summary

An object of the present invention is to newly provide a copper plating solution for PR pulse electrolysis and a copper plating method by a PR pulse electrolysis method. Provided is a copper plating solution for PR pulse electrolysis, comprising a copper (II) ion, a polyvalent metal ion (excluding copper (II) ions), and an unsaturated fatty acid.