Hyperbranched Polymer Primer for Electroless Plating

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Solution Overview

Problem

Conventional electroless plating processes are inefficient, environmentally impactful, and costly, particularly due to the use of chromium compounds and complex pretreatment steps, and require improvements for forming highly adhesive metal films on smooth substrates in fine electronic circuitry.

Innovation Solution

A primer comprising a hyperbranched polymer with an ammonium group, metal fine particles, and an alkoxysilane is used to create a priming layer for electroless metal plating, enhancing adhesion and platability with fewer steps and reduced costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electroless plating process is used, then metal plating film can be formed, but the process requires multiple complex pretreatment steps including chromium compound usage

Engineering Contradiction:
Improveadhesion of metal plating filmVSAvoidnumber of pretreatment steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple pretreatment functions (sensitization, adhesion promotion, and surface modification) into a single primer coating step. The primer contains metal fine particles for catalysis, polymer for adhesion, and coupling agents for surface bonding, replacing the conventional multi-step process of roughening, sensitization, and adhesion promotion.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts and eliminates the chromium compound roughening step from the conventional process. Instead of using toxic chromium-based etchants, the invention uses a polymer-based primer that provides adhesion without requiring chemical roughening, thereby removing the harmful step while maintaining plating quality.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If chromium compound is used in roughening step, then surface adhesion is improved, but environmental impact increases

Engineering Contradiction:
Improveadhesion between base material and plating filmVSAvoidenvironmental impact of chromium compound
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the adhesion function previously achieved by harmful chromium compounds into a beneficial polymer-based system. The primer uses metal fine particles and polymer matrices to provide catalytic activity and adhesion without introducing toxic substances, transforming a harmful process into an environmentally friendly one while maintaining or improving adhesion performance.

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

3Manufacturing precision

If multiple pretreatment steps are used, then plating quality is improved, but manufacturing cost increases

Engineering Contradiction:
Improveuniformity of plating filmVSAvoidmanufacturing cost of pretreatment process
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent merges multiple sequential pretreatment operations into a single coating and drying step. The primer application replaces roughening, sensitization, and adhesion promotion steps, reducing the number of process stages from four or five to one or two, thereby lowering manufacturing costs while maintaining uniform plating quality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The primer is applied in advance to provide all necessary surface modifications before plating. By pre-loading the surface with metal catalyst particles and adhesion promoters in a single coating step, the invention eliminates the need for subsequent separate treatment steps, streamlining the manufacturing process.

Inventive Principle:
Principle #10Preliminary action

4Manufacturing precision

If smooth substrate is used for fine electronic circuitry, then manufacturing precision is improved, but adhesion of plating film becomes difficult

Engineering Contradiction:
Improvefine line width capabilityVSAvoidadhesion on smooth surface
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces a polymer-based primer as an intermediary layer between the smooth substrate and the metal plating film. This intermediary contains metal fine particles that provide catalytic function and polymer matrices that provide adhesion, bridging the gap between the smooth non-porous surface and the plating requirements without compromising the underlying fine circuit patterns.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 primer enables the formation of a metal plating film with excellent adhesion and uniformity, suitable for fine line widths, simplifying the electroless plating process and reducing environmental impact.

Implementation Method 1

hyperbranched polymer having an ammonium group at a molecular terminal, metal fine particles

Methodology Applied
Scientific EffectElectrostatic interaction: Electrostatics

Implementation Method 2

alkoxysilane having an amino group optionally substituted with an aliphatic group, or an epoxy group

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 3

alkoxysilane having an amino group optionally substituted with an aliphatic group, or an epoxy group

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

metal fine particles, and an alkoxysilane... excellent platability and adhesion as a priming layer for electroless metal plating

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP2896720B1Electroless plating base agent
Publication Date: 2017.11.22 NISSAN CHEM CORP
  • EP2896720B1 patent drawingFigure 1~4
  • EP2896720B1 patent drawingFigure 5
  • EP2896720B1 patent drawing

AI summary

It is an object of the present invention to provide a novel primer for use in pretreatment steps in electroless plating which is environmentally friendly, by which process is easy with fewer steps, and which can realize cost reduction. A primer for forming a metal plating film on a base material by electroless plating, the primer comprising: a hyperbranched polymer having an ammonium group at a molecular terminal and a weight-average molecular weight of 500 to 5,000,000; a metal fine particle; and an alkoxysilane.