Wiring Circuit Board Dummy Pattern for Uniform Thickness Near Openings

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Solution Overview

Problem

Existing methods for producing printed wiring boards with openings struggle to achieve uniform thickness of conductive patterns near openings due to the formation of dummy patterns outside the printed wiring board region.

Innovation Solution

A method involving region setting, insulating layer formation, conductive pattern formation with varying thickness layers, and etching to create a dummy pattern in the opening region, ensuring uniform metal ion concentration and thickness of the conductive pattern, and covering it with a cover insulating layer to prevent contact with surrounding members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a dummy pattern is formed outside the printed wiring board region, then the conductive pattern can be formed, but the thickness of the conductive pattern near the opening becomes non-uniform

Engineering Contradiction:

Improveuniformity of conductive pattern thicknessVSAvoiddifficulty in achieving uniform thickness near opening

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The dummy pattern is formed in advance within the opening forming region before the actual conductive pattern formation. This preliminary placement of conductive material (dummy pattern) in the opening region balances the metal ion distribution in the plating solution, ensuring that when the actual conductive pattern is formed nearby, the thickness remains uniform even near the opening edges.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The dummy pattern acts as an intermediary element that mediates the metal ion distribution in the plating solution. By placing this dummy conductive structure in the opening forming region, it serves as a buffer that regulates the flow and concentration of metal ions, thereby enabling uniform thickness formation of the actual conductive pattern without requiring complex process control.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If the support layer is etched in the opening forming region, then the opening is created, but the conductive pattern may contact surrounding members

Engineering Contradiction:

Improveopening formationVSAvoidcontact between conductive pattern and surrounding members

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The support layer material in the opening forming region is selectively removed (etched away) to create the opening. This extraction of the support layer material allows the opening to be formed while the dummy pattern remains in place to provide protective coverage, preventing the conductive pattern from contacting surrounding members through the opening.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The dummy pattern serves as a protective copy or surrogate structure that replicates the protective function needed. By having this dummy conductive layer in the opening region, it provides the necessary coverage and protection against contact, while the actual conductive pattern can be formed with proper spacing.

Inventive Principle:

Principle #26Copying

3Manufacturing precision

If a dummy pattern is formed in the opening forming region, then uniform metal ion concentration is achieved, but the device complexity increases

Engineering Contradiction:

Improveuniform metal ion concentrationVSAvoidcomplexity of pattern formation process

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The formation of the dummy pattern and the actual conductive pattern are merged into a single plating process step. By designing the patterning structure to include both dummy and functional patterns that can be formed simultaneously in one plating operation, the process complexity is minimized while still achieving uniform metal ion concentration distribution.

Inventive Principle:

Principle #5Merging (Combining)

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 method achieves a uniform thickness of conductive patterns near openings and protects them by forming a dummy pattern with a cover insulating layer, supporting the pattern during etching and preventing contact with the surrounding environment.

Implementation Method 1

in at least one of a first pattern step and a second pattern step, a dummy pattern is formed in the opening forming region... it is possible to achieve the uniform metal ion concentration around the first conductive layer or the second conductive layer

Methodology Applied

Scientific EffectElectroplating: Electroplating

Implementation Method 2

an etching step of etching at least a portion of the support layer in the opening forming region

Methodology Applied

Scientific EffectChemical etching:

Data Source

PatentUS20240164024A1Method for producing wiring circuit board, wiring circuit board with dummy pattern, and assembly sheet

Publication Date: 2024.05.16 NITTO DENKO CORP

AI summary

A method for producing a wiring circuit board includes a region setting step of setting a pattern forming region and an opening forming region in a support layer; an insulating layer forming step of forming a base insulating layer on the support layer in the pattern forming region; a pattern step of forming a conductive pattern having a first conductive layer and a second conductive layer on the base insulating layer; and an etching step of etching the support layer in the opening forming region, and in the pattern step, a dummy pattern is formed in the opening forming region.