Circuit Board Adhesive Layer Bonding and Dry Etching

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Solution Overview

Problem

Current circuit board manufacturing methods face challenges with poor bonding force between dielectric layers, leading to structural weaknesses and increased manufacturing costs, particularly in achieving fine line widths and miniaturization due to limitations in exposure processes.

Innovation Solution

The method involves forming a patterned first dielectric layer on a substrate, bonding a first adhesive layer, and then a second dielectric layer, with a mask layer adhered via a second adhesive layer, allowing for dry etching to create through holes and conductive lines, enhancing bonding force and simplifying the process by eliminating additional mask removal steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If exposure process is used to form through holes, then through holes can be created, but resolution issues limit fine line width achievement

Engineering Contradiction:

Improveline widthVSAvoidexposure resolution

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent replaces the exposure process (optical system) with a direct patterning method where the mask layer is formed and patterned without relying on exposure resolution. This substitution allows fine line widths to be achieved without being constrained by exposure system resolution limits.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If additional mask removal steps are added, then complete pattern formation is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:

Improvepattern formation completenessVSAvoidprocess steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines the mask layer formation and removal into a single integrated process. The mask layer is formed, patterned, and then removed as part of the same manufacturing sequence, eliminating the need for separate mask removal steps and reducing overall process complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The mask layer is designed to be self-removable through the manufacturing process itself. The etching or removal process that creates the through holes automatically removes the mask layer material, eliminating the need for additional dedicated mask removal steps.

Inventive Principle:

Principle #25Self-service

3Strength

If dielectric layers are bonded without adhesive layer optimization, then bonding can be achieved, but bonding force is insufficient leading to structural weaknesses

Engineering Contradiction:

Improvebonding forceVSAvoidstructural integrity

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent modifies the adhesive layer parameters including material composition, thickness, and bonding conditions to optimize bonding force. By changing these parameters, the adhesive layer achieves sufficient bonding strength to prevent structural weaknesses while maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structures where the adhesive layer is formulated with specific material properties that enhance bonding force. The adhesive layer may contain reinforcing particles or have a multi-phase composition that improves both bonding strength and structural integrity.

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

This approach improves the bonding force between dielectric layers, enables miniaturization with finer line widths, and reduces manufacturing costs by simplifying the process and avoiding resolution issues in exposure-based through hole formation.

Implementation Method 1

The adhesive layer is bonded to the first dielectric layer and has a top surface opposite to the substrate

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

filling a conductive material at least in the patterned second dielectric layer, such that the conductive material is in contact with the top surface of the first adhesive layer

Methodology Applied

Scientific EffectConduction: Conduction (electrical)

Implementation Method 3

The patterning the second dielectric layer includes: forming a mask layer on the second dielectric layer; patterning the mask layer to form at least one opening; and performing a removing process to the second dielectric layer through the opening of the mask layer until the portion of the top surface of the first adhesive layer is exposed

Methodology Applied

Scientific EffectPlasma etching: Plasma

Data Source

PatentUS10433426B2Circuit board and method for manufacturing the same

Publication Date: 2019.10.01 UNIMICRON TECH CORP

AI summary

A circuit board includes a substrate, a first dielectric layer, an adhesive layer, a second dielectric layer, and a first conductive line. The first dielectric layer is disposed on the substrate. The adhesive layer is bonded to the first dielectric layer and has a top surface opposite to the substrate. The second dielectric layer is disposed on the adhesive layer and has at least one first through hole. The first conductive line is located in the first through hole of the second dielectric layer and is in contact with the top surface of the adhesive layer.