Stacked Wiring Adhesion Layer Wet Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In ink jet recording heads, the adhesion layer is side-etched during wet etching, leading to peeling off of the lead electrode and conduction failures between the lead electrode and the inclined wiring, resulting in poor ink ejection reliability.
Innovation Solution
Forming a first wiring with a wider side opposite to the adhesion layer, covering it with a second adhesion layer of the same material, and using wet etching to form a second wiring, which prevents side-etching of the adhesion layer and maintains the first wiring's adhesion to the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet etching method is used to form inclined wiring, then wiring formation is achieved, but adhesion layer is side-etched causing lead electrode peeling off
Solution Approach 1:
A protective layer is formed on the adhesion layer before wet etching to prevent side-etching. This preliminary protective measure allows the wet etching process to proceed without damaging the adhesion layer, thereby maintaining both manufacturability and reliability.
Solution Approach 2:
The protective layer acts as an intermediary between the adhesion layer and the etchant. It mediates the etching process by blocking direct contact between the etchant and adhesion layer, enabling wiring formation while protecting the underlying adhesion structure.
2Productivity
If adhesion layer is side-etched, then etching process progresses, but lead electrode peels off resulting in conduction failure
Solution Approach 1:
The protective layer is applied in advance before etching begins. This preliminary action ensures that the adhesion layer is protected throughout the entire etching process, preventing side-etching and maintaining conduction integrity from the start of manufacturing.
Solution Approach 2:
The protective layer, which initially adds process complexity, ultimately converts the harmful effect of aggressive etching into a beneficial outcome. It allows complete etching of the wiring pattern while preventing damage to the adhesion layer, achieving both productivity and precision.
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 method effectively suppresses peeling off of the first wiring, ensuring reliable electrical connection and improved ink ejection performance by preventing side-etching of the adhesion layer during wet etching.
Implementation Method 1
forming a second wiring on the first wiring via the second adhesion layer through a wet etching method with the etchant
Data Source
AI summary
A method of forming a stacked wiring includes forming a first adhesion layer on a substrate, forming a first wiring on the first adhesion layer, etching the first adhesion layer and the first wiring by the same first wet etching so that the first wiring is in a reverse trapezoid shape in which a first width of a top surface is larger than a second width of a bottom surface contacting the first adhesion layer as a cross-section in a direction intersecting with a first wiring extending direction, covering the top surface and a side surface of the first wiring with a second adhesion layer, forming a second wiring on the second adhesion layer, and etching the second adhesion layer and the second wiring by the same second wet etching so that the second adhesion layer and the second wiring remain on only the top surface of the first wiring.