Liquid Ejection Head Insulating Layer Recess Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face challenges in achieving high-speed recording while maintaining long-term electrical reliability due to increased flow resistance and corrosion issues, particularly when the insulating layer is removed near the penetration port, leading to rapid degradation of electrical components.
Innovation Solution
A liquid ejection head design featuring a recessed region in the insulating layer with a protective layer having a lower etch rate than the substrate, which reduces flow resistance and enhances long-term reliability by preventing corrosion, includes a supply path with a recessed region formed by etching the insulating layer and a protective layer applied to the substrate surface to shield electrical components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the insulating layer is removed near the penetration port to reduce flow resistance, then the refilling speed of the flow path is improved, but the electrical components degrade rapidly due to corrosion from the ejection liquid
Solution Approach 1:
The insulating layer is segmented into two regions: a first region with sufficient thickness to provide electrical insulation and protect wiring layers, and a second region (recessed portion) with reduced thickness to minimize flow resistance. This segmentation allows the structure to simultaneously achieve both low flow resistance and adequate electrical protection.
Solution Approach 2:
The insulating layer exhibits local quality variation where different regions have different thicknesses tailored to their specific functional requirements. The first region maintains thick insulation for electrical protection, while the second region has thin insulation for fluid flow efficiency, optimizing both electrical reliability and refilling speed in their respective locations.
2Reliability
If the insulating layer is kept thick to protect electrical components, then electrical reliability is maintained, but flow resistance increases and refilling speed decreases
Solution Approach 1:
The insulating layer is divided into functional segments where the first region provides thick insulation for electrical protection while the second region provides thin insulation for low flow resistance, enabling both high reliability and high productivity simultaneously.
Solution Approach 2:
Different thicknesses of the insulating layer are applied locally to different regions based on their functional needs, with the first region having thick insulation for electrical protection and the second region having thin insulation for fluid flow, thus resolving the contradiction between protection and flow efficiency.
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 design effectively reduces flow resistance and improves the long-term reliability of the liquid ejection head by extending the time before electrical components are affected by the ejection liquid, ensuring stable performance over time.
Implementation Method 1
a protective layer formed of a material having a lower etch rate with respect to the ejection liquid, than that of the substrate
Data Source
AI summary
A liquid ejection head includes: a substrate in which a supply path which opens on a first surface and supplies an ejection liquid is formed; an insulating layer provided on the first surface of the substrate; an energy generating element provided on a surface of the insulating layer; an electric wiring layer electrically connected to the energy generating element and electrically insulated from the ejection liquid by the insulating layer; and an ejection orifice member which forms an ejection orifice and forms a flow path of the ejection liquid from an opening of the supply path to a formation position of the energy generating element. In the vicinity of the opening of the supply path, the insulating layer forms a recessed region by being dented closer to the substrate than the surface on which the energy generating element is provided or by being removed.