Nozzle Substrate Ink Ejecting Path Shape Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for producing nozzle substrates for ink-jet print heads result in ink ejecting paths on water repellent films that have a radial expansion, leading to a depression of the inner circumference surface compared to the ink ejecting paths on silicon substrates, which affects the shape and size consistency.
Innovation Solution
A nozzle substrate configuration with a recessed part having a truncated cone shape and ink ejecting paths formed on both the silicon substrate and water repellent film, where the transverse sectional area of the third ink ejecting path on the water repellent film is approximately equal to that on the silicon substrate, with an inner circumference surface depression of less than 1.5 μm, and an adhesion layer and water repellent film formed using SiOC and FDTS materials respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If isotropic etching is performed on the silicon substrate to form the nozzle hole, then the nozzle hole penetrates through the silicon substrate, silicon oxide film, and water repellent film, but the inner circumference surface of the ink ejecting path on the water repellent film is depressed outward by 2 μm or more, causing shape and size inconsistency
Solution Approach 1:
A recessed part with a truncated cone shape is formed on the silicon substrate before forming the ink ejecting paths. This preliminary action compensates for the radial expansion that occurs during subsequent etching processes, ensuring that the final ink ejecting paths on the water repellent film have the desired shape and size consistency with those on the silicon substrate.
Solution Approach 2:
The shape of the recessed part is specifically designed with a truncated cone configuration, where the cross-sectional area gradually decreases from the top surface toward the bottom. This geometric parameter change compensates for the radial expansion during etching, maintaining the depression amount within 1.5 μm and achieving consistent ink ejecting path dimensions across different layers.
2Reliability
If the water repellent film is formed on the silicon oxide film which is formed on the silicon substrate, then the water repellent film provides the necessary surface properties, but the ink ejecting path on the water repellent film has a larger cross-sectional area compared to the ink ejecting path on the silicon substrate
Solution Approach 1:
The recessed part is formed on the silicon substrate before depositing the silicon oxide film and water repellent film. This preliminary structuring allows the subsequent layers to conform to the compensated geometry, ensuring that the ink ejecting paths maintain consistent cross-sectional areas despite the radial expansion tendency during etching through multiple layers.
Solution Approach 2:
The recessed part creates a localized geometric modification on the silicon substrate that specifically addresses the ink ejecting path formation area. This local quality change ensures that only the relevant regions undergo shape compensation, while other areas of the substrate maintain their original properties, allowing the water repellent film to retain its necessary surface properties.
Data Source
AI summary
There is provided a nozzle substrate including a nozzle hole penetrating in a thickness direction. The nozzle substrate includes a main substrate including a first surface and a second surface, an adhesion layer formed on the second surface of the main substrate, and a water repellent film formed on a surface at an opposite side to the main substrate side of the adhesion layer. The nozzle hole includes a recessed part formed on the first surface of the main substrate, and an ink ejecting path formed on a bottom surface of the recessed part and penetrating a bottom wall of the recessed part. The ink ejecting path includes a first ink ejecting path, a second ink ejecting path, and a third ink ejecting path. An inner circumference surface of the third ink ejecting path is approximately perpendicular to the second surface of the main substrate.