Inkjet Print Head Nozzle Geometry via Layered Substrate Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet print head technologies face challenges in forming nozzles with precise geometry and uniform thickness, which affects ink ejection accuracy and resistance, and often require additional adhesive layers or complex processing steps.
Innovation Solution
The method involves etching nozzles into a separate nozzle layer of a multi-layer substrate, which can be thinned and bonded to a flow path module using direct silicon bonding or anodic bonding, allowing for precise control of nozzle geometry and thickness, and reducing ink flow resistance by eliminating orthogonal surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If nozzles are formed in a traditional single-layer substrate, then the structure is simpler to manufacture, but the nozzle geometry precision and thickness uniformity are insufficient
Solution Approach 1:
The substrate is divided into multiple functional layers: a first substrate layer containing the flow path, a second substrate layer containing the nozzle structures, and an intermediate adhesive layer. This segmentation allows independent optimization of each layer's geometry and thickness, achieving precise nozzle formation while maintaining manufacturability through separate processing steps for each layer.
2Manufacturing precision
If adhesive layers are used to bond substrate layers, then the bonding process is simplified, but the nozzle geometry precision is reduced
Solution Approach 1:
Nozzle apertures are formed in the second substrate layer before bonding to the first substrate layer. This preliminary action allows precise nozzle geometry to be established in the second layer independently, then maintained during the subsequent bonding process, rather than attempting to form nozzles after bonding which would compromise precision.
3Ease of manufacture
If orthogonal surfaces are present in the nozzle structure, then manufacturing is easier, but ink flow resistance increases and air trapping occurs
Solution Approach 1:
The nozzle aperture in the second substrate layer is designed with asymmetric geometry, specifically a tapered configuration where the aperture size varies along the flow direction. This asymmetric design eliminates orthogonal surfaces that cause air trapping, while the tapered shape reduces ink flow resistance by creating a smoother flow transition, and can still be manufactured using standard photolithography and etching processes.
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 enables the formation of nozzles with desired depths and geometries, reducing air trapping and ink flow resistance, while allowing for independent control of nozzle layer thickness and additional processing steps, enhancing the precision and efficiency of ink ejection in inkjet print heads.
Implementation Method 1
bonded to a flow path module using direct silicon bonding or anodic bonding
Implementation Method 2
bonded to a flow path module using direct silicon bonding or anodic bonding
Implementation Method 3
An aperture is etched into a first surface of a nozzle layer
Data Source
AI summary
Techniques are provided for forming nozzles in a microelectromechanical device. The nozzles are formed in a layer prior to the layer being bonded onto another portion of the device. Forming the nozzles in the layer prior to bonding enables forming nozzles that have a desired depth and a desired geometry. Selecting a particular geometry for the nozzles can reduce the resistance to ink flow as well as improve the uniformity of the nozzles across the microelectromechanical device.