Photoimageable Nozzle Plate Solvent Resistance via Photoresist Layer
Solution Overview
Problem
Conventional photoimageable nozzle plates for fluid jet ejection heads are not compatible with all solvents, leading to swelling and delamination due to solvent absorption, which affects the dimensional stability and performance of the ejection head.
Innovation Solution
A nozzle plate structure with a strategically placed reinforcing member made of a multi-functional epoxy compound-based photoresist layer, increasing the thickness between nozzle arrays to enhance resistance to solvent-induced deformation and delamination, allowing for wider fluid supply vias without compromising fluid jetting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional photoimageable nozzle plate is used, then the device structure is simple and easy to manufacture, but the nozzle plate absorbs solvents causing swelling, deformation, and delamination
Solution Approach 1:
The nozzle plate is constructed as a composite structure with a substrate layer and a photoresist layer having different properties. The photoresist layer is specifically designed to be resistant to solvent absorption, while the substrate provides structural support. This composite approach allows the device to maintain simplicity in manufacturing while achieving superior solvent resistance and dimensional stability.
2Reliability
If the nozzle plate thickness is increased to reduce solvent absorption, then solvent resistance improves, but the fluid jetting performance and velocity are compromised
Solution Approach 1:
The photoresist layer is applied selectively to specific regions of the nozzle plate where solvent resistance and dimensional stability are critical, such as areas prone to swelling or delamination. This localized application provides enhanced solvent resistance in critical zones without uniformly increasing the overall plate thickness, thereby preserving fluid jetting performance and velocity in the nozzle regions.
3Reliability
If a thicker nozzle plate is used to prevent delamination, then reliability improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The photoresist layer is applied to the substrate before final assembly and testing. This preliminary application of the solvent-resistant layer ensures that dimensional stability and delamination resistance are established early in the manufacturing process, simplifying subsequent steps and reducing the need for complex post-processing or reinforcement structures.
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 solution significantly reduces deformation and delamination of the nozzle plate in the presence of solvents, enabling the use of wider fluid supply vias and maintaining fluid jetting performance and velocity over an extended period.
Implementation Method 1
Many of the solvents used for such fluids are absorbed by the photoresist materials used to make the nozzle plates causing swelling of the photoresist materials
Implementation Method 2
The first negative photoresist layer is imaged and developed to provide a plurality of flow features therein
Data Source
AI summary
A nozzle plate of a fluid ejection head for a fluid ejection device, a fluid ejection head containing the nozzle plate, and a method for making the fluid ejection head containing the nozzle plate. The nozzle plate includes at least two arrays of nozzle holes on opposing sides of a fluid supply via etched in an ejection head substrate and a photoresist layer attached to an exposed surface of the nozzle plate spanning a section of the nozzle plate between the at least two arrays of nozzle holes. The photoresist layer increases a thickness of the nozzle plate between the at least two arrays of nozzle holes to greater than 25 microns up to about 100 microns.