Inkjet Nozzle Priming Feature for Meniscus Control
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Solution Overview
Problem
Inkjet printing faces challenges in priming MEMS printheads due to ink meniscus pinning at small apertures, which can stop ink flow to chambers, especially during initial priming, as the meniscus can strongly adhere to the aperture lip, preventing ink from reaching the nozzle chambers.
Innovation Solution
A method of fabricating inkjet nozzles with a priming feature extending from the rim of the ink inlet aperture, redirecting the surface tension of the ink meniscus to facilitate flow into the nozzle chamber, involving steps such as depositing sacrificial material, forming chamber sidewalls and priming features, and etching nozzle apertures, to ensure effective ink distribution and chamber priming.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ink inlet openings are used in conventional inkjet printheads, then ink can be supplied to nozzle chambers, but the ink meniscus pins at the inlet opening and prevents ink flow to certain chambers during initial priming
Solution Approach 1:
The ink inlet opening is segmented by adding a protrusion that divides the opening into multiple paths. This segmentation prevents the meniscus from pinning at a single location and allows ink to flow into the chamber through alternative paths, ensuring reliable priming of all chambers.
Solution Approach 2:
A protrusion is added into the ink inlet opening from the chamber side, creating a three-dimensional feature that redirects the meniscus. This dimensional change causes the meniscus to form at the protrusion tip rather than at the inlet rim, redirecting surface tension forces to pull ink into the chamber instead of pushing it back.
2Quantity of substance
If the ink meniscus pins at the inlet aperture, then surface tension holds the ink back, but this prevents ink from reaching the chambers during initial priming
Solution Approach 1:
The protrusion acts as an intermediary feature between the ink inlet and the chamber. It provides a surface for the meniscus to form at its tip, which then redirects the surface tension force to pull ink through the inlet and into the chamber, ensuring consistent ink delivery to all chambers.
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 introduction of a priming feature redirects the ink meniscus, preventing it from pinning at the aperture, ensuring successful priming of all chambers and maintaining continuous ink flow, thereby improving the reliability and efficiency of the inkjet printing process.
Implementation Method 1
redirecting surface tension to pull ink along the intend flow path rather than push it back into the inlet
Data Source
AI summary
A method of fabricating a plurality of inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber having a roof spaced apart from said substrate and sidewalls extending from said roof to said substrate, said chamber having an entrance for receiving ink from at least one ink inlet defined in said substrate, said at least one ink inlet having at least one priming feature extending from a respective rim thereof, said method comprising the steps of:(a) providing a substrate having a plurality of trenches corresponding to said ink inlets;(b) depositing sacrificial material on said substrate so as fill said trenches and form a scaffold on said substrate;(c) defining openings in said sacrificial material, said openings being positioned to form said chamber sidewalls and said at least one priming feature when filled with roof material;(d) depositing roof material over said sacrificial material to form simultaneously said nozzle chambers and said at least one priming feature;(e) etching nozzle apertures through said roof material, each nozzle chamber having at least one nozzle aperture; and(f) removing said sacrificial material.By introducing a priming feature into the plane of the inlet aperture, the surface tension in the ink meniscus can be redirected to pull the ink along the intend flow path rather than push it back into the inlet.