Inkjet Nozzle Geometry for Precise Bipolar Element Alignment
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Solution Overview
Problem
Existing inkjet printing devices struggle to align bipolar elements with high precision and orientation, particularly in the manufacturing of display devices like OLEDs and LCDs, which affects the efficiency and durability of inorganic light emitting diodes.
Innovation Solution
The inkjet printing device incorporates an electric field generation system with nozzles of varying diameters and inclined side surfaces, along with electric field generation electrodes and coils, to orient and align bipolar elements before deposition on a target substrate, ensuring precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional inkjet printing is used to transfer inorganic light emitting diode elements, then the manufacturing process can be simplified, but the alignment precision and orientation control of bipolar elements deteriorate
Solution Approach 1:
The nozzle structure is designed with an inclined side surface and diameter variation before the bipolar elements are ejected, pre-aligning them in a specific orientation during the ejection process itself, rather than requiring post-ejection alignment steps
Solution Approach 2:
The patent replaces conventional mechanical alignment methods with an electric field-based alignment system. Electric field generation electrodes create a field that orients bipolar elements during ejection and deposition, achieving precise alignment without complex mechanical positioning mechanisms
2Productivity
If conventional transfer methods are used for inorganic light emitting diodes, then the process can be completed quickly, but the durability and efficiency of the resulting display device deteriorate
Solution Approach 1:
The patent changes physical parameters of the ejection system, specifically the nozzle geometry (inclined side surface and diameter variation), to control the orientation and alignment of bipolar elements during high-speed ejection, maintaining both speed and quality
3Device complexity
If simple nozzle structure is used in inkjet printing device, then the device complexity is reduced, but the ability to control orientation and alignment of ejected bipolar elements deteriorates
Solution Approach 1:
The nozzle is designed with an asymmetric inclined side surface and non-uniform diameter along its length, creating a flow path that naturally orients bipolar elements in a specific direction during ejection, achieving precise orientation control through geometric asymmetry rather than complex mechanical actuators
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 method enables high alignment accuracy of bipolar elements, enhancing the manufacturing process of display devices by improving the orientation and placement of inorganic light emitting diodes, thereby increasing efficiency and durability.
Implementation Method 1
an electric field generation part including a stage, and a probe part generating an electric field on the stage
Implementation Method 2
a transfer method using a dielectrophoresis (DEP) method has been developed
Implementation Method 3
an inkjet head positioned above the stage and including nozzles from which ink is ejected
Implementation Method 4
spraying the ink including a bipolar element oriented in an extension direction onto a target substrate
Data Source
AI summary
Provided are an inkjet printing device, a method for aligning a bipolar element, and a method for manufacturing a display device. The inkjet printing device is for ejecting ink and includes a bipolar element extending in one direction. The inkjet printing device comprises: an electric field generation unit which includes a stage and a probe unit for generating an electric field on the stage; and an inkjet head which is positioned above the stage and includes a plurality of nozzles through which the ink is ejected, wherein the nozzles includes an inlet having a first diameter and an outlet connected to the inlet and having a second diameter smaller than the first diameter.