Droplet Ejection Nozzle Grouping for Landing Position Accuracy
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Solution Overview
Problem
Existing droplet ejecting methods for forming devices like metal wiring and color filters face challenges in accurately controlling droplet landing positions, particularly in the sub-scanning direction, leading to inaccuracies and potential mixing of different liquid materials.
Innovation Solution
Classifying nozzles into groups based on landing position accuracy and performing separate main scanning and sub-scanning movements for each group, with correction information used to adjust the relative positions and ejection timings to achieve high accuracy in droplet placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional droplet ejection methods are used with single scanning process, then device formation is achieved, but droplet landing position accuracy deteriorates in sub-scanning direction
Solution Approach 1:
The patent divides the ejection process into two separate scanning operations: main scanning (X-direction) and sub-scanning (Y-direction). Each scanning process handles specific nozzle groups with characteristic correction values, segmenting the complex positioning problem into manageable directional components that can be controlled independently.
Solution Approach 2:
The patent performs preliminary classification of nozzles into multiple groups based on their landing position characteristics before ejection. Correction values for each nozzle group are calculated in advance based on preliminary landing position measurements, enabling predictive compensation for positioning errors during actual droplet ejection.
2Manufacturing precision
If head correction is performed using conventional methods, then some landing position errors are corrected, but accurate control of droplet landing positions in sub-scanning direction remains difficult
Solution Approach 1:
The patent performs preliminary measurement of droplet landing positions for each nozzle group and calculates correction values before actual device fabrication. This preliminary correction information is stored and reused, eliminating the need for time-consuming real-time measurements during production while maintaining high positioning accuracy.
Solution Approach 2:
The patent changes the parameter approach by introducing direction-specific correction values (X-direction and Y-direction corrections) rather than using single scalar correction. This parameter differentiation enables precise control of landing positions in the previously problematic sub-scanning direction without requiring excessive correction time.
3Productivity
If high-definition target regions are arranged closely, then device density is improved, but droplet placement accuracy deteriorates due to positioning errors
Solution Approach 1:
The patent calculates and stores correction values for each nozzle group in advance based on preliminary landing position measurements. This preliminary correction enables accurate droplet placement even in high-density target region arrangements by compensating for systematic positioning errors before actual high-precision deposition begins.
Solution Approach 2:
The patent applies different correction values to different nozzle groups based on their specific landing position characteristics. Each nozzle group receives localized correction tailored to its performance, enabling high-precision droplet placement in high-density arrangements where uniform correction would be insufficient.
Data Source
AI summary
A method for ejecting a liquid material includes classifying the plurality of nozzles of a head into a plurality of nozzle groups having different landing position accuracies for droplets; and performing ejection includes main scanning for ejecting droplets of the liquid material through selected nozzles while generating relative movement in a main-scanning direction between the head and a target substrate, and sub-scanning for generating relative movement between the head and the target substrate in a sub-scanning direction orthogonal to the main-scanning direction. The main scanning and the sub-scanning are performed separately for each of the plurality of nozzle groups. During the sub-scanning, relative movement is generated in accordance with correction information for the corresponding nozzle group for correcting landing positions of the droplet. During the main scanning, a droplet is ejected through at least one nozzle selected from the corresponding nozzle group.