Variable Resistor Nozzle Grounding for ESD and Dispensing Precision
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Solution Overview
Problem
Existing substrate treatment technologies face challenges in maintaining equilibrium stress and surface tension while preventing contamination and Electrostatic Discharge (ESD) phenomena due to electrostatic forces, particularly during chemical dispensing processes.
Innovation Solution
An apparatus and method utilizing a nozzle unit connected to a ground line with a variable resistor, which changes resistance values to manage electrostatic forces by grounding the nozzle appropriately during movement, dispensing, and stopping, thereby controlling the electrostatic discharge and preventing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the nozzle is grounded with a fixed low resistance value, then ESD protection is improved, but chemical dispensing precision deteriorates due to electrostatic force interference
Solution Approach 1:
The grounding resistance of the nozzle is made dynamic rather than fixed. The resistance value is automatically adjusted based on the operational state: during chemical dispensing, a higher resistance value is used to maintain surface tension and prevent Taylor cone-jet formation, while during non-dispensing periods, a lower resistance value is applied for ESD protection. This dynamic adjustment resolves the contradiction between ESD protection and dispensing precision.
Solution Approach 2:
The electrical resistance parameter of the nozzle grounding is changed according to different operational phases. By switching between different resistance values (high resistance during dispensing, low resistance during idle periods), the system optimizes both ESD protection and chemical dispensing precision without compromising either function.
2Manufacturing precision
If the nozzle is grounded with a fixed high resistance value, then chemical dispensing precision is improved, but ESD protection deteriorates
Solution Approach 1:
The grounding resistance is dynamically switched based on operational requirements. During chemical dispensing, high resistance prevents electrostatic interference with surface tension and chemical flow precision. During non-dispensing periods, low resistance provides adequate ESD protection. This dynamic switching resolves the contradiction between precision and protection.
Solution Approach 2:
The grounding resistance is periodically switched between high and low values according to the dispensing cycle. The system alternates between high-resistance mode during dispensing phases and low-resistance mode during idle phases, ensuring both precision and ESD protection are maintained at appropriate times.
3Object-affected harmful factors
If electrostatic force is increased to prevent contamination, then substrate protection is improved, but chemical dispensing control deteriorates due to disruption of surface tension
Solution Approach 1:
The electrical resistance parameter is changed based on operational phase to balance contamination protection and dispensing control. During dispensing, high resistance maintains surface tension for precise control. During idle periods, low resistance provides electrostatic protection against contamination. This parameter switching resolves the contradiction between protection and control.
Solution Approach 2:
The system prepares the appropriate resistance value in advance for each operational phase. Before dispensing begins, the resistance is switched to high value to ensure precise control. Before idle periods, the resistance is switched to low value to provide electrostatic protection. This preliminary preparation prevents the contradiction from arising during operation.
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 effectively maintains a balance between equilibrium stress and surface tension, preventing substrate contamination and ESD phenomena by managing electrostatic forces, ensuring efficient and reliable substrate treatment.
Implementation Method 1
controlling an electrostatic force... preventing contamination of a substrate and an ESD phenomenon
Implementation Method 2
a variable resistor is provided on the ground line... a resistance value of the variable resistor may be changed to a first resistance value or a second resistance value
Data Source
AI summary
The inventive concept relates to an apparatus for treating a substrate. The apparatus includes a support unit that supports the substrate and a nozzle unit having a nozzle that dispenses a chemical onto the substrate, in which the nozzle is connected with a ground line, and a variable resistor is provided on the ground line.