Dynamic Metal Etching Endpoint Control for LCD Panels
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Solution Overview
Problem
Existing metal etching methods for LCD panel manufacturing face challenges in achieving consistent etching quality due to varying metal film thicknesses, leading to over etching of thinner films and under etching of thicker films when using a single total real etching time for a batch.
Innovation Solution
A metal etching method that uses an end point sensor to determine the etching end time and multiplies it by a constant ratio to calculate the over etching time, ensuring each film is etched to completion based on its specific thickness, with the ability to adjust the ratio based on etching times and acid solution concentration degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single total real etching time is used for a batch of metal films, then the etching process can be simplified and executed efficiently, but the etching quality becomes unstable due to varying metal film thicknesses
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed etching time to a dynamic etching time that adapts to each substrate's specific conditions. The system dynamically adjusts the total real etching time based on real-time detection of metal film thickness and etching rate variations, allowing each substrate to receive customized etching treatment while maintaining high throughput production efficiency
Solution Approach 2:
The patent implements parameter changes by modifying the etching time parameter based on detected metal film characteristics. The system measures actual metal film thickness and etching rate during the process, then adjusts the total real etching time parameter accordingly to ensure complete etching for all substrates in the batch, resolving the contradiction between production efficiency and etching quality consistency
2Reliability
If an over etching time is added to prevent remaining metal film, then complete etching is ensured, but thinner metal films become over etched
Solution Approach 1:
The patent applies preliminary action by performing detection of metal film thickness and etching rate before finalizing the etching time determination. The system proactively identifies substrates with varying thickness characteristics and pre-calculates appropriate etching times, preventing both under-etching and over-etching by preparing customized etching parameters in advance based on detected substrate characteristics
Solution Approach 2:
The patent implements parameter changes by adjusting the total real etching time parameter based on detected metal film thickness and etching rate. Instead of using a fixed over-etching time that causes over-etching of thin films, the system dynamically modifies the etching time parameter to match each substrate's specific requirements, ensuring complete etching without excessive removal of material
3Measurement precision
If the etching end time is determined by sensor detection, then the etching endpoint can be accurately identified, but the total real etching time cannot be precisely determined for each substrate
Solution Approach 1:
The patent applies feedback by using sensor detection results as input for calculating the total real etching time. The system continuously monitors the etching process, detects the endpoint based on metal film removal, and feeds this information back to adjust and determine the precise total real etching time for each substrate, creating a closed-loop control system that ensures accurate etching time determination
Solution Approach 2:
The patent implements parameter changes by using the detected etching endpoint information to modify and determine the total real etching time parameter. The system changes the etching time parameter from a predetermined fixed value to a dynamically determined value based on actual detection results, enabling precise determination of etching time for each substrate while maintaining accurate endpoint detection
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 approach allows for precise determination of the total real etching time for each metal film, stabilizing etching quality and improving yield in LCD panel manufacturing by accounting for variations in film thickness and acid solution concentration.
Implementation Method 1
The working theory of the end point detector is based on the light reflection/penetration. As the metal film remains on the substrate 100, the light generated by the sensor of the end point detector is still reflected by the metal film because the light cannot penetrate the metal film.
Implementation Method 2
The metal wet etching process is to load the substrate 100 carrying the plated metal film (metal layer) in an etching bath full of acid solution. Then, etching is performed to the area unprotected by the photoresist to obtain the patterns protected by the photoresist.
Data Source
AI summary
Disclosed is a metal etching method, a metal etching control method and a control device thereof. The metal etching control method is employed in a metal wet etching machine and comprises steps below: performing etching to a metal film and acquiring an etching end time of the metal film; multiplying the etching end time with a constant ratio to acquire the over etching time of the metal film; and performing etching to the metal film with the over etching time to complete the etching to the metal film. The present invention can precisely judge a total real etching time needed for each of a batch of metal films as performing metal etching to the metal films to reduce the issue of unstable etching qualities as the metal film thicknesses are not regular.