Substrate Edge Etching Sensor Layout for Low-Cost Wafer Detection
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Solution Overview
Problem
Conventional substrate edge etching apparatuses face challenges such as damage to substrates due to unstable chuck pin fixation, foreign substance contamination, and high production costs due to the use of vision cameras for substrate sensing, which are expensive and difficult to mount in narrow spaces.
Innovation Solution
A substrate edge etching apparatus equipped with a substrate sensing unit featuring low-priced light-transmitting and receiving sensors, where a light transmission part and reception part are integrated within the purge gas supply assembly, allowing for substrate detection through a light through hole, reducing production costs and preventing substrate damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If vision cameras are used for substrate sensing, then substrate detection capability is improved, but production cost increases significantly
Solution Approach 1:
The patent replaces expensive vision cameras with inexpensive light sensors (transmitters and receivers) that can be easily manufactured and installed. The light sensors use simple optical components rather than complex imaging systems, dramatically reducing production costs while maintaining adequate substrate detection functionality.
Solution Approach 2:
The patent substitutes the mechanical/optical complex system of vision cameras with a simpler optical detection system using light transmitters and receivers. This replacement eliminates the need for complex image processing hardware while achieving the essential function of substrate presence detection through light blockage sensing.
2Measurement precision
If vision cameras are used for substrate sensing, then substrate detection capability is improved, but installation difficulty increases due to narrow spaces
Solution Approach 1:
The patent divides the sensing function into separate light transmitter and receiver components that can be independently positioned and installed. This segmentation allows the components to be mounted in distributed locations around the substrate path, making installation feasible in narrow spaces where a single bulky camera could not fit.
Solution Approach 2:
The patent transitions from a single-point camera detection approach to a distributed optical path approach. By positioning light transmitters and receivers at different locations and using light beams that traverse through space, the system achieves detection capability in three-dimensional space rather than being constrained to a single installation point.
3Ease of operation
If substrates are fixed by chuck pins during etching, then substrate positioning is achieved, but substrate damage occurs due to unstable fixation
Solution Approach 1:
The patent implements substrate detection before the etching process begins. The light sensors detect substrate presence and proper positioning in advance, allowing the system to verify correct fixture engagement before applying etching chemicals or initiating rotation, thereby preventing damage from mispositioned substrates.
Solution Approach 2:
The patent incorporates a feedback mechanism where light sensors continuously monitor substrate presence and position. This feedback allows the control system to detect improper substrate fixation or displacement during the etching process and take corrective action, preventing substrate damage caused by unstable positioning.
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 apparatus effectively detects substrates during rotation, preventing damage and reducing production costs by utilizing low-cost light sensors, ensuring reliable operation and minimizing structural changes for easy installation.
Implementation Method 1
a substrate sensing unit having a light transmission part disposed inside the hollow hole of the purge gas supply assembly and a light reception part disposed apart above the light through hole of the chuck base, wherein light that is transmitted from the light transmission part and passes through the hollow hole and the light through hole is sensed by means of the light reception part
Data Source
AI summary
The present invention relates to a substrate edge etching apparatus including: a substrate support assembly having a horizontally rotatable chuck base with a light through hole vertically penetrating a center thereof and chuck pins disposed on top of the chuck base; a spin motor for rotating the substrate support assembly; a purge gas supply assembly connected to the driving shaft through a bearing, extending vertically from the underside center of the chuck base, and having a hollow hole penetratingly extending therealong to supply a purge gas to the light through hole; and a substrate sensing unit having a light transmission part disposed inside the hollow hole of the purge gas supply assembly and a light reception part disposed apart above the light through hole of the chuck base.