Substrate Transport Apparatus Positional Deviation Correction
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Solution Overview
Problem
In semiconductor and flat panel display manufacturing, substrate transport systems face challenges with positional deviations due to vacuum mechanism failures, pad abrasion, and other issues, leading to improper substrate placement, which can cause system downtime and production disruptions.
Innovation Solution
A substrate transport method and apparatus that includes a holding unit with vacuum suction, detectors for positional deviation measurement, and a controller to calculate and determine positional displacement during transport, ensuring the substrate remains within a predetermined range, thereby correcting and preventing misplacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pads are used to improve adhesion between the fork and substrate, then the substrate can be firmly held during transport, but the pads wear down over time causing substrate positional deviation
Solution Approach 1:
The detection unit measures the positional deviation of the substrate before transport to predict potential placement errors. By performing this measurement in advance, the system can identify substrates that may not be properly positioned due to pad wear, allowing for corrective action before the substrate is placed on the processing stage.
Solution Approach 2:
The system uses detection units to continuously monitor substrate position and provides feedback to the control unit. This feedback mechanism allows the system to track substrate positional deviation caused by pad wear and adjust operations accordingly, maintaining placement precision despite pad degradation.
2Difficulty of detecting and measuring
If visual inspection is used to check pad abrasion during maintenance, then pad wear can be detected, but it is difficult to quantitatively determine the degree of abrasion
Solution Approach 1:
The system replaces manual visual inspection with an automated optical detection unit that uses light to measure substrate position. This substitution enables precise quantitative measurement of substrate deviation, which indirectly provides accurate measurement of pad wear extent, transforming a subjective visual assessment into an objective numerical measurement.
Solution Approach 2:
Instead of directly measuring pad wear, the system uses the substrate's positional deviation as an intermediary indicator. The detection unit measures how much the substrate has shifted from its intended position, which serves as a quantitative proxy for pad wear, making the measurement process more precise and objective.
3Reliability
If the substrate processing system stops operation to inspect pad condition, then potential issues can be identified, but productivity is reduced due to downtime
Solution Approach 1:
The detection unit operates continuously during substrate transport without requiring system shutdown. This allows the system to maintain continuous production while simultaneously monitoring substrate position and detecting pad wear, eliminating the need to stop operations for inspection and maintaining both reliability and productivity.
Solution Approach 2:
The system performs self-diagnosis by automatically detecting substrate positional deviation and identifying potential pad wear issues during normal operation. This self-monitoring capability allows the system to maintain reliability through continuous detection without requiring external inspection or production stoppage.
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 method and apparatus effectively detect and correct positional deviations, ensuring accurate substrate placement, reducing downtime and improving manufacturing efficiency by quantitatively assessing pad wear and other potential causes of displacement.
Implementation Method 1
a holding unit configured to hold the substrate by vacuum suction
Data Source
AI summary
A substrate transporting method includes: after a holding unit of a substrate holding apparatus receives a substrate from one placement location for a substrate and holds it, detecting a first positional deviation of the substrate from a reference position of the substrate on the holding unit; transporting the substrate held by the holding unit to a position facing another placement location; detecting a second positional deviation of the substrate from the reference position of the substrate on the holding unit, when the substrate is located at the position facing the another placement location; calculating, based on the first and second positional deviations, a positional displacement of the substrate relative to the holding unit that occurred during the transporting of the substrate to the position facing the another placement location; and determining whether or not the positional displacement thus calculated falls within a predetermined range.