Vacuum Hand Height Timing for Accurate Substrate Pickup
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Solution Overview
Problem
Existing semiconductor manufacturing conveyance systems face productivity disadvantages due to difficulties in accurately and efficiently measuring the height of a hand holding a substrate at the start of contact, caused by delays in suction pressure reaching a threshold, leading to interference and reduced productivity.
Innovation Solution
A method that involves detecting the pressure of a vacuum line connected to a suction mechanism on the hand, obtaining a height profile, and determining the hand's height at a predetermined time before the pressure reaches a threshold, allowing for accurate and efficient measurement of the hand's height at the start of contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the hand is stopped and suction pressure is monitored to determine substrate chucking, then measurement reliability is improved, but productivity deteriorates due to standby time delay
Solution Approach 1:
The patent applies preliminary action by continuously monitoring suction pressure during the hand's upward movement before substrate chucking occurs. This allows the system to predict the hand height at the moment of contact by extrapolating from pressure data collected during the approach phase, eliminating the need to stop and wait for pressure stabilization after contact.
Solution Approach 2:
The patent replaces the mechanical stopping and pressure-waiting approach with a computational method. Instead of physically stopping the hand and waiting for pressure equilibrium, the system uses pressure sensor data combined with height sensor data to calculate and predict the hand height at contact timing through signal processing and timing calculation.
2Productivity
If the hand moves continuously without stopping, then productivity is improved, but measurement precision deteriorates due to inability to accurately detect contact timing
Solution Approach 1:
The patent implements feedback by continuously monitoring both suction pressure and height position during the hand's upward movement. The control unit uses this real-time feedback to detect the relationship between pressure changes and height changes, enabling accurate determination of contact timing and hand height without interrupting the continuous motion.
Solution Approach 2:
The patent applies dynamics by analyzing the dynamic relationship between suction pressure and hand height during motion. Instead of treating the system statically (stopped state), the invention captures the dynamic interaction between pressure changes and height changes during the hand's upward movement to determine contact characteristics.
3Reliability
If standby time is extended to allow pressure to reach threshold, then measurement reliability is improved, but loss of time increases
Solution Approach 1:
The patent applies preliminary action by collecting suction pressure data during the hand's approach to the substrate, before contact occurs. This preliminary data collection allows the system to predict contact timing and hand height in advance, eliminating the need for extended standby time after contact to ensure reliable measurement.
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 enables precise and efficient measurement of the hand's height at the start of contact, reducing interference and improving productivity by estimating the delay time in suction pressure changes, thus enhancing the conveyance process.
Implementation Method 1
a vacuum pump 170 and a vacuum line 112 connected to the suction hole 111a
Implementation Method 2
the hand 110 is made to hold the substrate 100 by moving up the hand 110 from below the substrate 100
Data Source
AI summary
The present invention provides a measurement method of measuring a height of a hand at a start timing of contact between the hand and a substrate in a process of causing the hand to hold the substrate by moving up the hand from below the substrate, wherein the hand has an upper surface provided with a suction hole connected to a vacuum line, the method comprising: performing the process while detecting a pressure of the vacuum line; obtaining a height profile indicating a change in a height of the hand in the process; and determining a height of the hand at a second timing which is a predetermined time period before a first timing when a pressure of the vacuum line decreases and reaches a threshold, based on the height profile, as a height of the hand at the start timing.