Spin Coating Chuck Electromagnetic Balancing
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Solution Overview
Problem
In semiconductor manufacturing, particularly for LED and IC chip production, the deviation between the geometric center and center of gravity of workpieces with a 'flat' form causes unbalanced centrifugal forces during high-speed spin coating, leading to vibrations and potential damage due to wobbling, especially with heavy substrates like sapphire.
Innovation Solution
A spin coating apparatus equipped with an electromagnetic induction device under the chuck, which generates variable magnetic forces to balance the chuck by adjusting its surface levelness through repulsive and attractive forces, compensating for unbalanced centrifugal forces without human intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed rotation is used for spin coating, then coating efficiency is improved, but vibration and wobbling increase due to centrifugal force imbalance
Solution Approach 1:
The electromagnetic induction device generates a magnetic force that acts as a counterbalancing force to offset the unbalanced centrifugal force. The device includes a magnet and a coil that, when energized, produce a magnetic field interacting with the magnet to generate a controllable counterbalancing force, thereby reducing vibration and wobbling during high-speed rotation.
Solution Approach 2:
The system dynamically adjusts the electromagnetic force parameters (current through the coil) to compensate for changes in centrifugal force as rotation speed varies. By changing the electrical parameter (current) in response to rotation speed, the system maintains balance across different operating conditions, enabling both high-speed operation and stable coating.
2Ease of operation
If workpiece geometric center does not coincide with gravitational center, then workpiece can be manufactured with flat form for alignment, but unbalanced centrifugal force is generated during rotation
Solution Approach 1:
The electromagnetic induction device provides a dynamic counterbalancing force that compensates for the fixed geometric imbalance caused by the flat form. The magnetic force generated by the coil-magnet interaction acts as an active counterweight that can be adjusted to offset the centrifugal force imbalance, maintaining rotational stability while preserving the alignment-providing flat form.
Solution Approach 2:
Instead of using mechanical counterweights or physical adjustments to balance the chuck, the invention substitutes a magnetic field-based electromagnetic system. This replaces traditional mechanical balancing methods with a controllable electromagnetic force generation system, allowing for dynamic compensation without mechanical contact or physical modification of the balanced components.
3Stability of the object's composition
If electromagnetic induction device is added to balance the chuck, then rotational stability is improved, but device complexity increases
Solution Approach 1:
The electromagnetic induction device is designed to automatically sense and respond to imbalance conditions without requiring external control systems. The system self-regulates by using the rotation-induced current in the coil to generate the appropriate magnetic force, eliminating the need for complex sensors, controllers, and power supplies that would otherwise be required.
Solution Approach 2:
The invention replaces complex mechanical balancing mechanisms (such as adjustable counterweights, mechanical linkages, or active mass balancing systems) with a relatively simple electromagnetic induction device. The electromagnetic system achieves the same balancing function with fewer moving parts and less mechanical complexity, reducing overall system complexity while maintaining effectiveness.
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 stabilizes the chuck's rotation, reduces wobbling, and enhances photoresist coating quality by automatically adjusting electromagnetic forces, thereby preventing equipment damage and improving process efficiency.
Implementation Method 1
an electromagnetic induction device being disposed in the apparatus to produce variable electromagnetic forces for the tilted chuck to maintain balance of the chuck
Implementation Method 2
exerting by an electromagnetic induction device a repulsive force to a portion of the chuck having a smaller height and an attractive force to another portion of the chuck having a greater height
Data Source
AI summary
A spin coating device and method. The spin coating device includes a rotatable rotary shaft and sucker fixed on an end portion of the shaft, and an electromagnetic induction device below the sucker which includes an annular magnet fixed below the sucker, coil group formed by a first and second coil, and strip-shaped magnet fixed at the rotary shaft. A base on the sucker has a notch. The unbalanced centrifugal force during rotation of the sucker causes vibration. The electromagnetic induction device enables the centrifugal force generated during rotation of the sucker to be in balance with the magnetic force generated by the electromagnetic induction device to adjust the levelness of the sucker surface. The device does not need manual manipulation, enables the sucker to be more stable, reduces damage to the equipment due to vibration, and improves the effect of photoresist spin-coating while saving time and labor.