Linear bearings in semiconductor machinery and equipment applications
Principle of operation and characteristics of linear bearings
- High-precision positioning: Linear bearings ensure precise positioning of equipment at the micron or even nanometer level, which is critical for semiconductor manufacturing.
- High speed movement: In some processes, equipment needs to move at high speeds, and linear bearings provide stable motion.
- High Repeatability: Linear bearings ensure consistency over multiple repetitions, improving product yields.
- Low friction: Low friction reduces energy consumption and improves equipment efficiency.
- Long Life: High quality linear bearings can withstand long time operation and reduce maintenance cost.
Linear bearings in semiconductor machinery and equipment applications
The linear bearing type is widely used in semiconductor equipment to achieve precise motion control. They play an integral role in the semiconductor manufacturing process as a key mechanical element that allows the object to slide in a straight line.
Handwerks has previously shared a selection guide for linear bearings, which you can refer to if you'd like to learn more: 【Bearing System Selection Guide: Maximize Your Application with the Perfect Bearing】
The following are some common semiconductor equipment and the parts where linear bearings are used:
The main applications are as follows:
- Wafer Transfer System: Linear bearings are used in wafer transfer systems to ensure accurate positioning and smooth movement of wafers in the process, and to prevent wafers from being scratched or damaged.
- Application: Transferring wafers between different process equipment.
- Linear bearings are used for the movement of the wafer clamping jaws and the sliding of the conveyor rail.
- Stepper/Scanner: Linear bearings are used in the precision positioning system of the exposure machine to ensure the accuracy of alignment between the photomask and the wafers, which affects the yield of the final product.
- Usage: Transferring the pattern from the photomask to the wafer.
- Linear bearings are used for X-Y axis movement of the exposure table and precise positioning of the photomask stage.
- Etcher: Linear bearings are used to move the platform of the etcher to ensure that the etchant is uniformly sprayed on the wafer surface to achieve the desired etching depth.
- Use: To etch the surface of wafers by chemical or physical means.
- Linear bearings are used for the movement of etching chambers and the positioning of wafer fixtures.
- CMP (Chemical Mechanical Planarization) Mills
- Application: Leveling the wafer surface.
- Linear bearings are used for: movement of the grinding disk, positioning of wafer fixtures.
- Thin Film Deposition Equipment: Linear bearings are used to move the substrate fixtures of the thin film deposition equipment to ensure uniform deposition of thin films on the wafer surface.
- Application: Thin film deposition on wafer surface.
- Linear bearings are used for the movement of substrate fixtures and the positioning of the deposition source.
- Inspection Equipment: Linear bearings are used to move the sample table of inspection equipment to facilitate all kinds of inspections on wafers. Use: To detect defects on wafers.
- Use: To detect defects on wafers.
- Linear bearings are used for the movement of the sample table and the scanning of probes.
- Other Equipment
- Dicing machine: For cutting wafers.
- Packaging equipment: For packaging wafers into ICs.
- Test equipment: To test the function of IC.
“Aligner” are the heart of semiconductor manufacturing.
We have selected the aligner as a case study for the following applications.
Aligner is a key equipment in the semiconductor manufacturing process. It is like a machine that “photographs” the wafer and “prints” the pre-designed circuit pattern onto the wafer precisely.
How it works:
- Coating photoresist: A layer of light-sensitive material, called photoresist, is applied to the wafer surface.
- Alignment Exposure: A photomask (a stencil with a circuit pattern engraved on it) is aligned with the wafer coated with the photoresist.
- Exposure: A light source such as ultraviolet or extreme ultraviolet light is used to project the circuit pattern onto the photoresist through the photomask.
- Developing: The exposed wafer is placed in a developing solution, and the unexposed portion of the wafer is dissolved, leaving the circuit pattern.
- Etching: Chemical or physical methods are used to etch off the part of the wafer that is not protected by the photoresist to form the circuit.
Importance of the Aligner
- Accuracy: The accuracy of the exposure machine directly affects the performance and yield of the wafer.
- Complexity: The increasing complexity of modern wafer circuit patterns requires higher resolution of the exposure machine.
- Cost: Exposure machines are one of the most expensive pieces of semiconductor manufacturing equipment, and their performance has a direct impact on the overall cost of wafer fabrication.
Types of Linear Bearings Used in Aligner
Linear Bearing Applications in Aligner
In aligner, linear bearings are mainly used:
- X-Y axis movement of the wafer table: To control the precise positioning of wafers during the exposure process.
- Precise positioning of the photomask table: to ensure that the photomask is aligned with the wafer.
- Other auxiliary movements: e.g. lens adjustment, mask movement, etc.
Types of Linear Bearings Commonly Used in Exposure Machines
Considering the very high requirements for precision, speed and life of exposure machines, the following types of linear bearings are often used:
- Ball type linear bearings.
- Advantages: low friction coefficient, high precision, high speed, long life.
- Application: Precise positioning of wafer table and photomask table.
- Common types: open type, closed type, V-groove type.
- Roller linear bearings.
- Advantage: Large load capacity, high rigidity.
- Application: Parts subject to large loads, such as the base of exposure machines.
- Air Bearings: Advantage: Extremely low friction.
- Advantages: Extremely low friction, no wear, high positioning accuracy.
- Application: Parts that require high precision, such as fine adjustment of mask tables.
- Ceramic Linear Bearings: Advantages: High temperature resistance, low friction, high positioning accuracy.
- Advantages: high temperature resistance, corrosion resistance, high hardness, low coefficient of linear expansion.
- Application: Special environment, such as high temperature process or vacuum environment.
As the demand for semiconductors continues to grow, the size of the supplier base is bound to expand. As a related industry, how do we create demand, enhance quality and improve processes for our customers in this supply chain?
■ Confirmation of the process environment → Consultation with a professional precision component supplier → Evaluation → Correct selection
HEADWAY specializes in providing a wide range of precision metal components through research and development, production, and sales in one, with an emphasis on after-sales service. If you have components under development in the field of semiconductor applications, and would like to seek professional technical services to enhance the quality of the products in line with the overall efficiency of the equipment, or would like to learn more about the linear bearings in semiconductor production applications, please feel free to contact us, HEADWAY - Millions of parts. One solution.
