Pump vibration project Advisor Dr Dave Turcic Team

Pump vibration project Advisor Dr. Dave Turcic Team members Duc Le Ron Pahle Sponsor Edwards Vacuum Ltd. Thanh Nguyen Khoa Tran

Background • The pump system from Edwards is used on Intel’s manufacturing floor. • Vibrations from this system can affect the chip fabrication process Figure 1. A frame and pumps system from Edwards Co. Ltd.

Objective • Design a system to reduce the vibration transmitted from the pump to the ground by at least 25% (measured by acceleration) • Requirements: Cost less than $1000. Require no power (passive). Work across the entire frequency range (30 -105 Hz) Fit within the current frame.

Timeline

Current status • Quantifying the problem is still in progress. Testing difficulties have setback this process. • External search and internal search is completed. • Evaluation and selection is in progress. • The team will move forward with the selection and detailed design once diagnostic testing is completed. • The project is behind schedule.

Overview of concepts 1/ Spring and mass vibration isolator (2 DOF) Figure 2. Model for the current system • Pros: Availability of components • Cons: Complex analysis Model may not fully describe the real system

Overview of concepts Implementation of compound mass – spring system a. Mounting on a concrete plate: • Pros: No changes to current frame Stiffness and damping can be easily adjusted • Cons: Large size Add elevation to the system Takes more time to maintain Figure 2. Concept drawing for the concrete plate solution

Overview of concepts Implementation of compound mass – spring system b. Adjust mass and stiffness of the frame (i. e. Fill with concrete) • Pros: Compact size • Cons: Requires modification to the frame Figure 3. Concept drawing for the spring mounting solution

Overview of concepts 2/ Filling the hollow frame with low-wave-speed media to reduce the peak acceleration amplitudes. Figure 4. A steel tube filled with 3 M™ Glass Bubbles K 1 • Pros: Aesthetic Easy to implement • Cons: Availability of materials Only applicable at high frequencies

Overview of concepts 3/ Use of viscoelastic materials to coat the frame • Viscoelastic materials can dissipate energy in the form of heat in each loading/unloading cycle • Pros: Easy to install Light weight and compact • Cons: High cost Temperature dependent Figure 5. 3 M™ Damping Foil 2552

Overview of concepts • Apply coating to the critical points on the frame. • Critical points are found from testing Figure 6. 3 D drawing for a coated frame. Coating is shown in red.

Overview of concepts 4/ Isolating the upper pump from frame Back Front

Evaluation and selection • The concrete base mounting method is rejected due to large size and maintenance issues. • Currently there is not enough data to choose one solution. • List of possible solutions: 1. Coating the frame with viscoelastic materials. 2. Isolating the pump from the frame. 3. Compound mass – spring isolation system.

Plan for spring term 1. Finish diagnosis testing by March 21 th 2. Finish detail design by April 10 th 3. Design implementation by May 1 st 4. Evaluation testing by May 20 th 5. Review and improvement by May 30 th

Questions and Answers

Preliminary testing results

Published results for low-wave-speed media

Picture of a pump-and-frame system