Design and Mechanical Engineering Portfolio

Bowen Zeng (BEng Mechanical Engineering, BS Mathematical Science)

zbowen@umich.edu | 734-395-6332

Development and Optimization of an Ultra-Precision Step Stage for Silicon Wafer Scanner• Aim & Personal Role

In response to the demand of silicon wafer manufacturing industry, develop and optimize an new ultra-

precision step stage prototype for silicon wafer scanner, which has higher throughput while satisfying

stringent precision and accuracy requirements.

• Approaches

1. Quantify design targets, specify prototype scales, and brainstorm more than 15 possible solutions with

different methods/systems to realize all design targets.

Baseline

Design 2Design 1 Design 3 Design 4

2. Funnel those 15 solutions down to the 4 most promising candidates, establish

dynamic system models of them as well as a baseline model for comparison; code a

MATLAB program to simulate and compare all 5 models’ motion performances.

State Space Model Frequency Domain Simulation Reference Trajectory Profile Time Domain Simulation

3. After the best design is found, which is design 3, design the whole stage 3D CAD model in detail via

SolidWorks; at the mean time, conduct engineering analysis to select suitable components (i.e. actuators,

bearings, sensors, etc.) for the stage via parameters on supplier technical catalogs.

4. Once the first CAD draft is finished, iteratively optimize the design according to FEA results to avoid

potential failure by structural yielding and increase the stage’s resonant frequencies to achieve higher

control bandwidth.

3D Model Sketch FEA (Static & Frequency) Final 3D CAD

5. Once the CAD model is finalized, deploy knowledge of GD&T to craft 2D engineering drawings and

manufacturing plans of all components needed to be manufactured.

6.Operate CNC milling and waterjet machines to effectively manufacture those components.

Current Assembling Process

7. Accurately assemble the stage.

8. Design and implement a MATLAB/Simulink based control architecture and data acquisition system to accurately control the stage motion with sub-micrometer resolution.

Actuator Drivers and Wiring

• Results

A new ultra-precision step stage prototype for silicon wafer

scanner is designed, and optimized.

• Future Works

1. Apply principles of design of experiment to create case

studies to validate the effectiveness of the stage design.

2. Investigate seamless control architectures of the stage

further.