Design Review

Video Lecture

Video, Slides

updated Fa 2020

Description

The design review is a 30-minute meeting intended to make sure that the team has a successful project. Students will present and defend their design while instructors and TAs critique it, identifying any infeasible or unsafe aspects and steering the team toward success. Instructors and TAs will ask questions throughout and may choose the order of blocks to be discussed. Specifically, here is what the course staff are looking for:
  1. Evidence that the overall design and high-level requirements solve the problem stated.
  2. Check if the overall design has suitable difficulty for course standards and completion in one semester. Scope may need to be adjusted if otherwise.
  3. Check team members' engineering preparedness to implement each module.
  4. Check that each team member is assigned an equal portion of the project effort.
Prepare for the following sequence.
  1. Promptly project the design document on projector.
  2. Introduce team members (name, major, and the project part each is in charge of).
  3. Present problem statement and proposed solution (<1 minutes) following the template in DDC (see Description 1.a)
  4. Present design overview (<5 minutes)
    1. High-level requirements: check DDC
    2. Block diagram: check DDC
    3. Physical design
  5. For the remainder of the review, you will participate in a detailed discussion of the design. Plan to cover each block, one at a time, beginning with the most critical. The course staff will ask questions and may step in to guide the discussion. Be prepared to discuss all aspects of your design with a focus on the following.
    1. Requirements & Verification: (see DDC); We'll look at all the important block requirements. Prepare to justify the components chosen and compare with important alternatives.
    2. Evidence that the design meets requirements (use the following as applicable)
      • Simulations
      • Calculations
      • Measurements
      • Schematics
      • Flowcharts
      • Mechanical drawings
      • Tolerance analysis: check DDC
      • Schedule: Suggestions:
        1. Think about what you can do in parallel, what has to be sequential;
        2. Work on hardware before software;
        3. Perform unit testing before system testing;
        4. Unit test each module on a breadboard before starting PCB design);
        5. Leave margin for unexpected delays or accidents. You are mostly responsible for those exceptions, just as if you were the owner of this senior design business;
      • Cost:hourly rate is ~$50 not $10. In addition, apply the 2.5x overhead multiplier ($125/hr is the cost of your senior design business), which includes the cost of salaries of you, your boss, CxOs, sales, janitors, etc.

Grading

The DR Grading Rubric is available to guide your DR preparation. Two sample Design Review documents are available as examples of what we expect: a Good Sample DR, a Moderate Sample DR, and a good example R&V table as it was presented in a final report. Notes are made in red type to point out what is lacking. Note that the grading rubrics and point structure may have evolved since these reports were generated, so use them only as a guide as to what we are generally expecting.

Submission and Deadlines

Your design document should be uploaded to PACE in PDF format by Midnight the Friday before design review. If you uploaded a mock DR document to PACE, please make sure that it has been removed before uploading the final DR..

Tech must-know and FAQ for design

Here is the link of "Tech must-know and FAQ for design" which is accessible after logging into g.illinois.edu.

Over semesters, ECE445 course staff have encountered repeated mistakes from students. The document above is designed to provide students with the essential knowledge needed in order to have a good design. Spending 5 min reading it might save you 15 hours later. Also, there might be some quiz questions in your DDC or Design Review. Please help us improve this document. We value your feedback!

Four Point Probe

Simon Danthinne, Ming-Yan Hsiao, Dorian Tricaud

Four Point Probe

Featured Project

# Four Point Probe

Team Members:

Simon Danthinne(simoned2)

Ming-Yan Hsiao(myhsiao2)

Dorian Tricaud (tricaud2)

# Problem:

In the manufacturing process of semiconductor wafers, numerous pieces of test equipment are essential to verify that each manufacturing step has been correctly executed. This requirement significantly raises the cost barrier for entering semiconductor manufacturing, making it challenging for students and hobbyists to gain practical experience. To address this issue, we propose developing an all-in-one four-point probe setup. This device will enable users to measure the surface resistivity of a wafer, a critical parameter that can provide insights into various properties of the wafer, such as its doping level. By offering a more accessible and cost-effective solution, we aim to lower the entry barriers and facilitate hands-on learning and experimentation in semiconductor manufacturing.

# Solution:

Our design will use an off-the-shelf four point probe head for the precision manufacturing tolerances which will be used for contact with the wafer. This wafer contact solution will then be connected to a current source precisely controlled by an IC as well as an ADC to measure the voltage. For user interface, we will have an array of buttons for user input as well as an LCD screen to provide measurement readout and parameter setup regarding wafer information. This will allow us to make better approximations for the wafer based on size and doping type.

# Solution Components:

## Subsystem 1: Measurement system

We will utilize a four-point probe head (HPS2523) with 2mm diameter gold tips to measure the sheet resistance of the silicon wafer. A DC voltage regulator (DIO6905CSH3) will be employed to force current through the two outer tips, while a 24-bit ADC (MCP3561RT-E/ST) will measure the voltage across the two inner tips, with expected measurements in the millivolt range and current operation lasting several milliseconds. Additionally, we plan to use an AC voltage regulator (TPS79633QDCQRQ1) to transiently sweep the outer tips to measure capacitances between them, which will help determine the dopants present. To accurately measure the low voltages, we will amplify the signal using an JFET op-amp (OPA140AIDGKR) to ensure it falls within the ADC’s specifications. Using these measurements, we can apply formulas with corrections for real-world factors to calculate the sheet resistance and other parameters of the wafer.

## Subsystem 2: User Input

To enable users to interact effectively with the measurement system, we will implement an array of buttons that offer various functions such as calibration, measurement setup, and measurement polling. This interface will let users configure the measurement system to ensure that the approximations are suitable for the specific properties of the wafer. The button interface will provide users with the ability to initiate calibration routines to ensure accuracy and reliability, and set up measurements by defining parameters like type, range, and size tailored to the wafer’s characteristics. Additionally, users can poll measurements to start, stop, and monitor ongoing measurements, allowing for real-time adjustments and data collection. The interface also allows users to make approximations regarding other wafer properties so the user can quickly find out more information on their wafer. This comprehensive button interface will make the measurement system user-friendly and adaptable, ensuring precise and efficient measurements tailored to the specific needs of each wafer.

## Subsystem 3: Display

To provide output to users, we will utilize a monochrome 2.4 inch 128x64 OLED LCD display driven over SPI from the MCU. This display will not only present data clearly but also serve as an interface for users to interact with the device. The monochrome LCD will be instrumental in displaying measurement results, system status, and other relevant information in a straightforward and easy-to-read format. Additionally, it will facilitate user interaction by providing visual feedback during calibration, measurement setup, and polling processes. This ensures that users can efficiently navigate and operate the device, making the overall experience intuitive and user-friendly.

# Criterion for Success:

A precise constant current can be run through the wafer for various samples

Measurement system can identify voltage (10mV range minimum) across wafer

Measurement data and calculations can be viewed on LCD

Button inputs allow us to navigate and setup measurement parameters

Total part cost per unit must be less than cheapest readily available four point probes (≤ 650 USD)

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