Design and test RS232
communication to the
Design and test
as a web server
Sends parameters to webserver
Sends commands to controller
Sets up furnace
Responds to controller
Sends feedback to webserver
Updates data on browser
The Microelectronics Research Center has a diffusion furnace that is used as part of the EE 432/532 courses titled “Microelectronics Fabrication Techniques”. However, the temperature controllers of this furnace were quite outdated and still used analog technology to be operated. Our senior design team upgraded the furnace by implementing new temperature controllers, providing hardware as well as a software interface so that the temperature of the furnaces can be controlled and monitored remotely. The end product will be an upgraded furnace which has a digital temperature controller which is accurate to within +/- 1° Celsius. This controller will be able to communicate with a dedicated computer, which in turn is connected to a dedicated server. We need this controller to be able to control three separate zones within each oven chamber, thus it must have at least 3 thermocouple inputs.
Resources and Schedule
- Problem Statement
- Problem: The old analog temperature controllers of the furnace at the Microelectronics Research Center are starting to lose their stability and will likely malfunction soon.
- Hardware interfacing of a new controller that will accurately control temperatures within a certain tolerance.
- A new remote system allows the client to login to a webserver remotely and control temperatures.
- Environment, Uses and Users
- Operating environment is a noisy laboratory at the Microelectronics Research Center . The diffusion furnace is mostly used by ISU students taking the E E 432/532 course for performing extensive laboratory exercises utilizing fabrication methods to build electronic chip wafers. Faculty and graduate students may use this laboratory as well. By controlling the temperature of the three different chambers of the furnace, the students will be able to perform fabrication methods to build electronic chip wafers.
- Project Deliverables
- Hardware Interface
- • A fully functional digital temperature controller installed and properly implemented in the diffusion furnace. This controller will have a temperature tolerance within +/- 1 degree Celsius. It will also have communication capability and will be able to sample and store information for every cycle. The controller will be able to control temperatures independently of each section.
- Software Interface
- • We also plan to develop software with a user-friendly graphical interface that will monitor and control the parameters of the temperature controller. It will be able to support simultaneous use by multiple students and will be able to display graphs of the ramp up process. The software will be accessible via an online web browser.
- Functional Requirements
- For this project, the new temperature controller needs to be able handle multiple control scenarios at once since there are multiple furnaces and zones.
- Also the controller needs to be able to communicate with a computer in order to allow the remote system to work.
- Non-Functional Requirements
- For interfacing, all designs need to follow industry standards and connections must be compatible with each other.
Table 1 – Projected Project Costs
Figure 4 – Project Gantt Chart
Figure 3 – System overview
Figure 1 – SCR Interfacing Circuit
- Technologies Considered
- CN616 series controllers
- Eagle PCB
- Apache webserver set up for students to access the website
- The webserver communicates with the controller through RS-232 using CGI scripts
- The webserver gets feedback from the webserver and provides information to the student
Get detailed specifications from customer.
Test prototype and
make necessary changes
Figure 5 – Hardware block diagram
Test the revised circuit
Implement both Hardware and Software
- The hardware section has been completed and the test results show that the controller, combined with the interfacing circuitry has effectively replaced the old analog system. Since this is the main priority, all expectations were met.
- The software developed allows students and faculty to set up the controller parameters in a way that is more user friendly than using the controller’s front panel directly. It also allows for remote controlling the furnace from any mobile device with internet capabilities.
Test and verify proper functionality and tune
- Testing Considerations
- SCR test with loadBlack box testing
- Short circuit testTest RS232 com in Mac
- Full interfacing testTest the webserver
Figure 2 – Website used to setup furnace
SD Dec 11-14
Team MembersClient / Advisor Acknowledgements
Victor VillagomezCprE Joe Grady E E Dr. Gary Tuttle Leland Harker
Prakalp Sudhakar E E James Crow E E Robert Mayer
Hongyu Chen S E