Diffusion Furnace Controller Design

Team 14 Joe Grady

James CrowHongyu Chen

Prakalp SudhakarVictor Villagomez

Client/Faculty Advisor: Dr. Gary Tuttle

Problem StatementThe objective of the senior design project is to design a new

set of temperature controllers to use on a set of diffusion

furnaces located at the Microelectronics Research Center.

The project goals include:

• Temperature calibration of the furnaces

• Implementing of new temperature controllers into the

current furnace system

• Providing a computer interface so that temperature of the

furnaces can be controlled and monitored remotely.

• Providing extended remote control of the valves that

control the gases released in the furnace, if time and funds

permit.

System OverviewSystem Overview

Functional Requirements• Controller must have a temperature tolerance within

+/- 1 degree Celsius

• Controller must be digital and programmable (∆T/ ∆t)

• Controller must have communication capability

• Controller must be able to sample and store information for every cycle

• Controller must be able to control temperatures independently of each section

Functional Requirements• Software must be able to monitor and control the

parameters of the temperature controller

• Software must be able to support simultaneous use

by multiple students

• Software must be able to display graphs of the

process and of chemical flow

• Software needs to be accessed online via web

browser

• Graphical interface of the software must be user-

friendly

• Error checking and deviation

Non-functional Requirements• The new controllers need to be placed

where the old ones were so they need to able to fit within a certain space

• Connectors must be compatible with the new controller

Schedule – 1st Semester

Schedule – 2nd Semester

RS-232 Serial Communication

RS-232 Serial Communication• Baud Rate = 4800• Data Bits = 8• Parity = N• Stop = 1

Operating Protocol• Controllers do not initiate

communication, Command Module does.

• All communication is in ASCII format

• To start communication Command Module sends alert code followed by ID

Software Architecture

Software Architecture – Sequence Diagram

Software Architecture – Use Cases

BudgetParts and Materials: a) Suitable controller(s) b) Miscellaneous parts c) Poster

Without Labor$1,250.00$50.00$50.00

With Labor$1,250.00$50.00$50.00

Services:a)Website Upkeep (for 1 year) $60.00 $60.00

Labor ($12.50 per hour):a)Crow, James b)Villagomez, Victorc)Sudhakar, Prakalpd)Grady, Joee)Chen, Hongyu

$1125.00$1125.00$1125.00$1125.00$1125.00

Parts and Materials: a) Suitable controller(s) b) Miscellaneous parts c) Poster

Without Labor$620.00$0.00$0.00

With Labor$620.00$0.00$0.00

Services:a)Website Upkeep (for 1 year) $0.00 $0.00Labor ($12.50 per hour):a)Crow, James b)Villagomez, Victorc)Sudhakar, Prakalpd)Grady, Joee)Chen, Hongyu

$375.00$375.00$375.00$375.00$375.00

Current Expenses

Total Expected Expenses

Schematic – Old Controller

Hardware Interface Issues

• The existing controller/oven has the thermocouple’s negative (-) leads connected internally to the oven, but the new controller’s require them to be directly connected.

• The existing SCR firing circuits are 0-5 mA current controlled devices, but the new controller’s output to the SCR firing circuit is designed to operate a 0-5 V voltage controlled device.

ResourcesProfessor• Thorough knowledge about current

microcontrollers, and advice for digital microcontrollers

User Manuals• Manual for current analog microcontrollers• Manual for new digital microcontroller.Manufacturers• Websites to purchase new digital

microcontrollers• Omega.com – New microcontroller• Easysw.com – Serial Programming Guide

Questions ?