Team #55 Reflow Oven

Project Manager: Patrick Selzer (ME)

Team Members:

Michael Ladd (ME), Patrick Mooney (EE), Corey Seidel (EE)

Executive SummaryProblem Statement

Small scale solder ovens sacrifice quality and precision for cost.

Executive SummaryDeliverables

Completed oven Maximum temperature of 300 degree Celsius

Uniform thermal transfer rate

>0.45 reflow space

Profile library

Testing data

Executive SummaryTeam Responsibilities

Control System (CS)

User Interface (PM)

Heating System (PS/ML)

Cooling System (PS/ML)

Executive SummaryResources

$200.00

Oven by Mar. 14th

Profiles and Testing Data by Apr. 28th

Market OutlookProfessional Models

Expensive

Precise performance data

Accurate temperature control

Higher reliability

Faster cycle times

Model Cost Cycle Time User Interface

Control Unit Solder Area Heating Element

T962A $369.99 8 min B/W with function buttons

Micro-processor

300 x320 mm Infrared

T962 $429.49 8 min LCD display with function buttons

Micro-processor(Self-Contained)

180 x 235 mm Infrared

T962C $799.00 8 min LCD display with function buttons

Micro-processor(Self-Contained)

400 x 600 mm Infrared

AS-5060 $850.00 N/A B/W with function buttons

Micro-processor

460 x 275 mm Infrared

2011 D.A $2950.00 5 min B/W with function buttons

Control Unit with EPROM

400 x 350 mm Convection

BT300CP $1249.99 6 min B/W with function buttons

PID control 230 x 370 mm Convection

850 $1499.99 5.5 min B/W with function buttons

PID control 340 x 430 mm Convection

GF-B-HT $999.99 7 min B/W with function buttons

Micro-processor

305 x305 mm Convection

GF-C^2-HT $799.99 7 min Computer out Outside Computer

305 x 305 mm Convection

HHL3000 $1059.00 6 min B/W with function buttons

Micro-processor

360 x 385 mm Convection

Market OutlookDo-It-Yourself (DIY) Ovens

Cheap

No performance data

Untested reliability

Higher cycle times

Build After Oven Cost ($)

Automatic

Control Temperature Uniformity

Ease of Use

Ease of Build

Spectrum 154.00 Yes Good Fair Good Fair

Freetronics 70.00 No Poor Poor Poor Very Good

Instructables 120.00 Yes Good Poor Good Fair

Die4laser 148.00 Yes Good Poor Good Good

Mad-science 85.00 Yes Fair Poor Good Very Good

Market OutlookTarget Markets

Small Business

Reliable

High Performance

Tighter constraints

Low cost

Lower cycle times

Home Hobbyist

Versatile

Ease of use

Low cost

Specifications

Oven Requirements:

Maximum temperature of 300 degree Celsius

Uniform thermal transfer rate

Low Maintenance/Low Budget

>0.45 reflow space

Solder

Lead-Free

Bias against reflow defects

Flux Methods

Relies on solder choice

NoClean flux if oven and defects permit

User Interface

<$50 CPU

Digital Display

Profile Library

Control System

2% overshoot

Thermal Profile

Base profile of low ramp-up rate, low peak, high ramp-down rate

Calibrated with respect to solder, flux, oven

Block Diagram

Temperature Profiles

Profile Types

Ramp to Spike

Ramp, Soak, Spike

Low Void Profile

Eliminating Defects

Heating Rate 3°C/s

Cooling Rate of -4°C/s

Time above liquidus 30-60 sec

Heating and Cooling Systems

Resistive heating element

Max oven temperature of 300°C

Internal Convection Fan

79 ft3/min

120 mm

Aluminum

External Vents

Solenoid controlled

In-line with convection fan.

Control System

Arduino

Temperature= User Input – Actual Temperature

Applies corrections to within 2%

Output pulse width modulated signal

MOSFET bridge

Act as solid state relay

High-current switching operation

Expandability

Modular to accommodate future expansion

User Interface

Arduino TFT digital display

Standard 4 buttons

Arrange buttons to proximity of text

Up to 12 buttons available

Stop button integrated

Action Item List (AIL)

Activity Person Assigned Due

Acquire Oven ML 1/13 1/20

Stock-oven Experiments All 1/20 2/3

Install vent and fan PS/ML 1/27 2/10

Implement Control CS 2/10 2/24

Install User Interface PM 2/10 3/3

Synchronize subsystems ALL 2/17 3/10

FEA heat flux analysis ML/PS 2/24 3/17

Solder Testing All 3/10 3/31

Compile Temp. Profiles All 3/17 4/28

Perfect Device All 3/31 4/28

Document Design All 4/7 5/5

Resources

Part Item Quantity Price Cost Total

1 Black and Decker Toaster Oven 1 $40.00 $40.00 $40.00

2 Arduino Duo 1 $43.00 $43.00 $83.00

3 Arduino TFT 1 $26.00 $26.00 $109.00

4 Solenoid 2 $7.00 $14.00 $123.00

5 Computer Fan 1 $8.00 $8.00 $131.00

6 Wire - On Hand   $131.00

7 Buttons - On Hand   $131.00

8 Solder - On Hand   $131.00

9 Thermistor 10 $1.00 $10.00 $141.00

10 Super Glue 1 $2.00 $2.00 $143.00

11 Metal Sheeting - On Hand    

12 Arduino Software   On Hand    

13 Contingency 1 $57.00 $57.00 $200.00

        Total: $200.00

Conclusion

Modify Standard Convection Oven

Arduino Board

External Vents

Internal Fan

User Interface

Objectives

Reach 300°C

Heating Rate 3°C/s

Cooling Rate of -4°C/s

Questions?