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?