Conveyor Belt Furnace Thermal Processing (eBook)

Ken Kuang is President of Torrey Hills Technologies, LLC, a leader in the supply of quality microelectronics packaging components. From 2004-2013, Kuang led Torrey Hills to rank #188 in INC500 Fast Growing Private Companies in America and rank #2 in San Diego Business Journal 100 Fastest Growing Private Companies in San Diego. Kuang was three times the finalist for the Most Admired CEO in San Diego.Jinlong Xu is General Manager at Hengli Eletek Co., Ltd in Anhui, China.Joyce Zhang is Marketing Manager at Torrey Hills Technologies, LLC. 

Dedication 5
Foreword 6
Preface 8
Contents 10
Introduction 16
What Is Thermal Processing? 16
Different Types of Thermal Processing 16
What Is a Conveyor Belt Furnace? 18
Basic Structure of Conveyor Belt Furnace 18
Typical Applications 21
Understanding the Influence of Belt Furnace and Firing Parameters on Efficiency of Silicon Solar Cells 27
Introduction 27
Screen Printing 27
Firing 28
Effect of Peak Temperature 29
Effect of Soak Time 29
Belt Furnace Parameters 30
Furnace for Firing Operation 30
Conclusion 32
References 32
Understanding the Influence of Belt Furnace and Firing Parameters on Efficiency of Thin-­Film CIGS Solar Cells 34
Introduction 34
Processing CIGS in a Belt Furnace 35
Effect of Selenization Profile on the Efficiency of Solar Cell 36
Belt Furnace for CIGS Processing 37
Conclusion 39
References 39
Understanding the Influence of Belt Furnace and Sintering Parameters on Efficiency of Dye-Sensitized Solar Cells 40
Introduction 40
Structure 40
Electricity Generation Schematics 41
Material Selection 41
Advantages 42
Process of Sintering in a Belt Furnace 43
Influence of Sintering Temperature on Performance of DSSCs 43
Furnace for DSSC Application 44
Belt Furnace Parameters 46
References 46
Manufacturing Solar Cells: Assembly and Packaging 47
Introduction 47
First Generation 48
Phosphorus Diffusion 48
Silicon Wafer Metallization 48
Solar Module Assembly 49
Second Generation 49
Thin-Film Deposition 50
Thin-Film Annealing 50
Metallization 51
Third Generation 51
Similar to Semiconductor 52
Conclusion 53
A Practical Guide for Improving Crystalline Solar Cell Efficiencies Through Optimization of the Firing Process 54
Introduction 54
Thermal Process Development 54
Trial and Error Experimentation for Improved Wafer Profiles 55
Transferring the Process from the Pilot Line to the Production Lines 59
Periodic Adjustment of the Production Furnaces to Consistently Produce Higher Efficiency Cells 61
Conclusion 61
Study on the Effect of the Firing Process to the Energy Conversion Efficiency of Solar Cells 62
Background 62
Principle of Experiment 62
Material and Equipment List 62
Experiment 63
Analysis and Discussion 63
Conclusion 65
Thermal Profiling of Silicon Solar Cells During the Metallization Process 66
Introduction 66
Thermocouple Junction Design 67
Test Conditions 67
Measurement Accuracy and Reproducibility 70
Discussion and Highlights 72
Conclusions 72
References 72
PID Temperature Control 74
Introduction 74
Different Types of Temperature Control 75
Control Loop Basics 75
On-Off Control 76
Proportional Control 77
PID Control 77
PID Control 78
Introduction 78
PID Controller Theory 78
Proportional Term 79
Steady-State Error 79
Integral Term 79
Derivative Term 80
Loop Tuning 81
Stability 81
Optimum Behavior 82
Overview of Methods 82
Manual Tuning 82
Ziegler-Nichols Method 83
PID Tuning Software 84
Limitations of PID Control 84
Linearity 85
Noise in Derivative 86
Modification of PID Control 86
Integral Windup 86
Overshooting from Known Disturbances 86
Future Pattern of PID Control 87
References 87
Introduction to Materials and Firing Parameters in Thick Film Firing 88
Introduction 88
Material 88
Conductor Pastes 89
Resistor Pastes 89
Dielectrics Pastes 90
Paste Selection 90
Firing Parameters 90
Temperature Profile 91
Airflow 91
References 93
Influence of Belt Furnace on Engine Valve Heat Treatment 94
Introduction 94
Engine Valve Heat Treatment Description 94
References 96
The Influence of a Belt Furnace on the Brazing Process 97
Introduction 97
Parameters of Brazing Process 98
Atmosphere Control in a Belt Furnace 98
Selecting a Furnace for Brazing 100
Conclusion 102
The Influence of Belt Furnace on Post Mold Cure Process 103
Introduction 103
PMC Process in IC Encapsulation 103
Applications of PMC 104
The Influence of PMC on Material Properties 105
Furnace Selection of PMC 107
Furnace Control of PMC 109
Belt Furnace for PMC 109
Conclusion 111
An Introduction to Glass-to-Metal Seals 112
Introduction 112
Types of Glass-to-Metal Seals 112
Fabrication of Glass-to-Metal Seals 114
Copper-to-Glass Seals (Fig. 4) 115
Summary 117
Furnaces for Glass-to-Metal Seal Applications 117
HSA1310-0611NH 117
Furnace Specification 118
Furnace Layout 118
HSA 1503-0409NH 119
Advantages 119
Main Characteristics 120
References 121
Furnace Temperature and Atmosphere Influences on Producing Lithium Iron Phosphate (LiFePO4) Powders for  Lithium-Ion Batteries 122
Introduction 122
Solid State Processing Methods 123
Solution-Based Processing Methods 125
Firing Temperature Influence on Powder Formation 126
Influence of Atmospheric Conditions on Characteristics of LiFePO4 128
Furnace for LiFePO4 Manufacturing 129
Conclusion 129
References 130
Direct Bond Copper (DBC) Technologies 131
Introduction 131
DBC Process 132
Patterned Substrates 134
Plating 135
Electrical Properties 136
Thermal Properties 136
Mechanical Properties 138
Future Development 138
Conclusion 139
Influence of Firing Temperature and Atmospheric Conditions on Processing of Direct Bond Copper (DBC) 141
Introduction 141
Process of DBC 142
Characteristic Features of DBC 144
Effect of Temperature and Atmosphere in Bonding 144
Firing Operations Using a Belt Furnace 144
Conclusion 147
References 147
Ultrasonic Belt Cleaning 148
Introduction 148
Principles Behind Ultrasonic Cleaning Technology 148
Process of Cavitation: A Microscopic Brush 149
Advantages of Ultrasonic Belt Cleaning 150
Equipment Maintenance and Belt Cleaning Guidelines 150
How Challenging Conventional Wisdom Can Optimize Solder Reflow 151
A Standard Profile? 151
Avoid Reflow of Double-Sided PCBs? 152
What Really Causes “Tombstoning”? 153
Using Nitrogen (Vs. Air) Improves the Process? 154
Lower Oxygen, Better Results? 154
Processing in N2 Means More Maintenance/Downtime? 155
References 156
Common Maintenance and Troubleshooting 157
Introduction 157
Common Maintenance 157
Daily Maintenance 157
Replacement of Heating Elements 158
Maintenance of the Motor 160
Transportation 160
Equipment Storing Up 161
Storage of Motor 161
Troubleshooting 161
Overheating 161
Heating Up Problem 162
Heating Elements Broken 162
Belt Movement Problem 163
Breaker Tripping 164
Black Screen of Industrial Computer Display 164
Future Development 166
Introduction 166
New Materials Result in Different Thermal Profiling 166
Solar Cells 166
Engine Valves 168
Brazing Process 168
Technology Innovations and Their Influence on Thermal Processes 169
Thick Film 169
Glass-to-Metal Seal Process 170
DBC Technology 170
Brazing Process 171
Optimizing the Heating Process 171
Precise Temperature Control 172
Mass Production 172
Line Speed 172
Cleaning 173
References 173
Index 175