Reflow Soldering: Apparatus and Heat Transfer Processes

Description

Reflow Soldering: Apparatus and Heat Transfer Processes investigates the technology of reflow soldering from the aspect of the soldering ovens and apparatus. The authors begin by introducing the concept of surface mount technology. This is followed by three chapters exploring: Infrared ovens, convection ovens, Vapor Phase Soldering (VPS), and special reflow ovens. Each of these chapters includes a discussion of the physical background, structure and working principle, and characterization of the heating, flow and vapor parameters; and concludes with a review of the application of the techniques and typical solder failures. The book concludes with a discussion of the various numerical simulations of the different ovens. This book will be useful for researchers and process and quality and research and design engineers within the electronics and manufacturing industries. Cover Reflow Soldering Copyright Contents 1 Introduction to surface-mount technology 1.1 Electronic components 1.1.1 Through-hole components 1.1.2 Surface-mounted components 1.2 Reflow soldering technology 1.2.1 Overview of the reflow soldering technology steps 1.2.2 Rheology of solder pastes 1.3 Stencil printing 1.3.1 The process of stencil printing 1.3.2 Process parameters and related printing failures 1.3.3 Numerical modeling of stencil printing 1.4 Component placement 1.4.1 Gage R&R study 1.4.2 Measuring component placement position 1.4.3 Machine and process capability index 1.5 Reflow soldering 1.5.1 Reflow soldering profile 1.5.2 Intermetallic layer formation 1.5.3 Component movements during reflow soldering 1.6 Pin-in-paste technology 1.6.1 Steps of pin-in-paste technology 1.6.2 Calculating solder paste volume for pin-in-paste technology 1.6.3 Controlling the solder paste deposition for pin-in-paste technology References 2 Infrared reflow soldering 2.1 Introduction 2.2 Basics of IR heat transfer 2.2.1 Physical background 2.2.2 Equilibrium–nonequilibrium reflow cases 2.3 Basic configurations of IR ovens 2.3.1 Near-IR systems 2.3.2 Medium to far-IR systems 2.3.3 Medium-IR systems mixed with convection 2.3.4 Pros and cons 2.3.5 Improving quality with inert gas 2.4 IR emitters 2.4.1 Tube emitters 2.4.2 Panel or plate emitters 2.4.3 Thermal inertia 2.5 Batch-type IR oven examples 2.5.1 Batch-type oven with drawer design 2.5.2 Batch-type oven with C/I heat transfer setup 2.5.3 Batch-type oven with advanced C/I heat transfer setup 2.5.4 Cheap bench-top IR solutions for hobbyists 2.6 Example of conveyor-based in-line IR ovens 2.7 Rework and other special applications with IR 2.8 Latest improvements, optimizations, and findings 2.9 Temperature measurements inside IR and other reflow ovens 2.9.1 Basics of thermocouples 2.9.2 Thermocouple types 2.9.3 Thermocouple attachment 2.9.4 Data logging 2.9.5 Voltage-to-temperature conversion 2.9.6 Typical devices for reflow temperature logging 2.9.7 Temperature logging of IR ovens in the literature References 3 Convection reflow ovens 3.1 Basics of convection heating 3.1.1 Basics of steady-state fluid dynamics 3.1.2 Convective heat transfer 3.2 Structure and operating principle of convection reflow ovens 3.2.1 Typical structure of convection reflow ovens 3.2.2 Analysis of the operating principle of a convection reflow oven 3.3 Characterization of the convection reflow ovens 3.3.1 Distribution of the HTC parameter under the nozzle matrix 3.3.2 Direction characteristics of the heat transfer coefficient in radial flow layers 3.3.3 General HTC values in convection reflow oven References 4 Vapor-phase reflow soldering ovens 4.1 Introduction 4.2 History of vapor-phase soldering 4.3 Basics of boiling and heating 4.4 The heat transfer medium 4.5 Physical background 4.5.1 Basics of condensation heating 4.5.2 Analytical solutions for heating PCBs in saturated vapor 4.5.3 Heat transfer coefficients during vapor-phase soldering 4.6 Vapor-phase soldering ovens 4.6.1 Basic vapor-phase soldering ovens 4.6.2 Heat-level vapor-phase soldering ovens 4.6.3 Soft-vapor-phase soldering and plateau capable ovens 4.6.4 Vacuum vapor-phase soldering ovens 4.6.5 Custom vapor-phase soldering ovens 4.6.6 Batch and in-line ovens 4.6.7 Medium extraction and filtration 4.7 Quality and reliability concerns in the lead-free era 4.7.1 On the joints and alloys 4.7.2 Tombstones 4.7.3 Voids and void separation in vacuum 4.7.4 Electrochemical migration, contaminations, flux 4.7.5 Popcorning and package stability 4.8 Special applications 4.8.1 3D-MID devices 4.8.2 Flexible circuits 4.8.3 Biodegradables 4.8.4 Curing 4.8.5 Special components, stacked systems, pin-in-paste 4.8.6 Special substrates 4.8.7 Space technologies 4.8.8 Rework 4.9 Measurements inside vapor-phase soldering ovens 4.9.1 Thermocouples 4.9.2 Height detection with special sensors References 5 Special reflow techniques 5.1 Die-attach technologies 5.1.1 First-level interconnections 5.1.2 Die-attach techniques 5.2 Gold–silicon eutectic soldering 5.3 Die-attach with soft solders 5.4 Thermal transient characteristics of die-attaches 5.5 Effect of void formation on the properties of die-attaches 5.6 Low temperature, fluxless soldering References 6 Numerical simulation of reflow ovens 6.1 Numerical simulations of vapor phase soldering ovens 6.1.1 Numerical simulations of vapor space formation 6.1.1.1 Model description 6.1.1.2 Results of the vapor space formation model 6.1.2 Numerical simulation of the condensate layer formation 6.1.2.1 Model description 6.1.2.2 Formation of the condensate layer on horizontal and inclined substrates 6.1.2.3 Heat transfer coefficient on different substrate materials 6.1.3 Numerical simulation of the vacuum vapor phase soldering system 6.1.3.1 Model description 6.1.3.2 Results of the vacuum vapor phase soldering model 6.2 Numerical simulations of other types of reflow ovens 6.2.1 Numerical simulations of convection reflow ovens 6.2.1.1 Investigation of the gas flow field 6.2.1.2 Investigation of the heat transfer in convection 6.2.2 Numerical simulations of infrared reflow ovens 6.2.3 Numerical simulations of die bonding ovens References Index Back Cover