Thermal Stress and Strain in Microelectronics Packaging

Conditions for the Coefficient Functions.- 3.9 Determination of the Deformation Parameters B, C, and O.- 3.10 Solution of the Eigenvalue Problem.- 3.11 Isotropic and Specially Orthotropic Laminates.- 3.12 Thermal Stress in the Vicinity of a Curved Free Edge.- 3.13 Layered Beams.- 3.14 Refinement and Regression of the Polynomial Approximation.- 3.15 Measures of the Criticality of the Interlaminar Stresses.- 3.16 Examples: Three-Layer Anisotropic Laminates and Isotropic Beams.- 3.17 Concluding Remarks.- Nomenclature.- Appendix 3A.- References.- 4. Transient Thermal Stresses in Multilayered Devices.- 4.1 Introduction.- 4.2 Transient Heat Transfer Solutions.- 4.3 Variational Principle for the Thermoelasticity Problem.- 4.4 Asymptotic Thermal Stress Distribution Near Free Edge.- 4.4.1 Homogeneous Asymptotic Solution.- 4.4.2 Particular Asymptotic Solution.- 4.5 Formulations of Hybrid Singular Element.- 4.5.1 Formulation.- 4.5.2 Verification of the Special Hybrid Element.- 4.6 Green's Function Integration Method.- 4.7 Transient Behaviors of Multilayered Devices.- 4.8 Design Based on Transient Thermal Stresses.- 4.8.1 Crack Initiation.- 4.8.2 Thermal Fatigue.- 4.9 Discussion and Summary.- References.- 5. Temperature Dependence of Thermal Expansion of Materials for Electronics Packages.- 5.1 Introduction.- 5.2 Theory.- 5.3 Experimental.- 5.4 Results and Discussion.- 5.4.1 Ceramics.- 5.4.2 Metals.- 5.4.3 Sandwiches (Cu-Invar-Cu and Cu-Mo-Cu).- 5.4.4 Organic Boards and Packages.- 5.5 Summary.- References.- 6. Thermal Stress Considerations in Die-Attachment.- 6.1 Introduction.- 6.2 Properties of Die-Attach Materials for Various Applications.- 6.3 Analytical Consideration of Thermal Stresses in Die-Attach.- 6.3.1 Timoshenko and Other Models.- 6.3.2 Calculation of Maximum Die Stress.- 6.3.3 Suhir's Model.- 6.3.4 Numerical Calculation of Die Stress.- 6.4 Die Stress Measurement.- 6.4.1 Piezoresistive Stress Sensors.- 6.4.2 Fractional Fringe Moiré Interferometry.- 6.5 Quality of Die-Attach (Effect of Voids) and Relationship to Die Stress.- 6.5.1 Voids and Die Stress.- 6.5.2 Nondestructive Determination of Die-Attach Quality.- 6.5.3 Methods of Improving Die-Attach Quality.- 6.6 Conclusion.- Nomenclature.- References.- 7. Die Stress Measurement Using Piezoresistive Stress Sensors.- 7.1 Introduction.- 7.2 Theory of Piezoresistive Sensors.- 7.2.1 Background.- 7.2.2 Phenomenological Theory.- 7.2.3 Theory of the Piezoresistive Coefficients.- 7.3 Experimental Measurements of Piezoresistive Coefficients.- 7.4 Stress Sensor Geometries.- 7.5 Experimental Designs and Calibration.- 7.5.1 Chip Layout.- 7.5.2 Calibration.- 7.6 Experimental Stress Measurements.- 7.7 Summary.- References.- 8. Analysis of the Thermal Loading on Electronics Packages by Enhanced Moiré Interferometry.- 8.1 Introduction.- 8.1.1 Displacement Measurements.- 8.2 Essentials of Moiré Interferometry.- 8.2.1 Specimen Grating.- 8.2.2 Moiré Interferometry.- 8.3 Digital Image Analysis Enhanced Moiré Interferometry.- 8.3.1 Mechanism of Fringe Formation.- 8.3.2 Fractional Fringe Analysis.- 8.3.3 Digital Image Processing.- 8.4 Full-Field Analysis of Thermally Induced Deformations.- 8.4.1 Thermal Strain Measurements in IC-Packages.- 8.4.2 Effect of Conformal Coating on Strain Relief in Packages.- 8.5 Conclusions and Future Trends.- References.- 9. Correlation of Analytical and Experimental Approaches to Determination of Thermally Induced Printed Wiring Board (PWB) Warpage.- 9.1 Introduction.- 9.2 Finite Element Analysis for PWB Warpage.- 9.2.1 PWB Geometric Configurations.- 9.2.2 Modeling Assumptions and Techniques.- 9.2.3 Sensitivity Analysis for Mechanical Properties.- 9.2.4 Mechanical Property Measurements.- 9.2.5 Discussion of Analytical Results.- 9.3 Experimental Verification of PWB Warpage.- 9.3.1 Overview of Experimental Technique - Shadow Moiré.- 9.3.2 Sample Preparation.- 9.3.3 Experimental Setup.- 9.3.4 Experimental Procedures.- 9.3.5 Comparison of Experimental and Analytical Results.- 9.3.6 Implications and Ramifications.- 9.4 Conclusions.- References.- 10. Thermal Stress-Induced Open-Circuit Failure in Microelectronics Thin-Film Metallizations.- 10.1 Introduction.- 10.2 Thermodynamics of Stressed Solids.- 10.3 A Stress-Induced Diffusion Failure Model.- 10.4 Discussion of Experimental Results of Isothermal Aging.- 10.4.1 Temperature Effect.- 10.4.2 Line Width Effect.- 10.4.3 Line Thickness Effect.- 10.4.4 Passivation Effect.- 10.5 Failure of Interconnects Under Thermal Fatigue.- 10.5.1 Sample Preparation.- 10.5.2 Testing and Results.- 10.5.3 Comparison of Experiment and Theoretical Prediction.- 10.6 Summary.- Appendix 10A.- Nomenclature.- References.- 11. Thermal Stress and Stress-Induced Voiding in Passivated Narrow Line Metallizations on Ceramic Substrates.- 11.1 Introduction.- 11.2 Measurement of Stresses in Metallizations.- 11.2.1 Wafer Curvature Methods.- 11.2.2 X-Ray Diffraction Stress Measurement.- 11.3 Estimation of Thermal Stresses in Passivated Line Metallizations.- 11.3.1 Eshelby Theory of Inclusions.- 11.3.2 Reduction to Two-Dimensional Problem.- 11.3.3 The Problem of the Heterogeneous Inclusion.- 11.3.4 The Effects of Finite Passivation.- 11.4 Stress Relaxation and Void Formation.- 11.4.1 Stresses After Redistribution.- 11.4.2 Void Nucleation.- 11.4.3 Stress Relaxation by Void Growth.- 11.5 Summary.- References.- 12. Predicted Bow of Plastic Packages of Integrated Circuit (IC) Devices.- 12.1 Introduction.- 12.2 Thin Plastic Package.- 12.2.1 Basic Equations.- 12.2.2 Curvature.- 12.2.3 Maximum Bow.- 12.2.4 Zero Bow Condition.- 12.2.5 Special Case: Bimaterial Assembly.- 12.2.6 Numerical Examples and Discussion.- 12.3 Large Plastic Package.- 12.3.1 Basic Equations.- 12.3.2 Deflection Surface.- 12.3.3 Special Cases.- 12.3.4 Numerical Examples.- 12.3.5 Approximate Formula for Maximum Bow.- 12.4 Summary.- Nomenclature.- References.- 13. Thermal and Moisture Stresses in Plastic Packages.- 13.1 Introduction.- 13.2 Plastic Package Structure and Fabrication.- 13.2.1 Structure.- 13.2.2 Fabrication.- 13.3 Stress-Related Failures.- 13.3.1 Die/Adhesive Cracks.- 13.3.2 Metal Displacement and Passivation Cracks.- 13.3.3 Resin Cracks.- 13.4 Thermal Stress Measurement and Analysis.- 13.4.1 Criterion for Crack Risk Under Thermal Shock.- 13.4.2 Stress Measurement.- 13.4.3 Stress Analysis.- 13.4.4 Basic Assumptions for Plastic Package Modeling.- 13.4.5 Metal Displacement.- 13.5 Summary.- References.- 14. Solutions to Moisture Resistance Degradation During Solder Reflow of Plastic Surface Mount Components.- 14.1 Introduction.- 14.2 Moisture-Induced Phenomena.- 14.3 Review of Mechanisms.- 14.3.1 Thermal Stresses.- 14.3.2 Kinetics of Moisture Absorption and Desorption.- 14.3.3 Interfacial Adhesion and Delamination.- 14.3.4 Fracture and Mechanical Behavior of Plastic.- 14.4 Measurement Techniques.- 14.5 Solutions.- References.- 15. Thermomechanical Fatigue of 63Sn-37Pb Solder Joints.- 15.1 Constitutive Equation.- 15.1.1 General.- 15.1.2 Mechanisms.- 15.1.3 Constitutive Equations.- 15.2 Experimental.- 15.3 Computer Simulation.- 15.4 Crack Initiation and Growth.- 15.5 Life Prediction.- 15.6 Summary and Conclusions.- References.- 16. A Prediction of the Thermal Fatigue Life of Solder Joints Using Crack Propagation Rate and Equivalent Strain Range.- 16.1 Introduction.- 16.2 Tensile Properties of Cast Solders.- 16.3 Thermal Fatigue Fracture Mechanism.- 16.4 Thermal Fatigue Crack Propagation Rate.- 16.5 Simulation of Thermal Fatigue Strain Range.- 16.6 Thermal Fatigue Life of Solder Joints.- 16.7 Summary.- References.- 17. Microstructural Evaluation of Sn-Pb Solder and Pd-Ag Thick-Film Conductor Metallization Under Thermal Cycling and Aging Conditions.- 17.1 Introduction.- 17.2 Experimental Techniques and Instrumentation.- 17.3 Characteristics of the Conductor.- 17.4 Morphology and Elemental Distribution in the As-Fired Conductor.- 17.5 Aging Effects on Soldered Thick-Film Joints.- 17.5.1 Adhesion Loss Mechanism.- 17.5.2 Influence of the Phase Distribution in the Solder Joints.- 17.6 Thermal Cycle Effect on Soldered Thick Film.- 17.7 Summary.- References.- 18. Solder Joint Reliability of Leadless Chip Carriers.- 18.1 Introduction.- 18.2 Intrinsic Reliability of the Chip Carrier.- 18.2.1 Hermetic Leadless Chip Carriers.- 18.2.2 Hermetic Leaded Chip Carriers.- 18.2.3 Plastic Surface Mountable Packaging.- 18.3 The Reliability of Chip Carrier Solder Attachment.- 18.3.1 The Philosophy of a Reliability Program.- 18.3.2 Test Vehicles for Chip Carriers Attached to Thick-Film Alumina Substrates.- 18.3.3 Test Program and Results.- 18.3.4 Interpretation of Results.- 18.3.5 Comparison with Chip Carriers Solder-Attached to Printed Wiring Boards.- 18.4 Power Cycling.- 18.4.1 The Value of Power Cycling.- 18.4.2 Derivation of Test Program.- 18.4.3 Test Plan and Results.- 18.4.4 Interpretation of Power Cycling Results.- 18.4.5 Power Cycling on Printed Wiring Boards.- 18.5 Other Reliability Considerations.- 18.5.1 The Effect of Flux on Surface Mount Solder Joint Reliability.- 18.5.2 The Effect of Thick-Film Multilayers and Leaded Components on Chip Carrier Reliability.- 18.5.3 The Effect of Cyclic Mechanical Stresses on Flexible Surface Mount Assemblies.- 18.6 Conclusions.- References.- 19. Solder Creep-Fatigue Interactions with Flexible Leaded Surface Mount Components.- 19.1 Introduction.- 19.2 Modeling of Solder Creep-Fatigue Interactions.- 19.2.1 Use of Coffin-Manson Relationships to Account for Creep Strain.- 19.2.2 Solder Constitutive Relationships.- 19.2.3 Finite Element Creep-Fatigue Modeling.- 19.3 Role of Lead Stiffness in Isothermal Loading.- 19.3.1 Creep Strain During Stress Relaxation.- 19.3.2 Strain Range During Isothermal Mechanical Cycling.- 19.3.3 Complex Strain Behavior with Leaded Parts.- 19.4 Role of Lead Stiffness with Thermal Cycling.- 19.4.1 Creep Ratcheting.- 19.4.2 Strain Development During Isothermal Mechanical Cycling.- 19.4.3 Strain Development During Thermal Cycling.- 19.4.4 Damage Prediction with Combined Creep Ratcheting and Fatigue.- 19.5 Discussion and Concluding Summary.- References.- 20. Thermal Stress Issues in Plated-Through-Hole Reliability.- 20.1 Introduction.- 20.2 Finite Element Modeling of a PTH.- 20.2.1 Boundary Conditions.- 20.2.2 Material Properties.- 20.2.3 Stress Averaging.- 20.2.4 Critical Stresses.- 20.2.5 Comparison Between 3D and Axisymmetric Analysis.- 20.3 Parametric Studies of PTH Geometry.- 20.3.1 PTH Spacing.- 20.3.2 Innerplanes.- 20.3.3 Nonfunctional Internal Pads.- 20.3.4 Aspect Ratio.- 20.3.5 Plating Thickness.- 20.4 Solder-Filled PTH and Voids in Solder-Filled PTH.- 20.4.1 Modeling.- 20.4.2 Results.- 20.5 Transient Thermal Stress in a PTH Subjected to Wave Soldering.- 20.5.1 Materials.- 20.5.2 Transient Finite Element Model.- 20.5.3 Results and Discussion.- 20.6 Summary.- References.- 21. Nonlinear Analysis of a Ceramic Pin Grid Array (PGA) Soldered to an Orthotropic Epoxy Substrate.- 21.1 Introduction.- I-Reliability of Pin Grid Array Interconnects.- 21.2 Boundary-Value Problem.- 21.3 Local Thermal Expansion Mismatch by Finite Element Analysis.- 21.3.1 Finite Element Modeling.- 21.3.2 Finite Element Analysis and Results.- 21.4 Global Thermal Expansion Mismatch by Fatigue Testing.- 21.4.1 Specimen Preparation and Test Setup.- 21.4.2 Experimental Results and Discussion.- 21.5 Fatigue Life of PGA Solder Joint and PTH Copper.- 21.6 Effects of Solder Geometry on the Fatigue Life of PGA Solder Joints.- 21.6.1 PGA Solder Joints without Solder Fillet.- 21.6.2 PGA with Half-Filled Solder Joints.- 21.7 Summary.- II-Effect of Rework on the Reliability of Pin Grid Array Interconnects.- 21.8 Rework Procedures.- 21.9 Cross-Sections of Reworked PGA Interconnects (Before Test).- 21.10 Fatigue Test of Reworked PGA Interconnect.- 21.10.1 Fatigue Test Setup and Preparation.- 21.10.2 Experimental Results and Discussion.- 21.11 Cross-Sections of Reworked PGA Interconnects (After Test).- 21.12 Reliability of Reworked PGA Solder Joints and PTH Copper.- 21.13 Summary.- References.- 22. Mechanics of Wirebond Interconnects.- 22.1 Introduction.- 22.1.1 What is Wirebonding?.- 22.1.2 Wirebond Types and Representative Geometries.- 22.1.3 Typical Metallurgical Systems.- 22.1.4 Wire Selection.- 22.1.5 Methods of Wirebond Evaluation.- 22.1.6 Observed Wirebond Failures.- 22.1.7 Role of Thermomechanical Properties.- 22.2 Thermomechanical Considerations During the Bonding Process.- 22.2.1 Cratering.- 22.2.2 Pad Cleanliness.- 22.2.3 Intermetallic Formation.- 22.2.4 Metallizations.- 22.2.5 Pad Lifting.- 22.2.6 Bonding Parameters.- 22.2.7 Geometries.- 22.2.8 Post-Bond Testing.- 22.3 Thermomechanical Considerations During Use.- 22.3.1 Intermetallic Formation and Kirkendall Voiding.- 22.3.2 Wire Flexure Fatigue.- 22.3.3 Wirebond Fatigue.- 22.3.4 Axial Fatigue of the Wire in Plastic-Encapsulated Devices.- 22.3.5 Corrosion.- 22.3.6 Dendritic Growth.- 22.3.7 Electrical Noise.- 22.3.8 Vibration Fatigue.- 22.3.9 Resistance Change.- 22.4 Wirebond Interconnect Design Guidelines.- 22.4.1 Input Information and Design Goals.- 22.4.2 Wirebond Interconnect Design Process.- 22.5 Summary.- References.- 23. Corrosion in Microelectronics Packages.- 23.1 Introduction.- 23.2 Forms of Corrosion.- 23.3 Thermodynamics of Corrosion Reactions.- 23.4 Kinetics of Corrosion Reactions.- 23.5 Generic Corrosion Processes and Reaction Mechanisms of Corrosion.- 23.6 Corrosion Modeling.- 23.6.1 Governing Equations of Corrosion Processes.- 23.6.2 Calculation of Time-to-Failure.- 23.6.3 Pitting and Crevice Corrosion.- 23.6.4 Stress Corrosion Cracking.- 23.6.5 Stress Corrosion Fatigue.- 23.7 Methods of Preventing or Minimizing Corrosion.- 23.8 Laboratory Experimental Techniques and Standard Tests.- 23.9 Summary.- Nomenclature.- References.- Author Biographies.