Adhesives Technology for Electronic Applications: Materials, Processing, Reliability

Dedication......Page 1
 Adhesives Technology for Electronic Applications: Materials, Processing, Reliability......Page 2
 Copyright......Page 3
 Preface......Page 4
5......Page 6
7 Test and Inspection Methods......Page 351
 Disclaimer......Page 7
5 Applications......Page 8
6.1.1 Physics of failure step-by-step approach......Page 296
1.1.1 Classification by form......Page 9
1.1.2 Classification by polymer or chemical type......Page 10
1.1.4.2 Ultraviolet (UV)/visible-light-cured adhesives......Page 12
1.1.5.2 Electrical connection......Page 13
1.1.6.1 Die attachment......Page 15
1.1.6.3 Lid attachment......Page 16
1.1.6.5 Underfill for flip-chip-attached devices......Page 17
1.1.6.8 Particle getters......Page 18
1.2.1 Single-chip packaging......Page 19
1.2.1.2 Quad-flat packs (QFPs)......Page 20
1.2.1.3.3 Pin-grid array (PGA)......Page 21
1.2.1.4 Chip-scale packages (CSPs)......Page 22
1.2.1.4.3 Flex interposer-based CSPs......Page 24
1.2.1.6 Chip stacks......Page 25
1.2.3 Multichip packaging......Page 26
1.2.3.1 Hybrid microcircuits......Page 27
1.2.3.2 Multichip modules......Page 28
1.2.3.3 High-density interconnect (HDI) overlay process......Page 29
1.2.3.5 Flexible circuits......Page 30
1.3 History of adhesives in electronic applications......Page 31
1.5 Specifications......Page 36
1.6 Market and market trends......Page 37
 References......Page 39
2 Functions and theory of adhesives......Page 42
2.1 Mechanical attachment......Page 43
2.1.1 Wettability theory......Page 44
2.1.1.1 Factors affecting wettability......Page 46
2.1.1.2 Excessive wetting and bleedout......Page 47
2.1.2 Rheology......Page 48
2.1.2.1 Newtonian and non-Newtonian flow......Page 49
2.1.2.2 Capillary flow......Page 50
2.1.2.2.1 Material factors affecting capillary flow......Page 51
2.1.2.2.2 Physical factors affecting capillary flow......Page 52
2.1.3 Adhesion mechanisms......Page 54
7.2.4 Current-carrying capacity and interconnect resistance......Page 363
2.1.3.2 Direct bonding......Page 55
6.2.3 Adhesive fracture/fracture mechanics∗......Page 309
6.2.3.1 Fracture mechanics design approach......Page 56
2.1.3.5 Vitreous bonding......Page 57
2.2.1 Conductivity and resistivity......Page 58
3.1.6 Modified Cyclo-olefin Thermosets (MCOT)......Page 105
2.2.2.1 Isotropic conduction......Page 59
2.2.2.2 Anisotropic conduction......Page 60
3.3.1 Paste adhesives......Page 124
2.3.1 Thermal conductance and thermal conductivity......Page 62
2.3.3 Effect of fillers on thermal conductivity......Page 65
2.4 Stress dissipation......Page 67
2.4.1 Thermal expansion and stresses......Page 68
2.4.2 Glass-transition temperature and stresses......Page 69
2.4.3 Residual stresses......Page 73
2.4.4 Effect of curing conditions on the glass-transition temperature......Page 75
 References......Page 78
3 Chemistry, Formulation, and Properties of Adhesives......Page 82
4.1 Cleaning......Page 84
3.1.1.1 Epoxy resins......Page 85
6.2.1 Loss of adhesion (delamination)......Page 298
3.1.1.4 Polyamides......Page 89
3.1.1.5 Amide-amine curing agents (Dicy)......Page 91
3.1.1.6 Anhydride curing agents......Page 92
3.1.1.7 Catalytic-curing agents (Lewis bases and Lewis acids)......Page 93
3.1.1.8 Levels of curing agents used......Page 94
3.1.2 Silicones......Page 95
3.1.2.2 Addition-cured silicones......Page 96
5.2.4.1 Miniaturization......Page 254
3.1.3 Polyimides......Page 98
3.1.4 Polyurethanes......Page 101
3.1.4.1 Moisture-curing polyurethanes......Page 102
3.1.7.1 Basic acrylate chemistry......Page 107
3.2 Formulation additives......Page 108
3.2.1.1 Electrical and thermal conductivity......Page 109
6.2.6.2 Ionic impurities......Page 114
7.5.5 Bond strength......Page 373
3.2.1.6 Improved flow properties......Page 115
3.2.2 Nanofillers and Nanotechnology......Page 117
3.2.2.1 Preparation of nanoparticles......Page 118
4.5.1 Thermal curing......Page 207
3.2.3 Thixotropic Agents......Page 119
3.2.6 Flexibilizers......Page 120
3.2.7 Flame Retardants......Page 121
3.2.8 Stabilizers......Page 123
3.3.2 Film or preform adhesives......Page 125
3.4.1 Properties of epoxy adhesives......Page 128
3.4.1.1 Purity......Page 129
3.4.1.4 Thermal expansion properties......Page 130
3.4.1.5 Electrical properties......Page 131
3.4.2.1 Thermal and thermomechanical properties......Page 132
3.4.2.4 Physical properties......Page 133
3.4.3 Properties of polyimide adhesives......Page 134
3.4.4 Properties of polyurethane adhesives......Page 135
3.4.5 Properties of cyanate esters......Page 136
3.4.7 Properties of acrylates and UV-curing adhesives......Page 138
3.4.8 Properties of film adhesives......Page 139
3.4.9 Properties of silver-glass adhesives......Page 140
 References......Page 144
4 Adhesive Bonding Processes......Page 149
4.1.1.1 Organic solvents......Page 152
4.1.1.2 Aqueous and semi-aqueous cleaners......Page 153
4.1.1.3 Measuring solvency and cleaning ability......Page 158
4.1.2.1 Vapor degreasing......Page 165
4.1.2.2 Spray cleaning......Page 167
4.1.2.4 Centrifugal cleaning......Page 170
4.1.2.5.1 Plasma-cleaning mechanisms......Page 172
4.1.2.5.2 Plasma-cleaning equipment......Page 173
4.1.3 Methods for testing and assuring cleanliness......Page 174
4.2 Surface treatments......Page 178
4.3 Adhesive dispensing......Page 179
4.3.1 Screen printing and stencil printing......Page 180
4.3.1.1 Stencil fabrication and design......Page 182
5.2.5 Chip-scale packages (CSP)......Page 256
4.3.1.3 Stencil/screen printing process and equipment......Page 186
6.2.5 Electrical stability......Page 188
4.3.4 Automated selective dispensing (contact type)......Page 189
4.3.4.1 Automated dispensing of die-attachment adhesives......Page 191
4.3.4.2 Automated dispensing for surface-mount adhesives......Page 192
4.3.4.2.1 Needle selection......Page 194
4.3.4.2.2 Equipment......Page 195
4.3.4.3 Automated dispensing of underfill adhesives......Page 198
4.3.4.4 Material factors affecting automated dispensing......Page 200
4.3.5 Jet dispensing (non-contact type)......Page 201
4.4 Placement of devices and components......Page 203
4.5 Curing......Page 204
4.5.2 Ultraviolet/visible light curing......Page 208
4.5.4 Moisture curing......Page 209
4.5.5 Cure schedule and degree of cure......Page 210
4.6 Rework......Page 215
4.6.2 Rework of high-density modules......Page 216
6.4.6.3 Specifications for underfill adhesives......Page 217
 References......Page 218
11......Page 223
5.1.1 Surface-mount technology......Page 224
5.1.3.1 Capillary-flow underfill adhesives......Page 230
5.1.3.2 No-flow underfill adhesives......Page 232
6.2.1.3 Stresses......Page 301
5.1.3.4 Alternate underfill approaches......Page 244
5.1.4 Conductive adhesives as solder replacements......Page 246
5.2.1 Military applications......Page 248
5.2.2 Space applications......Page 252
5.2.3 Automotive applications......Page 253
5.2.4.4 Sterilization......Page 255
7.4 Thermal tests......Page 366
5.2.6.2 Package stacking......Page 257
5.2.6.4 Wafer stacking......Page 260
5.2.6.5 Through-silicon vias......Page 265
5.2.8.1 Front and rear panel processing......Page 266
5.2.8.2 Display cell assembly......Page 268
5.2.8.3 Module assembly......Page 271
5.2.9 LED lighting and display applications......Page 273
5.2.10 Organic light emitting diodes (OLED)......Page 278
5.2.11 Electromagnetic interference (EMI) shielding and grounding......Page 280
5.2.12 Optoelectronics......Page 281
5.2.13 Smart cards and RFIDs......Page 286
5.2.14 Lid sealing......Page 288
5.2.15 Power circuits and power devices......Page 290
 References......Page 291
6 Reliability......Page 295
6.2.1.1 Contaminated surfaces and poor wettability......Page 300
6.2.1.3.1 Residual stress......Page 302
6.2.1.3.2 Modulus of elasticity......Page 303
6.2.1.3.3 CTE mismatches......Page 304
6.2.1.3.4 Voids and moisture absorption......Page 306
6.2.2 Die fracture......Page 308
6.2.3.2 Fracture mechanics design methodology......Page 312
7.3.3 Radiation effects......Page 313
6.2.4.2 Bond line thickness......Page 314
6.2.5.1 Effect of cure and current on contact resistance......Page 315
6.2.5.2 Loss of backside electrical contact on semiconductor devices......Page 316
6.2.5.3 Stability of solder replacements on non-noble metal surfaces......Page 318
6.2.6.1 Corrosion from curing agents......Page 320
7.5 Mechanical and thermomechanical tests......Page 371
6.2.7 Outgassing and moisture......Page 322
6.2.9 Adhesives quality......Page 326
6.3 Reliability prediction and modeling......Page 327
6.3.1 Weibull analysis......Page 329
6.3.3 MIL-HDBK-217......Page 331
6.4 Qualification, quality control, and specifications......Page 334
6.4.3 Receiving inspection and acceptance testing......Page 335
6.4.5 Screen tests and product acceptance......Page 336
6.4.6.2 Specifications for surface-mount adhesives......Page 337
6.4.8 Hazardous materials restrictions......Page 342
 References......Page 348
7.1.1 Viscosity and thixotropy......Page 352
7.1.3 Density and specific gravity......Page 358
7.1.5 Visual......Page 359
7.2 Electrical tests......Page 361
7.2.2 Dielectric constant and dissipation factor......Page 362
7.3.1 Solvent and chemical resistance......Page 364
7.3.4 Fungus resistance......Page 365
7.4.1 Differential scanning calorimetry (DSC)......Page 367
7.4.2.1 Guarded-hot-plate method......Page 368
7.4.2.2 Heat-flow-meter method......Page 369
7.4.3 Thermogravimetric analysis......Page 370
7.5.2 Modulus and elongation (flexural)......Page 372
7.5.5.3 Die-shear strength......Page 374
7.5.6 Acoustic microscopy......Page 375
7.5.7 Radius of curvature......Page 376
7.6.1 Weight loss during cure......Page 377
7.6.4 Mass spectrometry and residual gas analysis (RGA)......Page 378
7.6.5 Total-mass loss and water regained......Page 379
7.6.6 Ionic content......Page 380
 References......Page 381
 Conversion factors......Page 384
 Abbreviations, Acronyms, and Symbols......Page 385
 Index......Page 390