Chapter C: Polymer Bonding
by Henrik Hvims and Helle Rønsberg
TABLE OF CONTENTS
C1.
Level 1. Introduction to polymer bonding
C1.1
Introduction to polymer bonding
C1.2
Adhesive options
C1.3
General benefits and limitations of Conductive Adhesives
C1.4
Conductive Adhesives General
C1.4.1 Materials
– types of polymers
C1.4.1.1
Thermoplastics
C1.4.1.2 Thermosets
C1.4.1.3 Fillers
C1.5
Basic types of Conductive Polymers
C1.5.1
Intrinsically Conductive Polymers
C1.5.2
Isotropically Conductive Adhesives
C1.5.3
Anisotropic Conductive Adhesives
C1.5.3.1 Patterned
Conductive Type
C1.5.3.2 Random
Conductor Type
C1.5.4
Nonconductive Adhesives Used for Electrical Connections
C1.6 Why look for
alternatives to solder?
C1.6.1 Solder
joint stress cracking
C1.6.2 Thermal
mismatch problems
C1.6.3 Leaching
C1.6.4
Environmental aspects
C1.6.4.1 Flux
C1.6.4.2 Lead
C2. Level 2.
Conclusions and guidelines
C2.1
Design and production issues
C2.1.1 Applying
the adhesive to the board
C2.1.2 The pick
and place operation
C2.1.3 The
curing operation
C2.1.4 Bleed out
C2.2
Basic facts about electrically conductive adhesives
C2.2.1
Isotropic electrically conductive adhesives
C2.2.1.1
Filled isotropic electrically conductive adhesives
C2.2.2
Non-filled isotropic electrically conductive adhesives
C2.2.3
Anisotropic electrically conductive adhesives
C2.2.4
Thermosetting adhesives
C2.2.4.1 One component
thermosetting adhesives
C2.2.4.2 Two-component
thermosetting adhesives
C2.2.4.3
The polymeric matrix in thermosetting adhesives
C2.2.4.4 The
epoxy-based polymeric matrix
C2.2.4.5 The silicone
based polymeric matrix
C2.2.4.6 The polyimide
based polymeric matrix
C2.2.5
Thermoplastic adhesives
C2.2.6
Electrically conductive filler particles
C2.2.6.1 Material
C2.2.6.2 Particle
shape and size
C2.2.7 Additives
C2.2.7.1
Reactive solvents
C2.2.7.2
Flexibility compounds
C2.3 Discussions of
parameters relevant to the evaluation of the properties of adhesives
C2.3.1
Electrical conductivity
C2.3.2 Thermal
conductivity
C2.3.3
Coefficient of thermal expansion (CTE)
C2.3.4
Reworkability
C2.3.5 Rheology
C2.3.6 Ionic
impurities
C2.3.7 Weight
loss
C2.3.8
Flexibility
C2.3.9 Die shear
strength
C2.3.10
Substrate
C2.3.11 Glass
transition temperature
C2.3.12 Cost
C2.3.13
Reliability
C2.3.13.1
Electrical conductivity
C2.3.13.2
Shear strength
C2.3.13.3
Ageing of substrate or component
C2.3.13.4
Pre-tinned surfaces
C2.3.14
Environmental tests
C2.3.14.1
Thermal ageing
C2.3.14.2
Temperature shock/cycling
C2.3.14.3
Humidity storage
C2.3.14.4
Pressure cooker test/HAST
C2.4
The advantage of Adhesive Technology for SMT on rigid PCB
C2.5
Reliability
C2.5.1
Reliability investigations of ICA joints
C2.5.2
Reliability of amisotropic conductive Adhesives
C2.6
Failure causes
C2.6.1 Oxidation
and corrosion (SnPb, Cu)
C2.6.2 Crack
formation/delamination
C2.6.3 Silver
depleted layer
C2.6.4 Creep of
the adhesive
C2.6.5 Formation
of an intermetallic layer
C2.6.6 Ag
migration
C2.6.7
Processing defects
C2.7
The influence on internal and external environments
C2.7.1 External
environmental aspects
C2.7.2
Internal environmental aspects
C3. Level 3. Background
information
C3.1
Reports
C3.2
Papers
C4. Level 4. References
