Key Engineering Materials
Vols. 373-374
Vols. 373-374
Key Engineering Materials
Vols. 368-372
Vols. 368-372
Key Engineering Materials
Vol. 367
Vol. 367
Key Engineering Materials
Vols. 364-366
Vols. 364-366
Key Engineering Materials
Vols. 361-363
Vols. 361-363
Key Engineering Materials
Vols. 359-360
Vols. 359-360
Key Engineering Materials
Vols. 353-358
Vols. 353-358
Key Engineering Materials
Vol. 352
Vol. 352
Key Engineering Materials
Vol. 351
Vol. 351
Key Engineering Materials
Vol. 350
Vol. 350
Key Engineering Materials
Vols. 348-349
Vols. 348-349
Key Engineering Materials
Vol. 347
Vol. 347
Key Engineering Materials
Vols. 345-346
Vols. 345-346
Key Engineering Materials Vols. 353-358
Paper Title Page
Abstract: The environmental experiments of the thermal cycling (-40~125°C) and the high
temperature/humidity (85°C, 85%RH) aging were used to evaluate the reliability of the specimens
bonded with ACFs. It was found that the high temperature/humidity was the harshest condition to
the ACFs bonding. The DSC testing and interfacial stresses analysis has been done under the high
temperature/humidity condition. The mechanisms of the bonding strength decrease were
investigated.
2875
Abstract: Isotropic Conductive Adhesives (ICAs) were prepared using epoxy resin as matrix, latent
curing agent as hardener, and silver particles as the conducting filler. The effects of nano-fillers
(SiO2 nano-particles and carbon nanotubes) on the conductivity, adhension strength and reliability
of ICAs were investigated experimentally in this paper. The results showed that these two nano
fillers can improve both the conductivity and adhesion strength of ICAs, which maybe attributed to
the nano-particles forming physico-chemical bonds with epoxy resin. These physico-chemical
bonds increase the contact area and then minish the interspace of Ag particles, so it reduces
electrical resistance and enables a high current flow. And the increasing contact area will improve
the contact strength between Ag particles and epoxy resin. Under the reliability testing with the high
temperature and high humidity (85°C/85RH), the SiO2 nano-particles can improve the reliability of
ICAs apparently, while carbon nanotubes can not. This is because insulating material can prevent
silver migration.
2879
Abstract: Microstructure and mechanical properties of the 55%, 60% and 67% Mo/Cu composites
for electronic packaging application fabricated by a patent squeeze casting route have been
investigated. The results show that Mo particles are homogeneously distributed in the matrix, and the
Mo-Cu interfaces are clean, free from interfacial reaction products and amorphous layers. The
densification of the Mo/Cu composites is higher than 99%. The as-received composites exhibit a
Brinell hardness varying from HB178.1 to HB196.9 and an elastic modulus varying from 177GPa to
213 GPa. The tensile strength of the composites is higher than 480MPa. Moreover, the composites
display favorable plasticity, while the elongation of the 55% Mo/Cu composite is as high as 5%.
Obtaining high tensile strength and elongation in the composite is attributed to the high densification,
as well as the clean and smooth Mo-Cu interfaces, both resulting from the cost-effective
squeeze-casting technology.
2883
Abstract: Sip/4032Al composites for electronic packaging applications with high volume fraction
of Si particles were fabricated by squeeze-casting technology. The microstructure observation
showed that the composites were dense and Si particles distributed uniformly, The interfaces and
the existance of the interface reaction were the important factors which affected the properties of the
composites; The linear CTEs of Sip/4032Al composites was between (8.1~12) ×10-6°C-1, and they
were decreased with the increasing content of Si particles as well as annealing treatment. Kerner
model can predict the CTEs of Sip/4032Al composites moderately; the thermal conductivity can
reach 103W/ (m·°C), which was decreased with the increasing contents of Si particles as well as
annealing treatment. The thermal conductivity of composite calculated was larger than tested values.
The composites had excellent mechanical properties and also could be recycled.
2887
Abstract: The mostly working time of airborne electronic equipment is under preliminary depletion
failure phase, and inspection & maintenance at intervals can’t lower the failure probability. In this
paper, the law of airborne electronic equipment failure is introduced firstly. Then, methods for failure
prediction are summarized and analyzed. Finally, an example for predicting the airborne radar failure
using the Auto-Regressive (AR) and Support Vector Regression (SVR) model is presented. On this
basis, it is possible to achieve the goal that increases the reliability in working phase and establish a
more scientific maintenance system and to assure the safety of airborne electronic equipment.
2892
Abstract: Based on the analyses of reliability and life characteristics in electronic equipment, a new
concept of Electronic Equipment Life Envelope (EELE) is presented. The basic approach to EELE
establishment is investigated in detail. The interrelationship between storage life and working life of
electronic equipment is demonstrated by virtue of EELE, which validates its preliminary application
and advantages. The new philosophy can be further applied to accelerated experiments and service
life prediction for electronic equipments.
2896
Abstract: Passivation cracking is one of the main failures of Integrated circuits (ICs). A major cause
for these failures is due to the mismatch of Coefficients of Thermal Expansion (CTE), Young’s
modulus, Poisson’s ratios of package materials. In this paper, in order to analysis the stress
distribution around the passivation layer corner, the finite element simulations and simplified
analytical solutions are both applied. Then the comparison of stress values is made between the FEM
result and simplified analytical solution, which shows that there is a good agreement. Based on these
analyses, a conclusion can be drawn out that the simplified analytical model can be used to analyze the
maximum stress around the passivation layer corner fast when design a chip preliminarily.
2900
Abstract: With the increasing of packaging integration the power and the quantity of heat of
integrate circuit will increase, it will bring more and more temperature distributions and problems
about thermal stresses in package. In this paper a finite element thermal stress model of
substrate-adhesive-chip is established, thermal stress distribution of substrate-chip interfaces and
the affects of geometrical structure on thermal stresses are analyzed by finite element method,
especially discuss interfacial thermal stresses distributions on chip-adhesive interface and
adhesinve-substrate interface.
2904
Abstract: A series of torsional fatigue tests were conducted on 63Sn-37Pb and Sn-0.7Cu solders. A
continuous load drop was observed during the test. It was found that the load drop percentage had
little effect on the elastic strain-life curve but strong effect on the plastic strain-life curve. The fatigue
strength coefficient, fatigue strength exponent and fatigue ductility exponent had no great changes
with the load drop. However, fatigue ductility coefficient showed a great difference and was linearly
varying with load drop. A fatigue criterion of Coffin-Manson type was proposed in relation to load
drop. The descending curve of the stress range with cycle was observed to consist of transient, steady
state and tertiary regions. The percentage of load drop corresponding to the turning point from the
steady state to the tertiary region was about 25% for all strain ranges of 63Sn-37Pb, and 30% for all
strain ranges of Sn-0.7Cu. The torsional fatigue lives were correlated with von Mises equivalent strain
amplitudes well. The fatigue behavior of Sn-0.7Cu is better than that of 63Sn-37Pb.
2908
Abstract: Creep property of solder alloys is one of the important factors to effect the reliability of
surface mount technology (SMT) soldered joints. The creep behavior and its rupture life of
Sn2.5Ag0.7CuXRE lead-free soldered joints were separately investigated and predicted under
constant temperature by a single shear lap creep specimen with a 1mm2 cross sectional area and
finite element method (FEM) in this paper. Results show that the creep property of
Sn2.5Ag0.7Cu0.1RE is superior to that of the commercial employed lead-free solder Sn3.8Ag0.7Cu
and the creep rupture life of its soldered joints is 8.4 times more than that of Sn2.5Ag0.7Cu solder.
The creep rupture life of Sn2.5Ag0.7CuXRE lead-free soldered joints indirectly predicted by FEM
is better in accord with that of actual testing results, which are important to design the reliability of
lead-free soldered joints for SMT.
2912