共查询到20条相似文献,搜索用时 15 毫秒
1.
G. Ghosh 《Journal of Electronic Materials》2000,29(10):1182-1193
A comparative study of the kinetics of interfacial reaction between the eutectic solders (Sn-3.5Ag, Sn-57Bi, and Sn-38Pb)
and electroplated Ni/Pd on Cu substrate (Cu/Ni/NiPd/Ni/Pd) was performed. The interfacial microstructure was characterized
by imaging and energy dispersive x-ray analysis in scanning electron microscope (SEM). For a Pd-layer thickness of less than
75 nm, the presence or the absence of Pd-bearing intermetallic was found to be dependent on the reaction temperature. In the
case of Sn-3.5Ag solder, we did not observe any Pd-bearing intermetallic after reaction even at 230°C. In the case of Sn-57Bi
solder the PdSn4 intermetallic was observed after reaction at 150°C and 180°C, while in the case of Sn-38Pb solder the PdSn4 intermetallic was observed after reaction only at 200°C. The PdSn4 grains were always dispersed in the bulk solder within about 10 μm from the solder/substrate interface. At higher reaction
temperatures, there was no Pd-bearing intermetallic due to increased solubility in the liquid solder. The presence or absence
of Pd-bearing intermetallic was correlated with the diffusion path in the calculated Pd-Sn-X (X=Ag, Bi, Pb) isothermal sections.
In the presence of unconsumed Ni, only Ni3Sn4 intermetallic was observed at the solder-substrate interface by SEM. The presence of Ni3Sn4 intermetallic was consistent with the expected diffusion path based on the calculated Ni-Sn-X (X=Ag, Bi, Pb) isothermal sections.
Selective etching of solders revealed that Ni3Sn4 had a faceted scallop morphology. Both the radial growth and the thickening kinetics of Ni3Sn4 intermetallic were studied. In the thickness regime of 0.14 μm to 1.2 μm, the growth kinetics always yielded a time exponent
n >3 for liquid-state reaction. The temporal law for coarsening also yielded time exponent m >3. The apparent activation energies
for thickening were: 16936J/mol for the Sn-3.5Ag solder, 17804 J/mol for the Sn-57Bi solder, and 25749 J/mol for the Sn-38Pb
solder during liquid-state reaction. The corresponding activation energies for coarsening were very similar. However, an apparent
activation energy of 37599 J/mol was obtained for the growth of Ni3Sn4 intermetallic layer during solid-state aging of the Sn-57Bi/substrate diffusion couples. The kinetic parameters associated
with thickening and radial growth were discussed in terms of current theories. 相似文献
2.
M. L. Huang T. Loeher D. Manessis L. Boettcher A. Ostmann H. Reichl 《Journal of Electronic Materials》2006,35(1):181-188
A comparative study of solid/solid interfacial reactions of electroless Ni-P (15 at.% P) with lead-free solders, Sn-0.7Cu,
Sn-3.5Ag, Sn-3.8Ag-0.7Cu, and pure Sn, was carried out by performing thermal aging at 150°C up to 1000 h. For pure Sn and
Sn-3.5Ag solder, three distinctive layers, Ni3Sn4, SnNiP, and Ni3P, were observed in between the solder and electroless Ni-P; while for Sn-0.7Cu and Sn-3.8Ag-0.7Cu solders, two distinctive
layers, (CuNi)6Sn5 and Ni3P, were observed. The differences in morphology and growth kinetics of the intermetallic compounds (IMCs) at the interfaces
between electroless Ni-P and lead-free solders were investigated, as well as the growth kinetics of the P-enriched layers
underneath the interfacial IMC layers. With increasing aging time, the coarsening of interfacial Ni3Sn4 IMC grains for pure Sn and Sn-3.5Ag solder was significantly greater than that of the interfacial (CuNi)6Sn5 IMC grains for Sn-0.7Cu and Sn-3.8Ag-0.7Cu solders. Furthermore, the Ni content in interfacial (CuNi)6Sn5 phase slightly increased during aging. A small addition of Cu (0.7 wt.%) resulted in differences in the type, morphology,
and growth kinetics of interfacial IMCs. By comparing the metallurgical aspects and growth kinetics of the interfacial IMCs
and the underneath P-enriched layers, the role of initial Cu and Ag in lead-free solders is better understood. 相似文献
3.
In flip chip technology, Al/Ni(V)/Cu under-bump metallization (UBM) is currently applicable for Pb-free solder, and Sn−Ag−Cu
solder is a promising candidate to replace the conventional Sn−Pb solder. In this study, Sn-3.0Ag-(0.5 or 1.5)Cu solder bumps
with Al/Ni(V)/Cu UBM after assembly and aging at 150°C were employed to investigate the elemental redistribution, and reaction
mechanism between solders and UBMs. During assembly, the Cu layer in the Sn-3.0Ag-0.5Cu joint was completely dissolved into
solders, while Ni(V) layer was dissolved and reacted with solders to form (Cu1−y,Niy)6Sn5 intermetallic compound (IMC). The (Cu1−y,Niy)6Sn5 IMC gradually grew with the rate constant of 4.63 × 10−8 cm/sec0.5 before 500 h aging had passed. After 500 h aging, the (Cu1−y,Niy)6Sn5 IMC dissolved with aging time. In contrast, for the Sn-3.0Ag-1.5Cu joint, only fractions of Cu layer were dissolved during
assembly, and the remaining Cu layer reacted with solders to form Cu6Sn5 IMC. It was revealed that Ni in the Ni(V) layer was incorporated into the Cu6Sn5 IMC through slow solid-state diffusion, with most of the Ni(V) layer preserved. During the period of 2,000 h aging, the growth
rate constant of (Cu1−y,Niy)6Sn5 IMC was down to 1.74 × 10−8 cm/sec0.5 in, the Sn-3.0Ag-1.5Cu joints. On the basis of metallurgical interaction, IMC morphology evolution, growth behavior of IMC,
and Sn−Ag−Cu ternary isotherm, the interfacial reaction mechanism between Sn-3.0Ag-(0.5 or 1.5)Cu solder bump and Al/Ni(V)/Cu
UBM was discussed and proposed. 相似文献
4.
Guh-Yaw Jang Jeng-Gong Duh Hideyuki Takahashi Szu-Wei Lu Jen-Chuan Chen 《Journal of Electronic Materials》2006,35(9):1745-1754
Sn-Ag-Cu solder is a promising candidate to replace conventional Sn-Pb solder. Interfacial reactions for the flip-chip Sn-3.0Ag-(0.5
or 1.5)Cu solder joints were investigated after aging at 150°C. The under bump metallization (UBM) for the Sn-3.0Ag-(0.5 or
1.5)Cu solders on the chip side was an Al/Ni(V)/Cu thin film, while the bond pad for the Sn-3.0Ag-0.5Cu solder on the plastic
substrate side was Cu/electroless Ni/immersion Au. In the Sn-3.0Ag-0.5Cu joint, the Cu layer at the chip side dissolved completely
into the solder, and the Ni(V) layer dissolved and reacted with the solder to form a (Cu1−y,Niy)6Sn5 intermetallic compound (IMC). For the Sn-3.0Ag-1.5Cu joint, only a portion of the Cu layer dissolved, and the remaining Cu
layer reacted with solder to form Cu6Sn5 IMC. The Ni in Ni(V) layer was incorporated into the Cu6Sn5 IMC through slow solid-state diffusion, with most of the Ni(V) layer preserved. At the plastic substrate side, three interfacial
products, (Cu1−y,Niy)6Sn5, (Ni1−x,Cux)3Sn4, and a P-rich layer, were observed between the solder and the EN layer in both Sn-Ag-Cu joints. The interfacial reaction
near the chip side could be related to the Cu concentration in the solder joint. In addition, evolution of the diffusion path
near the chip side in Sn-Ag-Cu joints during aging is also discussed herein. 相似文献
5.
Three kinds of Sn-Ag-based lead-free solders, Sn-3.5Ag-0.7Cu, Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge, and Sn-3.5Ag-0.07Ni (in wt.%),
were selected to explore the effect of microelements (Ni and Ge) on the interfacial reaction between the solder and the Cu
substrate. The thickness of the interfacial intermetallics formed with the Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge and Sn-3.5Ag-0.07Ni
solders is several times that of the Sn-3.5Ag-0.7Cu solder. The added microelements converted the feature of interfacial intermetallics
from pebble shape to worm shape. However, the results of x-ray diffraction (XRD) analysis suggest that the interfacial intermetallics
formed with both solders have the same crystal structure. The results of energy dispersive spectroscopy (EDS) analysis show
that the major interfacial intermetallic formed with the Sn-3.5Ag-0.7Cu solder is Cu6Sn5, while it is (Cux,Ni1−x)6Sn5 with Sn-3.5Ag-0.5Cu-0.07Ni-0.01Ge. Ni influences the interfacial intermetallics and plays the influential role on the difference
of interfacial reaction rate between liquid solder and solid Cu and the morphology of interfacial intermetallics. Additionally,
the growth kinetics of the interfacial intermetallic compounds (IMCs) formed in the systems of Cu/Sn-3.5Ag-0.7Cu and Cu/Sn-3.5Ag-0.07Ni
at high-temperature storage was also explored. 相似文献
6.
(Cu,Ni)6Sn5 is an important intermetallic compound (IMC) in lead-free Sn-Ag-Cu solder joints on Ni substrate. The formation, growth, and microstructural evolution of (Cu,Ni)6Sn5 are closely correlated with the concentrations of Cu and Ni in the solder. This study reports the interfacial behaviors of (Cu,Ni)6Sn5 IMC (Sn-31 at.%Cu-24 at.%Ni) with various Sn-Cu, Sn-Ni, and Sn-Cu-Ni solders at 250°C. The (Cu,Ni)6Sn5 substrate remained intact for Sn-0.7 wt.%Cu solder. When the Cu concentration was decreased to 0.3 wt.%, (Cu,Ni)6Sn5 significantly dissolved into the molten solder. Moreover, (Cu,Ni)6Sn5 dissolution and (Ni,Cu)3Sn4 formation occurred simultaneously for the Sn-0.1 wt.%Ni solder. In Sn-0.5 wt.%Cu-0.2 wt.%Ni solder, many tiny (Cu,Ni)6Sn5 particulates were formed and dispersed in the solder matrix, while in Sn-0.3 wt.%Cu-0.2 wt.%Ni a lot of (Ni,Cu)3Sn4 grains were produced. Based on the local equilibrium hypothesis, these results are further discussed based on the liquid–(Cu, Ni)6Sn5–(Ni,Cu)3Sn4 tie-triangle, and the liquid apex is suggested to be very close to Sn-0.4 wt.%Cu-0.2 wt.%Ni. 相似文献
7.
Sang-Su Ha Jong-Woong Kim Jin-Ho Joo Seung-Boo Jung 《Microelectronic Engineering》2007,84(11):2640-2645
This study was focused on the formation and reliability evaluation of solder joints with different diameters and pitches for flip chip applications. We investigated the interfacial reaction and shear strength between two different solders (Sn-37Pb and Sn-3.0Ag-0.5Cu, in wt.%) and ENIG (Electroless Nickel Immersion Gold) UBM (Under Bump Metallurgy) during multiple reflow. Firstly, we formed the flip chip solder bumps on the Ti/Cu/ENIG metallized Si wafer using a stencil printing method. After reflow, the average solder bump diameters were about 130, 160 and 190 μm, respectively. After multiple reflows, Ni3Sn4 intermetallic compound (IMC) layer formed at the Sn-37Pb solder/ENIG UBM interface. On the other hand, in the case of Sn-3.0Ag-0.5Cu solder, (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4 IMCs were formed at the interface. The shear force of the Pb-free Sn-3.0Ag-0.5Cu flip chip solder bump was higher than that of the conventional Sn-37Pb flip chip solder bump. 相似文献
8.
Au/Ni metallization has become increasingly common in microelectronic packaging when Cu pads are joined with Pb-Sn solder.
Recent work has shown that a ternary compound with stoichiometry Au0.5Ni0.5Sn4 redeposits onto the interface during aging, compromising the strength of the joint. In the present work the growth of the
Au0.5Ni0.5Sn4 layer is documented and methods for inhibiting its growth were investigated. It was determined that multiple reflows, both
with and without additional aging, can substantially limit the thickness of the ternary layer. 相似文献
9.
The mechanical alloying (MA) process is considered an alternative approach to produce solder materials. In this study, the
effect of Cu concentration in the ternary Sn-3.5Ag-xCu (x=0.2, 0.7, and 1) solder by MA was investigated. The (Cu,Sn) solid
solution was precipitated as the Cu6Sn5 intermetallic compound (IMC), which was distributed nonuniformly through the microstructure. The Cu6Sn5 IMC, which was present in the SnAgCu solder with high Cu composition, causes the as-milled MA particle to fracture to a smaller
size. Appreciable distinction on morphology of as-milled MA powders with different Cu content was revealed. When the Cu concentration
was low (x=0.2), MA particle aggregated to a spherical ingot with large particle size. For higher Cu concentration (x=0.7
and x=1), the MA particle turned to flakes with smaller particle size. The distinction of the milling mechanism of Sn-3.5Ag-xCu
(x=0.2, 0.7, and 1) solder by the MA process was discussed. An effective approach was developed to reduce the particle size
of the SnAgCu solder from 1 mm down to 10–100 μm by doping the Cu6Sn5 nanoparticle during the MA process. In addition, the differential scanning calorimetry (DSC) results also ensure the compatibility
to apply the solder material for the reflow process. 相似文献
10.
The 0.2Co + 0.1Ni dual additives were used to dope a Sn-3.5Ag solder matrix to modify the alloy microstructure and the solder
joint on an organic solderability preservative (OSP) Cu pad. The refined microstructure of the Sn-3.5Ag-0.2Co-0.1Ni solder
alloy or the reduced β-Sn size was attributed to the depressed undercooling achieved by the Co-Ni addition. After soldering
on the OSP Cu pad, a large Ag3Sn plate was formed at the Sn-3.5Ag/OSP solder joint, whereas it was absent at the Sn-3.5Ag-0.2Co-0.1Ni/OSP solder joints.
With isothermal aging at 150°C, large Ag3Sn plates formed at the Sn-3.5Ag/OSP solder joint were still observed. A coarsened and dispersed Ag3Sn phase was found in the solder joints with Co-Ni additions as well. Compared to Cu6Sn5, the (Co,Ni)Sn2 intermetallic compound showed much lower microhardness values. However, (Co,Ni)Sn2 hardness was comparable to that of the Ag3Sn phase. Pull strength testing of Sn-3.5Ag-0.2Co-0.1Ni/OSP revealed slightly lower values than for Sn-3.5Ag/OSP during aging.
Such results are thought be due to the phase transformation of (Co,Ni)Sn2 to (Cu,Co,Ni)6Sn5. 相似文献
11.
Influence of interfacial reaction layer on reliability of chip-scale package joint from using Sn-37Pb and Sn-8Zn-3Bi solder 总被引:1,自引:0,他引:1
Chung-Hee Yu Kyung-Seob Kim Hyung-Il Kim Hyo-Joeng Jeon 《Journal of Electronic Materials》2005,34(2):161-167
The microstructure of Sn-37Pb and Sn-8Zn-3Bi solders and the full strength of these solders with an Au/Ni/Cu pad under isothermal
aging conditions were investigated. The full strengths tended to decrease as the aging temperature and time increased, regardless
of the properties of the solders. The Sn-8Zn-3Bi had higher full strength than Sn-37Pb. In the Sn-37Pb solder, Ni3Sn4 compounds and irregular-shaped Pb-rich phase were embedded in a β-Sn matrix. The Ni3Sn4 compounds were observed at the interface between the solder and pad. The microstructure of the as-reflowed Sn-8Zn-3Bi solder
mainly consists of the β-Sn matrix scattered with Zn-rich phase. Zinc first reacted with Au and then was transformed to the
AuZn compound. With aging, Ni5Zn21 compounds were formed at the Ni layer. Finally, a Ni5Zn21 phase, divided into three layers, was formed with column-shaped grains, and the thicknesses of the layers were changed. 相似文献
12.
The effects of adding a small amount of Cu into eutectic PbSn solder on the interfacial reaction between the solder and the
Au/Ni/Cu metallization were studied. Solder balls of two different compositions, 37Pb-63Sn (wt.%) and 36.8Pb-62.7Sn-0.5Cu,
were used. The Au layer (1 ± 0.2 μm) and Ni layer (7 ± 1 μm) in the Au/Ni/Cu metallization were deposited by electroplating.
After reflow, the solder joints were aged at 160°C for times ranging from 0 h to 2,000 h. For solder joints without Cu added
(37Pb-63Sn), a thick layer of (Au1−xNix)Sn4 was deposited over the Ni3Sn4 layer after the aging. This thick layer of (Au1−xNix)Sn4 can severely weaken the solder joints. However, the addition of 0.5wt.%Cu (36.8Pb-62.7Sn-0.5Cu) completely inhibited the
deposition of the (Au1−xNix)Sn4 layer. Only a layer of (Cu1-p-qAupNiq)6Sn5 formed at the interface of the Cu-doped solder joints. Moreover, it was discovered that the formation of (Cu1-p-qAupNiq)6Sn5 significantly reduced the consumption rate of the Ni layer. This reduction in Ni consumption suggests that a thinner Ni layer
can be used in Cu-doped solder joints. Rationalizations for these effects are presented in this paper. 相似文献
13.
N. Dariavach P. Callahan J. Liang R. Fournelle 《Journal of Electronic Materials》2006,35(7):1581-1592
Soldering with the lead-free tin-base alloys requires substantially higher temperatures (∼235–250°C) than those (213–223°C)
required for the current tin-lead solders, and the rates for intermetallic compound (IMC) growth and substrate dissolution
are known to be significantly greater for these alloys. In this study, the IMC growth kinetics for Sn-3.7Ag, Sn-0.7Cu, and
Sn-3.8Ag-0.7Cu solders on Cu substrates and for Sn-3.8Ag-0.7Cu solder with three different substrates (Cu, Ni, and Fe-42Ni)
are investigated. For all three solders on Cu, a thick scalloped layer of η phase (Cu6Sn5) and a thin layer of ε phase (Cu3Sn) were observed to form, with the growth of the layers being fastest for the Sn-3.8Ag-0.7Cu alloy and slowest for the Sn-3.7Ag
alloy. For the Sn-3.8Ag-0.7Cu solder on Ni, only a relatively uniform thick layer of η phase (Cu,Ni)6Sn5 growing faster than that on the Cu substrate was found to form. IMC growth in both cases appears to be controlled by grain-boundary
diffusion through the IMC layer. For the Fe-42Ni substrate with the Sn-3.8Ag-0.7Cu, only a very thin layer of (Fe,Ni)Sn2 was observed to develop. 相似文献
14.
The aim of the present work is to develop a comparative evaluation of the microstructural and mechanical deformation behavior of Sn-Ag-Cu (SAC) solders with the minor addition of 0.05 wt.% Ni. Test results showed that, by adding 0.05Ni element into SAC solders, generated mainly small rod-shaped (Cu,Ni)6Sn5 intermetallic compounds (IMCs) inside the β-Sn phase. Moreover, increasing the Ag content and adding Ni could result in the change of the shape and size of the IMC precipitate. Hence, a significant improvement is observed in the mechanical properties of SAC solders with increasing Ag content and Ni addition. On the other hand, the tensile results of Ni-doped SAC solders showed that both the yield stress and ultimate tensile strengths decrease with increasing temperature and with decreasing strain rate. This behavior was attributed to the competing effects of work hardening and dynamic recovery processes. The Sn-2.0Ag-0.5Cu-0.05Ni solder displayed the highest mechanical properties due to the formation of hard (Cu,Ni)6Sn5 IMCs. Based on the obtained stress exponents and activation energies, it is suggested that the dominant deformation mechanism in SAC (205)-, SAC (0505)- and SAC (0505)-0.05Ni solders is pipe diffusion, and lattice self-diffusion in SAC (205)-0.05Ni solder. In view of these results, the Sn-2.0Ag-0.5Cu-0.05Ni alloy is a more reliable solder alloy with improved properties compared with other solder alloys tested in the present work. 相似文献
15.
The eutectic Sn-Ag solder alloy is one of the candidates for the Pb-free solder, and Sn-Pb solder alloys are still widely
used in today’s electronic packages. In this tudy, the interfacial reaction in the eutectic Sn-Ag and Sn-Pb solder joints
was investigated with an assembly of a solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. In the Sn-3.5Ag solder joints reflowed at 260°C, only the (Ni1−x,Cux)3Sn4 intermetallic compound (IMC) formed at the solder/Ni interface. For the Sn-37Pb solder reflowed at 225°C for one to ten cycles,
only the (Ni1−x,Cux)3Sn4 IMC formed between the solder and the Ni/Cu under-bump metallization (UBM). Nevertheless, the (Cu1−y,Niy)6Sn5 IMC was observed in joints reflowed at 245°C after five cycles and at 265°C after three cycles. With the aid of microstructure
evolution, quantitative analysis, and elemental distribution between the solder and Ni/Cu UBM, it was revealed that Cu content
in the solder near the solder/IMC interface played an important role in the formation of the (Cu1−y,Niy)6Sn5 IMC. In addition, the diffusion behavior of Cu in eutectic Sn-Ag and Sn-Pb solders with the Ni/Cu UBM were probed and discussed.
The atomic flux of Cu diffused through Ni was evaluated by detailed quantitative analysis in an electron probe microanalyzer
(EPMA). During reflow, the atomic flux of Cu was on the order of 1016−1017 atoms/cm2sec in both the eutectic Sn-Ag and Sn-Pb systems. 相似文献
16.
Yoon Jeong-Won Kim Sang-Won Koo Ja-Myeong Kim Dae-Gon Jung Seung-Boo 《Journal of Electronic Materials》2004,33(10):1190-1199
The interfacial reactions between two Sn-Cu (Sn-0.7Cu and Sn-3Cu, wt.%) ball-grid-array (BGA) solders and the Au/Ni/Cu substrate
by solid-state isothermal aging were examined at temperatures between 70°C and 170°C for 0 to 100 days. For the Sn-0.7Cu solder,
a (Cu,Ni)6Sn5 layer was observed in the samples aged at 70–150°C. After isothermal aging at 170°C for 50 days, the solder/Ni interface
exhibited a duplex structure of (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4. For the Sn-3Cu solder, only the (Cu,Ni)6Sn5 layer was formed in all aged samples. Compared to these two Sn-Cu solders, the Cu content in the (Cu,Ni)6Sn5 layer formed at the interface increased with the Cu concentration in the Sn-xCu solders. And, the shear strength was measured
to evaluate the effect of the interfacial reactions on the mechanical reliability as a function of aging conditions. The shear
strength significantly decreased after aging for 1 day and then remained nearly unchanged by further prolonged aging. In all
the samples, the fracture always occurred in the bulk solder. Also, we studied the electrical property of Cu/Sn-3Cu/Cu BGA
packages with the number of reflows. The electrical resistivity increased with the number of reflows because of an increase
of intermetallic compound (IMC) thickness. 相似文献
17.
Hiroshi Nishikawa Jin Yu Piao Tadashi Takemoto 《Journal of Electronic Materials》2006,35(5):1127-1132
The interfacial reaction between Sn-0.7mass%Cu-(Ni) solders and a Cu substrate was investigated to reveal the effect of the
addition of Ni to Sn-Cu solder on the formation of intermetallic compounds (IMCs). Sn-0.7Cu-xNi solders (x=0, 0.05, 0.1, 0.2
mass%) were prepared. For the reflow process, specimens were heated in a radiation furnace at 523 K for 60 sec, 300 sec, and
720 sec to estimate the interfacial reaction between the molten solder and Cu substrate. Then, for the aging process, some
specimens were heat-treated in an oil bath at 423 K for 168 h and 504 h. The cross sections of soldered specimens were observed
to measure the dissolution thickness of the Cu substrate and the thickness of the IMC and to investigate the microstructures
of IMC. The results showed that, just after the reflow process, the dissolution thickness of the Cu substrate increased with
the increase of Ni content in the Sn-0.7Cu-xNi solder and the thickness of the IMC between the solder and Cu substrate was
the minimum in the Sn-0.7Cu-0.05Ni solder. After the aging process, the IMC grew with the increase of aging time. In the case
of 0.05% Ni, the IMC thickness was the thinnest regardless of aging time. It is clear that 0.05% Ni addition to Sn-0.7Cu solder
very effectively inhibits the formation and growth of the IMC between solder and Cu substrate. Electron probe microanalysis
of the IMC showed that the IMC layer in the Sn-0.7Cu-Ni solder contained Ni, and the IMC was expressed as (Cu1−y
,Ni
y
)6Sn5. 相似文献
18.
T. Laurila V. Vuorinen T. Mattila J. K. Kivilahti 《Journal of Electronic Materials》2005,34(1):103-111
Interfacial reactions between SnPbAg, SnAg, and SnAgCu solders and Ni/Au surface finish on printed wiring board and especially
the redeposition of AuSn4 intermetallic compound have been investigated. The following major results were obtained. The first phase to form during
soldering in the (SnPbAg)/Ni/Au and the (SnAg)/Ni/Au systems was Ni3Sn4. During the subsequent solid-state annealing, the redeposition of AuSn4 as (Au,Ni)Sn4 occurred in both systems. This was explained with the help of the concept of local equilibrium and the corresponding ternary
phase diagrams. It was concluded that the stabilizing effect of Ni on the (Au,Ni)Sn4 provided the driving force for the redeposition. Contrarily, when the solder alloy contained some Cu, the first intermetallic
to form was (Cu,Ni,Au)6Sn5 and no redeposition of AuSn4 was observed. Thus, a very small addition of Cu to the Sn-rich solder alloys changed the behavior of the interconnection
system completely. This behavior was explained thermodynamically by using Cu-Ni-Sn and Au-Cu-Sn ternary phase diagrams. The
growth kinetics of the interfacial reaction products in the three systems was observed to be somewhat different. The reasons
for the observed differences are also discussed. 相似文献
19.
Chien-Sheng Huang Jenq-Gong Duh Yen-Ming Chen Jyh-Hwa Wang 《Journal of Electronic Materials》2003,32(2):89-94
Flip-chip interconnection technology plays a key role in today’s electronics packaging. Understanding the interfacial reactions
between the solder and under-bump metallization (UBM) is, thus, essential. In this study, different thicknesses of electroplated
Ni were used to evaluate the phase transformation between Ni/Cu under-bump metallurgy and eutectic Sn-Pb solder in the 63Sn-37Pb/Ni/Cu/Ti/Si3N4/Si multilayer structure for the flip-chip technology. Interfacial reaction products varied with reflow times. After the first
reflow, layered (Ni1−x,Cux)3Sn4 was found between solder and Ni. However, there were two interfacial reaction products formed between solders and the UBM
after three or more times reflow. The layered (Ni1−x,Cux)3Sn4 was next to the Ni/Cu UBM. The islandlike (Cu1−y,Niy)6Sn5 intermetallic compound (IMC) could be related to the Ni thickness and reflow times. In addition, the influence of Cu contents
on phase transformation during reflow was also studied. 相似文献
20.
C. E. Ho Y. W. Lin S. C. Yang C. R. Kao D. S. Jiang 《Journal of Electronic Materials》2006,35(5):1017-1024
The volume difference between the various types of solder joints in electronic devices can be enormous. For example, the volume
difference between a 760-μm ball grid array solder joint and a 75-μm flip-chip solder joint is as high as 1000 times. Such
a big difference in volume produces a pronounced solder volume effect. This volume effect on the soldering reactions between
the Sn3AgxCu (x=0.4, 0.5, or 0.6 wt.%) solders and Ni was investigated. Three different sizes of solder spheres (300, 500,
and 760 μm in diameter) were soldered onto Ni soldering pads. Both the Cu concentration and the solder volume had a strong
effect on the type of the reaction products formed. In addition, (Cu,Ni)6Sn5 massively spalled from the interface under certain conditions, including smaller joints and those with lower Cu concentration.
We attributed the massive spalling of (Cu,Ni)6Sn5 to the decrease of the available Cu in the solders. The results of this study suggest that Cu-rich SnAgCu solders can be
used to prevent this massive spalling. 相似文献