共查询到20条相似文献,搜索用时 31 毫秒
1.
Effect of Cr additions on interfacial reaction between the Sn-Zn-Bi solder and Cu/electroplated Ni substrates 总被引:2,自引:0,他引:2
Intermetallic compounds (IMCs) growth on the Sn-8Zn-3Bi (-Cr) solder joints with Cu and electroplated Ni substrates was investigated after aging at 150 °C. It was found that the IMCs were the Cu5Zn8 and Ni5Zn21 at the solder/Cu and solder/Ni interface, respectively. The IMCs growth rate at the Sn-8Zn-3Bi-Cr/Cu and Ni interface was slower than that at Sn-8Zn-3Bi/Cu interface (about 1/2 times) and Sn-8Zn-3Bi/Ni interface (about 1/4 times) during aging. The reason may be that Cr reacts with Zn and forms the Sn-Zn-Cr phase which block the diffusion of Zn atom to the interface and slow down the IMCs growth rate. 相似文献
2.
The thermal property of lead-free Sn-8.55Zn-1Ag-XAl solder alloys and their wetting interaction with Cu 总被引:1,自引:0,他引:1
The wetting behaviors between the quaternary Sn-8.55Zn-1Ag-XAl solder alloys and Cu have been investigated with the wetting
balance method. The Al contents, x, of the quaternary solder alloys investigated were 0.01–0.45 wt.%. The results of differential
scanning calorimeter (DSC) analysis indicate that the solders exhibit a solid-liquid coexisting range of about 7–10°C. The
solidus temperature of the quaternary Sn-8.55Zn-1Ag-XAl solder alloys is about 198.2°C, while the liquidus temperatures are
205–207°C. The experimental results showed that the wettability of the Sn-8.55Zn-1Ag-XAl solder alloys is improved by the
addition of Al. The mean maximum wetting force of the solders with Cu is within 0.75–1.18 mN and the mean wetting time is
around 1.0–1.1 sec, better than the ∼1.3 sec of eutectic Sn-9Zn and Sn-8.55Zn-1Ag solder alloys. The addition of Al also depresses
the formation of ε-Ag-Zn compounds at the interface between Sn-8.55Zn-1Ag-XAl solders and copper. 相似文献
3.
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
4.
In this work, the shear strengths and the interfacial reactions of Sn-9Zn, Sn-8Zn-1Bi, and Sn-8Zn-3Bi (wt.%) solders with
Au/Ni/Cu ball grid array (BGA) pad metallization were systematically investigated after extended reflows. Zn-containing Pb-free
solder alloys were kept in molten condition (240°C) on the Au/electrolytic Ni/Cu bond pads for different time periods ranging
from 1 min. to 60 min. to render the ultimate interfacial reaction and to observe the consecutive shear strength. After the
shear test, fracture surfaces were investigated by scanning electron microscopy equipped with an energy dispersive x-ray spectrometer.
Cross-sectional studies of the interfaces were also conducted to correlate with the fracture surfaces. The solder ball shear
load for all the solders during extended reflow increased with the increase of reflow time up to a certain stage and then
decreased. It was found that the formation of thick Ni-Zn intermetallic compound (IMC) layers at the solder interface of the
Au/electrolytic Ni/Cu bond pad with Sn-Zn(-Bi) alloys deteriorated the mechanical strength of the joints. It was also noticed
that the Ni-Zn IMC layer was larger in the Sn-Zn solder system than that in the other two Bi-containing solder systems. 相似文献
5.
Law C.M.T. Wu C.M.L. Yu D.Q. Li M. Chi D.Z. 《Advanced Packaging, IEEE Transactions on》2005,28(2):252-258
Rare earth (RE) elements, primarily La and Ce, were doped in Sn-Zn solder to improve its properties such as wettability. The interfacial microstructure evolution and shear strength of the Sn-9Zn and Sn-9Zn-0.5RE (in wt%) solder bumps on Au/Ni/Cu under bump metallization (UBM) in a ball grid array (BGA) were investigated after thermal aging at 150 /spl deg/C for up to 1000 h. In the as-reflowed Sn-9Zn solder bump, AuSn/sub 4/ intermetallic compounds (IMCs) and Au-Zn circular IMCs formed close to the solder/UBM interface, together with the formation of a Ni-Zn-Sn ternary IMC layer of about 1 /spl mu/m in thickness. In contrast, in the as-reflowed Sn-9Zn-0.5RE solder bump, a spalled layer of Au-Zn was formed above the Ni layer. Sn-Ce-La and Sn-Zn-Ce-La phases were found near the interface at positions near the surface of the solder ball. Upon thermal aging at 150 /spl deg/C, the concentration of Zn in the Ni-Zn-Sn ternary layer of Sn-9Zn increased with aging time. For Sn-9Zn-0.5RE, the Au-Zn layer began to dissolve after 500 h of thermal aging. The shear strength of the Sn-9Zn ball was decreased after the addition of RE elements, although it was still higher than that of the Sn-37Pb and Sn-36Pb-2Ag Pb-bearing solders. The fracture mode of the Sn-9Zn system was changed from ductile to partly brittle after adding the RE elements. This is mainly due to the presence of the brittle Au-Zn layer. 相似文献
6.
7.
The microstructures and mechanical properties of Sn-8.55Zn-0.5Ag-0.45Al-yGa (wt.%) lead-free solders were investigated. The
y content of the solders investigated was 0.5–3.0 wt.%. The results indicate that Ga exhibits prominent influence in the microstructure
as well as mechanical properties of the solders. By increasing Ga, the fraction of the Sn/Zn eutectic region decreases and
the Sn-matrix region increases. An increase in the Ga content from 0.5 wt.% to 2.0 wt.% enhances the tensile strength while
degrading the ductility. The mechanical properties and differential scanning calorimetry (DSC) behavior have been compared
with that of the 63Sn-37Pb solder. Gallium lowers the melting point of the Sn-8.55Zn-0.5Ag-0.45Al-yGa solders. The Sn-8.55Zn-0.5Ag-0.45Al-0.5Ga
solders exhibit greater tensile strength and better ductility than the 63Sn-37Pb solder. 相似文献
8.
The effect of Ag content on the wetting behavior of Sn-9Zn-xAg on aluminum and copper substrates during soldering, as well as the mechanical properties and electrochemical corrosion
behavior of Al/Sn-9Zn-xAg/Cu solder joints, were investigated in the present work. Tiny Zn and coarsened dendritic AgZn3 regions were distributed in the Sn matrix in the bulk Sn-9Zn-xAg solders, and the amount of Zn decreased while that of AgZn3 increased with increasing Ag content. The wettability of Sn-9Zn-1.5Ag solder on Cu substrate was better than those of the
other Sn-9Zn-xAg solders but worse than that of Sn-9Zn solder. The wettability of Sn-9Zn-1.5Ag on the Al substrate was also better than
those of the other Sn-9Zn-xAg solders, and even better than that of Sn-9Zn solder. The Al/Sn-9Zn/Cu joint had the highest shear strength, and the shear
strength of the Al/Sn-9Zn-xAg/Cu (x = 0 wt.% to 3 wt.%) joints gradually decreased with increasing Ag content. The corrosion resistance of the Sn-9Zn-xAg solders in Al/Sn-9Zn-xAg/Cu joints in 5% NaCl solution was improved compared with that of Sn-9Zn. The corrosion potential of Sn-9Zn-xAg solders continuously increased with increasing Ag content from 0 wt.% to 2 wt.% but then decreased for Sn-9Zn-3Ag. The
addition of Ag resulted in the formation of the AgZn3 phase and in a reduction of the amount of the eutectic Zn phase in the solder matrix; therefore, the corrosion resistance
of the Al/Sn-9Zn-xAg/Cu joints was improved. 相似文献
9.
Seung Wook Yoon Chang Jun Park Sung Hak Hong Jong Tae Moon Ik Seong Park Heung Sup Chun 《Journal of Electronic Materials》2000,29(10):1233-1240
Chip scale packages (CSP) have essential solder joint quality problems, and a board level reliability is a key issue in design
and development of the CSP type packages. There has been an effort to eliminate Pb from solder due to its toxicology. To evaluate
the various solder balls in CSP package applications, Pb-free Sn-Ag-X (X=In, Cu, Bi) and Sn-9Zn-1Bi-5In solder balls were
characterized by melting behavior, phases, interfacial reaction, and solder joint reliability. For studying joint strength
between solders and under bump metallurgy (UBM) systems, various UBMs were prepared by electroplating and electroless plating.
After T/C (temperature cycle) test, Sn3.5Ag8.5In solder was partially corroded and its shape was distorted. This phenomenon
was observed in a Sn3Ag10In 1Cu solder system, too. Their fractured surface, microstructure of solder joint interface, and
of bulk solder ball were examined and analyzed by optical microscopy, SEM and EDX. To simulate the real surface mounting condition
and evaluate the solder joint reliability on board level, Daisy chain test samples using LF-CSP packages were prepared with
various Pb-free solders, then a temperature cycle test (−65∼ 150°C) was performed. All tested Pb-free solders showed better
board level solder joint reliability than Sn-36Pb-2Ag. Sn-3.5Ag-0.7Cu and Sn-9Zn-1Bi-5In solders showed 35%, 100% superior
solder joint reliability than Sn-36Pb-2Ag solder ball, respectively. 相似文献
10.
This work investigates the effect of reflow and the thermal aging process on the microstructural evolution and microhardness
of five types of Sn-Ag based lead-free solder alloys: Sn-3.7Ag, Sn-3.7Ag-1Bi, Sn-3.7Ag-2Bi, Sn-3.7Ag-3Bi, and Sn-3.7Ag-4Bi.
The microhardness and microstructure of the solders for different cooling rates after reflow at 250°C and different thermal
aging durations at 150°C for air-cooled samples have been studied. The effect of Bi is discussed based on the experimental
results. It was found that the microhardness increases with increasing Bi addition to Sn-3.7Ag solder regardless of reflow
or thermal aging process. Scanning electron microscopy images show the formation of Ag3Sn particles, Sn-rich phases, and precipitation of Bi-rich phases in different solders. The increase of microhardness with
Bi addition is due to the solution strengthening and precipitation strengthening provided by Bi in the solder. The trend of
decrease in microhardness with increasing duration of thermal aging was observed. 相似文献
11.
Jong-Kai Lin De Silva A. Frear D. Guo Y. Hayes S. Jin-Wook Jang Li L. Mitchell D. Yeung B. Zhang C. 《Electronics Packaging Manufacturing, IEEE Transactions on》2002,25(4):300-307
A variety of Pb-free solders and under bump metallurgies (UBMs) was investigated for flip chip packaging applications. The result shows that the Sn-0.7Cu eutectic alloy has the best fatigue life and it possess the most desirable failure mechanism in both thermal and isothermal mechanical tests regardless of UBM type. Although the electroless Ni-P UBM has a much slower reaction rate with solders than the Cu UBM, room temperature mechanical fatigue is worse than on the Cu UBM when coupled with either Sn-3.8Ag-0.7Cu or Sn-3.5Ag solder. The Sn-37Pb solder consumes less Cu UBM than all other Pb-free solders during reflow. However, Sn-37Pb consumes more Cu after solid state annealing. Studies on aging, tensile, and shear mechanical properties show that the Sn-0.7Cu alloy is the most favorable Pb-free solder for flip chip applications. When coupled with underfill encapsulation in a direct chip attach (DCA) test device, the Sn-0.7Cu bump with Cu UBM exhibits a characteristic life or 5322 cycles under -55/spl deg/C/+150/spl deg/C air-to-air thermal cycling condition. 相似文献
12.
Wetting interaction between Sn-Zn-Ag solders and Cu 总被引:4,自引:0,他引:4
The wetting interaction of Sn-(7.1–9)Zn-(0–3)Ag solders with Cu was investigated from 230°C to 300°C. The wetting time, wetting
forces, and activation energy of the wetting reaction were studied. The wetting time decreases with increasing temperature
and increases with Ag content. The wetting force exhibits a disproportional correlation to temperature rise, while no trend
was observed with respect to Ag content. The wetting behavior was ascribed to the interaction between Cu and Zn. The AgZn3 compound was formed at the interface when the solder contains 0.3% Ag and above, while it was formed within the bulk solder
at 2% Ag and above. 相似文献
13.
通过成分设计形成了Sn-Zn-Bi-Ag系钎料合金。针对微电子产业的应用要求研究了钎料的物理性能,分析了Sn-Zn-Bi-Ag系钎料中合金元素对钎料物理性能的影响。发现:Sn-Zn-Bi-Ag系钎料的合金元素中Bi、Ag含量(质量分数)的增加会使钎料的密度增大,而Zn含量对钎料的密度影响不大。Zn含量5.0%~6.5%,Bi含量1.5%~3.0%,Ag含量0.5%~0.8%范围的Sn-Zn-Bi-Ag钎料具有较好的润湿性能。Sn-Zn-Bi-Ag系钎料中Bi含量不高时,钎料的电阻率均比传统Sn-37Pb钎料小。随着Bi含量的增加,钎料的电阻率有明显增大的趋势。 相似文献
14.
Tao-Chih Chang Min-Hsiung Hon Moo-Chin Wang Dong-Yih Lin 《Advanced Packaging, IEEE Transactions on》2004,27(1):158-164
The effect of thermal cycling on the adhesion strength of the Sn-9Zn-xAg-Cu interface has been investigated by using pull-off tester, X-ray diffractometer, scanning electron microscope and energy dispersive spectrometer. The Sn-9Zn-xAg lead-free solders offer a better thermal cyclic resistance than the 63Sn-37Pb and Sn-9Zn solder alloys. The adhesion strength of the Sn-9Zn-Cu interface increases from 4.4 /spl plusmn/ 0.4 MPa to 13.8 /spl plusmn/ 0.9 MPa with increasing the thermal cycles from zero to three times but it decreases to 8.5 /spl plusmn/ 0.8 MPa for five cycles. The Sn-9Zn-xAg solder alloys (x=0.5, 2.5, and 3.5 wt%) have a similar tendency and the maximum adhesion strength of 21.41 /spl plusmn/ 1.5 MPa for the Sn-9Zn-2.5Ag solder alloy has been obtained after three thermal cycles. The adhesion strength of the Sn-9Zn-1.5Ag-Cu interface increases from 7.8 /spl plusmn/ 0.6 to 16.6 /spl plusmn/ 0.9 MPa with increasing the thermal cycles from 0 to 5 times. 相似文献
15.
Dissolution behavior of Cu and Ag substrates in molten solders 总被引:1,自引:0,他引:1
This study investigated the dissolution behavior of Cu and Ag substrates in molten Sn, Sn-3.5Ag, Sn-4.0Ag-0.5Cu, Sn-8.6Zn
and Sn-8.55Zn-0.5Ag-0.1Al-0.5Ga lead-free solders as well as in Sn-37Pb solder for comparison at 300, 350, and 400°C. Results
show that Sn-Zn alloys have a substantially lower dissolution rate of both Cu and Ag substrates than the other solders. Differences
in interfacial intermetallic compounds formed during reaction and the morphology of these compounds strongly affected the
substrate dissolution behavior. Soldering temperature and the corresponding solubility limit of the substrate elements in
the liquid solder also played important roles in the interfacial morphology and dissolution rate of substrate. 相似文献
16.
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
17.
M. J. Rizvi Y. C. Chan C. Bailey H. Lu M. N. Islam B. Y. Wu 《Journal of Electronic Materials》2005,34(8):1115-1122
The wettability of newly developed Sn-2.8Ag-0.5Cu-1.0Bi lead-free solder on Cu and Ni substrates was assessed through the
wetting balance tests. The wettability assessment parameters such as contact angle (ϑc) and maximum wetting force (Fw) were documented for three solder bath temperatures with three commercial fluxes, namely, no-clean (NC), nonactivated (R),
and water-soluble organic acid flux (WS). It was found that the lead-free Sn-2.8Ag-0.5Cu-1.0Bi solder exhibited less wetting
force, i.e., poorer wettability, than the conventional Sn-37Pb solder for all flux types and solder bath temperatures. The
wettability of Sn-2.8Ag-0.5Cu-1.0Bi lead-free solder on Cu substrate was much higher than that on Ni substrate. Nonwetting
for Sn-2.8Ag-0.5Cu-1.0Bi and Sn-Pb solders on Ni substrate occurred when R-type flux was used. A model was built and simulations
were performed for the wetting balance test. The simulation results were found very close to the experimental results. It
was also observed that larger values of immersion depth resulted in a decrease of the wetting force and corresponding meniscus
height, whereas the increase in substrate perimeter enhanced the wettability. The wetting reactions between the solder and
Cu/Ni substrates were also investigated, and it was found that Cu atoms diffused into the solder through the intermetallic
compounds (IMCs) much faster than did the Ni atoms. Rapid formation of IMCs inhibited the wettability of Sn-2.8Ag-0.5Cu-1.0Bi
solder compared to the Sn-Pb solder. 相似文献
18.
Electrochemical corrosion behaviors of Sn-9Zn-3Bi-xCr solder in 3.5 wt.% NaCl solution were investigated in this work through potentiodynamic polarization measurements. After
electrochemical testing, fracture surfaces were investigated by scanning electron microscopy, energy-dispersive x-ray spectroscopy,
and x-ray diffractometry. The results show that adding a small amount of Cr can improve the corrosion resistance of Sn-9Zn-3Bi-xCr solder. The corrosion potential of Sn-9Zn-3Bi solder is −1.251 V. For Sn-9Zn-3Bi-0.5Cr solder, it is −1.200 V. The corrosion
potential increased when raising the Cr content, and the Sn-9Zn-3Bi-0.5Cr solder showed the best corrosion resistance. After
polarization, a passivation film covered the surface of the Cr-bearing solders. The higher the Cr content, the more compact
the passivation film. Long-term aging worsened the corrosion resistance. After 4 days of aging, the corrosion potential of
Sn-9Zn-3Bi solder was −1.254 V. After 9 days, it was −1.268 V. 相似文献
19.
The specific heat capacities (C
p) of Sn-Zn-based solders and Sn-Ag-Cu solders have been studied using differential scanning calorimetry. The procedure of
measuring the specific heat capacity followed the standard test method designed by the American Society for Testing and Materials
(ASTM) E1269-05. The results of this work are lists of specific heat capacities of Sn-9Zn, Sn-9Zn-xAg (x = 0.1, 0.5, 1, 2, and 3), Sn-9Zn-0.5Ag-yAl (y = 0.1, 0.2, and 0.5), Sn-9Zn-0.5Ag-yGa (y = 0.1, 0.2, and 0.5), Sn-8.5Zn-0.5Ag-0.01Al-0.1Ga, and Sn-zAg-0.5Cu (z = 1.0, 2.0, 3.0, and 3.5). The study also found that C
p increased with increasing heating temperature. Furthermore, the lead-free solders investigated have a higher specific heat
capacity than the traditional Sn-37Pb solder. Among the studied lead-free solders, Sn-3.5Ag-0.5Cu has the lowest C
p and Sn-9Zn-0.1Ag has the highest C
p. Increased silver content in the Sn-9Zn-xAg and Sn-xAg-0.5Cu solder alloys was also found to effectively lower their C
p. 相似文献
20.
An investigation of Sn pest in pure Sn and Sn-based solders 总被引:1,自引:0,他引:1
Weiqun Peng 《Microelectronics Reliability》2009,49(1):86-118
Five solders Sn-0.7Cu, Sn-3.4Ag-0.8Cu, Sn-3.5Ag, Sn-36Pb-2Ag, and pure Sn, and two mobile phone boards were tested at low temperatures for tin pest. The samples were stored at −196 °C for 50 h, −40 °C for 4 years, and finally −17 °C for 1.5 years. Tin pest was observed in pure tin but not in any of the solder alloys or the boards tested. It is suggested that the mechanical properties of tin-based solders play a key role in tin pest formation. Any factor that strengthens the materials can increase the resistance to tin pest. Influential factors such as solder composition, test temperature, and types of alloys are discussed. 相似文献