共查询到20条相似文献,搜索用时 15 毫秒
1.
The electromigration-induced failure of Sn95/Sb5 flip chip solder bumps was investigated. The failure of the joints was found
at the cathode/chip side after current stressing with a density of 1×104 A/cm2 at 150°C for 13 sec. The growth of intermetallic compounds (IMCs) was observed at the anode side after current stressing.
Voids were found near the current crowding area in the cathode/chip side, and the (Cu,Ni)6Sn5 IMC at the cathode/chip end was transformed into the Sn phase. The failure mechanism for Sn95/Sb5 flip chip solder joint
is proposed in this paper. 相似文献
2.
Lead-free solder bumps have been widely used in current flip-chip technology (FCT) due to environmental issues. Solder joints
after temperature cycling tests were employed to investigate the interfacial reaction between the Ti/Ni/Cu under-bump metallization
and Sn-Ag-Cu solders. The interfacial morphology and quantitative analysis of the intermetallic compounds (IMCs) were obtained
by electron probe microanalysis (EPMA) and field emission electron probe microanalysis (FE-EPMA). Various types of IMCs such
as (Cu1−x,Agx)6Sn5, (Cu1−y,Agy)3Sn, and (Ag1−z,Cuz)3Sn were observed. In addition to conventional I–V measurements by a special sample preparation technique, a scanning electron
microscope (SEM) internal probing system was introduced to evaluate the electrical characteristics in the IMCs after various
test conditions. The electrical data would be correlated to microstructural evolution due to the interfacial reaction between
the solder and under-bump metallurgy (UBM). This study demonstrated the successful employment of an internal nanoprobing approach,
which would help further understanding of the electrical behavior within an IMC layer in the solder/UBM assembly. 相似文献
3.
Flip-chip technology with the layout of ball grid array has been widely used in today’s microelectronics industry. The elemental
distribution in the edge of the solder bump is crucial for its correlation with the bump strength. In this study, Ni/Cu under-bump
metallization (UBM) was used to evaluate the intermetallic compound (IMC) formation in the edge of the solder bump between
the UBM and eutectic Sn-Pb solder in the 63Sn-37Pb/Ni/Cu/Ti/Si3N4/Si multilayer structure. During reflows, layered-type (Ni1−xCux)3Sn4 and island-like (Cu1−yNiy)6Sn5 IMCs formed in the interface between the solder and UMB, while only the (Cu1−yNiy)6Sn5 IMC was observed in the sideway of the Ni/Cu UBM. After high-temperature storage (HTS) at 150°C for 1,000 h, both (Cu1−yNiy)6Sn5 and (Cu1−zNiz)3Sn were found in the sideway of the Ni/Cu UBM. Two other IMCs, (Ni1−xCux)3Sn4 and (Cu1−yNiy)6Sn5, formed in the interface between the solder and UBM. The growth of the (Cu1−yNiy)6Sn5 IMC was relatively fast during HTS. 相似文献
4.
In this work we studied the initial microstructure and microstructural evolution of eutectic Au-Sn solder bumps on Cu/electroless
Ni/Au. The solder bumps were 150–160 m in diameter and 45–50 m tall, reflowed on Cu/electroless Ni/Au, and then aged at 200°C
for up to 365 days. In addition, Au-Ni-Sn-alloys were made and analyzed to help identify the phases that appear at the interface
during aging. The detailed interfacial microstructure was observed using a transmission electron microscope (TEM). The results
show that the introduction of Au from the substrate produces large islands of-phase in the bulk microstructure during reflow.
Two Au-Ni-Sn compounds are formed at the solder/substrate interface and grow slowly during aging. The maximum solubility of
Ni in the—phase was measured to be about 1 at.% at 200°C, while Ni in the-phase is more than 20 at.%. The electroless Ni layer
is made of several sublayers with slightly different compositions and microstructures. There is, in addition, an amorphous
interaction layer at the solder/electroless Ni interface. 相似文献
5.
Ying-Chao Hsu Tung-Liang Shao Ching-Jung Yang Chih Chen 《Journal of Electronic Materials》2003,32(11):1222-1227
This paper investigates the electromigration-induced failures of SnAg3.8Cu0.7 flip-chip solder joints. An under-bump metallization
(UBM) of a Ti/Cr-Cu/Cu trilayer was deposited on the chip side, and a Cu/Ni(P)/Au pad was deposited on the BT board side.
Electromigration damages were observed in the bumps under a current density of 2×104 A/cm2 and 1×104 A/cm2 at 100°C and 150°C. The failures were found to be at the cathode/chip side, and the current crowding effect played an important
role in the failures. Copper atoms were found to move in the direction of the electron flow to form intermetallic compounds
(IMCs) at the interface of solder and pad metallization as a result of current stressing. 相似文献
6.
Nickel-based under bump metallization (UBM) has been widely used as a diffusion barrier to prevent the rapid reaction between
the Cu conductor and Sn-based solders. In this study, joints with and without solder after heat treatments were employed to
evaluate the diffusion behavior of Cu in the 63Sn-37Pb/Ni/Cu/Ti/Si3N4/Si multilayer structure. The atomic flux of Cu diffused through Ni was evaluated from the concentration profiles of Cu in
solder joints. During reflow, the atomic flux of Cu was on the order of 1015–1016 atoms/cm2s. However, in the assembly without solder, no Cu was detected on the surface of Ni even after ten cycles of reflow. The diffusion
behavior of Cu during heat treatments was studied, and the soldering-process-induced Cu diffusion through Ni metallization
was characterized. In addition, the effect of Cu content in the solder near the solder/intermetallic compound (IMC) interface
on interfacial reactions between the solder and the Ni/Cu UBM was also discussed. It is evident that the (Cu,Ni)6Sn5 IMC might form as the concentration of Cu in the Sn-Cu-Ni alloy exceeds 0.6 wt.%. 相似文献
7.
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
8.
Chien-Sheng Huang Jenq-Gong Duh Yen-Ming Chen 《Journal of Electronic Materials》2003,32(12):1509-1514
Several international legislations recently banned the use of Pb because of environmental concerns. The eutectic Sn-Ag solder
is one of the promising candidates to replace the conventional Sn-Pb solder primarily because of its excellent mechanical
properties. In this study, interfacial reaction of the eutectic Sn-Ag and Sn-Pb solders with Ni/Cu under-bump metallization
(UBM) was investigated with a joint assembly of solder/Ni/Cu/Ti/Si3N4/Si multilayer structures. After reflows, only one (Ni,Cu)3Sn4 intermetallic compound (IMC) with faceted and particlelike grain feature was found between the solder and Ni. The thickness
and grain size of the IMC increased with reflow times. Another (Cu,Ni)6Sn5 IMC with a rod-type grain formed on (Ni,Cu)3Sn4 in the interface between the Sn-Pb solder and the Ni/Cu UBM after more than three reflow times. The thickness of the (Ni,Cu)3Sn4 layer formed in the Sn-Pb system remained almost identical despite the numbers of reflow; however, the amounts of (Cu,Ni)6Sn5 IMC increased with reflow times. Correlations between the IMC morphologies, Cu diffusion behavior, and IMC transformation
in these two solder systems will be investigated with respect to the microstructural evolution between the solders and the
Ni/Cu UBM. The morphologies and grain-size distributions of the (Ni,Cu)3Sn4 IMC formed in the initial stage of reflow are crucial for the subsequent phase transformation of the other IMC. 相似文献
9.
Mechanism of interfacial reaction for the Sn-Pb solder bump with Ni/Cu under-bump metallization in flip-chip technology 总被引:1,自引:0,他引:1
Guh-Yaw Jang Chien-Sheng Huang Li-Yin Hsiao Jenq-Gong Duh Hideyuki Takahashi 《Journal of Electronic Materials》2004,33(10):1118-1129
Nickel-based under-bump metallization (UBM) has been widely used in flip-chip technology (FCT) because of its slow reaction
rate with Sn. In this study, solder joints after reflows were employed to investigate the mechanism of interfacial reaction
between the Ni/Cu UBM and eutectic Sn-Pb solder. After deliberate quantitative analysis with an electron probe microanalyzer
(EPMA), the effect of Cu content in solders near the interface of the solder/intermetallic compound (IMC) on the interfacial
reaction could be probed. After one reflow, only one layered (Ni1−x,Cux)3Sn4 with homogeneous composition was found between the solder bump and UBM. However, after multiple reflows, another type of
IMC, (Cu1−y,Niy)6Sn5, formed between the solder and (Ni1−x,Cux)3Sn4. It was observed that if the concentration of Cu in the solders near the solder/IMC interface was higher than 0.6 wt.%, the
(Ni1−x,Cux)3Sn4 IMC would transform into the (Cu1−y,Niy)6Sn5 IMC. The Cu contents in (Ni1−x,Cux)3Sn4 were altered and not uniformly distributed anymore. With the aid of microstructure evolution, quantitative analysis, elemental
distribution by x-ray color mapping, and related phase equilibrium of Sn-Ni-Cu, the reaction mechanism of interfacial phase
transformation between the Sn-Pb solder and Ni/Cu UBM was proposed. 相似文献
10.
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
11.
Investigation of interfacial reaction between Sn-Ag eutectic solder and Au/Ni/Cu/Ti thin film metallization 总被引:3,自引:0,他引:3
J. Y. Park C. W. Yang J. S. Ha C. -U. Kim E. J. Kwon S. B. Jung C. S. Kang 《Journal of Electronic Materials》2001,30(9):1165-1170
This paper reports the formation of intermetallic compounds in Au/Ni/Cu/Ti under-bump-metallization (UBM) structure reacted with Ag-Sn eutectic solder. In this study, UBM is prepared by evaporating Au(500 Å)/Ni(1000 Å)/Cu(7500 Å) /Ti (700 Å) thin films on top of Si substrates. It is then reacted with Ag-Sn eutectic solder at 260 C for various times to induce different stages of the interfacial reaction. Microstructural examination of the interface, using both chemical and crystallographic analysis, indicates that two types of intermetallic compounds are formed during the interfacial reaction. The first phase, formed at the intial stage of the reaction, is predominantly Ni3Sn4. At longer times the Ni3Sn4 phase transforms into (Cu, Ni)6Sn6, probably induced by interdiffusion of Cu and Ni. At this stage, the underlying Cu layer also reacts with Sn and forms the same phase, (Cu,Ni)6Sn5. As a result, the fully reacted interface is found to consist of two intermetallic layers with the same phase but different morphologies. 相似文献
12.
13.
A. Zribi A. Clark L. Zavalij P. Borgesen E. J. Cotts 《Journal of Electronic Materials》2001,30(9):1157-1164
The evolution of intermetallics at and near SnAgCu/Cu and SnAgCu/Ni interfaces was examined, and compared to the behavior,
near PbSn/metal and Sn/metal interfaces. Two different solder compositions were considered, Sn93.6Ag4.7Cu1.7 and Sn95.5Ag3.5Cu1.0 (Sn91.8Ag5.1 Cu3.1 and Sn94.35Ag3.8Cu1.85 in atomic percent). In both cases, phase formation and growth at interfaces with Cu were very similar to those commonly observed
for eutectic SnPb solder. However, the evolution of intermetallics at SnAgCu/Ni interfaces proved much more complex. The presence
of the Cu in the solder dramatically altered the phase selectivity at the solder/Ni interface and affected the growth kinetics
of intermetallics. As long as sufficient Cu was available, it would combine with Ni and Sn to form (Cu,Ni)6)Sn5 which grew instead of the Ni3Sn4 usually observed in PbSn/Ni and Sn/Ni diffusion couples. This growing phase would, however, eventually consume essentially
all of the available Cu in the solder. Because the mechanical properties of Sn-Ag-Cu alloys, depend upon the Cu content, this
consumption can be expected to alter the mechanical properties of these Pb-free solderjoints. After depletion of the Cu from
the solder, further annealing then gradually transformed the (Cu,Ni)6Sn5 phase into a (Ni,Cu)3Sn4 phase. 相似文献
14.
In this study, we used microstructure evolution and electron microprobe analysis (EPMA) to investigate the interfacial reactions
in Sn-Zn and Sn-Zn-Al solder balls with Au/Ni surface finish ball-grid-array (BGA) bond pad over a period of isothermal aging
at 150°C. During reflow, Au dissolved into the solder balls and reacted with Zn to form γ-Au3Zn7 and γ2-AuZn3. As aging progressed, γ and γ2 transformed into γ3-AuZn4. Finally, Zn precipitated out next to γ3-AuZn4. The Zn reacted with the Ni layer to form Ni5Zn21. A thin layer (Al, Au, Zn) intermetallic compound (IMC) formed at the interface of the Sn-Zn-Al solder balls, inhibiting
the reaction of Ni with Zn. Even after 50 days of aging, no Ni5Zn21 was observed. Instead, fine (Al, Au, Zn) particles similar to Al2 (Au, Zn) in composition formed and remained stable in the solder. The lower ball shear strength corresponded with the brittle
fracture morphology in Sn-Zn-Al solder ball samples. 相似文献
15.
C. M. Tsai W. C. Luo C. W. Chang Y. C. Shieh C. R. Kao 《Journal of Electronic Materials》2004,33(12):1424-1428
The cross-interaction of the under-bump metallurgy (UBM)/solder interface and the solder/surface-finish interface in flip-chip
solder joints was investigated. In this study, the UBM on the chip side was a single layer of Cu (8.5 μm), and the surface
finish on the substrate side was a 0.2-μm Au layer over 5-μm Ni. It was shown that, after two reflows, the Ni layer of the
surface finish had been covered with (Cu1−xNix)6Sn5. This shows that the effect of cross-interaction of the two interfaces is important even during the reflow stage. During
subsequent solid-state aging at 115°C, 135°C, and 155°C, the formation of (Cu1−xNix)6Sn5 over the Ni layer was found to have the effect of reducing the Ni consumption rate. At the same time, the Cu consumption
rate of the UBM was accelerated. The results of this study show that the selection of the UBM and the surface finish has to
be considered together because the cross-interaction of the two interfaces plays an important role. 相似文献
16.
The morphological and compositional evolutions of intermetallic compounds (IMCs) formed at three Pb-free solder/electroless
Ni-P interface were investigated with respect to the solder compositions and reflow times. The three Pb-free solder alloys
were Sn3.5Ag, Sn3.5Ag0.75Cu, and Sn3Ag6Bi2In (in wt.%). After reflow reaction, three distinctive layers, Ni3Sn4 (or Ni-Cu-Sn for Sn3.5Ag0.75Cu solder), NiSnP, and Ni3P, were formed on the electroless Ni-P layer in all the solder alloys. For the Sn3.5Ag0.75Cu solder, with increasing reflow
time, the interfacial intermetallics switched from (Cu,Ni)6Sn5 to (Cu,Ni)6Sn5+(Ni,Cu)3Sn4, and then to (Ni,Cu)3Sn4 IMCs. The degree of IMC spalling for the Sn3.5Ag0.75Cu solder joint was more than that of other solders. In the cases of
the Sn3.5Ag and Sn3Ag6Bi2In solder joints, the growth rate of the Ni3P layer was similar because these two type solder joints had a similar interfacial reaction. On the other hand, for the Sn3.5Ag0.75Cu
solder, the thickness of the Ni3P and Ni-Sn-P layers depended on the degree of IMC spalling. Also, the shear strength showed various characteristics depending
on the solder alloys and reflow times. The fractures mainly occurred at the interfaces of Ni3Sn4/Ni-Sn-P and solder/Ni3Sn4. 相似文献
17.
The Ni-based under-bump metallurgies (UBMs) are of interest because they have a slower reaction rate with Sn-rich solders
compared to Cu-based UBMs. In this study, several UBM schemes using Ni as the diffusion barrier are investigated. Joints of
Sn-58Bi/Au/electroless nickel (EN)/Cu/Al2O3 and Sn-58Bi/Au/electroplated nickel/Cu/Al2O3 were aged at 110°C and 130°C for 1–25 days to study the interfacial reaction and microstructural evolution. The Sn-Bi solder
reacts with the Ni-based multimetallization and forms the ternary Sn-Ni-Bi intermetallic compound (IMC) during aging at 110°C.
Compositions of ternary IMC were (78–80)at.%Sn-(12–16)at.%Ni-(5–8)at.%Bi in joints of Sn-58Bi/Au/Ni-5.5wt.%P/Cu, Sn-58Bi/Au/Ni-12wt.%P/Cu,
and Sn-58Bi/Au/Ni/Cu. Elevated aging at 130°C accelerates the IMC growth rate and results in the formation of (Ni,Cu)3Sn4 and (Cu,Ni)6Sn5 adjacent to the ternary Sn-Ni-Bi IMC for the Sn-58Bi/Au/Ni-12wt.%P/Cu and Sn-58Bi/Au/Ni/Cu joints, respectively. The Cu content
in the (Cu,Ni)6Sn5 IMC is six times that in (Ni,Cu)3Sn4. Electroplated Ni fails to prevent Cu diffusion toward the Ni/solder interface as compared to EN-based joints. Cracks are
observed in the Sn-58Bi/Au/Ni-5.5wt.%P/Cu/Al2O3 joint aged at 130°C for 25 days. It is more favorable to employ Ni-12wt.%P for the Sn-58Bi/Au/EN/Cu joint. Electroless nickel,
with the higher P content of 12 wt.%, is a more effective diffusion barrier during aging. In addition, P enrichment occurs
near the interface of the EN/solder, and the degree of P enrichment is enhanced with aging time. The Au(Sn,Bi)4, with pyramidal and cubic shape, is observed in the Sn-58Bi/Au/Ni/Cu/Al2O3 joint. 相似文献
18.
Electroless Ni-P/Cu under-bump metallization (UBM) is widely used in electronics packaging. The Sn3.0Ag0.5Cu lead-free composite
solder pastes were produced by a mechanical alloying (MA) process doped with Cu6Sn5 nanoparticles. In this study, the detailed interfacial reaction of Sn3.0Ag0.5Cu composite solders with EN(P)/Cu UBM was investigated
after reflow. A field-emission scanning electron microscope (FESEM) was employed to analyze the interfacial morphology and
microstructure evolution. The intermetallic compounds (IMCs) formed at the interface between the Sn3.0Ag0.5Cu composite solders
and EN(P)/Cu UBM after one and three reflows were mainly (Ni1−x,Cux)3Sn4 and (Cu1−y,Niy)6Sn5. However, only (Ni1−x,Cux)3Sn4 IMC was observed after five reflows. The elemental distribution near the interfacial region was evaluated by an electron
probe microanalyzer (EPMA) as well as field-emission electron probe microanalyzer (FE-EPMA). Based on the observation and
characterization by FESEM, a EPMA, and an FE-EPMA, the reaction mechanism of interfacial phase transformation between Sn3.0Ag0.5Cu
composite solders and EN(P)/Cu UBM after various reflow cycles was discussed and proposed. 相似文献
19.
The effects of various elements of substrate metallization, namely, Au, Ni, and P, on the solder/under-bump metallization
(UBM), (Al/Ni(V)/Cu) interfacial reactions in flip-chip packages during multiple reflow processes were systematically investigated.
It was found that Au and P had negligible effects on the liquid-solid interfacial reactions. However, Ni in the substrate
metallization greatly accelerated the interfacial reactions at chip side and degraded the thermal stability of the UBM through
formation of a (Cu,Ni)6Sn5 ternary compound at the solder/UBM interface. This phenomenon can be explained in terms of enhanced grain-boundary grooving
on (Cu,Ni)6Sn5 in the molten solder during the reflow process. This could eventually cause the rapid spalling of an intermetallic compound
(IMC) from the solder/UBM interface and early failure of the packages. Our results showed that formation of multicomponent
intermetallics, such as (Cu,Ni)6Sn5 or (Ni,Cu)3Sn4, at the solder/UBM interface is detrimental to the solder-joint reliability. 相似文献
20.
The effect of soldering process variables on the microstructure and mechanical properties of eutectic Sn-Ag/Cu solder joints 总被引:2,自引:0,他引:2
Wenge Yang Lawrence E. Felton Robert W. Messler 《Journal of Electronic Materials》1995,24(10):1465-1472
Fundamental understanding of the relationship among process, microstructure, and mechanical properties is essential to solder
alloy design, soldering process development, and joint reliability prediction and optimization. This research focused on the
process-structure-property relationship in eutectic Sn-Ag/Cu solder joints. As a Pb-free alternative, eutectic Sn-Ag solder
offers enhanced mechanical properties, good wettability on Cu and Cu alloys, and the potential for a broader range of application
compared to eutectic Sn-Pb solder. The relationship between soldering process parameters (soldering temperature, reflow time,
and cooling rate) and joint microstructure was studied systemati-cally. Microhardness, tensile shear strength, and shear creep
strength were measured and the relationship between the joint microstructures and mechani-cal properties was determined. Based
on these results, low soldering tempera-tures, fast cooling rates, and short reflow times are suggested for producing joints
with the best shear strength, ductility, and creep resistance. 相似文献