共查询到20条相似文献,搜索用时 15 毫秒
1.
Yi-Shao Lai Kuo-Ming Chen Chin-Li Kao Chiu-Wen Lee Ying-Ta Chiu 《Microelectronics Reliability》2007,47(8):1273-1279
We examine electromigration fatigue reliability and morphological patterns of Sn–37Pb and Sn–3Ag–1.5Cu/Sn–3Ag–0.5Cu composite solder bumps in a flip–chip package assembly with Ti/Ni(V)/Cu UBM. The flip–chip test vehicle was subjected to test conditions of five combinations of applied electric currents and ambient temperatures, namely, 0.4 A/150 °C, 0.5 A/150 °C, 0.6 A/125 °C, 0.6 A/135 °C, and 0.6 A/150 °C. The electrothermal coupling analysis was employed to investigate the current crowding effect and maximum temperature in the solder bump in order to correlate with the experimental electromigration reliability using the Black’s equation as a reliability model. From available electromigration reliability models, we also present a comparison between fatigue lives of Sn–37Pb solder bumps with Ti/Ni(V)/Cu and those with Al/Ni(V)/Cu UBM under different current stressing conditions. 相似文献
2.
《Components and Packaging Technologies, IEEE Transactions on》2009,32(2):317-324
3.
Baated A. Jiang J. Kim K.-S. Suganuma K. Huang S. Jurcik B. Nozawa S. Ueshima M. 《Electronics Packaging Manufacturing, IEEE Transactions on》2010,33(1):38-43
4.
Kimihiro Yamanaka Yutaka Tsukada Katsuaki Suganuma 《Microelectronics Reliability》2007,47(8):1280-1287
This paper aims to understand the solder bump electromigration phenomenon in the Cu/Sn–3Ag–0.5Cu/Cu system. A temperature of 453 K with a current density of 10 kA/cm2 was applied. A void nucleated at the highest current density point at the cathode. As the void grew along the cathode side, a solder depletion occurred on the opposite side of the electron entry point, resulting in an open failure. A unique purposely-designed 3D model simulation methodology provides a good understanding of the void nucleation and growth behavior. The temperature of the solder joint during the electromigration test was measured successfully by the resistance change in the junction line between the two joints. 相似文献
5.
Liang Zhang Song-bai Xue Li-li Gao Zhong Sheng Sheng-lin Yu Yan Chen Wei Dai Feng Ji Zeng Guang 《Microelectronics Reliability》2010,50(12):2071-2077
The reliability of Sn–Ag–Cu–Ce lead-free soldered joints in quad flat packages under thermal cycling was investigated based on finite element simulation and experiments. The stress and strain response of fine pitch QFP device lead-free soldered joints were analyzed using finite element method based on Garofalo–Arrhenius model. The simulated results indicate that the creep distribution is not uniform, the heel of joints is the maximum creep strain concentrated sites. And comparisons were then made with experimental results of the cracks observed in the Sn–Ag–Cu–Ce soldered joints subjected to the temperature cycled experiment. In addition, the relative mechanical and metallurgical factors, which dominate the failure of soldered joints, were utilized to analyze the phenomena. The fracture surfaces indicate that crack initiate and propagate along the interface among bulk Cu6Sn5 phases in Sn–Ag–Cu–Ce soldered joints. 相似文献
6.
《Components and Packaging Technologies, IEEE Transactions on》2008,31(4):767-775
7.
Fei Su Ronghai Mao Xiaoyan Wang Guangzhou Wang Haiyan Pan 《Microelectronics Reliability》2011,51(5):1020-1024
In this paper, creep behaviour of Sn-3.8Ag-0.7Cu (SAC) lead-free solder under the collective effect of electromigration, stress and temperature was investigated. Firstly, the conventional creep test was improved so that high current density can be applied to the ribbon sample and serve as one of the experimental control variables. Experimental results indicate that creep rate of the SAC was greatly affected by electromigration (EM) and its linear dependence on current density and stress was revealed. Then a unified phenomenological creep model with variables of stress, temperature and current density was set up based on the fact that both the mechanisms of conventional creep and electromigration are vacancy diffusion type. Coefficients in the unified creep model were determined from the experimental results by curve fitting, and numerical results of the unified creep model are found to fit the experimental results quite well. 相似文献
8.
The lead free Sn–Ag–y%Cu (y = 0.0, 0.5, 1.0 and 2.0) interconnect interfacial microstructures and the microstructure evolution under thermal treatment (isothermal aging, 150 °C/1000 h) were studied in detail by using surface microetching microscopy and cross section microscopy. The corresponding mechanical and reliability behaviors were evaluated by performing shear test and fracture mode analysis before and after the thermal treatment. The results indicate: (i) The interconnects could have different microstructures and intermetallic compound (IMC), depending on the Cu content. The Cu–Sn IMC could have microstructures that were clusters or protrusion-like, Augustine grass leaf-like, scissor-like, tweezers-like, etc. (ii) Ag3Sn IMCs were not observed at time zero for any interconnect groups, but they occurred after the aging for all groups. The Ag3Sn IMC could have different microstructures, again depending on Cu content. For low Cu content, the Ag3Sn IMCs were granules or nodules; for higher Cu content, Ag3Sn IMCs were plate-like. (iii) The growth of Ag3Sn plates was promoted by the growth of Cu–Sn IMCs, but indirectly linked to the Cu content. (iv) High Cu content (1.0 wt% and higher) could degrade the mechanical and reliability performances of the LF interconnect by providing a brittle joint, which was mainly achieved through the substantial growth of Cu–Sn IMCs and Ag3Sn plates. 相似文献
9.
Keun-Soo Kim Takayuki Imanishi Katsuaki Suganuma Mimoru Ueshima Rikiya Kato 《Microelectronics Reliability》2007,47(7):1113-1119
The metallurgical and mechanical properties of Sn–3.5 wt%Ag–0.5 wt%Bi–xwt%In (x = 0–16) alloys and of their joints during 85 °C/85% relative humidity (RH) exposure and heat cycle test (−40–125 °C) were evaluated by microstructure observation, high temperature X-ray diffraction analysis, shear and peeling tests. The exposure of Sn–Ag–Bi–In joints to 85 °C/85%RH for up to 1000 h promotes In–O formation along the free surfaces of the solder fillets. The 85°C/85%RH exposure, however, does not influence the joint strength for 1000 h. Comparing with Sn–Zn–Bi solders, Sn–Ag–Bi–In solders are much stable against moisture, i.e. even at 85 °C/85%RH. Sn–Ag–Bi–In alloys with middle In content show severe deformation under a heat cycles between −40 °C and 125 °C after 2500 cycles, due to the phase transformation from β-Sn to β-Sn + γ-InSn4 or γ-InSn4 at 125 °C. Even though such deformation, high joint strength can be maintained for 1000 heat cycles. 相似文献
10.
The interfacial reactions and ball shear properties of ball grid array (BGA) solder joints aged at 170 °C for up to 21 days were investigated with different displacement rates. Two different kinds of solders, Sn–37Pb and Sn–3.5Ag (all wt.%), and an electroplated Ni/Au BGA substrate were employed in this work. A continuous Ni3Sn4 intermetallic compound (IMC) layer was formed at the interfaces between both the Sn–37Pb and Sn–3.5Ag solders and the substrate during reflow. After aging, two different reaction layers, consisting of (AuxNi1−x)Sn4 IMC and Pb-rich phase, were additionally observed between the Sn–37Pb solder and the Ni3Sn4 IMC layer. The thicknesses of these interfacial reaction layers increased with increasing aging time. After reflow, all the fractures occurred inside the bulk solder. The fracture location of the Sn–37Pb solder joints was shifted toward the solder/Ni interface with increasing aging time and displacement rate, whereas the fracture of the Sn–3.5Ag solder joints mainly occurred inside the bulk solder, irrespective of the aging time and displacement rate. Consequently, the shear properties of the Sn–37Pb solder joints significantly decreased with increasing aging time, whereas those of the Sn–3.5Ag solder joints slightly decreased. The tendency toward brittle fracture of the Sn–37Pb solder joints was intensified with increasing displacement rate. The shear properties of the ductile solder joints increased with increasing displacement rate, while the displacement until fracture, deformation energy and displacement rate sensitivity of the brittle solder joints significantly decreased with increasing displacement rate. 相似文献
11.
《Components and Packaging Technologies, IEEE Transactions on》2008,31(4):849-858
12.
An experimental investigation was combined with a non-linear finite element analysis using an elastic–viscoplastic constitutive model to study the effect of ball shear speed on the shear forces of flip chip solder bumps. A solder composition used in this study was Sn–3mass%Ag–0.5mass%Cu. A low cost bumping process has been employed using electroless Ni and immersion Au followed by solder paste stencil printing. A thin layer of intermetallic compound, (Ni1−xCux)3Sn4, was formed by the reaction between the solder and electroless Ni with a thickness of about 1.4 μm, while some discontinuous (Cu1−yNiy)6Sn5 particles were also formed at the interface. The compositions of the resulting compounds were identified using energy dispersive spectrometer (EDS) and electron microprobe analysis (EPMA). Shear tests were carried out over a shear speed range from 20 to 400 μm/s at a shear ram height of 20 μm. The shear force was observed to linearly increase with shear speed and reach the maximum value at the fastest shear speed in both experimental and computational results. The optimum shear speeds for the shear test of solder bumped flip chip were recommended to be not exceeding 200 μm/s. The failure mechanisms were discussed in terms of von Mises stresses and plastic strain energy density distributions. 相似文献
13.
C.K. Wong J.H.L. Pang J.W. Tew B.K. Lok H.J. Lu F.L. Ng Y.F. Sun 《Microelectronics Reliability》2008,48(4):611-621
This paper examines various aspects of SAC (Sn–3.8Ag–0.7Cu wt.%) solder and UBM interactions which may impact interconnection reliability as it scales down. With different solder joint sizes, the dissolution rate of UBM and IMC growth kinetics will be different. Solder bumps on 250, 80 and 40 μm diameter UBM pads were investigated. The effect of solder volume/pad metallization area (V/A) ratio on IMC growth and Ni dissolution was investigated during reflow soldering and solid state isothermal aging. Higher V/A ratio produced thinner and more fragmented IMC morphology in SAC solder/Ni UBM reflow soldering interfacial reaction. Lower V/A ratio produced better defined IMC layer at the Ni UBM interface. When the ratio of V/A is constant, the IMC morphology and growth trend was found to be similar. After 250 h of isothermal aging, the IMC growth rate of the different bump sizes leveled off. No degradation in shear strength was observed in these solder bump after 500 h of isothermal aging. 相似文献
14.
High temperature reliability and interfacial reaction of eutectic Sn–0.7Cu/Ni solder joints during isothermal aging 总被引:2,自引:2,他引:0
The interfacial reactions and growth kinetics of intermetallic compound (IMC) layers formed between Sn–0.7Cu (wt.%) solder and Au/Ni/Cu substrate were investigated at aging temperatures of 185 and 200 °C for aging times of up to 60 days. After reflow, the IMC formed at the interface was (Cu, Ni)6Sn5. After aging at 185 °C for 3 days and at 200 °C for 1 day, two IMCs of (Cu, Ni)6Sn5 and (Ni, Cu)3Sn4 were observed. The growth of the (Ni, Cu)3Sn4 IMC consumed the (Cu, Ni)6Sn5 IMC at an aging temperature of 200 °C due to the restriction of supply of Cu atoms from the solder to interface. After aging at 200 °C for 60 days, the Ni layer of the substrate was completely consumed in many parts of the sample, at which point a Cu3Sn IMC was formed. In the ball shear test, the shear strength decreased with increasing aging temperature and time. Until the aging at 185 °C for 15 days and at 200 °C for 3 days, fractures occurred in the bulk solder. After prolonged aging treatment, fractures partially occurred at the (Cu, Ni)6Sn5 + Au/solder interface for aging at 185 °C and at the (Ni, Cu)3Sn4/Ni interface for aging at 200 °C, respectively. Consequently, thick IMC layer and thermal loading history significantly affected the integrity of the Sn–0.7Cu/Ni BGA joints. 相似文献
15.
Yi-Shao Lai Chiu-Wen Lee 《Components and Packaging Technologies, IEEE Transactions on》2007,30(3):526-531
The near-eutectic Sn-Pb-Cu and Sn-Pb-Ni ternary solder alloys were developed based on the consideration of strength and fatigue reliability enhancement of solder joints in part via the altering of formation of interfacial intermetallic compounds. In this work, we examine electromigration reliability and morphologies of 62Sn-36Pb-2Ni and 62Sn-36Pb-2Cu flip-chip solder joints subjected to two test conditions that combine different average current densities and ambient temperatures: 5 kA/cm2 at 150 degC and 20 kA/cm2 at 3 degC. Under the test condition of 5 kA/cm2 at 150 degC, 62Sn-36Pb-2Cu is overwhelmingly better than 62Sn-36Pb-2Ni in terms of electromigration reliability. However, under the test condition of 20 kA/cm2 at 30 degC, the electromigration fatigue life of 62Sn-36Pb-2Ni shows a profuse enhancement and exceeds that of 62Sn-36Pb-2Cu. Electromigration-induced morphologies are also examined on the cross sections of solder joints using scanning electron microscopy. 相似文献
16.
Solder joint reliability depends on several service parameters such as temperature extremes encountered, dwell times at these temperatures, and the ramp-rates representing the rate at which the temperature changes are imposed. TMF of Sn–Ag based solder alloy joints of realistic dimensions were carried out with dwell of 115 min and 20 min at 150 °C and −15 °C, respectively. Different heating rates were obtained by controlling the power input during heating part of TMF cycles. Surface damage and residual mechanical strength of these solder joints were characterized after 0, 250, 500, and 1000 TMF cycles to evaluate the role of TMF heating rate on the solder joint integrity. 相似文献
17.
Lili Gao Liang Zhang Feng Ji Sheng-lin Yu Guang Zeng 《Microelectronic Engineering》2010,87(11):2025-7059
Recent years, the SnAgCu family of alloys has been found a widely application as a replacement for the conventional SnPb solders in electronic industry. In order to further enhance the properties of SnAgCu solder alloys, alloying elements such as rare earth, Bi, Sb, Fe, Co, Mn, Ti, In, Ni, Ge and nano-particles were selected by lots of researchers as alloys addition into these alloys. Rare earth (RE) elements have been called the ‘‘vitamin” of metals, which means that a small amount of RE elements can greatly enhance the properties of metals, such as microstructure refinement, alloying and purification of materials and metamorphosis of inclusions. In addition, a small amount of Zn addition has the ability to reduce undercooling efficiently and suppress the formation of massive primary Ag3Sn plates, and Bi/Ga has the ability to enhance the wettability of SnAgCu alloys as well as Ni. Moreover, adding Co/Fe/Ge can effectively refine microstructure, modify interfacial Cu-Sn compounds and increase the shear strength of joints with Cu. This paper summarizes the effects of alloying elements on the wettability, mechanical properties, creep behavior and microstructures of SnAgCu lead-free solder alloys. 相似文献
18.
S. Gamerith A. Klug H. Scheiber U. Scherf E. Moderegger E. J. W. List 《Advanced functional materials》2007,17(16):3111-3118
The field of organic electronics has seen tremendous progress over the last years and all‐solution‐based processes are believed to be one of the key routes to ultra low‐cost roll‐to‐roll device and circuit fabrication. In this regard a variety of functional materials has been successfully designed for inkjet printing. While orthogonal‐solvent approaches have frequently been used to tackle the solubility issue in multilayer solution processing, the focus of this work lies on printed metal electrodes for organic field‐effect transistors (OFET) and their curing concepts. Two metallic inkjet‐printable materials are studied: i) a silver‐copper nanoparticle based dispersion and ii) a soluble organic silver‐precursor. Photoelectron spectroscopy reveals largely metallic properties of the cured materials, which are compared with respect to OFET performance and process‐related issues. Contact resistance of the prepared metal electrodes is significantly larger than that of evaporated top‐contact gold electrodes. As direct patterning via inkjet printing limits the reliably achievable channel length to values well above 10 μm, the influence of contact resistance is rather small, however, and overall device performance is comparable. 相似文献
19.
Sn-Ag-Cu composite solders reinforced with nano-sized, nonreacting, noncoarsening 1 wt% TiO2 particles were prepared by mechanically dispersing TiO2 nano-particles into Sn-Ag-Cu solder powder and the interfacial morphology of the solder and flexible BGA substrates were characterized metallographically. At their interfaces, different types of scallop-shaped intermetallic compound layers such as Cu6Sn5 for a Ag metallized Cu pad and Sn-Cu-Ni for a Au/Ni and Ni metallized Cu pad, were found in plain Sn-Ag-Cu solder joints and solder joints containing 1 wt% TiO2 nano-particles. In addition, the intermetallic compound layer thicknesses increased substantially with the number of reflow cycles. In the solder ball region, Ag3Sn, Cu6Sn5 and AuSn4 IMC particles were found to be uniformly distributed in the β-Sn matrix. However, after the addition of TiO2 nano-particles, Ag3Sn, AuSn4 and Cu6Sn5 IMC particles appeared with a fine microstructure and retarded the growth rate of IMC layers at their interfaces. The Sn-Ag-Cu solder joints containing 1 wt% TiO2 nano-particles consistently displayed a higher hardness than that of the plain Sn-Ag-Cu solder joints as a function of the number of reflow cycles due to the well-controlled fine microstructure and homogeneous distribution of TiO2 nano-particles which gave a second phase dispersion strengthening mechanism. 相似文献
20.
The formation and growth of intermetallic compounds and shear strength at Sn–Zn solder/Au–Ni–Cu interfaces 总被引:2,自引:2,他引:0
The microstructures and shear strength of the interface between Sn–Zn lead-free solders and Au/Ni/Cu interface under thermal aging conditions was investigated. The intermetallic compounds (IMCs) at the interface between Sn–Zn solders and Au/Ni/Cu interface were analyzed by field emission scanning electron microscopy and transmission electron microscopy. The results showed the decrease in the shear strength of the interface with aging time and temperature. The solder ball with highly activated flux had about 8.2% increased shear strength than that with BGA/CSP flux. Imperfect wetting and many voids were observed in the fracture surface of the latter flux. The decreased shear strength was influenced by IMC growth and Zn grain coarsening. In the solder layer, Zn reacted with Au and then was transformed to the β-AuZn compound. Although AuZn grew first, three diffusion layers of γ-Ni5Zn21 compounds were formed after aging for 600 h at 150 °C. The layers divided by Ni5Zn21 (1), (2), and (3) were formed with the thickness of 0.7 μm, 4 μm, and 2 μm, respectively. 相似文献