共查询到20条相似文献,搜索用时 187 毫秒
1.
L.C. Tsao 《Journal of Alloys and Compounds》2011,509(33):8441-8448
This study investigated the effects of adding 0.5 wt.% nano-TiO2 particles into Sn3.5Ag0.5Cu (SAC) lead-free solder alloys on the growth of intermetallic compounds (IMC) with Cu substrates during solid-state isothermal aging at temperatures of 100, 125, 150, and 175 °C for up to 7 days. The results indicate that the morphology of the Cu6Sn5 phase transformed from scallop-type to layer-type in both SAC solder/Cu joints and Sn3.5Ag0.5Cu-0.5 wt.% TiO2 (SAC) composite solder/Cu joints. In the SAC solder/Cu joints, a few coarse Ag3Sn particles were embedded in the Cu6Sn5 surface and grew with prolonged aging time. However, in the SAC composite solder/Cu aging, a great number of nano-Ag3Sn particles were absorbed in the Cu6Sn5 surface. The morphology of adsorption of nano-Ag3Sn particles changed dramatically from adsorption-type to moss-type, and the size of the particles increased.The apparent activation energies for the growth of overall IMC layers were calculated as 42.48 kJ/mol for SAC solder and 60.31 kJ/mol for SAC composite solder. The reduced diffusion coefficient was confirmed for the SAC composite solder/Cu joints. 相似文献
2.
Jie Chen Jun Shen Shiqiang Lai Dong Min Xiaochuan Wang 《Journal of Alloys and Compounds》2010,489(2):631-637
In this paper, the microstructural evolution of IMCs in Sn–3.5Ag–X (X = 0, 0.75Ni, 1.0Zn, 1.5In)/Cu solder joints and their growth mechanisms during liquid aging were investigated by microstructural observations and phase analysis. The results show that two-phase (Ni3Sn4 and Cu6Sn) IMC layers formed in Sn–3.5Ag–0.75Ni/Cu solder joints during their initial liquid aging stage (in the first 8 min). While after a long period of liquid aging, due to the phase transformation of the IMC layer (from Ni3Sn4 and Cu6Sn phases to a (Cu, Ni)6Sn5 phase), the rate of growth of the IMC layer in Sn–3.5Ag–0.75Ni/Cu solder joints decreased. The two Cu6Sn5 and Cu5Zn8 phases formed in Sn–3.5Ag–1.0Zn/Cu solder joints during the initial liquid aging stage and the rate of growth of the IMC layers is close to that of the IMC layer in Sn–3.5Ag/Cu solder joints. However, the phase transformation of the two phases into a Cu–Zn–Sn phase speeded up the growth of the IMC layer. The addition of In to Sn–3.5Ag solder alloy resulted in Cu6(Snx,In1?x)5 phase which speeded up the growth of the IMC layer in Sn–3.5Ag–1.5In/Cu solder joint. 相似文献
3.
The intermetallic compounds (IMC) in the solder and at the interface of Sn-3.0Ag-0.5Cu (SAC)/Cu and Sn-3.0Ag-0.3Cu-0.05Cr (SACC)/Cu joints were investigated after isothermal aging at 150 °C for 0, 168 and 500 h. Different shaped Ag3Sn phases were found near the IMC layer of the latter joint. Interestingly, fine rod-shaped and branch-like Ag3Sn were detected near the interface after soldering and long Ag3Sn changed into shorter rods and small particles during aging. It is investigated that the Cr addition and thermal aging have effect on the evolution of Ag3Sn morphologies and it is controlled by interfacial diffusion. Energy minimization theory and the redistribution of elements are used to explain the morphological evolution of Ag3Sn. Small Ag3Sn particles were also found on the IMC layer after aging, unlike the large Ag3Sn at that of SAC/Cu joints. In conclusion, a favorable morphology of the joint interface leads to better bonding properties for SACC/Cu joints against thermal aging than that for SAC/Cu. 相似文献
4.
Asit Kumar Gain Tama Fouzder Y.C. Chan Ahmed Sharif Winco K.C. Yung 《Journal of Alloys and Compounds》2010,489(2):678-684
The formation of intermetallic compounds and the shear strength of Sn–Zn–Bi solder alloys with various (0, 1, 3, 5 and 7 wt%) weight percentages of Sn–Ag–Cu were investigated on Au/Ni metallized Cu pads depending on the number of reflow cycles. In Sn–Zn–Bi solder joints, scallop-shaped AuZn3 intermetallic compound (IMC) particles were found at the interfaces and in the solder ball regions, fine Bi- and needle-shaped Zn-rich phase were observed in the Sn matrix. After Sn–Ag–Cu additions, an additional Ag–Zn intermetallic compound layer was adhered to the top surface of the AuZn3 layer at the interface and fine spherical-shaped AgZn3 intermetallic compound particles were detected in the solder ball regions together with Bi- and Zn-rich phase volumes. After the addition of Sn–Ag–Cu, the shear strength of Sn–Zn–Bi solder joints increased due to the formation of the fine AgZn3 intermetallic compound particles. The shear strengths of Sn–Zn–Bi and Sn–Zn–Bi/7 wt% Sn–Ag–Cu solder joints after one reflow cycle were about 44.5 and 53.1 MPa, respectively and their shear strengths after eight reflow cycles were about 43.4 and 51.6 MPa, respectively. 相似文献
5.
《Science & Technology of Welding & Joining》2013,18(6):555-559
AbstractThe present work investigates the effects of adding a small amount of Cu to Sn–3Ag–1·5Sb solders. The present results indicate that adding 0·5 and 1·0 wt-%Cu to Sn–3Ag–1·5Sb solders causes the liquidus temperature to decrease from its original value of 233·4°C to 231·6°C and to 231·4°C, respectively. Furthermore, it is noted that the addition of 1·0 wt-%Cu reduces the difference between the liquidus and solidus temperatures. It is shown that the added Cu reacts with the Sn content of the solder to form Cu6Sn5 particles in the β-Sn matrix, which are distributed non-uniformly since the Cu content is low. The experimental results also reveal that the growth rate of the solder joint interfacial intermetallic compound layers increases at higher levels of Cu addition. Finally, it is established that adding Cu to the Sn–3Ag–1·5Sb solder not only improves the adhesive strength of the solder joints, but also reduces the rate of degradation of the adhesive strength of the joints during thermal storage. 相似文献
6.
以0805封装片式电容器件焊点为研究对象,建立了多周期温度冲击下Sn96.5/Ag3/Cu0.5的焊点有限元分析模型,开展了多周期温度冲击条件下焊点剪切力测试工作,获得了Sn96.5/Ag3/Cu0.5和Sn63/Pb37两种焊点的周期-剪切力测试数据,并利用非线性最小二乘法得到了1 500个周期内的焊点热疲劳状态拟合曲线.结果表明,在规定试验条件下,在有限的1 500个周期内0805封装电容的Sn96.5/Ag3/Cu0.5焊点的热疲劳劣化速率略慢于Sn63/Pb37焊点. 相似文献
7.
T. L. Su L. C. Tsao S. Y. Chang T. H. Chuang 《Journal of Materials Engineering and Performance》2002,11(4):365-368
For the soldering of recycled Ag sputtering targets, the interfacial reaction between liquid Sn and an Ag substrate at temperatures
ranging from 250 –425°C has been investigated. Experimental results show that a scallop-shaped layer of Ag3Sn intermetallic compounds formed during the soldering reaction. Kinetics analysis indicated that the growth of such interfacial
Ag3Sn intermetallic compounds is diffusion-controlled with activation energy of 70.3kJ/mol. During the reaction, the Ag substrate
dissolves into the molten Sn solder and causes the appearance of needle-shaped Ag3Sn precipitates in the Sn matrix. 相似文献
8.
The effect of adding a small amount of rare earth cerium (Ce) element to low Ag containing Sn-1wt%Ag Pb-free solder on its interfacial reactions with Cu substrate was investigated. The growth of intermetallic compounds (IMCs) between three Sn-1Ag-xCe solders with different Ce contents and a Cu substrate was studied and the results were compared to those obtained for the Ce-free Sn-1Ag/Cu systems. In the solid-state reactions of the Sn-1Ag(-xCe)/Cu solder joints, the two IMC layers, Cu6Sn5 and Cu3Sn, grew as aging time increased. Compared to the Sn-1Ag/Cu joint, the growth of the Cu6Sn5 and Cu3Sn layers was depressed for the Ce-containing Sn-1Ag-xCe/Cu joint. The addition of Ce to the Sn-Ag solder reduced the growth of the interfacial Cu-Sn IMCs and prevented the IMCs from spalling from the interface. The evenly-distributed Ce elements in the solder region blocked the diffusion of Sn atoms to the interface and retarded the growth of the interfacial IMC layer. 相似文献
9.
Lihua Qi Jihua Huang Hua Zhang Xingke Zhao Haitao Wang Donghai Cheng 《Journal of Materials Engineering and Performance》2010,19(1):129-134
The growth behavior of reaction-formed intermetallic compounds (IMCs) at Sn3.5Ag0.5Cu/Ni and Cu interfaces under thermal-shear
cycling conditions was investigated. The results show that the morphology of (Cu
x
Ni1–x
)6Sn5 and Cu6Sn5 IMCs formed both at Sn3.5Ag0.5Cu/Ni and Cu interfaces gradually changed from scallop-like to chunk-like, and different IMC
thicknesses developed with increasing thermal-shear cycling time. Furthermore, Cu6Sn5 IMC growth rate at the Sn3.5Ag0.5Cu/Cu interface was higher than that of (Cu
x
Ni1–x
)6Sn5 IMC under thermal-shear cycling. Compared to isothermal aging, thermal-shear cycling led to only one Cu6Sn5 layer at the interface between SnAgCu solder and Cu substrate after 720 cycles. Moreover, Ag3Sn IMC was dispersed uniformly in the solder after reflow. The planar Ag3Sn formed near the interface changed remarkably and merged together to large platelets with increasing cycles. The mechanism
of formation of Cu6Sn5, (Cu
x
Ni1–x
)6Sn5 and Ag3Sn IMCs during thermal-shear cycling process was investigated. 相似文献
10.
Ternary Pb-free solders, Sn–3.5Ag–X, containing 0.5 wt.% of Zn, Mn and Cr, were reacted with Cu UBM, which was electroplated using SPS additive. Characteristics of Cu–Sn IMCs and Kirkendall void formation at the Cu/Sn–3.5Ag solder joints were significantly affected by the third element, and the potency to suppress Kirkendall voids at the solder joint increased in the order of Cr, Mn, Zn, which was indeed the order of the drop reliability improvement. From the AES analyses, it was suggested that the sulfide-forming elements in the solder diffused into the Cu UBM and reduced the segregation of S atoms to the Cu/Cu3Sn interface by scavenging S, which led to the suppression of Kirkendall void nucleation at the Cu/Cu3Sn interface and the drop reliability improvement. In the case of the Zn-containing solder joint, Cu3Sn phase, known to be a host of Kirkendall voids, did not form at all even after extended aging treatments. The magnitude of the tensile stress at the Cu3Sn/Cu interface which drove the Kirkendall void growth was estimated to be 10–100 MPa. 相似文献
11.
12.
《Acta Materialia》2001,49(14):2609-2624
The dissolution and interfacial reactions involving thin-film Ti/Ni/Ag metallizations on two semiconductor devices, diode and metal-oxide-semiconductor field-effect transistor (MOSFET), a Sn–3.0Ag–0.7Cu solder, and a Au-layer on the substrates are studied. To simulate the dissolution kinetics of the Ag-layer in liquid solder during the reflow process, the computational thermodynamics (Thermo-Calc) and kinetics (DICTRA: DIffusion Controlled TRAnsformations) tools are employed in conjunction with the assessed thermochemical and mobility data. The simulated results are found to be consistent with the observed as-reflowed microstructures and the measured Ag contents in the solder. In the as-reflowed joints two different intermetallic compounds (IMC) are found near the diode/solder interface. Both are in the form of particles of different morphologies, not a continuous layer, and are referred to as IMC-I and IMC-II. The former corresponds to Ni3Sn4 with Cu atoms residing in the Ni sublattice. It is uncertain whether IMC-II is Cu6Sn5 phase with Ni atoms residing in the Cu sublattice or a Cu–Ni–Sn ternary phase. Near the as-reflowed MOSFET/solder interface, both particles and a skeleton-like layer of Ni3Sn4 are observed. The primary microstructural dynamics during solid state aging are the coarsening of IMC particles and the reactions involving the unconsumed (after reflow) Ni- and the Ti-layer with Sn and Au. While the reaction with the Ni-layer yields only Ni3Sn4 intermetallic, the reaction involving the Ti-layer suggests the formation of Ti–Sn and Au–Sn–Ti intermetallics. The latter is due to the diffusion of Au from the substrate side to the die side. It is postulated that the kinetics of Au–Sn–Ti layer is primarily governed by the diffusion of Au through the Ni3Sn4 layer by a grain boundary mechanism. 相似文献
13.
Hongbo Xu Mingyu Li Jongmyung Kim Daewon Kim 《Journal of Materials Processing Technology》2009,209(6):2781-2787
A rapid yet simple methodology to form the solder joints used in electronic packaging has been demonstrated through an induction heating system in this paper. The objective is to control the shapes of the solder joints precisely and form the hourglass-shaped solder joint using local melting phenomenon. For Sn–Ag eutectic solder bullet-shaped solder bumps and hourglass-shaped solder joints can be obtained easily within 2.3 s. The reason for the formation of hourglass-shaped solder joints has been analyzed using different morphologies of Ag3Sn intermetallic compound (IMC), and is explained by the non-uniform temperature distribution caused by a local melting phenomenon and skin effect. 相似文献
14.
《Journal of Alloys and Compounds》2006,407(1-2):208-214
Intermetallic compound (IMC) formations of Sn–2.8Ag–0.5Cu solder with additional 1 wt% Bi were studied for Cu-substrate during soldering at 255 °C and isothermal aging at 150 °C. It was found that addition of 1 wt% Bi into the Sn–2.8Ag–0.5Cu solder inhibits the excessive formation of intermetallic compounds during the soldering reaction and thereafter in aging condition. Though the intermetallic compound layer was Cu6Sn5, after 14 days of aging a thin Cu3Sn layer was also observed for both solders. A significant increase of intermetallic layer thickness was observed for both solders where the increasing tendency was lower for Bi-containing solder. After various days of aging, Sn–2.8Ag–0.5Cu–1.0Bi solder gives comparatively planar intermetallic layer at the solder–substrate interface than that of the Sn–2.8Ag–0.5Cu solder. The formation of intermetallic compounds during aging for both solders follows the diffusion control mechanism and the diffusion of Cu is more pronounced for Sn–2.8Ag–0.5Cu solder. Intermetallic growth rate constants for Sn–2.8Ag–0.5Cu and Sn–2.8Ag–0.5Cu–1.0Bi solders were calculated as 2.21 × 10−17 and 1.91 × 10−17 m2/s, respectively, which had significant effect on the growth behavior of intermetallic compounds during aging. 相似文献
15.
The chemical interfacial reaction of Ni plates with eutectic Sn–3.5Ag lead-free solder was studied by microstructural observations and mathematical calculations. Compared with the Sn–3.5Ag–0.75Ni/Ni interfacial reaction, based on a simple model of the growth of the liquid/solid chemical compound layer, the growth mechanism of Ni3Sn4 in the Sn–3.5Ag/Ni interfacial reaction is discussed and presented. The growth process of Ni3Sn4 in the Sn/Ni liquid/solid reaction interface involves the net effect of several interrelated phenomena, such as volume diffusion, grain boundary diffusion, grain boundary grooving, grain coarsening, and dissolution into the molten solder. The growth time exponent n and morphology of Ni3Sn4 were found to be dependent on these factors. 相似文献
16.
The effect on the growth kinetics of the intermetallic compounds (IMCs) in solder/Cu joints, caused by adding Bi to eutectic
Sn-3.5Ag solder alloy, was examined at the aging temperatures of 150°C and 180°C. The Cu6Sn5 layer growth was significantly enhanced, but the Cu3Sn layer growth was slightly retarded by the addition of Bi, resulting in significant growth enhancement of the total (Cu6Sn5+Cu3Sn) IMC layer with increasing Bi addition. The IMC layer growth in the Bi-containing solder joints was accompanied by the
accumulation of Bi ahead of the Cu6Sn5 layer that resulted in the formation of a liquid layer at the Cu6Sn5/solder interface. A kinetic model was developed for the planar growth of the Cu6Sn5 and Cu3Sn layers in the solder joints, accounting for the existence of interfacial reaction barriers. Predictions from the kinetic
model showed that the experimental results could be well explained by the hypothesis that the formation of a Bi-rich liquid
layer at the Cu6Sn5/solder interface reduces the interfacial reaction barrier at the interface. 相似文献
17.
We electroplated Co–P films with nanocrystalline, amorphous and nanocrystalline/amorphous mixed structures and used them as under-bump metallization (UBM) joined with Sn–Ag–Cu lead-free solder. We systematically investigated the interfacial reaction between the Sn–Ag–Cu solder and the Co–P UBM and analyzed the growth mechanisms of the intermetallic compounds formed at the interfaces of the Sn–Ag–Cu/Co–P joints through multiple reflows. Among the three kinds of Co–P films, the film with a mixed structure shows the best diffusion-barrier properties and is a good candidate for the UBM joined with the Sn–Ag–Cu solder. For the nanocrystalline Co–P UBM, Co diffuses quickly toward the solder and Sn does not diffuse into the UBM, whereas for the amorphous Co–P film not only does Co diffuse into the solder, but also Sn diffuses into the Co–P film with a large diffusion rate. In addition, the first-principles calculation shows that the exchange coupling between Co(3d74s2) and Sn(5s25p2) electrons and between Sn(5s25p2) and P(3s23p3) electrons results in the formation of CoSn and SnP3, which originate from the diffusion and reaction of Co and Sn atoms, respectively; this is consistent with the experimental data of transmission electron microscopy characterization. 相似文献
18.
A comprehensive transmission electron microscopy (TEM) study was conducted to investigate the growth mechanisms of Cu3Sn on polycrystalline and single crystalline Cu substrates in solder joints. On single crystalline Cu the solder reflow process resulted in the growth of columnar Cu3Sn grains aligned in a thin uniform layer perpendicular to the interface, while a thick Cu3Sn layer formed from fine equiaxed grains on the polycrystalline substrate. In the subsequent solid state aging, columnar growth of Cu3Sn continued on the single crystalline Cu before it was replaced by nucleation and growth of new triangular Cu3Sn grains at the triple junction sites of the Cu/Cu3Sn interface. On the polycrystalline Cu the solid state aging caused much more rapid growth of the Cu3Sn layer due to nucleation and the growth of new Cu3Sn grains at both the Cu/Cu3Sn and Cu6Sn5/Cu3Sn interfaces. These different growth behaviors of Cu3Sn were related to the diffusive supply of reactive elements. 相似文献
19.
Chi-Pu LinChih-Ming Chen Yee-Wen YenHsin-Jay Wu Sinn-Wen Chen 《Journal of Alloys and Compounds》2011,509(8):3509-3514
Interfacial reactions between high-Pb solders (Pb-10Sn, Pb-5Sn, and Pb-3Sn, in wt.%) and immersion Ag layer at 350 °C are investigated. Upon decreasing the Sn concentration from 10 wt.% to 5 wt.%, the reaction product formed at the solder/Ag interface changes from the Ag3Sn phase to the Ag4Sn phase. When the Sn concentration reduces to only 3 wt.%, the reaction product is the Ag4Sn phase at the initial stage of reaction but transforms to the (Ag) phase dissolved with Sn at the later stage of reaction. Pb penetrates across the (Ag) phase via grain boundary and forms a continuous Pb-rich layer between the (Ag) phase and the bottom Cu layer. The correlation between the phase transformation and the solder composition is discussed based on the calculated Sn-Pb-Ag isothermal section. 相似文献
20.
《Acta Materialia》2008,56(19):5514-5523
Solder joints of Cu/Sn–3.5Ag were prepared using Cu foil or electroplated Cu films with or without SPS additive. With a high level of SPS in the Cu electroplating bath, voids tended to localize at the Cu/Cu3Sn interface during subsequent aging at 150 °C, which was highly detrimental to the drop impact resistance of the solder joints. In situ Auger electron spectroscopy of fractured joints revealed S segregation on the Cu/Cu3Sn interface and void surfaces, suggesting that segregation of S to the Cu/Cu3Sn interface lowered interface energy and thereby the free energy barrier for Kirkendall void nucleation. Once nucleated, voids can grow by local tensile stress, originating from residual stress in the film and/or the Kirkendall effect. Vacancy annihilation at the Cu/Cu3Sn interface can induce tensile stress which drives the Kirkendall void growth. 相似文献