scholarly journals Phase equilibria investigation and alloys characterization in Sn-In-Ag system

2008 ◽  
Vol 62 (3) ◽  
pp. 148-152
Author(s):  
Aleksandra Milosavljevic ◽  
Dragana Zivkovic ◽  
Dragan Manasijevic ◽  
Nadezda Talijan ◽  
Aleksandar Grujic ◽  
...  
Keyword(s):  
Phase Equilibria ◽  
Xrd Analysis ◽  
Lead Free ◽  
Solder Alloys ◽  
Standard Lead ◽  
Free Solder ◽  
Dsc Method ◽  
Lead Free Solders ◽  
Thermocalc Software

Lead-free soldering has become very popular in the world recently, especially in electronics, because of high ecological demands in industry. Some of lead-free solder alloys are already used in electronic industry, but despite that investigations are still going in order to find suitable replacement for Pb-Sn standard solder. In this paper phase equilibria and characterization of Sn-In-Ag alloys in section In:Ag = 7:3 are investigated. The results of phase diagram calculation are obtained by ThermoCalc software, and characteristic temperatures by DSC method. The results of XRD analysis, optical microscopy, microhardness and electrical conductivity are also presented. These results are given in order to contribute the knowledge about lead-free solders, especially Sn-In-Ag solder alloys, which are potential candidates for replacement standard lead solders.

Solder Joint Reliability of Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys Solidified on Copper Substrates with Different Surface Roughnesses

2015 ◽  
Vol 830-831 ◽  
pp. 265-269
Author(s):  
Satyanarayan ◽  
K.N. Prabhu
Keyword(s):  
Solder Joint ◽  
Solder Matrix ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Cu Substrate ◽  
Cu Substrates ◽  
Free Solder ◽  
Substrate Surfaces ◽  
Lead Free Solders

In the present work, the bond strength of Sn-0.7Cu, Sn-0.3Ag-0.7Cu, Sn-2.5Ag-0.5Cu and Sn-3Ag-0.5Cu lead free solders solidified on Cu substrates was experimentally determined. The bond shear test was used to assess the integrity of Sn–Cu and Sn–Ag–Cu lead-free solder alloy drops solidified on smooth and rough Cu substrate surfaces. The increase in the surface roughness of Cu substrates improved the wettability of solders. The wettability was not affected by the Ag content of solders. Solder bonds on smooth surfaces yielded higher shear strength compared to rough surfaces. Fractured surfaces revealed the occurrence of ductile mode of failure on smooth Cu surfaces and a transition ridge on rough Cu surfaces. Though rough Cu substrate improved the wettability of solder alloys, solder bonds were sheared at a lower force leading to decreased shear energy density compared to the smooth Cu surface. A smooth surface finish and the presence of minor amounts of Ag in the alloy improved the integrity of the solder joint. Smoother surface is preferable as it favors failure in the solder matrix.

Nanoindentation Characterization of Lead-free Solders and Intermetallic Compounds under Thermal Aging

2010 ◽  
Vol 2010 (1) ◽  
pp. 000314-000318
Author(s):  
Tong Jiang ◽  
Fubin Song ◽  
Chaoran Yang ◽  
S. W. Ricky Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Solder Joints ◽  
Lead Free ◽  
Small Range ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Aging Test ◽  
Free Solder ◽  
Lead Free Solders

The enforcement of environmental legislation is pushing electronic products to take lead-free solder alloys as the substitute of traditional lead-tin solder alloys. Applications of such alloys require a better understanding of their mechanical behaviors. The mechanical properties of the lead-free solders and IMC layers are affected by the thermal aging. The lead-free solder joints on the pads subject to thermal aging test lead to IMC growth and cause corresponding reliability concerns. In this paper, the mechanical properties of the lead-free solders and IMCs were characterized by nanoindentation. Both the Sn-rich phase and Ag3Sn + β-Sn phase in the lead-free solder joint exhibit strain rate depended and aging soften effect. When lead-free solder joints were subject to thermal aging, Young's modulus of the (Cu, Ni)6Sn5 IMC and Cu6Sn5 IMC changed in very small range. While the hardness value decreased with the increasing of the thermal aging time.

Characterization of Nanoparticles of Lead Free Solder Alloys

2006 ◽  
Author(s):  
Wanbing Guan ◽  
Suresh Verma ◽  
Yulai Gao ◽  
Cristina Andersson ◽  
Qijie Zhai ◽  
...  
Keyword(s):  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Free Solder

Electrical Resistivity of Fe-Bearing Sn1Ag0.5Cu Lead-Free Solder Alloys

2014 ◽  
Vol 895 ◽  
pp. 575-579
Author(s):  
Nur Aishah Aminah Mohd Amin ◽  
Dhafer Abdul Ameer Shnawah ◽  
Mohd Faizul Mohd Sabri ◽  
Suhana Binti Mohd Said
Keyword(s):  
Electrical Resistivity ◽  
Solder Alloy ◽  
Low Cost ◽  
Lead Free ◽  
Solder Alloys ◽  
Hazardous Element ◽  
Sac105 Solder ◽  
Free Solder ◽  
Lead Free Solders ◽  
Fe Addition

This paper reports on the effect of Fe addition in the range of 0.1 wt.% to 0.5 wt.% on the electrical resistivity of the Sn-1Ag-0.5Cu (SAC105) solder alloy. The electrical resistivity is characterized by the four-point probe technique. Results showed that the Fe-bearing SAC105 solder alloys exhibit lower electrical resistivity compared with the standard SAC105 solder alloy. Moreover, the electrical resistivity further decreases with increasing the amount of Fe addition. As Fe is a low-cost and non-hazardous element, along with the high mechanical reliability, the Fe-bearing SAC105 solder alloys also demonstrate good electrical characteristics, and hence may be an attractive candidate for a low cost, reliable formulation for lead free solders in electronics packaging.

scholarly journals Effects Of Nickel On The Microstructure And The Mechanical Properties Of Sn-0.7Cu Lead-Free Solders

2015 ◽  
Vol 60 (2) ◽  
pp. 1449-1454 ◽  
Author(s):  
A. Gyenes ◽  
A. Simon ◽  
P. Lanszki ◽  
Z. Gácsi
Keyword(s):  
Mechanical Properties ◽  
Morphological Evolution ◽  
Nickel Content ◽  
Lead Free ◽  
Solder Alloys ◽  
Nickel Addition ◽  
Free Solder ◽  
Ni Additions ◽  
Lead Free Solders ◽  
Addition Level

AbstractThis paper investigates the effects of small amount nickel addition (0, 200, 400, 800, 1800 ppm) on the microstructure and the mechanical properties of Sn-0.7Cu lead-free solder alloys. It is known that even ppm level Ni additions have significant effects on the microstructure of Sn-Cu solder alloys. Ni suppresses the growth ofβ-Sn dendrites in favour of eutectic formation. As the nickel content increases, the microstructure undergoes a morphological evolution from hypoeutectic through fully eutectic to hypereutectic. Along with these transformations, the mechanical properties of the alloy also significantly change. Based on the experimental results presented in this paper, the Sn-0.7Cu solder achieves maximum strength at the addition level of 800 ppm Ni, when the microstructure becomes fully eutectic.

How Silver Powder Metallurgy Affects the Physical Properties of Low Temperature Firing Silver Conductor

2011 ◽  
Vol 2011 (1) ◽  
pp. 000099-000106 ◽  
Author(s):  
Samson Shahbazi ◽  
Mark Challingsworth
Keyword(s):  
Powder Metallurgy ◽  
Thick Film ◽  
Silver Powder ◽  
Lead Free ◽  
Lead Free Solder ◽  
Pure Silver ◽  
Solder Alloys ◽  
Film Conductor ◽  
Free Solder ◽  
Lead Free Solders

With the implementation of RoHS (the Restriction of Hazardous Substance) Directive banning the use of Lead, Cadmium, Mercury and Hexavalent Chromium, hybrid microelectronic manufacturers are globally embracing the lead free movement. These manufacturers must not only understand the implications of their material choice but must be aware of the interaction between lead free solder alloys and their RoHS compliant thick film materials. It is commonly known that lead free solder alloys process at much higher reflow temperatures than lead containing solder which can directly impact the fired film leach resistance and the loss of adhesion. There are also other concerns; lead free solders alloys generally require a different organic flux system to promote wetting and reflow, but this change may cause a fired film conductor to leach more easily than the flux used in the lead containing solders. The use of lead free solders such as SAC305, SAC405 or 95/5 on a low firing (550–570 °C) pure silver conductor has the tendency of leaching the fired film more readily than conductors containing small amounts of palladium or platinum. Many of these situations provide new challenges for the hybrid circuit manufacturer. There is little information available regarding the effects of the lead free solders on low firing silver thick film conductors. This paper discusses the results of a newly developed Pb and Cd free silver thick film conductor paste with a modified silver powder metallurgy to improve the leach resistance, solder acceptance and adhesion using lead free solder. In addition, the pure silver conductor was fired on top of a low temperature dielectric paste. This conductor was evaluated by comparing lead free solder alloys to traditional tin-lead-silver solder alloys. This study included evaluations based on SEM photos, solderability, leach resistance, and initial and long term adhesions. Results are published describing the difference in behavior between the different solder alloys in conjunction with the different silver powder metallurgy.

Characterization of Lead-Free Solder Interconnects Reliability Under Torsional Loads

2009 ◽  
Author(s):  
Vikram Srinivas ◽  
Moustafa Al-Bassyiouni ◽  
Michael Osterman ◽  
Michael Pecht
Keyword(s):  
Rapid Assessment ◽  
Lead Free ◽  
Solder Paste ◽  
Solder Interconnects ◽  
Portable Electronics ◽  
Snpb Solder ◽  
Torsional Loads ◽  
Free Solder ◽  
Lead Free Solders

Mechanical torsion loads often arise in portable electronics under life cycle conditions. With increased market pressure, drive to reduce time to market, and varying use conditions, it is critical to develop accelerated tests to evaluate reliability quickly. Mechanical torsion testing can provide a rapid assessment technique to characterize solder interconnect durability. This paper presents an evaluation of select lead-free solders, SAC305 (96.5Sn-3.0Ag-0.5Cu) and SN100C (99.25Sn-0.7Cu-0.05Ni+Ge), under mechanical torsion loading. For comparison, SnPb (63Sn-37Pb) solder was also evaluated. Common test vehicles with resistor 2512 packages were used for these tests. For the mechanical cycle tests, no statistical difference in reliability was observed between SAC305 and SnPb solder paste while SN100C solder pastes were found to exhibit lower durability during Weibull analysis.

Aging Induced Mechanical Property Degradation and Microstructure Evolution of SAC+X Lead Free Solder Alloys

2013 ◽  
Author(s):  
Zijie Cai ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall ◽  
Michael J. Bozack
Keyword(s):  
Thermal Cycling ◽  
Aging Time ◽  
Aging Temperature ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Stress Strain ◽  
Free Solder ◽  
Effects Of Aging ◽  
Lead Free Solders

The microstructure, mechanical response, and failure behavior of lead free solder joints in electronic assemblies are constantly evolving when exposed to isothermal aging and/or thermal cycling environments. In our prior work on aging effects, we have demonstrated that large degradations occur in the material properties (stiffness and strength) and creep behavior of Sn-Ag-Cu (SAC) lead free solders during aging. These effects are universally detrimental to reliability and are exacerbated as the aging temperature and aging time increases. Conversely, changes due to aging are relatively small in conventional Sn-Pb solders. In our current work, we are exploring several doped SAC+X alloys in an attempt to reduce the aging induced degradation of the material behavior of SAC solders. The doped materials are lead free SAC solders that have been modified by the addition of small percentages of one or more additional elements (X). Using dopants (e.g. Bi, In, Ni, La, Mg, Mn, Ce, Co, Ti, Zn, etc.) has become widespread to enhance shock/drop reliability, wetting, and other properties; and we have extended this approach to examine the ability of dopants to reduce the effects of aging and extend thermal cycling reliability. In this paper, we concentrate on presenting the results for SAC+X (X = Zn, Co, Ni). The enhancement of aging resistance for the doped lead free solders was explored. Comparisons were made to the responses of non-doped SAC lead free solder alloys. The effects of aging on mechanical behavior have been examined by performing stress-strain and creep tests on solder samples that were aged for various durations (0–6 months) at elevated temperature (100 °C). Variations of the mechanical and creep properties (elastic modulus, yield stress, ultimate strength, creep compliance, etc.) were observed and modeled as a function of aging time and aging temperature. Our findings show that the doped SAC+X alloys illustrate reduced degradations with aging for all of the aging temperatures considered. Also, the stress-strain and creep mechanical properties of doped solders are better than those of reference solders after short durations of aging. After long term aging, doped solder alloys were found to have more stable behaviors than those of the standard SAC alloys. A parallel microstructure study has shown that less degradation and coarsening of the phases occurs in doped solder materials relative to non-doped solders after severe aging.

Bismuth-Antimony as an Alternative for High Temperature Lead Free Solder

2012 ◽  
Vol 476-478 ◽  
pp. 1163-1168 ◽  
Author(s):  
M.Z. Shahrul Fadzli ◽  
M.A. Azmah Hanim ◽  
T. Sai Hong ◽  
A. Aidy ◽  
R. Rohaizuan
Keyword(s):  
High Temperature ◽  
Solder Alloy ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Bulk Analysis ◽  
Rich Phase ◽  
Solder Bulk ◽  
Free Solder ◽  
Lead Free Solders

The development works on high temperature lead free solder are mostly discussed nowadays. To replace the current high temperature lead free solders, further research need to be done. A great deal of effort has been put into the development of lead free solder alloys. Bi (Bismuth) and Sb (Antimony) solder system proved as one of the promising candidates for electronic assembly. Melting temperature of three Bi-Sb solder alloys studied in this research enhanced their potential as the alternative solder candidates for high temperature lead free solder. At interface, Cu3Sb IMC layer was formed for 95Bi-5Sb solder alloy. Spallation of Cu3Sb IMC layer took placed with the results of Cu3Sb IMC also found in the solder bulk. Analysis of 97.5Bi-2.5Sb solder alloy classified as no metallurgical reaction at the interface and only the mechanical joining existed at the interface. The dissolution of Cu from subtrate affected the formation of Cu rich phase and the unstable Bi-Cu rich phase phenomena act as the isothermal product found in solder bulk. Mechanical grain boundary grooving observed in 98.5Bi-1.5Sb solder alloys at interface. Different compositions of Bi-Sb solder alloys resulted in different types of microstructures at interface and in solder bulk after reflow.

Electrodeposition as an Alternative Route to Prepare Nanostructured Lead-Free Solder Alloy: A Short Review

2015 ◽  
Vol 1113 ◽  
pp. 554-559
Author(s):  
Sakinah Mohd Yusof ◽  
Md Amin Hashim ◽  
Junaidah Jai ◽  
Abdul Hadi
Keyword(s):  
Solder Alloy ◽  
Short Review ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Electronic Manufacturing ◽  
Melting Temperatures ◽  
Magnetization Density ◽  
Free Solder ◽  
Lead Free Solders

With world-wide strict legislation for reduction or removal of lead from industrial waste, development of a large number of lead-free alternative solder materials had been intensively examined. The drive for lead-free solders development was towards systems that can imitate conventional lead containing solder alloys in terms of melting temperatures and improvement of mechanical properties. Nanostructured solder alloy, with a grain size of typically < 100 nm, was a new class of materials with properties distinct from and frequently distinguished to those of the conventional alloy. In comparison, nanostructured solder alloys exhibit higher strength and hardness, enhanced diffusivity, and excellent soft and hard magnetic properties. Numerous different techniques were performed to synthesize these nanostructured solder alloys. Electrodeposition method has generated huge interest in nanostructured solder preparation, mainly due to its ability to deposit solders selectively and uniformly at nanoscale. These factors bring significant influences on the behaviors of products, such as magnetization, density, ductility, wear resistance, corrosion resistance, porosity, molecular structure, and crystal properties which plays a vital part in the field of electronic manufacturing. In this paper, a short review on the electrodeposition, a useful technique to deposit different metals and alloys, as a method for nanostructured lead-free solder alloys preparation is presented.

Sign in / Sign up

Export Citation Format

Share Document