scholarly journals Structural and mechanical characteristics of some lead-free Cu-Sn based solder alloys

2008 ◽  
Vol 62 (3) ◽  
pp. 160-163 ◽  
Author(s):  
Aleksandra Mitovski ◽  
Ljubisa Balanovic ◽  
Dragana Zivkovic ◽  
Sasa Marjanovic ◽  
Bata Marjanovic ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Dendritic Structure ◽  
Production Method ◽  
Experimental Results ◽  
Lead Free ◽  
Solder Alloys ◽  
Slow Cooling ◽  
Mechanical And Electrical Properties ◽  
Additional Thermal Treatment ◽  
Lead Free Solders

The results of structural and mechanical characteristics of lead-free Cu-Sn based solder alloys, produced in Company "11. mart" AD Srebrenica (Republic of Srpska), are presented in this paper. The results of investigation of samples - alloys CuSnl4, CuSnlFelAlO.5, CuSnlOFelAllMnO.5 and CuA110Fe3Mn produced by different processing methods, include the data obtained by optical microscopy and measurements of hardness, micro hardness and electroconductivity, in order to characterize mentioned alloys and define the influence of processing method applied on their structural and mechanical properties. Microstructural experimental results of samples produced by casting in a metal mould with fast water cooling showed clearly sharp dendritic structure. Samples obtained by casting in a sand mould, displayed structure with big crystals, higher amount of segregation and inclusions on the grain boundaries, as a result of the slow cooling process. Hardness and microhardness tests showed increasing values as the amount of tin raised. Sample 3 showed the lowest value, as a result of the crystallization process and lackness of additional thermal treatment. Experimental results of the electroconductivity test showed that mentioned sample has got the highest value, which can be also explained by its production method. Results presented in this paper can contribute to investigations of copper-tin lead-free alloys, having in mind that various potential lead-free solders still haven't been completely investigated from the aspects of their structural, mechanical and electrical properties.

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.

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.

scholarly journals Research Status of Evolution of Microstructure and Properties of Sn-Based Lead-Free Composite Solder Alloys

2020 ◽  
Vol 2020 ◽  
pp. 1-25
Author(s):  
Shuai Li ◽  
Xingxing Wang ◽  
Zhongying Liu ◽  
Feng Mao ◽  
Yongtao Jiu ◽  
...  
Keyword(s):  
Composite Solder ◽  
Lead Free ◽  
Research Progress ◽  
The Novel ◽  
Solder Alloys ◽  
New Novel ◽  
Microstructure Morphology ◽  
Evolution Of Microstructure ◽  
Lead Free Solders ◽  
Recent Research Progress

With the miniaturization of solder joints and deterioration of serving environment, much effort had been taken to improve the properties of Sn-based lead-free solders. And the fabrication of Sn-based lead-free composite solder alloys by the addition of nanoparticles is one of the effective ways to enhance the properties. In this paper, the recent research progress on the Sn-based lead-free composite solder alloys is reviewed by summarizing the relevant results in representative ones of Sn-Ag-Cu (SAC), Sn-Bi, and other multielement lead-free composite solder alloys. Specifically speaking, the effect of the added nanoparticles on the evolution of wettability, microstructure morphology, and mechanical properties of Sn-based lead-free composite solder alloys are summarized. It is hoped that this paper could supply some beneficial suggestions in developing the novel Sn-based lead-free composite solder alloys. Additionally, the existed issues and future development trends in the exploitation of new novel Sn-based lead-free composite solder alloys are proposed.

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.

Sedimentation of Cu-rich intermetallics in liquid lead-free solders

2007 ◽  
Vol 22 (12) ◽  
pp. 3432-3439 ◽  
Author(s):  
Jenn-Ming Song ◽  
Yu-Lin Shen ◽  
Hsin-Yi Chuang
Keyword(s):  
Intermetallic Compounds ◽  
Critical Value ◽  
Experimental Results ◽  
Lead Free ◽  
Liquid Lead ◽  
Complete Dissolution ◽  
Cu Content ◽  
Lead Free Solders ◽  
Dissolution Potential

This study investigated the behavior of Cu-containing intermetallic compounds (IMCs) in liquid Sn–Ag and Sn–Zn solders. Experimental results show that for the intermetallics investigated, Cu–Sn and Cu–Zn compounds, the occurrence of settling was dominated by the crystalline temperature of IMCs, buoyancy due to difference in densities, and dissolution potential for the compounds into the liquid. The complete dissolution of Cu–Zn compounds, which took place in the Sn–Zn solders when the Cu content exceeded a critical value, might be ascribed to the depletion of Zn in the melt.

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.

scholarly journals Mechanical Characteristics of Sn-Ag-Based Lead Free Solders.

2002 ◽  
Vol 5 (6) ◽  
pp. 551-558
Author(s):  
Masazumi AMAGAI ◽  
Masako WATANABE ◽  
Masaki OMIYA ◽  
Kikuo KISHIMOTO
Keyword(s):  
Mechanical Characteristics ◽  
Lead Free ◽  
Lead Free Solders

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.

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.

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