Intermetallic Study on the Modified Sn-3.5Ag-1.0Cu-1.0Zn Lead Free Solder

2016 ◽  
Vol 857 ◽  
pp. 3-7 ◽  
Author(s):  
Ramani Mayappan ◽  
Nur Nadiah Zainal Abidin ◽  
Noor Asikin Ab Ghani ◽  
Iziana Yahya ◽  
Norlin Shuhaime
Keyword(s):  
Electron Microscope ◽  
Powder Metallurgy ◽  
Joint Strength ◽  
Lead Free ◽  
Environmental Concerns ◽  
Lead Free Solder ◽  
Free Solder ◽  
Lead Free Solders ◽  
Powder Metallurgy Route ◽  
Scanning Electron

Due to environmental concerns, lead-free solders were introduced to replace the lead-based solders in microelectronics devices technology. Although there are many lead-free solders available, the Sn-Ag-Cu solders are considered the best replacement due to their good wettability and joint strength. Although the Sn-Ag-Cu solders are accepted widely, but there are still some room for improvement. In this study, 1wt% Zn, which can be considered high percentage for a dopant, was added into the solder via powder metallurgy route. The effects of adding this dopant into the Sn-3.5Ag-1.0Cu solder on the interface intermetallic and thickness were investigated. The intermetallics phases formed were observed under Scanning Electron Microscope (SEM) and their thicknesses were measured. The SEM results showed the presence of Cu6Sn5, Cu3Sn and (Cu,Zn)6Sn5 intermetallics. It can be concluded that Zn behaved as retarding agent and significantly retarded the growth of Cu-Sn intermetallics.

Intermetallic Evolution of Sn-3.5Ag-1.0Cu-0.1Zn/Cu Interface under Thermal Aging

2012 ◽  
Vol 620 ◽  
pp. 142-146 ◽  
Author(s):  
Iziana Yahya ◽  
Noor Asikin Ab Ghani ◽  
Nur Nadiah Zainal Abiddin ◽  
Hamidi Abd Hamid ◽  
Ramani Mayappan
Keyword(s):  
Powder Metallurgy ◽  
Lead Free ◽  
Environmental Concerns ◽  
Lead Free Solder ◽  
Intermetallic Formation ◽  
X Ray ◽  
Zn Addition ◽  
Free Solder ◽  
Lead Free Solders ◽  
Powder Metallurgy Route

Due to environmental concerns, lead-free solders were introduced in replacing the lead-based solders in microelectronics devices technology. Although there are many lead-free solder available, the Sn-Ag-Cu is considered the best choice. But the solder has its draw backs in terms of melting temperature and intermetallic formations. To improve the solder, a fourth element Zn was added into the solder. The new composite solders were synthesized via powder metallurgy route. This research studies the effect of 0.1wt% Zn addition on the hardness and intermetallic formation on Cu substrate. For the hardness results, the micro Vickers values were reported. For intermetallic, the solders were melted at 250°C and aged at 150°C until 400 hours. The microhardness value for Zn based composites solder shows higher micro Vickers hardness compared to un-doped counterparts. The phases formed and its growth was studied under SEM and by energy dispensive x-ray (EDX). The SEM results show the presence of Cu6Sn5and Cu3Sn intermetallics and the Cu5Zn8intermetallic was not detected. The addition of 0.1wt% Zn has retarded the growth of the Cu3Sn intermetallic but not the total intermetallic thickness.

Microstructure Evolution of Sn-3.5Ag-1.0Cu-0.5Ni/Cu System Lead Free Solder under Long Term Thermal Aging

2012 ◽  
Vol 620 ◽  
pp. 263-267 ◽  
Author(s):  
Noor Asikin Ab Ghani ◽  
Iziana Yahya ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Shamsuddin Saidatulakmar ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Copper Substrate ◽  
Lead Free ◽  
Environmental Concerns ◽  
Lead Free Solder ◽  
Melting Temperatures ◽  
Ni Addition ◽  
Free Solder ◽  
Lead Free Solders ◽  
Powder Metallurgy Route

Due to environmental concerns, lead-free solders were introduced in replacing the lead-based solders in microelectronics devices technology. Although there are many lead-free solder available, the Sn-Ag-Cu solder was considered the best choice. But the solder has its draw backs in terms of melting temperature and intermetallic formations. In this study, the effect of 0.5wt% Ni addition on the microstructure of the Sn-3.5Ag-1.0Cu solder was investigated. The solder was synthesized via powder metallurgy route which includes blending, compacting and sintering. The solders were characterized for its densities and melting temperatures. SEM was used to observe the microstructure of intermetallic phases. The solders were melted on copper substrate at 250°C for one minute and aged at 150°C from 0 to 400 hours. The phases formed were studied under SEM. The SEM results showed the presence of Cu6Sn5, Cu3Sn, Ag3Sn and (Cu,Ni)6Sn5 intermetallics.

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.

Wettability, Electrical and Mechanical Properties of 99.3Sn-0.7Cu/Si3N4 Novel Lead-Free Nanocomposite Solder

2011 ◽  
Vol 277 ◽  
pp. 106-111 ◽  
Author(s):  
Mohd Arif Anuar Mohd Salleh ◽  
Muhammad Hafiz Hazizi ◽  
Zainal Arifin Ahmad ◽  
Kamarudin Hussin ◽  
Khairel Rafezi Ahmad
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Solder Alloy ◽  
Base Alloy ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder ◽  
Nano Size ◽  
Nanocomposite Solder ◽  
Powder Metallurgy Route

A nanocomposite solder alloy with 99.3Sn-0.7Cu base alloy was successfully fabricated using the powder metallurgy route which consists of blending, compaction and sintering. Varying amount of nano size silicon nitride particulates were introduced as reinforcements to obtain a novel lead-free nanocomposite solder alloy. Following fabrication, the sintered nanocomposite solder were cut into thin solder disc and were analyzed in terms of their wettability, electrical and mechanical properties. Wettability, electrical and mechanical properties of the nanocomposite solder were compared to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder which were fabricated with the same method using powder metallurgy route. Wettability property of the nanocomposite solder was found to be in the accepted range with wettability angle below 45° similar to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder. Besides wettability, the results of electrical and mechanical properties analysis showed that additions of nano size Si3N4 had enhanced the strength and electrical conductivity of nanocomposite solder comparing to 99.3Sn-0.7Cu and 96.3Sn-3.0Ag-0.5Cu lead-free solder.

The Effects of Zinc Addition on the Microstructure, Melting Point and Microhardness of Sn-0.7Cu Lead-Free Solder Fabricated via Powder Metallurgy Method

2016 ◽  
Vol 857 ◽  
pp. 13-17 ◽  
Author(s):  
Nisrin Adli ◽  
Nurul Razliana Abdul Razak ◽  
Norainiza Saud
Keyword(s):  
Powder Metallurgy ◽  
Melting Point ◽  
Lead Free ◽  
Powder Metallurgy Method ◽  
Lead Free Solder ◽  
Zn Addition ◽  
The World ◽  
Zinc Addition ◽  
Free Solder ◽  
Lead Free Solders

The attempt to produce various types of lead-free solder has been actively investigated around the world in order to substitute the harmful SnPb solders. The effects of Zn addition on the microstructure, melting point and microhardness of Sn-0.7Cu lead-free solder were investigated with 1 wt% and 5 wt% of Zn additions. Powder metallurgy (PM) method was used to fabricate these Sn-0.7Cu-Zn lead-free solders. The results revealed that the addition of Zn was able to improve the solder properties. The melting point of Sn-0.7Cu-Zn lead-free solder was decreased drastically as the increasing of Zn additions. The Zn particles were distributed homogenously along the grain boundaries and produced refined dendrite β-Sn, which also lead to a superior microhardness values of solders.

Effect of aluminum content on structure, transport and mechanical properties of Sn-Zn eutectic lead free solder alloy rapidly solidified from melt.

2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Lead Free ◽  
Al Alloy ◽  
Lead Free Solder ◽  
Pronounced Increase ◽  
Mass Unit ◽  
Size Refinement ◽  
Free Solder ◽  
Lead Free Solders

The greatest advantage of Sn-Zn eutectic is its low melting point (198 oC) which is close to the melting point. of Sn-Pb eutectic solder (183 oC), as well as its low price per mass unit compared with Sn-Ag and Sn-Ag-Cu solders. In this paper, the effect of 0.0, 1.0, 2.0, 3.0, 4.0, and 5.0 wt. % Al as ternary additions on melting temperature, microstructure, microhardness and mechanical properties of the Sn-9Zn lead-free solders were investigated. It is shown that the alloying additions of Al at 4 wt. % to the Sn-Zn binary system lead to lower of the melting point to 195.72 ˚C.  From x-ray diffraction analysis, an aluminium phase, designated α-Al is detected for 4 and 5 wt. % Al compositions. The formation of an aluminium phase causes a pronounced increase in the electrical resistivity and microhardness. The ternary Sn-9Zn-2 wt.%Al exhibits micro hardness superior to Sn-9Zn binary alloy. The better Vickers hardness and melting points of the ternary alloy is attributed to solid solution effect, grain size refinement and precipitation of Al and Zn in the Sn matrix.  The Sn-9%Zn-4%Al alloy is a lead-free solder designed for possible drop-in replacement of Pb-Sn solders.  

Morphology and Intermetallic Study of (Sn-8Zn-3Bi)-1Ni Solder under Liquid State Aging

2015 ◽  
Vol 1087 ◽  
pp. 162-166
Author(s):  
Nor Aishah Jasli ◽  
Hamidi Abd Hamid ◽  
Ramani Mayappan
Keyword(s):  
Liquid State ◽  
Copper Substrate ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Time ◽  
Intermetallic Formation ◽  
X Ray ◽  
Ni Addition ◽  
Free Solder ◽  
Scanning Electron

This study investigated the effect of Ni addition on intermetallic formation in the Sn-8Zn-3Bi solder under liquid state aging. The intermetallic compounds were formed by reacting the solder alloy with copper substrate. Different reflow time was used at temperature 220°C. Morphology of the phases formed was observed using scanning electron microscope (SEM) and in order to determine elemental compositions of the phases, energy dispersive x-ray (EDX) was used. The formation of the reaction layer led by Cu5Zn8 intermetallic and then followed by Cu6Sn5 and Cu3Sn when reflow time increases. Keywords: lead free solder, intermetallic, Cu5Zn8, Cu6Sn5, liquid state aging.

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.

Effect of Aging on the Properties of Intermetallic Layers in SAC+Bi Solder Joints

2021 ◽  
Author(s):  
Mohammad Ashraful Haq ◽  
Mohd Aminul Hoque ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Aging Condition ◽  
Sac305 Solder ◽  
The Poor ◽  
Free Solder ◽  
Lead Free Solders ◽  
Overall Reliability ◽  
Intermetallic Layers

Abstract A major problem faced by electronic packaging industries is the poor reliability of lead free solder joints. One of the most common methods utilized to tackle this problem is by doping the alloy with other elements, especially bismuth. Researches have shown Bismuth doped solder joints to mostly fail near the Intermetallic (IMC) layer rather than the bulk of the solder joint as commonly observed in traditional SAC305 solder joints. An understanding of the properties of this IMC layer would thus provide better solutions on improving the reliability of bismuth doped solder joints. In this study, the authors have used three different lead free solders doped with 1%, 2% and 3% bismuth. Joints of these alloys were created on copper substrates. The joints were then polished to clearly expose the IMC layers. These joints were then aged at 125 °C for 0, 1, 2, 5 and 10 days. For each aging condition, the elastic modulus and the hardness of the IMC layers were evaluated using a nanoindenter. The IMC layer thickness and the chemical composition of the IMC layers were also determined for each alloy at every aging condition using Scanning Electron Microscopy (SEM) and EDS. The results from this study will give a better idea on how the percentage of bismuth content in lead free solder affects the IMC layer properties and the overall reliability of the solder joints.

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