A Replaceable Lead-Free Solder for Sn-37Pb

2011 ◽  
Vol 80-81 ◽  
pp. 108-112
Author(s):  
Yuan Shan Li ◽  
Xu Chen ◽  
Yu Feng Luo
Keyword(s):  
Mechanical Property ◽  
Melting Point ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Lead Free ◽  
Lead Free Solder ◽  
Melting Characteristics ◽  
Spinning Process ◽  
Free Solder ◽  
Bi Segregation

In this paper, a new kind of Sn-Bi lead-free solder was fabricated via rapid solidification method by adding a series of microelements which can optimize the properties of Sn-Bi solder. When the solder was manufactured by Single Roller Melt Spinning Process, the faster the cooling rate is, the better the effect of restraining Bi segregation is. When the melt spinning rate was up to 1000 rpm, it had the best result. The effects of microelements on the melting characteristics, microstructure and properties of the new solder were also systemically studied. The results show that when the added content of Ag is 0.7%, Cu 0.3%, Ge 0.1%, In 0.5% and Sb 0.5%, the microstructure of the solder is fine, the extent of Bi segregation obviously decreases and the mechanical property is similar to that of Sn-37Pb solder. The melting point of the new solder is close to that of the Sn-37Pb solder. The mechanical and soldering properties are also similar to that of it.

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.  

Evaluation of Emerging High Melting Point Lead-free Solder and Hybrid Sinter Paste as Attaching Material for Clip Bond Package

2020 ◽  
Vol 2020 (1) ◽  
pp. 000235-000241
Author(s):  
Fred Fuliang Le ◽  
Rinse van der Meulen ◽  
Yoon Kheong Leong ◽  
Manoj Balakrishnan ◽  
Zunyu Guan
Keyword(s):  
Melting Point ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reliability Testing ◽  
High Melting ◽  
High Melting Point ◽  
Basic Scheme ◽  
Free Solder ◽  
Lead Free Solders ◽  
High Lead

Abstract High melting point (HMP) lead-free solder, hybrid sinter and transient liquidus phase sinter (TLPS) are the emerging lead-free alternatives for the potential replacement of high-lead solder. Lead-free solder is perfectly compatible with existing high-lead soldering processes for clip bond packages. The benefit of hybrid sinter is that it has much higher thermal and electrical conductivity than lead-free or high-lead solder. In this study, ten materials (including lead-free solders, hybrid sinter paste and TLPS) were first evaluated via die shear test. With the initial material screening, two lead-free solders (solder 1 and 2), two hybrid Ag sinter pastes (sinter i and ii) and one TLPS proceeded to internal sample assembly. For the lead-free solders, a process optimization with the aid of vacuum reflow was made to reduce void rate. Due to the slow and unbalanced inter-diffusion of Ag-Cu sintering than Ag-Ag sintering, optimizations to enhance the hybrid Ag sintering include Ag finishing for the die metallization and Ag plating for the clip and bond area of the leadframe. In 0-hour package electrical test, solder 1 and sinter i passed and were sent for reliability testing while solder 2, sinter ii and TLPS failed due to intermetallic compound (IMC) cracking, material bleeding and die cracking, respectively. In the reliability testing, a basic scheme of thermal cycling (TC) 1000 cycles, intermittent operating life (IOL) 750 hrs and highly accelerated temperature and humidity stress test (HAST) 96 hrs was defined for the early feasibility study. 1 of 75 sinter i units failed by TC 1000 cycles due to separation between silver sinter structure and die bottom metallization. Solder 1 passed the basic scheme without defects, and next the material workability and clip bond strength need to be improved to the equivalent level of high-lead solders.

Microstructure Evolution, Thermal and Mechanical Property of Co Alloyed Sn-0.7Cu Lead-Free Solder

2020 ◽  
Vol 49 (4) ◽  
pp. 2660-2668 ◽  
Author(s):  
Jianglei Fan ◽  
Hengtao Zhai ◽  
Zhanyun Liu ◽  
Xiao Wang ◽  
Xiangkui Zhou ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Microstructure Evolution ◽  
Lead Free ◽  
Lead Free Solder ◽  
Free Solder

Effect of Cooling Rate on the Microstructural and Mechanical Properties of Sn-0.3Ag-0.7Cu-0.05Ni Solder Alloy

2017 ◽  
Vol 751 ◽  
pp. 9-13
Author(s):  
Kogaew Inkong ◽  
Phairote Sungkhaphaitoon
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Solder Alloy ◽  
Testing Machine ◽  
Optical Microscope ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cooling Systems ◽  
Lead Free Solder Alloy ◽  
Free Solder

The effect of cooling rate on the microstructural and mechanical properties of Sn-0.3Ag-0.7Cu-0.05Ni lead-free solder alloy was studied. The microstructure of specimens was characterized by using an optical microscope (OM) and an energy dispersive X-ray spectroscopy (EDX). The mechanical properties were performed by using a universal testing machine (UTM). The results showed that the cooling rate of water-cooled specimens was about 2.37 °C/s and the cooling rate of mold-cooled specimens was about 0.05 °C/s. To compare the different cooling rates, it was found that the grain size of water-cooled specimens was finer than that of the mold-cooled specimens, this resulted in an increment of mechanical properties of solder alloy. A higher tensile strength (33.10 MPa) and a higher elongation (34%) were observed when water-cooled and mold-cooled systems were used, respectively. The microstructure of Sn-0.3Ag-0.7Cu-0.05Ni lead-free solder alloy solidified by both cooling systems exhibited three phases: β-Sn, Ag3Sn and (Cu,Ni)6Sn5 IMCs.

Effect of Cooling Rate on Intermetallic Compounds Formation in Sn-Ag-Cu-In Solder

2018 ◽  
Vol 941 ◽  
pp. 2075-2080
Author(s):  
Kenji Miki ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Yusuke Nakata
Keyword(s):  
Solder Joint ◽  
Cooling Rate ◽  
Shear Force ◽  
Bonding Temperature ◽  
Lead Free ◽  
Joint Interface ◽  
Lead Free Solder ◽  
Vacuum Atmosphere ◽  
Free Solder ◽  
Large Formation

The effect of the cooling rate in bonding on IMCs formation and their morphology in the solder joint with Sn-3.0Ag-0.7Cu-5.0In (mass%) lead-free solder was investigated. As the substrate, the Cu plate and the Cu plate with electroplated Ni were prepared. Bonding was conducted in the vacuum atmosphere, and bonding temperature and time were 300°C and 10 minutes, respectively. The cooling rates in the bonding were changed from 0.02°C/s to 0.2°C/s. In both Cu/Cu and Cu/Ni joints, scallop-shaped IMCs form at the joint interfaces regardless of the cooling rate. In the Cu/Cu joint, Cu6(Sn,In)5 and Cu3(Sn,In) layers form at the joint interface. In the Cu/Ni joint, (Cu,Ni)6(Sn,In)5 and (Cu,Ni)3(Sn,In) layers form at the joint interface with Cu and the (Cu,Ni)6(Sn,In)5 layer forms at the joint interface with Ni. Die shear force of the Cu/Ni joints are a little larger than those of the Cu/Cu joints. Fracture occurs in the boundary between the scallop-shaped layer or the granular IMC layer and the layered IMC in both joints. The cooling rate from the peak temperature to solidification is an important factor to decide the shape of formed IMC. When the cooling rate is high and supercooling becomes large, formation of pillar-shaped IMCs occurs easily.

Physical and Mechanical Behaviors of SnCu-Based Lead-Free Solder Alloys with an Addition of Aluminium

2015 ◽  
Vol 815 ◽  
pp. 64-68 ◽  
Author(s):  
Nisrin Adli ◽  
Nurul Razliana Abdul Razak ◽  
Norainiza Saud
Keyword(s):  
Melting Point ◽  
Solder Alloy ◽  
Lead Free ◽  
Lead Free Solder ◽  
Mechanical Behaviors ◽  
Solder Alloys ◽  
Al Content ◽  
Homogenous Distribution ◽  
Lead Free Solder Alloy ◽  
Free Solder

The effect of Al addition on the microstructure, melting point and microhardness of SnCu-Al lead-free solder alloys were investigated with two different compositions of Al which were 1 wt% and 5 wt%. These solder alloys were fabricated through powder metallurgy (PM) method. The results showed that the melting point and the microhardness value of the SnCu-Al lead-free solder alloy were increased as the Al content increased from 1 wt% to 5 wt%. The grain growth of SnCu-Al lead-free solder alloy also tends to be retarded due to the homogenous distribution of Al at the grain boundaries.

Development and Characterisation of New Biocompatible Sn-Mg Lead-Free Solder

2019 ◽  
Vol 31 ◽  
pp. 6-10
Author(s):  
Martin Ďurišin ◽  
Juraj Ďurišin ◽  
Ondrej Milkovič ◽  
Alena Pietriková ◽  
Karel Saksl
Keyword(s):  
Melt Spinning ◽  
High Energy ◽  
Grain Structure ◽  
Lead Free ◽  
Lead Free Solder ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
Heterogeneous Distribution ◽  
X Ray ◽  
Free Solder

This work is focused on a development and research of a new lead-free Sn-Mg solder, alloy compatible with the human body. Tin and magnesium are biocompatible elements which do not cause an inflammation or allergic reactions with living tissues. We have prepared the Sn97Mg3 solder (wt. %) by a rapid solidification of its melt on a copper wheel (melt-spinning technique). This solder may find applications in electronic devices for intracorporeal utilisation. The microstructure of the prepared solder exhibits a heterogeneous distribution of the SnMg2 intermetallic particles within the β-Sn matrix. Structure of the solder was studied by an in-situ high energy X-ray diffraction experiment (energy of an X-ray photon: 60 keV) where 2D XRD patterns were collected from the sample in the temperature range from 298 K to 566 K. The experiment was performed at a high brilliance 3rd generation synchrotron source of radiation (PETRA III storage ring, DESY, Hamburg, Germany) at the P02 undulator beamline. From the measured X-ray diffraction data by applying the Rietveld refinement technique we have obtained thermal volume expansion data, mean positions of atoms as well as isotropic atomic displacement parameters of the constituent SnMg2 and the β-Sn crystalline phases. Thermal behaviour was studied by differential scanning calorimetry at heating rates of 5, 15, 30 and 60 K.min-1 and compared with the measured X-ray data. Our main goal lies in a preparation of a lead-free solder with fine grain structure made exclusively of biocompatible elements. We demonstrated that the rapid melt solidification technique leads to in an improvement and better thermal stability of this alloy.

Influence of Bismuth in Sn-Based Lead-Free Solder – A Short Review

2018 ◽  
Vol 273 ◽  
pp. 40-45
Author(s):  
Nurul Razliana Abdul Razak ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Norainiza Saud ◽  
Rita Mohd Said ◽  
Mohd Izrul Izwan Ramli
Keyword(s):  
Melting Point ◽  
Short Review ◽  
Lead Free ◽  
Service Reliability ◽  
Lead Free Solder ◽  
Alloying Element ◽  
Melting Temperatures ◽  
Intermetallic Growth ◽  
The Common ◽  
Free Solder

Since the implementation of RoHS in avoidance to useof lead in electronic packaging, the development of lead-free solder has become priority. However, some of the potential candidates for lead-free solder have weaknesses such as slightly higher of melting point, excessive of intermetallic growth (IMC) and uncertainty service reliability that need to overcome. One of the common methods used to improve the characteristic and properties of the lead-free solder is by the addition of another alloying element. One of the promising alloying elements is bismuth (Bi). A few researchers have found out that Bi has a capability to improve the microstructure, reduce the melting temperature and controlled the IMC growth, yet, its advantageous is believed have not been thoroughly explored. Influence of (Bi) in lead-free solder alloys give interest to be studied and understand from different perspective due to its capability to improve the wettability and solder spread, and also reduce the melting temperatures of the solder. In this paper, a review on influence of Bi inSn-based lead-free solder and its advantageous were discussed.

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