Free Solder Alloys Research Articles

Comparison of the Young’s modulus of the lead free solder alloy Sn-Ag3.8-Cu0.7 determined by hot tensile tests, ultrasonic measurements and [formula omitted]-Sn single crystal calculations

Comparison of the Young’s modulus of the lead free solder alloy Sn-Ag3.8-Cu0.7 determined by hot tensile tests, ultrasonic measurements and [formula omitted]-Sn single crystal calculations

Investigation of the Structural and Mechanical Properties of ((82-X) Sn –XCu -18 In) % Alloy with X= 1,2,3,4and 5

Materials Science is concerned with the development or synthesis of new materials . For this reason our interest is focused on the fabrication of new materials , such as lead free solder alloys . Sn-In alloys offer very low melting points and bond well with copper .This study aims to investigate The Structural and mechanical properties of (82-x)Sn -18In alloys with added copper .The Samples were prepared by melting technology From high purity (99 %) elements tin ,indium and copper .XRD showed the formation of a single phase hexagonal structure with a small copper plane, and the addition of copper decreased the particle size of the (82-x)Sn -18 In. The creep test results showed that Cu-containing solder alloys exhibited significant improvements in creep resistance. However, the average activation energy decreases with copper addition from 0.322 to 0.247 eV.

Modification Structure and their Effects on Physical Properties of Tin Based Lead Free Solder Alloys for Industrial Applications

Soldering properties such as melting temperature and wettability of tin-zinc alloy improved after adding different alloying elements such as indium, aluminum, cadmium and bismuth. Decreasing zinc content (Sn91Zn9) up to 4% (Sn96Zn4 alloy) increased corrosion resistance from -0.847 to -0.530 and decreased corrosion rate from 51.84 to 7.705 mpy. Microstructure of tin-zinc alloy changed with increasing hardness value of it after adding alloying elements. Tin-zinc alloys have lower melting temperature compared to Sn95Sb5, Sn96.5Ag3.5 and Sn99.3Cu0.7 alloys. The Sn90Zn4Bi6 alloy has beast solder properties for electronic industrial applications.

Electrochemical Corrosion Behavior of Sn–1.0Ag–0.5Cu and Sn–3.8Ag–0.7cu Lead Free Solder Alloys During Storage and Transportation Under Chloride Working Condition

Electrochemical Corrosion Behavior of Sn–1.0Ag–0.5Cu and Sn–3.8Ag–0.7cu Lead Free Solder Alloys During Storage and Transportation Under Chloride Working Condition

Analysis of the viscoplastic behavior of Pb-free solder using lap shear joints

The single lap shear tests were conducted on the most popular lead free solder alloy at two different shear strain rates ( γ ̇ =0.01 s −1 and 0.00001 s −1 ) in combination with three different temperatures ( T = 25° C , 75° C , and 125° C ) to determine the viscoplastic model parameters utilizing the shear stress-strain data. The yielding of shear stress-strain curves was predicted and a unified viscoplastic model was proposed to calculate the entire shear stress-strain curves using material parameters and shear modulus. The shear stress-strain curves, which were obtained through lap shear tests and calculated by the model, show a very good relationship. Moreover, a finite element model, which was developed to create a lap shear simulation, calculates the shear stress-strain curves that make a reasonable agreement with the experimental data too. Plastic work/volume for monotonic lap shear and hysteresis curves for cyclic lap shear that are important parameters for predicting crack initiation and propagation of solder joint were calculated using a finite element model. As predicted, the variation of plastic works and hysteresis curves were observed due to strain rate and temperature changes. A thermal cycling simulation, which was created by utilizing the finite element model of lap shear specimen, demonstrates accumulation of plastic work occurred during ramping step rather than dwelling step. • A constitutive model of the solder joint is proposed based on Anand model using lap shear test data. • The yielding of shear stress-strain curves was predicted. • The study implemented finite element analysis to simulate the viscoplastic behavior of a solder joint. • Investigations of Viscoplasticity were reported through monotonic shear, cyclic shear and plastic work. • The cracking behavior was predicted by the model and was ascribed to the ramping stage.

Effect Of 3% Molybdenum (Mo) Nanoparticles on The Melting, Microstructure and Hardness Properties of As- Reflowed Low Mass Sn-58Bi (SB) Solder Alloy

The Sn-58Bi (SB) lead free solder alloy tested in this research with addition of 3% Molybdenum (Mo) nanoparticles equivalent to 0.6g mass to analyse the influences in the thermal, microstructure and microhardness. Elevation of 3.8°C was observed from the Differential Scanning Calorimetry (DSC) for the 3% Mo nanoparticles added SB solder alloy compared to the bare Sn-58Bi (SB) solder alloy that has a melting temperature of 142.25°C. The microstructures of the reinforced SB solder alloy were refined with closer lamellar structures of ?-Sn and Bi phases compared to the unreinforced SB solder. The SEM/EDX and X-ray Diffraction (XRD) results validate the presence of the 3% Mo nanoparticles in the SB solder. Mechanical properties by means of Vickers microhardness of the Mo reinforced solder alloy showed an increment in hardness value by 2% compared to the bare SB solder alloy. The presence of 3% Mo as discrete particles (dispersion strengthening) contributes to the increase on the hardness value. The introduction of 3% Mo in to the SB solder alloy resulted in increase in the hardness due to the refinement of the microstructure and at the same time allows low temperature soldering in the electronic packaging industry.

Contact Angle of Sn-8Zn-3Bi Lead-free Solder Alloy on Copper Substrate

The wettability of Sn-8Zn-3Bi lead free solder alloy on the copper substrate was evaluated via measuring the contact angle of the solder and the substrate. The measured contact angle was then compared to the contact angle of the traditional and widely used eutectic Sn-37Pb solder alloy. Experiments to study the effect of temperature, flux, and surface roughness of the substrate on the contact angle were also carried out. The results show that the contact angle of Sn-8Zn-3Bi on copper substrate decreased as temperature increases. The minimum value of the contact angle obtained was approximately 23° for Sn-8Zn-3Bi. At the same experimental conditions, contact angle of Sn-8Zn-3Bi is higher than that of Sn-37Pb. When three types of fluxes were used, at 230°C, contact angle of Sn-8Zn-3Bi has the smallest value with the MHS37 flux, 25°, and it has the largest value with the zinc chloride flux, 47°. The surface roughness of the substrate has little influence on contact angle of Sn-8Zn-3Bi on copperand the contact angle has changed a few degrees as the roughness changed.

‌Influence of Small Amount of Cu Addition on Microstructure, Deformation Temperature, and the Tensile Behaviour of Sn-9Zn-1.5Ag Lead free Solder Alloy

‌Influence of Small Amount of Cu Addition on Microstructure, Deformation Temperature, and the Tensile Behaviour of Sn-9Zn-1.5Ag Lead free Solder Alloy

Investigations on the Corrosion Properties of Sn–0.5Cu–Bi–xAg Lead Free Solder Alloys in 3.5% NaCl Solution

Various environment legislations lead to the ban of Pb in solder alloy making. Solder alloy is an integral part of electronic packaging industry. As a result of this researchers were searching for new combinations without lead which can replace Sn–Pb solder alloy. The new lead free solder joint should possess good mechanical properties, good wetting properties and good corrosion resistance properties. Many lead free solder alloys were discovered. Sn–0.5Cu–3Bi is a good candidate for replacing the Sn–Pb alloy with good properties. The addition of Ag into the alloy enhanced the properties, especially 1% by wt. Ag. In this paper, investigations on the corrosion behavior of Sn–0.5Cu–3Bi–xAg (x = 0, 0.5, 1% by wt.) in 3.5% NaCl is carried out using weight loss method. Microstructure and EDAX analysis were also conducted in the analysis. It is found that the corrosion rate is minimum with 1% by wt. addition of Ag. Corrosion rate is less when compared with the SAC (Sn–Ag–Cu). Sn–0.5Cu–3Bi–1Ag can be considered as a potential lead free solder joint with good corrosion resistance.

Experimental Investigations on Impact Toughness and Shear Strength of Lead Free Solder Alloy Sn–0.5Cu–3Bi–xAg

Lead is banned in alloy making citing toxicity concerns and environmental legislations. Researchers around the world were in search of new lead free solder alloys which could replace the old Sn–Pb alloy. Solder alloys are important electronic material used in electronics package industries. In this study, shear strength and impact toughness tests were conducted on Sn–0.5Cu–3Bi when different amounts of Ag (0.25, 0.5, 0.75, 1 wt%) is added. Shear strength test is done using micro force test system. Impact toughness test is done using Charpy impact test set up by finding the energy difference before and after impact. Ultimate shear stress is found to be increased from 17.3 to 23 MPa. Yield strength is found to be increased from 23.4 to 28 MPa. Impact toughness of the alloys increased from 10.4 to 11.3 J. EDAX analysis and mapping of the Sn–0.5Cu–3Bi–1Ag is also obtained Sn–0.5Cu–3Bi–1Ag is found to be having good improved shear strength and impact toughness than Sn–0.5Cu–3Bi.

Factorial design and design of experiments for developing novel lead free solder alloy with Sn, Cu and Ni

Inherent toxicity makes lead a banned material in solder alloy making process. Lead-tin alloy was a favorable alloy used for soldering in electronic packaging manufacturers. As a result of the ban on lead, electronics package industries were looking for novel lead free alloys which can substitute the conventional Sn-Pb alloy. Many alloys were discovered by the scientists. None of them were able to substitute the Sn-Pb alloy and become the market leader. In this paper a new composition with Sn, Cu and Ni is made to analyze which can potentially replace the lead containing solder alloy. Using the design of experiments method, the optimized composition of Cu and Ni is predicted. The full factorial design of experiments with two replications is used to find the optimized composition. Melting temperature, contact angle and hardness were taken as the critical output parameters. Results obtained shows that the optimum composition of Cu and Ni are 1 and 1% by wt.

Investigation of Microstructure and Mechanical Properties of Different Nano - Particles Doped Sn-Zn Lead-Free Solder Alloys

This study investigate the effect of two different nano-particle additions; namely copper oxide (CuO) and/or titanium oxide (TiO2) to modify the properties of Sn-9wt. % Zn lead free solder alloy. The composite approach has been developed to enhance the microstructure and mechanical properties of lead free solder. The microstructure before and after alloy modification were investigated. Results indicated that 1wt.% of either CuO and /or TiO2 lead to microstructure refinement due to the the nanosized reinforced particles which dispersed uniformly in the solder matrix. A significant improvement is achieved by 1 wt.% TiO2 addition to Sn-9wt. % Zn. In the current work we have extended our studies to show the effect of different aging temperatures (75, 100, 125, 150 °C) on the solder alloy doped with 1wt.% TiO2. Anomalous effect was shown at the aging temperature of 100°C due to the dissolution of Zn-metal in the β-Sn rich phase. The stress exponent values for the solder alloy doped with TiO2 were found to be varied with aging temperatures between (4.7-14.9) respectively.

Interfacial reactions between different Sn-based lead- free solder alloys and CuNi substrates

The effect of the presence of Ni in Cu substrates on the interface reaction during soldering and the growth of Sn-Cu intermetallic compounds (IMCs) was studied. The study involved reflow soldering of Sn-0.7Cu, Sn- 3Ag-0.5Cu and Sn-0.7Cu-0.05Ni lead-free solders on pure Cu and Cu-6Ni substrates with holding times of 5, 10 and 15 minutes at 232 °C. The presence of 6 wt% Ni in the Cu substrate strongly affects the microstructural evolution and the growth of the IMCs. The presence of Ni in the substrate significantly increased the overall thickness of the (Cu,Ni)6Sn5 layer while suppressing the formation of the Cu3Sn layer. The thickness of the (Cu,Ni)6Sn5 layer increased with reflow time for both Cu and Cu-6Ni substrate.

Experimental Investigations on Impact Toughness and Shear Strength of Novel Lead Free Solder Alloy Sn-1Cu-1Ni-XAg

Abstract Lead is known to be banned in alloy making, highlighting toxicity concerns and environmental legislations. Researchers and scholars around the globe were in immediate search of new lead free solder alloys which could potentially replace the old Sn-Pb alloy. In this comprehensive study, shear strength and impact toughness tests were conducted on Sn-1Cu-1Ni when different amounts of Ag (0.25, 0.5, 0.75 1 % by wt.) is added. Shear strength test is tested using micro force test system. Impact toughness test is analyzed using Charpy impact test set up by calculating the energy difference before and after impact. The study reveals that, Ultimate shear stress increased from 19 MPa to 21.3 MPa. Yield strength increased from 27.4 MPa to 29.7 Mpa. Impact toughness of the alloys increased from 9.4 J to 10.1 J. Thus, Sn-1Cu-1Ni-1Ag is found to have improved shear strength and impact toughness than Sn-1Cu-1Ni.

An Experimental Investigation on the Properties of Two Novel Ternary Solder Alloys Sn–0.5Cu–3Bi and Sn–1Cu–1Ni Replacing Lead

Lead is banned in the solder alloy composition, citing its inherent toxicity. The researchers were working towards the development of new lead free solder alloys which can replace the old Sn–Pb alloy. In the present paper two new solder alloys are introduced, Sn–0.5Cu–3Bi (96.5% Sn, 0.5% Cu, 3% Bi, all are % by wt) i.e. SCB305 and Sn–1Cu–1Ni (98% Sn–1% Cu–1% Ni) i.e. SCN110. The melting temperature of SCB305 and SCN110 are found to be 231.5 and 232.8°C, respectively. Therefore these two alloys can be used as solder material in electronic packages exposed to moderately higher temperature. Hardness of SCB305 and SCN110 are obtained as 19.8 and 16.1 HV. SCB305 and SCN110 have very good wetting characteristics with contact angle of 28.74° and good wetting characteristics with contact angle of 36.75°, respectively. Microstructure of SCB305 and SCN110 shows that Bi and Ni are evenly distributed in the Sn-matrix. The cost analysis revealed that SCB305 and SCN110 have cost of 23.05 and 20.65 $/kg. The properties of the new alloys were compared with that of SAC305 and SAC405. SCB305 and SCN110 are found to be perfect replacement of Sn–Pb alloy.

Investigations on the properties of new lead free solder alloy composition – Sn-0.5Cu-3.5Bi

Abstract Lead is restricted in solder joints because of environmental legislations. In this study, a new ternary solder alloy Sn-0.5Cu-3.5Bi is proposed. Alloys prepared using induction furnace have been analysed for their material properties. Melting temperature lies in the range of 219.5−220.5 °C. Hardness value lies in the range of 20.5–20.8 Hv. Good wetting property have also been obtained. Grain boundaries were attained from the microstructure evaluation. A comparison with SAC305 and SAC405 also shows that the new alloy is having better properties. Sn-0.5Cu-3.5Bi is a new lead free solder alloy for electronic packages subjected to moderately high temperature surroundings.

Cyclic Plastic Properties of a Lead Free Solder

This paper shows some cyclic plastic properties of the lead free solder alloy Sn-3.5Ag-0.75 under fully reversed cyclic torsional loading. The low-cycle fatigue behavior of the material was evaluated too. The lead free solder material reveals a strong strain rate effect. A viscoplastic model was implemented into a commercial finite element program and calibrated using data from literature to can be used for simulations of all performed tests in a future work.

Experimental Investigation on the Effect of Ag Addition on Ternary Lead Free Solder Alloy –Sn–0.5Cu–3Bi

Lead cannot be used in the solder material anymore due to environmental legislations which is related to the inherent toxicity of lead. This paper investigates the effect of silver (Ag) addition on the melting behavior, microstructure, and microhardness of Ternary lead free solder alloy Sn–0.5Cu–3Bi. The contact angle between Sn–0.5Cu–3Bi and Cu-substrate were also analyzed. Samples with different Ag percentages (0, 0.25, 0.5, 0.75 and 1.0 wt%) in Sn–0.5Cu–3Bi were prepared using an induction furnace, annealing furnace with argon gas. Tests were conducted for melting temperature using TG–DTA analysis, chemical composition using ICP–OES, Hardness using Vickers’s hardness tester and the microstructure using Field emission scanning electron microscopy. The obtained results were thoroughly analyzed. The results show that the Ag addition has striking positive effects on enhancing the properties of the base solder alloy. Melting point is found to be decreasing with the increase in Ag content. Hardness and contact angle were improved with the addition of Ag. The microstructure observations revealed that the Ag was uniformly distributed on the surface of the solder matrix. The recommended content of the Ag to be added into the Sn–0.5Cu–3Bi solder alloy is 1.0 wt%. With the observed better properties it can be considered as the potential alternative to lead–tin alloy.

Finite element modeling and random vibration analysis of BGA electronic package soldered using lead free solder alloy − Sn-1Cu-1Ni-1Ag

As a result of the ban of lead from solder joints, many lead-free solder joints were developed. Most of the electronic equipment is subjected to random vibration. This study develops an analysis methodology based on finite element analysis and vibration tests to predict the failure and fatigue life of the electronic package soldered using Sn-1Cu-1Ni-1Ag under random vibration. A specially designed printed circuit board having ball grid array packages soldered is used in the study. Finite element model is developed in ANSYS and modal analysis was done. The finite element results were validated with experiments (impact test). Random vibration analysis was also done. These results were validated with random vibration experiments. Using the finite element results, it was predicted that the corner solder joints will fail first. It was observed in the random vibration experiment that corner solder joint failed first and the maximum stress generated was 12.8 MPa. Thus, Sn-1Cu-1Ni-1Ag is a promising lead-free solder joint alloy under random vibration combining with its mechanical properties.

Experimental investigations on the effect of addition of Ag into ternary lead free solder alloy Sn-1Cu-1Ni

Experimental investigations on the effect of addition of Ag into ternary lead free solder alloy Sn-1Cu-1Ni