scholarly journals The Effect of Thermal Annealing on the Microstructure and Mechanical Properties of Sn-0.7Cu-xZn Solder Joint

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 380
Author(s):  
Mohd Izrul Izwan Ramli ◽  
Mohd Arif Anuar Mohd Salleh ◽  
Rita Mohd Said ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Dewi Suriyani Che Halin ◽  
...  
Keyword(s):  
Shear Strength ◽  
Solder Joint ◽  
Annealing Time ◽  
Bulk Solder ◽  
Annealing Process ◽  
Shear Tests ◽  
Cu6sn5 Phase ◽  
Lap Shear ◽  
Mechanical Behaviours ◽  
Free Solder

The microstructural properties of a Pb-free solder joint significantly affect its mechanical behaviours. This paper details a systematic study of the effect of the annealing process on the microstructure and shear strength of a Zn-added Sn-0.7Cu solder joint. The results indicated that the IMC layer’s thickness at the solder/Cu interface increases with annealing time. The interfacial IMC layer of the Sn-0.7Cu solder joint gradually thickened with increasing annealing time and annealing temperature, while the interfacial IMC layer’s morphology changed from scallop-type to layer-type after the annealing process. However, the addition of 1.0 wt.% and 1.5 wt.% Zn in the Sn-0.7Cu effectively altered the interfacial IMC phase to Cu-Zn and suppressed the growth of Cu3Sn during the annealing process. The single-lap shear tests results confirmed that the addition of Zn decreased the shear strength of Sn-0.7Cu. The interfacial IMC of the Cu6Sn5 phase in Sn-0.7Cu changed to Cu-Zn due to the addition of Zn. The shear fractures in the annealed solder joint were ductile within the bulk solder instead of the interfacial IMC layer. Increased annealing time resulted in the increased presence of the Cu-Zn phase, which decreased the hardness and shear strength of the Sn-0.7Cu solder joint.

scholarly journals Shear Strength and Aging Characteristics of Sn-3.0Ag-0.5Cu/Cu Solder Joint Reinforced with ZrO2 Nanoparticles

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1295
Author(s):  
Sri Harini Rajendran ◽  
Seung Jun Hwang ◽  
Jae Pil Jung
Keyword(s):  
Shear Strength ◽  
Solder Joint ◽  
Solder Joints ◽  
Solder Matrix ◽  
Fracture Analysis ◽  
Zro2 Nanoparticles ◽  
Solder Paste ◽  
Lap Shear ◽  
Matrix Fracture ◽  
The Matrix

This study investigates the shear strength and aging characteristics of Sn-3.0Ag-0.5Cu (SAC 305)/Cu joints by the addition of ZrO2 nanoparticles (NPs) having two different particle size: 5–15 nm (ZrO2A) and 70–90 nm (ZrO2B). Nanocomposite pastes were fabricated by mechanically mixing ZrO2 NPs and the solder paste. ZrO2 NPs decreased the β-Sn grain size and Ag3Sn intermetallic compound (IMC) in the matrix and reduced the Cu6Sn5 IMC thickness at the interface of lap shear SAC 305/Cu joints. The effect is pronounced for ZrO2A NPs added solder joint. The solder joints were isothermally aged at 175 °C for 24, 48, 144 and 256 h. NPs decreased the diffusion coefficient from 1.74 × 10–16 m/s to 3.83 × 10–17 m/s and 4.99 × 10–17 m/s for ZrO2A and ZrO2B NPs added SAC 305/Cu joints respectively. The shear strength of the solder joints decreased with the aging time due to an increase in the thickness of interfacial IMC and coarsening of Ag3Sn in the solder. However, higher shear strength exhibited by SAC 305-ZrO2A/Cu joints was attributed to the fine Ag3Sn IMC’s dispersed in the solder matrix. Fracture analysis of SAC 305-ZrO2A/Cu joints displayed mixed solder/IMC mode upon 256 h of aging.

Interfacial Shear Strength of Thin Polymeric Coatings on Glass

1988 ◽  
Vol 130 ◽  
Author(s):  
J. E. Ritter ◽  
L. Rosenfeld ◽  
M. R. Lin ◽  
T. J. Lardner
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Indentation Test ◽  
Interfacial Shear ◽  
Polymeric Coatings ◽  
Shear Tests ◽  
Glass Substrates ◽  
Lap Shear ◽  
Order Of Magnitude ◽  
Intrinsic Strength

AbstractThe interfacial adhesive shear strengths of epoxy and acrylate coatings on glass substrates were measured by the indentation and lap shear tests. The lap shear strengths were about an order of magnitude less and exhibited considerably more variability than those measured by indentation. It is believed that the lap shear strength is controlled by large processing flaws (pores in this study); whereas, the indentation test measures the “intrinsic” strength of the coating.

The Effect of Temperature and Strain Rate on Selected Lead-Free Solder Alloys

2004 ◽  
Author(s):  
Jayamalar Vijayen ◽  
James G. Maveety ◽  
Emily L. Allen
Keyword(s):  
Strain Rate ◽  
Test Temperature ◽  
Bulk Solder ◽  
Effect Of Temperature ◽  
Strain Rate Effects ◽  
Lap Shear ◽  
Test Conditions ◽  
Rate Effects ◽  
Free Solder ◽  
Strength And Ductility

Abstract The temperature and strain rate effects on the shear properties of selected Pb-free solders were investigated. The experiments were performed using single lap shear specimens. All testing was performed using a standard tensile test metrology. The following results were found: 1) Sn-3.5 wt.% Ag outperformed all the other solders in terms of its mechanical strength at all test conditions due to the formation of Ag3Sn precipitates in the bulk solder and Cu6Sn5 intermetallic formation along the interface. However, ductility was sacrificed as this solder strain hardens. 2) The strength and ductility of the solder joint is strongly dependent on the test temperature and strain rate. Data in this work reflects a decrease in strength and ductility when the test temperature is increased. This phenomenon can be attributed to the increase in energy as temperature is increased to overcome dislocation barriers such as impurities and grain boundaries that impede the motion of dislocation. When strain rate is increased, the amount of plastic deformation experienced by the solder increases and more dislocations are formed. Due to the increase in proximity and number of the dislocations, the net result is that motion of the dislocations are hindered thus requiring more stress to deform the material.

Property of Sn-37Pb solder bumps with different diameter during thermal shock

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guisheng Gan ◽  
Donghua Yang ◽  
Yi-ping Wu ◽  
Xin Liu ◽  
Pengfei Sun ◽  
...  
Keyword(s):  
Shear Strength ◽  
Solder Joint ◽  
Thermal Shock ◽  
Solder Joints ◽  
Test Method ◽  
Content Type ◽  
Ball Size ◽  
Solder Bumps ◽  
Free Solder ◽  
The Impact

Purpose The impact strength of solder joint under high strain rate was evaluated by board level test method. However, the impact shear test of single solder bump was more convenient and economical than the board level test method. With the miniaturization of solder joints, solder joints were more prone to failure under thermal shock and more attention has been paid to the impact reliability of solder joint. But Pb-free solder joints may be paid too much attention and Sn-Pb solder joints may be ignored. Design/methodology/approach In this study, thermal shock test between −55°C and 125°C was conducted on Sn-37Pb solder bumps in the BGA package to investigate microstructural evolution and growth mechanism of interfacial intermetallic compounds (IMCs) layer. The effects of thermal shock and ball diameter on the mechanical property and fracture behavior of Sn-37Pb solder bumps were discussed. Findings With the increase of ball size, the same change tendency of shear strength with thermal shock cycles. The shear strength of the solder bumps was the highest after reflow; with the increase of the number of thermal shocks, the shear strength of the solder bumps was decreased. But at the time of 2,000 cycles, the shear strength was increased to the initial strength. Minimum shear strength almost took place at 1,500 cycles in all solder bumps. The differences between maximum shear strength and minimum shear strength were 9.11 MPa and 16.83 MPa, 17.07 MPa and 15.59 MPa in φ0.3 mm and φ0.4 mm, φ0.5 mm and φ0.6 mm, respectively, differences were increased with increasing of ball size. With similar reflow profile, the thickness of IMC decreased as the diameter of the ball increased. The thickness of IMC was 2.42 µm and 2.17 µm, 1.63 µm and 1.77 µm with increasing of the ball size, respectively. Originality/value Pb-free solder was gradually used to replace traditional Sn-Pb solder and has been widely used in industry. Nevertheless, some products inevitably used a mixture of Sn-Pb and Pb-free solder to make the transition from Sn-Pb to Pb-free solder. Therefore, it was very important to understand the reliability of Sn-Pb solder joint and more further research works were also needed.

Wettability and Bond Shear Strength of Sn-9Zn Lead-Free Solder Alloy Reflowed on Copper Substrate

2015 ◽  
Vol 830-831 ◽  
pp. 215-218 ◽  
Author(s):  
Sanjay Tikale ◽  
Mrunali Sona ◽  
K.N. Prabhu
Keyword(s):  
Shear Strength ◽  
Solder Alloy ◽  
Copper Substrate ◽  
Bulk Solder ◽  
Lead Free ◽  
Lead Free Solder ◽  
Reflow Time ◽  
Bond Shear Strength ◽  
Lead Free Solder Alloy ◽  
Free Solder

Lead-free solders are environment friendly and are in great demand for microelectronic applications. In the present study, Sn-9Zn lead free solder alloy was solidified on Cu substrate for different reflow times from 10 to 1000s. The influence of reflow time on wetting, formation of intermetallic compounds (IMCs) and bond shear strength was studied using dynamic contact angle analyzer, bond tester and scanning electron microscopy. The results indicate that, the wettability of the solder alloy increased with increase in reflow time. Microstructure study revealed the presence of Cu5Zn8 and CuZn5 IMCs at the interface. The thickness of an IMC increased with increase in the reflow time. The mean thickness of about 11μm for Cu5Zn8 IMC layer was observed for the reflow time of 1000s. The thickness of CuZn5 layer increased up to a reflow time of 100s and decreases thereafter. The bond shear strength increased up to 100s and decreased with increase in reflow time. The decrement in shear strength at higher reflow time is mainly due to excessive thickness of Cu5Zn8 IMC layer and diffusion of Sn from bulk solder towards the substrate. The excessive thick IMC layer exhibited pre micro-cracks led to the brittle failure of bond under the influence of shear stress.

On the Shear Strength and Mixed-mode Fracture Toughness of a Lead-Tin and a Tin-Silver Solder

1998 ◽  
Vol 515 ◽  
Author(s):  
M. Manoharan ◽  
K. S. SIOW ◽  
M. W. WEISER
Keyword(s):  
Shear Strength ◽  
Mixed Mode ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Bulk Solder ◽  
Shear Loading ◽  
Mixed Mode Fracture ◽  
Traditional Role ◽  
Mode Fracture ◽  
Lap Shear

ABSTRACTThe increasing demands on solder joints have made it imperative that they perform not only their traditional role of electrical connection but also possess good mechanical integrity. One such key mechanical property is the shear strength of the solder. A number of specimen geometries can be used to evaluate the shear strength of solders, each with its advantages and limitations. This study uses a modified double lap shear geometry to measure the shear strength of the solders as a function of strain rate. It is ahown that the shear strength measured this way is truly reflective of the complex composite formed by the copper, solder and intermetallics and may be more representative of actual conditions of use rather than measurements of the shear strengths of the bulk solder. The study also uses a modified compact tension specimen to measure the fracture of the solder under combined tensile-shear loading conditions. It is shown that the solder fracture under these conditions follows the general principles of a mixed-mode fracture mechanism map.

Deformation Characteristics and Constitutive Relationship of SnAgCu Lead (Pb)-Free Solder Alloys Under Thermo-Mechanical and Mechanical Loading

2006 ◽  
Author(s):  
Mohammad M. Hossain ◽  
Puligandla Viswanadham ◽  
Dereje Agonafer ◽  
Tommi Reinikainen
Keyword(s):  
Solder Joint ◽  
Strain Rate ◽  
Coefficient Of Thermal Expansion ◽  
Bulk Solder ◽  
Constitutive Relationship ◽  
Lead Free ◽  
Creep Model ◽  
Solder Alloys ◽  
Lap Shear ◽  
Constitutive Parameters

In this paper is reported the mechanical and thermomechanical aspect of SnAgCu solder alloys that have been tested for their deformation behavior. Commercially available Sn3.8Ag0.7Cu was considered as base alloy. The constant stress and strain-rate tests were performed in tensile and shear configuration. Mechanical deformations were measured using bulk solder tensile specimens and grooved lap shear specimens which enabled a stress-state of nearly pure shear in the solder joint. The strain rate range was between 0.1/sec and 10-6/sec, and test temperatures were 25°C, 75°C and 125°C. Both as-prepared and thermally aged samples were tested. The aging condition was 24hrs at 125°C. The measured tensile stress-strain data were utilized to determine the constants for the visco-plastic Anand's constitutive model. Thermo-mechanical properties like coefficient of thermal expansion (CTE) for those SnAgCu lead free alloys were measured in the temperature range of - 40 to 160°C using thermo-mechanical analyzer (TMA). The tensile and shear properties of 95.5Sn3.8Ag0.7Cu solder and solder joint specimens are highly dependent on test temperature and strain rate. The mechanical strength of SAC bulk solder and solder joint decreases with increase in temperature and increases with increase in strain rate. CTE for the SAC lead-free alloys were relatively lower compared with tin-lead solder. The steady-state creep test data for 95.53.8Ag0.7Cu solder was curve-fitted to a hyperbolic-sine creep model. The material constitutive parameters developed are in line with similar studies.

Intermetallic growth and shear strength of SAC305/EN-Boron

2016 ◽  
Vol 28 (3) ◽  
pp. 141-148
Author(s):  
Hardinnawirda Kahar ◽  
Zetty Akhtar Abd Malek ◽  
Siti Rabiatull Aisha Idris ◽  
Mahadzir Ishak
Keyword(s):  
Shear Strength ◽  
Solder Joint ◽  
Surface Finish ◽  
Air Cooling ◽  
Slow Cooling ◽  
Reflow Soldering ◽  
Content Type ◽  
Cu Substrate ◽  
Lap Shear ◽  
Scanning Electron

Purpose This paper aims to study the effect of aging and cooling rate on the reliability of the solder joint using electroless nickel boron (EN-Boron) as a surface finish in the electronic packaging area. Design/methodology/approach EN-Boron was plated on a Cu substrate through electroless plating method. This process was followed by reflow soldering of Sn–3.0Ag–0.5Cu solder alloy on metallized Cu substrate to form a joining. Then, the specimens were cooled using different cooling mediums such as air (slow cooling) with 15.7 °C/min and water (fast cooling) with 110.5 °C/min. After that, the specimens were subjected to isothermal aging at 150°C for 0, 250 and 1,000 h. Finally, they went through a lap shear test following ASTM D1002. Optical microscope and scanning electron microscopy were used for intermetallic compound (IMC) characterization. The type of IMC formed was confirmed by field emission scanning electron microscope-energy-dispersive X-ray spectroscopy (FESEM-EDX). Findings The results showed that the IMC type changed from the combination of Ni3Sn4 and (Ni, Cu)3Sn4 after reflow soldering into fully (Ni, Cu)3Sn4 when aged for 1,000 h. The formation of (Ni, Cu)3Sn4 and Cu3Sn underneath the IMC layer played a role in reducing the shear strength of joining. Overall, water cooling was reported to provide higher shear strength of solder joint compared to air cooling medium. Originality/value The shear strength when using EN-Boron as the surface finish is comparable to the surface finish conventionally used.

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