Wettability Of Solder Research Articles

Microstructural characterizations of metallized Al2O3 before/after surface treatment and Al2O3/Cu soldered joint

Joining Al2O3 ceramics to Cu heat pipes should be conducted at low temperatures since Cu heat pipes may fail at temperatures higher than 320 °C. Due to the poor wettability of low-temperature solder on Al2O3 ceramics, it is essential to metallize Al2O3 ceramics before joining Al2O3 to Cu with a low-temperature solder. Surface metallization of Al2O3 has been conducted using Ag-Cu-Ti active metal filler at 900 °C. Microanalysis indicates that an interfacial reaction occurs between the active metal filler and the Al2O3, leading to the formation of a Cu3Ti3O reaction layer. The metal layer on the surface of Al2O3 is primarily composed of Ag (s, s) (solid solution), Cu (s, s) and Ti2Cu. The polishing treatment of the surface metal layer in metallized Al2O3 results in a reduction of the oxide content and contaminants, which subsequently allows joining at low temperature. Low-temperature joining of metallized Al2O3 to Cu has been carried out using Sn-Ag-Cu solder at 280 °C. The joining area of the joint includes a Cu3Ti3O reaction layer, a metal layer and a solder layer. The solder layer mainly consists of Sn (s, s), Ag3Sn and Cu6Sn5. The Al2O3/Cu joint fractures in the solder layer after the shearing test, indicating that the strength of the solder is relatively low. However, the interfacial bonding between the metallized Al2O3, solder layer and Cu base material is satisfactory.

Investigation on the Thermal and Wettability Properties Aided with Mechanical Test Simulation of Tin (Sn) - Bismuth (Bi) Solder Alloy at Low Reflow Temperatures

The current study proposes to investigate the thermal, wettability and mechanical properties of a low temperature SnBi solder. The main aim is to investigate the performance of the SnBi solder alloy with different Bi composition. The study also establishes the relationship between melting temperature, spreading area and tensile stress of the SnBi with different Bi composition at different low reflow temperatures. The thermal and wettability tests are conducted experimentally, while the mechanical test will be analysed via finite element analyses (FEA). The single shear lap test method was adopted for the simulation. The thermal properties of the SnBi solder are investigated using the differential scanning calorimeter (DSC). The reflow temperature selected ranges from 160 °C to 220 °C to accommodate the purpose of low temperature soldering. Wetting test results showed that spreading area of Sn48Bi solder alloy increased to 28.1 and 42.88 at 180 °C and 210 °C respectively. The increase in the Bi composition reduced the tensile strength regardless of the increase of the reflow temperature. The preliminary results commend the characteristics of the SnBi solder as a possible alternative to the Pb solder.

Design of Ni-rGO reinforced Sn2.5Ag0.7Cu0.1Ce composite solder based on micro-alloying and composite principles: Microstructure and properties

Based on the principles of micro-alloying and composite, the graphene reinforced Sn2.5Ag0.7Cu0.1Ce composite solder was designed. Ni nanoparticle-modified reduced graphene oxide (Ni-rGO) was prepared by thermal decomposition method, and the powder-melting method was proposed for the first time to prepare Ni-rGO reinforced Sn2.5Ag0.7Cu0.1Ce composite solder. The microstructure, wettability, electrical resistivity, and mechanical properties of the composite solder were systematically studied. Results indicated that the Ni nanoparticles uniformly adhered to the rGO with a size of 26.3 nm. The effective incorporation of Ni-rGO into the solder matrix was achieved. The result broke the technical difficulty that graphene cannot be effectively added to low melting point metals. With the addition of Ni-rGO, the grain size gradually decreased, and the eutectic structures increased. Deep etching results revealed that columnar β-Sn was stacked from layered β-Sn, the addition of 0.05 wt% Ni-rGO led to an increase in sheet-like Ag3Sn within the eutectics. Additionally, Ni-rGO was found at the grain boundaries of composite solder, serving as nucleation sites for Ag3Sn and Cu6Sn5. At an addition of 0.05 wt%, the tensile strength reaches a maximum of 58.1 MPa, with elongation of 33.8%, surpassing the strength of commercial Sn3.0Ag0.5Cu solder. Therefore, the high-strength and tough composite solder was obtained. This study offered a new approach for the development of low-melting-point composite materials.

Mechanical properties and microstructure evolution of Sn–Bi-based solder joints by microalloying regulation mechanism

Sn–Bi based solders are used in electronic packaging for interconnection processes. However, the rate of research on the comprehensive performance of solders is difficult to match the rapid development of advanced manufacturing of integrated circuits, resulting in the inability to obtain interconnect structures with excellent reliability for electronic devices. To demand a more effective modification method, we chose to dope 1.0 wt % In element in Sn58Bi–1Sb alloy. The strength, micromechanical properties and creep resistance of the solder were improved due to the combined effect of solid solution strengthening and diffusely distributed second phase strengthening. Furthermore, the addition of In element dramatically improved the thermal properties and wettability due to the generation of Bi3In5 intermetallic compounds (88.9 °C) and the activation energy of the solder wettability reaction was reduced to 247.36 J/mol. Notably, the addition of In element increased the amount of β-Sn phase deviation and decreased the Schmid factor value of β-Sn phase, resulting in a significant increase in the strength and micro-zone creep resistance. Under the action of current, a large amount of uniform Bi particle deviations and sub-crystalline structures persist in the β-Sn phase of the Sn58Bi–1Sb1In solder matrix. In the Cu/Sn58Bi–1Sb1In/Cu joints, many Bi particles are staggered in the β-Sn phase. Since the resistivity of the β-Sn phase is smaller than that of the Bi phase, the energization process leads to a possible further increase of the local currents at certain locations in the β-Sn phase, which reduces the electromigration resistance of the β-Sn phase. After energization, the biphasic twin structure with excellent electromigration resistance starts to degrade. The results show that the doping of In element comprehensively improves the performance of Sn58Bi–1Sb solder. It opens up a new idea for the design of alloying modification of tin-bismuth based solder.

Numerical simulation and experimental study on wetting of Sn-based solder for laser soldering

Numerical simulation and experimental study on wetting of Sn-based solder for laser soldering

Effect of Matte-Sn Electroplating Parameters on the Thermo-mechanical Reliability of Lead-free Solder Joints

Most of the Cu/Cu alloy lead-frames of electronic components used for automotive applications contain electroplated matte-Sn terminal finish to improve the wettability of Sn-based Pb-free solders during reflow soldering process. When the solder joints are subjected to combined thermal and mechanical cyclic loading, the influence of matte-Sn electroplating parameters can lead to early and brittle failure of the solder joint. To test this hypothesis, a factorial design of experiments (DOE) has been conducted with LFPAK-MOSFET (hereafter referred to as LFPAK) components plated with different matte-Sn electroplating parameters and reflow soldered with two solder alloys (SAC 305 and Innolot). The LFPAK solder joints were then subjected to thermo-mechanical in-phase cyclic loading under different strain amplitudes. No electrical measurement is done to eradicate the effect of electrical current on the solder joint. The response to the DOE is the crack percentage obtained in the LFPAK solder joints after 1000 and 2000 cycles. The Innolot solder joints exhibited lower crack percentages than the SAC 305. The level of organic additives in the electroplating process of matte-Sn influences the failure mode of the solder joint. Microstructural investigation attributes the nature of failure to the morphology of the (Cu,Ni)6Sn5 IMC phase that forms on the component side of the solder joint.

Surface modification with Cu on Zr-based metallic glass using laser cladding and improvement of solder wettability

Zr55Al10Ni5Cu30 metallic glass (bulk amorphous alloy) has unique properties, such as highly resistant to corrosion, high strength and elastic deformation over whole deformation range, so that it is expected to be the next-generation engineering materials. To develop further industrial applications, joining technology for the metallic glass is necessary. In this study, surface modification with Cu on Zr55Al10Ni5Cu30 metallic glass using laser cladding and the consequent solderability improvement were studied. As a result, the interface between Cu foil and Zr55Al10Ni5Cu30 metallic glass were continuously welded by the laser cladding. XRD showed that there are no crystalline and reaction layer in the weld interface. Furthermore, it was found, by XPS, that the Cu-modified layer on the Zr55Al10Ni5Cu30 metallic glass surface inhibited the formation of a strong oxide film. Consequently, the Cu-modified layer played an important role in improving the solderability to the Zr55Al10Ni5Cu30 metallic glass.

Significant inhibition of interfacial Cu6Sn5 IMC and improvement of solder joint strength and reliability by applying (111) nanotwinned Cu substrate and vacuum soldering

In this research, (111) oriented nanotwinned Cu (nt-Cu) substrates, combined with vacuum soldering, were utilized to enhance the strength and reliability of the solder joints. The wettability of the composite solder Sn1.0Ag0.5Cu-Si3N4 (SAC105-Si3N4) was improved on the (111) nt-Cu substrates and the oxidization of the molten solder was avoided by the vacuum environment, ensuring the formation of regular and uniform solder joints. The (111) nt-Cu substrates, characterized by their low surface energy, are demonstrated to be highly efficient in restricting the growth of interfacial IMCs, and this effects becomes particularly pronounced in three-dimensional (3D) solder joints following extended high-temperature aging. In addition, with vacuum soldering, a continuous and uniform interfacial structure was obtained, which is essential for upgrading the reliability of 3D solder joints. Furthermore, the electron back scatter diffraction (EBSD) testing of the solder matrix and interface formed on the nt-Cu substrates revealed that the c-axis of the β-Sn grains was parallel to the (111) nt-Cu substrates, and that the c-axis of the Cu6Sn5 grains was approximated to be perpendicular to the (111) nt-Cu substrates in an air environment. Finally, the shear strength and fracture morphology of the solder joints were evaluated. The macroscopic voids inside the solder joints were suppressed under vacuum, and the solder joints formed on the (111) nt-Cu substrates provided the highest shear strength.

Preparation, characterization and mechanical properties analysis of SAC305-SnBi-Co hybrid solder joints for package-on-package technology

The development of hybrid solder for chip packing is a major 3D packaging research topic. The incorporation of with low melting points into solder materials has been used in low-temperature packaging. Hybrid solder struggles to enhance low-temperature solder efficiency and mechanical properties. This work examined the effects of Co elements on microstructure and intermetallic compound (IMC) morphology of SAC305-SnBi-Co hybrid solder generated by reflow welding on electroless nickel immersion gold (ENIG) substrate at various temperatures. Moreover, mechanical characteristics and failure behavior of joints were extensively explored. The results show that the addition of 0.05% Co reduced the melting range of the solder and improved the wettability of SnBi solder. According to transmission electron microscopes (TEM) and electron diffraction spots (EDS), the crystal structure of the grains is (Cu, Co)6Sn5 basic-centered monoclinic crystal. Fourier analysis of high-resolution images yields deformed lattice fringes, indicating that Co atoms fill Cu6Sn5's lattice gap in IMC. The shear strength of SAC305/SnBi hybrid solder joints with Co rises and then decreases with temperature. The highest shear strength of solder joints with 0.05% Co (40 nm) is 73.2 MPa at 220 °C, whereas joints with 0.1%Co are 67.5 MPa. Combined with the fracture morphology, the proportion of IMC fracture mode decreased after adding Co element.

Enhancement of SAC105 solder for vacuum soldering with Cu substrates through incorporation of activated Ti nanoparticles

This study incorporated activated Ti nanoparticles (Ti NPs) into Sn1·0Ag0·5Cu (SAC105) solder for vacuum soldering with Cu substrates. The wettability, microstructure, interfacial, and mechanical properties of SAC105-xTi (x = 0.1, 0.2, 0.3, 0.4, 0.5 wt%) composite solder were systematically investigated. The results showed that adding Ti NPs improved the wettability of SAC105 solder, in which the wetting angle of SAC105-0.3Ti solder was 19.51°. Additionally, Ti NPs helped to refine the microstructure and inhibited the growth of interfacial intermetallic compounds (IMC). The shear strength of SAC105/Cu joints increased and then decreased with increasing Ti NPs content, and the optimum shear strength was obtained for SAC105-0.3Ti/Cu joints at 27.98 MPa. The strength of the solder matrix and the IMC layer was altered by adding Ti NPs, resulting in a modification of the fracture path of the joint, bringing it closer to the IMC layer. Excessive addition of Ti NPs could lead to their agglomeration within the joints and result in damage to the mechanical properties of the joints. Furthermore, adding Ti NPs increased the microhardness of SAC105 solder.

Effect of Sn Plating Thickness on Wettability, Solderability, and Electrical Connections of Electronic Lead Connectors for Surface Mount Technology Applications

The wettability of solder is important to achieve good solderability between the electronic component and printed circuit board (PCB). Tin (Sn) plating is widely used to promote the wettability of the solder on the substrates. However, an adequate amount of Sn plating thickness must be taken into consideration to acquire good wettability and solderability. Thus, this study investigates the Sn plating thickness of the electronic lead connector and their effect on the wettability and electrical connection. Two types of Sn plating thicknesses, ~3 μm, and 5 μm were applied on the electronic lead connector surface. It was found that the thin Sn plating thickness of ~3 μm has shown failure in electrical connections and lack of solder joint wettability and solderability properties. A thicker Sn plating thickness of 5 μm, has shown better wettability and solderability properties. In addition, the electrical connections also passed which implies that the thicker Sn plating thickness provides good solder joint establishment leading to good electrical connections. It is also observed that the better wettability of solder has been achieved for thicker Sn plating thickness. The finding from the field emission scanning electron microscope (FESEM) shows that the intermetallic compound (IMC) layer growth in the lead connector surface is regarded as abnormal for thin Sn plating thickness (~3 μm), in which the IMC layer was consumed and penetrating up to the surface of Sn-coating. This has led to poor solderability of the thin Sn plating with the solder to establish solder joint. The findings from this study have shed some light upon a better understanding of the importance of considering the adequate amount of Sn coating thickness to avoid IMC consumption at the Sn plating, better wettability properties, solderability, and solder joint quality for surface mount technology (SMT) especially for electronic lead connector applications.

Effect of Si3N4 nanowires doping on microstructure and properties of Sn58Bi solder for Cu bonding

PurposeThe purpose of this study is to delve into the mechanism of Si3N4 nanowires (NWs) in Sn-based solder, thereby furnishing a theoretical foundation for the expeditious design and practical implementation of innovative lead-free solder materials in the electronic packaging industry.Design/methodology/approachThis study investigates the effect of adding Si3N4 NWs to Sn58Bi solder in various mass fractions (0, 0.1, 0.2, 0.4, 0.6 and 0.8 Wt.%) for modifying the solder and joining the Cu substrate. Meanwhile, the melting characteristics and wettability of solder, as well as the microstructure, interfacial intermetallic compound (IMC) and mechanical properties of joint were evaluated.FindingsThe crystal plane spacing and lattice constant of Sn and Bi phase increase slightly. A minor variation in the Sn58Bi solder melting point was caused, while it does not impact its functionality. An appropriate Si3N4 NWs content (0.2∼0.4 Wt.%) significantly improves its wettability, and modifies the microstructure and interfacial IMC layer. The shear strength increases by up to 10.74% when adding 0.4 Wt.% Si3N4 NWs, and the failure mode observed is brittle fracture mainly. However, excessive Si3N4 will cause aggregation at the junction between the solder matrix and IMC layer, this will be detrimental to the joint.Originality/valueThe Si3N4 NWs were first used for the modification of lead-free solder materials. The relative properties of composite solder and joints were evaluated from different aspects, and the optimal ratio was obtained.

Early wetting and interfacial behavior of Sn-based solder on copper substrates with different roughness

Purpose This paper aims to investigate the effect of solder composition and roughness on early wetting behavior and interfacial reaction under atmospheric conditions. Design/methodology/approach High-speed photography is used to observe the early wetting and spreading process of the solder on the substrate in real time. The morphology of intermetallic compounds (IMCs) was observed by scanning electron microscopy, and the composition of IMCs micro bumps was determined by energy dispersive spectroscopy. Findings With a roughness range of 0.320–0.539 µm, the solder is distributed in an elliptical trilinear pattern along the grinding direction. With a roughness range of 0.029–0.031 µm, the solder spreads in the direction of grinding and perpendicular, forming a perfect circle (except in the case of Sn63Pb37 solder). The effect of three types of solder on early wettability is Sn63Pb37 > Sn96.5Ag3Cu0.5 > Sn. The wetting behavior is consistent with the Rn∼t model. The rapid spreading stage (Stage I) is controlled by the interfacial reaction with n1 values between 2.4 and 4. The slow spreading stage (stage II) is controlled by diffusion with n2 values between 4 and 6.7. The size of Cu6Sn5 formed on a rough substrate is greater than that produced on a smooth substrate. Originality/value Investigating the effect of solder composition and roughness on early wettability. This will provide a powerful guide in the field of soft brazing.

Study on the properties of low silver Sn1.0Ag0.5Cu composite solder reinforced with nickel-plated zinc oxide and its soldering joint

Based on the preparation of nickel-plated zinc oxide (Ni-ZnO) by pyrolysis-reduction method, low silver Sn1.0Ag0.5Cu lead-free composite solders reinforced with Ni-ZnO were prepared by the powder metallurgy method, and the microstructure and properties of the soldering joints were investigated accordingly. The results showed that the particle size of ZnO was reduced after ball milling. The Ni-ZnO reinforcement phase was successfully prepared by pyrolysis-reduction method, in which Ni particles with an average particle size of 9.7 nm were uniformly and densely deposited on the surface of ZnO particles, and the interface between ZnO (002) and Ni (111) showed a semi-coherent relationship with a mismatch of 0.203. The moderate addition of Ni-ZnO had little effect on the electrical conductivity of the Sn1.0Ag0.5Cu composite solders reinforced with Ni-ZnO. But it refined the primary β-Sn grains in the composite solders and improved the wettability and tensile strength of the composite solders. At an addition of 1.0 wt% Ni-ZnO reinforcement phase, the tensile strength and shear strength of the composite solder and its soldering joint reached a maximum value of 41.8 MPa and 28.9 MPa, with an increase of 39.3 % and 41.7 % respectively compared to the base solder material. The fracture position of composite solder/Cu soldering joint occurred in the transition zone of the soldering seam and IMC (Intermetallic Compound) layers. With the increase of Ni-ZnO reinforcement phase addition, the shear fracture location of the soldering joint moved from the near copper substrate side to the near soldering seam side in the transition zone, and the fracture mode gradually changed from a mixed ductile-brittle fracture to a typical ductile fracture dominated by parabolic toughness dimples.

Effect of Au thin films thickness on the wetting characteristics of eutectic Pb-Sn solder on Ni/Ag solder bath

Wetting of Pb-Sn solder on Au/Ni surface is experimentally studied as a function of the thickness of Au coating on Ni buffer layer. While Au coating is known to increase the wettability of Pb-Sn solder on Ni surface, the effect of Au layer thickness was not examined systematically. This study shows that i) an increase in Au layer thickness from 0.15 to 0.3 µm decreases the surface coverage (spread) of the solder and ii) there is a compositional change in Pb-Sn solder on Au/Ni surface due to formation of a Sn rich region at the solder - Ni interface during a reflow process of the solder. The thickness of Sn rich region near the interface increases with increasing the Au layer thickness. A driving force for the formation of the Sn rich phase is explained using the negative mixing enthalpy of Au-Sn. Since an increase in the Sn content of Pb-Sn solder increases the surface energy and viscosity of the solder melt, an increase in the thickness of the Sn rich region at the solder-Ni interface suppressed the wetting of the solder.

Eddy current soldering of solar cell ribbons under a layer of glass

Thermal fatigue of soldered interconnections of silicon solar cells is considered one of the key failure modes in photovoltaic (PV) modules. Due to differences in thermal expansion coefficients of the used materials, cracks and disconnected wiring can occur, causing a local increase of resistance. This can lead to hot spots and early failure of a panel. In this research, we develop eddy current soldering as a non-contact soldering technique for tabbing the ribbon of PV cells under a layer of glass. The performance of eddy current soldering was studied in detail by changing an induction coil distance to the treated sample from 2 to 4 mm and varying exposure time. An IR camera monitored temperature profiles at the soldering zone, and I–V curves of samples were extracted to validate the soldering technique and the efficiency of the tabbing process. Electroluminescence imaging was deployed to monitor cracking after the soldering process; scanning electron microscopy (SEM) and scanning acoustic microscopy (SAM) were used to investigate the microstructure and cracking within the solder joint and silicon. The results showed that the shortest exposure times at a 2 mm heating distance caused higher risks for cracks in silicon. The intermediate exposures at a 3 mm heating distance increased the likelihood of cracking in the solder joint. For the longest heating times at a distance of 4 mm, the solder joint appeared crack free, although, in some areas, poor wetting of solder was observed. The performance of eddy current soldering under a layer of glass was compared to manually soldered samples. Based on the I–V curves, all samples were functional, and differences between exposure times and manually soldered samples were not evident. Thus, only electrical verification of the solder quality was insufficient. Due to the study, it was concluded that the proper solder interconnections through glass could be made by using the eddy current soldering process and a sufficient exposure time to avoid cracking within the solder joint configuration and silicon.

Effect of Ce on the microstructure and property of Sn0.7Cu solder

The effect of Ce multi-addition on wettability and microstructure of Sn-0.7Cu solder was investigated. The results indicated that the multi-addition of Ce could greatly improve the wettability of solder and refine the microstructure of solder matrix. The optimal property of solder was obtained when the addition of Ce reached 0.1 wt.%. With the increasing of Ce addition, black phase appeared and tend to be accumulated in the solder matrix. EDS results indicated that the composition of black phase contained varies elements including Sn, Cu, Ni, and Ce. Compared with the previous research results of solder with excessive Ce addition, no obviously Sn-Nd phase was observed while a small amount of Ga2Nd phase appeared in the solder matrix.

Effect of Surface Roughness and Droplet Size on Solder Wetting Angles.

Reactive wetting is a process ubiquitous in modern electronic soldering processes. Nonetheless, the dependencies of reactive wetting angles on surface roughness and droplet size are not well understood but become increasingly important for reliable miniaturization of devices. In this study, advancing contact angles of the Sn(l)/Cu(s) reactive solder system are investigated and the aforementioned dependencies are evaluated. Several surface roughnesses and a large array of droplet sizes are measured. Clear size dependencies are observed for both smooth and rough substrates, yet interestingly, the trends are inverted. This inversion of the size dependence of the wetting angle is discussed on the basis of the triple line pinning phenomenon, Wenzel's wetting model, and the consumption of Sn by a solder reaction. Quantitative models are proposed, with which size dependencies on rough and smooth surfaces can be better understood. Triple line pinning barrier energies are calculated. Larger pinning barriers are determined for rougher substrates.

Effect of Carbon Nanotubes on the Mechanical, Thermal, and Electrical Properties of Tin-Based Lead-Free Solders: A Review

Carbon nanotubes (CNTs) are being applied with increasing frequency for advanced soldering. They have excellent mechanical, electrical, and thermal properties and are primarily used to reinforce lead-free solders. This paper discusses the strengthening mechanism of CNTs, introduces the preparation methods of CNT composite solders, and focuses on the review of tin-based lead-free solders reinforced with unmodified CNTs and metal-modified CNTs. The addition of CNTs can effectively improve the ultimate tensile strength, microhardness, shear strength, and creep resistance of the solder. However, the practical application of CNT composite solders has been a challenge for researchers for decades. The most significant issue is uniform dispersion due to the large density and surface differences between CNTs and solders. Other concerns are the structural integrity of CNTs and their limited addition amount, solder wettability, and interfacial bonding. CNT composite solders can only be widely used in a real sense when these challenges are properly addressed and overcome. At present, there is a lack of comprehensive reviews covering the structure, the strengthening mechanism, the preparation method of CNT composite solders, and the influence of CNT types on their strengthening effects. Therefore, this paper aims to fill this gap and contribute to solving the problems faced by the application of CNTs in solder. Future work is expected to focus on improving the dispersion and bonding of CNTs and optimizing the preparation method.

Preparation and performance of Sn-based composite solder joints by solid-liquid low-temperature solder bonding technology

In the era of big data, the advantages of 3D packaging are becoming increasingly significant. In addition, the mismatch between the coefficient of thermal expansion (CTE) of the PCB and BGA components leads to dynamic warpage of the system, and the expansion and innovation of low-temperature soldering have been a new trend. We developed a fully mixed solder joint of a SAC305(Sn-3.0Ag-0.5Cu wt.%) solder ball and Sn–58Bi(wt.%) solder paste by solid-liquid low-temperature solder bonding technology. The mixing degree and diffusion process of the two were calculated and simulated by mathematical calculation and COMSOL Multiphysics. The results show that a completely mixed solder joint can be obtained after reflow at 210 °C for 5 min. The average shear strength of the composite solder joints was 63.68 ± 1.12 MPa, which was about twice that of the single SAC305 and Sn58Bi solder joints, and the shear fracture was a composite mode of brittle and ductile fracture, which appeared in the IMC and the solder, respectively. After complete mixing, the solder wettability angle was less than 26.68°, with outstanding wetting properties. No phase transition occurred after aging, the distribution of each phase remained uniform, and no enrichment of the brittle phase was observed at the interface. The shear strength decreased slightly with aging time, and the reduction value was less than 10 MPa, which has good reliability.