New Glass Sealing Method with Lead-Free Solders

2006 ◽  
Vol 45 ◽  
pp. 1604-1607 ◽  
Author(s):  
Koichi Sakaguchi ◽  
Shinjiro Domi ◽  
Katsuaki Suganuma

We have developed a novel technique of joining a pair of glass substrates. In the process, molten solder penetrates the gap between the glass substrates while the solder-glass interfaces are being activated by friction. The activation is given by a metal plate, which slides through the gap along the edge of the paired glass substrates and brings in the molten solder by capillary-action. A Ti-doped Sn-Zn eutectic solder showed good hermetic sealing of glass. A eutectic In-Sn solder also yielded good joining, especially at low sealing temperatures.

Author(s):  
Mohammad Faizan ◽  
Guo-X. Wang

Soldering has become an indispensable joining process in the electronic packaging industry. The industry is aiming for the use of environment friendly lead-free solders. All the lead-free solders are high tin-containing alloys. During the soldering process, an intense interaction of metallization on PCB and tin from the solder occurs at the metallization/solder interface. Intermetallic compound (IMC) is formed at the interface and subsequently PCB bond-metal (substrate) is dissolved into the molten solder. In the present study the terms bond-metal and substrate will be used interchangeably and the term 'substrate' refers to the top layer of the PCB which comes in contact with the molten solder during soldering reaction. Thickness of the intermetallic phase formed at the joint interface and amount of substrate lost is critical in achieving reliable solder joints. During the wet phase of soldering process, the IMC does not grow as layered structure; rather it takes the shape of scallops. The growth of scalloped IMC during the solder/substrate interaction entails complicated physics. Understanding of the actual kinetics involved in the formation of IMC phase is important in controlling the process to achieve desired results. This paper presents theoretical analysis of the kinetics involved in the formation of the scalloped intermetallic phase. The intermetallic phase growth is experimentally investigated to support the underlying kinetics of the process. Numerical model has been suggested to translate the physics of the process. The model is based on the basic mass diffusion equations and can predict the substrate dissolution and IMC thickness as a function of soldering time.


2003 ◽  
Vol 18 (7) ◽  
pp. 1528-1534 ◽  
Author(s):  
Chia-Wei Huang ◽  
Kwang-Lung Lin

The microstructure, melting point, and mechanical properties of Sn–8.55Zn–0.45Al–XAg lead-free solders were investigated. The Ag content of the solders investigated was 0–3 wt.%. The results indicate that the AgZn3 and Ag5Zn8 compounds are formed at the addition of Ag to Sn–8.55Zn–0.45Al solders. The adding of Ag also results in the formation of hypoeutectic structure, increasing the melting point of the solders and decreasing the ductility. Results of thermal analysis reveal that the Sn–8.55Zn–0.45Al–XAg solder has eutectic temperature at 198 °C when the addition of Ag is 0.5 wt.%. The eutectic solder exhibits greater tensile strength and higher ductility than the 63–Sn–37Pb solder.


2018 ◽  
Vol 32 (19) ◽  
pp. 1840059 ◽  
Author(s):  
Y. W. Yen ◽  
C. Y. Lin ◽  
J. Yan ◽  
Y. W. Chang ◽  
C. H. Wang ◽  
...  

The dissolution behavior of the Ni substrate and Ni3Sn4 phase was studied in the following molten lead-free solders: Sn, (wt.%) Sn–3.0Ag–0.5Cu (SAC), Sn–0.7Cu (SC), Sn–58Bi (SB) and Sn–9Zn (SZ) at 240[Formula: see text]C, 270[Formula: see text]C and 300[Formula: see text]C. The dissolution rate of the Ni substrate in solder decreased from Sn, SAC, SC, SB, to SZ. The thick Ni5(Zn, Sn)[Formula: see text] phase formed at the SZ/Ni interface hindering the Ni dissolution. Ni3Sn4 phase dissolution rate in molten solder decreased from Sn, SZ, SAC, SC, to SB at 240[Formula: see text]C and SC, Sn, SAC, SZ, to SB at 300[Formula: see text]C. The (Cu, Ni)6Sn5 phase spilling was observed at the SAC/Ni3Sn4 and SC/Ni3Sn4 interfaces. Zn in the SZ solder reacted with the Ni3Sn4 phase to form the (Ni, Sn)5Zn[Formula: see text] phase at the interface.


2003 ◽  
Vol 18 (11) ◽  
pp. 2540-2543 ◽  
Author(s):  
Chi-Won Hwang ◽  
Katsuaki Suganuma ◽  
Masayuki Kiso ◽  
Shigeo Hashimoto

The interface microstructures of Sn-Ag and Sn-Ag-Cu solders with Au/Ni-6P plating were studied primarily using transmission electron microscopy. During soldering at 230°C, Au dissolved into molten solder, and double reaction layers of Ni3Sn4/η–Ni3SnP formed between Sn-3.5Ag solder and Ni-6P layer. P content increases in the surface region of the Ni-6P layer due to the depletion of Ni diffused into molten solder, resulting in the formation of Ni3P+Ni layer. For Sn-3.5Ag-0.7Cu solder, an η-(Ni,Cu)3Sn2 single layer, containing Cu of about 50 at.%, formed as a reaction layer.


2015 ◽  
Vol 10 (1) ◽  
pp. 2641-2648
Author(s):  
Rizk Mostafa Shalaby ◽  
Mohamed Munther ◽  
Abu-Bakr Al-Bidawi ◽  
Mustafa Kamal

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.  


2013 ◽  
Vol 58 (2) ◽  
pp. 529-533 ◽  
Author(s):  
R. Koleňák ◽  
M. Martinkovič ◽  
M. Koleňáková

The work is devoted to the study of shear strength of soldered joints fabricated by use of high-temperature solders of types Bi-11Ag, Au-20Sn, Sn-5Sb, Zn-4Al, Pb-5Sn, and Pb-10Sn. The shear strength was determined on metallic substrates made of Cu, Ni, and Ag. The strength of joints fabricated by use of flux and that of joints fabricated by use of ultrasonic activation without flux was compared. The obtained results have shown that in case of soldering by use of ultrasound (UT), higher shear strength of soldered joints was achieved with most solders. The highest shear strength by use of UT was achieved with an Au-20Sn joint fabricated on copper, namely up to 195 MPa. The lowest average values were achieved with Pb-based solders (Pb-5Sn and Pb-10Sn). The shear strength values of these solders used on Cu substrate varied from 24 to 27 MPa. DSC analysis was performed to determine the melting interval of lead-free solders.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2549
Author(s):  
Wenchao Yang ◽  
Jun Mao ◽  
Yueyuan Ma ◽  
Shuyuan Yu ◽  
Hongping He ◽  
...  

Electrochemical corrosion behavior of ternary tin-zinc-yttrium (Sn-9Zn-xY) solder alloys were investigated in aerated 3.5 wt.% NaCl solution using potentiodynamic polarization techniques, and the microstructure evolution was obtained by scanning electron microscope (SEM). Eight different compositions of Sn-9Zn-xY (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, and 0.30 wt.%) were compared by melting. The experimental results show that when the content of Y reached 0.06 wt.%, the grain size of Zn-rich phase became the smallest and the effect of grain refinement was the best, but there was no significant effect on the melting point. With the increases of Y content, the spreading ratio first increased and then decreased. When the content of Y was 0.06 wt.%, the Sn-9Zn-0.06Y solder alloy had the best wettability on the Cu substrate, which was increased by approximately 20% compared with Sn-9Zn. Besides, the electrochemical corrosion experimental shows that the Y can improve the corrosion resistance of Sn-9Zn system in 3.5 wt.% NaCl solution, and the corrosion resistance of the alloy is better when the amount of Y added is larger within 0.02–0.30 wt.%. Overall considering all performances, the optimal performance can be obtained when the addition amount of Y is 0.06.


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