Effects of Different Fluxes on the Spreadability of Zn-20Sn Solders

2011 ◽  
Vol 337 ◽  
pp. 546-549
Author(s):  
Yang Yang Sheng ◽  
Yan Fu Yan ◽  
Kuai Le Zhao ◽  
Zhi Wei Xu
Keyword(s):  
Intermetallic Compounds ◽  
Solder Joints ◽  
Middle Layer ◽  
Cu Substrate ◽  
Medium Activity

The spreadability of Zn-20Sn solders on Cu substrate was researched by using self-made flux, silver brazing 102 and medium activity rosin (RMA), and the characteristics of intermetallic compounds the appearance of solder joints were compared and analyzed at soldering joints. Results indicated that Zn-20Sn solders exhibited excellent spreadability by using self-made flux. A shoot IMC layer was closed to the solder while a flat IMC layer was presenting adjacent to the Cu substrate and the middle layer. Moreover, the characteristics of IMC and the appearances of soldered joints varied by using different fluxes.

Effects of Bismuth Content on the Microstructure, Shear Strength and Thermal Properties of Sn-0.7Cu-0.05Ni Solder Joints

2020 ◽  
Vol 982 ◽  
pp. 115-120
Author(s):  
Phairote Sungkhaphaitoon ◽  
Tanyaporn Suwansukho
Keyword(s):  
Shear Strength ◽  
Thermal Properties ◽  
Solder Joint ◽  
Intermetallic Compounds ◽  
Interfacial Layer ◽  
Solder Joints ◽  
Peak Temperature ◽  
Cu Substrate ◽  
Bismuth Content ◽  
Pasty Range

The effects of bismuth content on the microstructure, shear strength and thermal properties of Sn-0.7Cu-0.05Ni solder joints were investigated. Adding 2 wt% elemental Bi to Sn-0.7Cu-0.05Ni solder joints reduced peak temperature by about 6.7 °C, increased pasty range by 4.2 °C and raised undercooling by 3.1 °C. The microstructure of the interfacial layer between solder and Cu substrate was composed of (Cu,Ni)6Sn5 and (Cu,Ni)3Sn intermetallic compounds (IMCs). The solder joint included a phase of SnBi and Cu6Sn5 IMCs. The addition of elemental Bi increased shear strength and suppressed the growth of IMCs in the interfacial layer of the solder joints.

Effect of Joint Size on Microstructure and Growth Kinetics of Intermetallic Compounds in Solid-Liquid Interdiffusion Sn3.5Ag/Cu-Substrate Solder Joints

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Ousama M. Abdelhadi ◽  
Leila Ladani
Keyword(s):  
Growth Rate ◽  
Intermetallic Compounds ◽  
Rate Constants ◽  
Solder Joints ◽  
Intermetallic Layer ◽  
Cu Substrate ◽  
Soldering Time ◽  
Diffusion Controlled ◽  
Solid Liquid ◽  
Intermetallic Layers

The effect of joint size on the interfacial reaction in the Sn3.5Ag/Cu-substrate soldering system was examined. An experiment was conducted in which parameters such as bonding time, temperature, and pressure were varied at multiple levels. The morphology and thickness of all intermetallic compounds (IMC) were analyzed using the scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques. An examination of the microstructures of solder joints of different sizes revealed that the size of the solder joint has no effect on the type of IMCs formed during the process. It was found that the joint size significantly affected the thickness of the intermetallic layers. The Cu3Sn intermetallic layers formed in the smaller sized solder joints were found to be thicker than those in the larger sized solder joints. In all specimen sizes, the increase in the thickness of Cu3Sn intermetallic layers with soldering time was found to obey a parabolic relationship. Additionally, for the cases when eutectic solder is available in the joints, a similar soldering time and temperature dependency were found for the Cu6Sn5 IMC phase. The intermetallic growth of the Cu3Sn phase was under a volume-diffusion controlled mechanism. The growth rate constants and activation energies of intermetallic layers were also reported for different joint thicknesses. Furthermore, the growth rate constants of the Cu3Sn intermetallic layer were found to depend upon the size of the joints.

Intermetallic compounds formed in Sn droplet on Cu substrate under the impact of electric currents

2021 ◽  
Author(s):  
Yueying Su ◽  
Rui Zhu ◽  
Tianqing Zheng ◽  
Yanping Shen ◽  
Yanyi Xu ◽  
...  
Keyword(s):  
Intermetallic Compounds ◽  
Electric Currents ◽  
Cu Substrate ◽  
The Impact

Intermetallic compounds growth between Sn–3.5Ag lead-free solder and Cu substrate by dipping method

2005 ◽  
Vol 392 (1-2) ◽  
pp. 192-199 ◽  
Author(s):  
D.Q. Yu ◽  
C.M.L. Wu ◽  
C.M.T. Law ◽  
L. Wang ◽  
J.K.L. Lai
Keyword(s):  
Intermetallic Compounds ◽  
Lead Free ◽  
Lead Free Solder ◽  
Cu Substrate ◽  
Free Solder

Experimental Study of Void Formation in High-Lead Solder Joints of Flip-Chip Assemblies

2004 ◽  
Vol 127 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Daijiao Wang ◽  
Ronald L. Panton
Keyword(s):  
Flip Chip ◽  
Solder Joints ◽  
Numerical Study ◽  
Void Formation ◽  
Middle Layer ◽  
Molten Solder ◽  
Previous Theory ◽  
Solder Interconnects ◽  
Heating Profiles ◽  
High Lead

Understanding the formation of voids in solder joints is important for predicting the long-term reliability of solder interconnects. This paper reports experimental research on the formation of void bubbles within molten solder bumps in flip-chip connections. For flip-chip-soldered electronic components, which have small solder volume, voids can be more detrimental to reliability. A previous theory based on thermocapillary flow reveals that the direction of heating influences void formation. Using different heating profiles, 480 solder joints of flip-chip assemblies were processed. A high-lead 90Pb∕8Sn∕2Ag solder was employed in the experiments. The solder samples were microsectioned to determine the actual size or diameter of the voids. A database on sizes and locations of voids was then constructed. More defective bumps, 80%, and higher void volume were found when the solder was melted from top (flip-chip side) to bottom (test board side). The observation on cases with melting direction from bottom to top had 40% defective bumps. The results show that a single big void is near the solder bump center with a few small voids near the edge. This supports the numerical study based on the thermocapillary theory. When the melting direction was reversed, many small voids appear near the edge. Big and middle-size voids tend to stay in the middle and outer regions from top towards middle layer of the bump. This experimental finding does not completely agree with the interpretation on the formation of voids by thermocapillary theory, however, the results do show that heat flux direction plays significant role in the formation and distribution of void bubbles in molten solder.

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