Effect of ultrasonic power on wettability, porosity and mechanical properties of ultrasonic-aided laser reflow soldering

2021 ◽  
Vol 35 (05) ◽  
pp. 2150063
Author(s):  
Bo Wang ◽  
Kailin Pan ◽  
Yubing Gong ◽  
Yuhong Long ◽  
Kai Shi
Keyword(s):  
Mechanical Properties ◽  
Solder Joint ◽  
Solder Joints ◽  
Xrd Analysis ◽  
Ultrasonic Power ◽  
X Ray Diffraction ◽  
Reflow Soldering ◽  
Cavitation Effect ◽  
Diffraction Peaks ◽  
Free Solder

Wettability, porosity and mechanical properties of ultrasonic-aided laser reflow soldering lead-free solder Sn-3.0Ag-0.5Cu (SAC305) on Cu pad have been investigated at ultrasonic vibration (USV) of different power. The parameters of laser reflow soldering are determined by the wetting experiment, and the effects of different ultrasonic powers on the performance of the solder joint are studied. Results showed that USV can improve wettability without keyholes on top of the solder joint, and the contact angle between the solder joint and the substrate decreases first and then increases as the ultrasonic power increases. The cavitation effect caused by USV effectively reduces the porosity of the solder joints. When the ultrasonic power is 225 W, the porosity of the solder joint is reduced from the initial 13.2% to 5.2%. Through X-ray Diffraction (XRD) analysis of the solder joint matrix, all solder joints have diffraction peaks of [Formula: see text]-Sn, Cu6Sn5 and Ag3Sn, and the solder joints show higher diffraction peak intensity with USV treated. Furthermore, the solder joints prepared by ultrasonic-aided laser reflow soldering show better shear strength compared with laser reflow soldering.

Effect of expandable and expanded graphites on the thermo-mechanical properties of polyamide 11

2018 ◽  
Vol 51 (2) ◽  
pp. 175-190 ◽  
Author(s):  
F Oulmou ◽  
A Benhamida ◽  
A Dorigato ◽  
A Sola ◽  
M Messori ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Xrd Analysis ◽  
Crystal Form ◽  
X Ray Diffraction ◽  
Polyamide 11 ◽  
X Ray ◽  
Diffraction Peaks ◽  
Graphite Composites ◽  
And Storage

The preparation and thermo-mechanical characterization of composites based on polyamide 11 (PA11) filled with various amounts of both expandable and expanded graphites are presented. Investigation conducted using X-ray diffraction (XRD), scanning electron microscopy and surface area analyses indicated how graphite expanded under the selected processing conditions. The XRD analysis on PA11/graphite composites revealed no change in the crystal form of the PA11, while the presence of diffraction peaks associated to the graphite-stacked lamellae can be still detected. All the investigated composites showed an improvement of the thermal stability and mechanical properties (elastic and storage moduli).

CHARACTERIZATION OF HYDROXYAPATITE/TI6AL4V COMPOSITE POWDER UNDER VARIOUS SINTERING TEMPERATURE

2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif
Keyword(s):  
Mechanical Properties ◽  
Composite Powder ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Two Phases ◽  
Work Interaction

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 

Elevated Stand-Off Heights in Solder Joint Interconnections of Surface Mounted IC Packages Result in Appreciable Stress and Warpage Relief

2018 ◽  
Vol 2018 (1) ◽  
pp. 000534-000542
Author(s):  
Ephraim Suhir ◽  
Sung Yi ◽  
Jennie S. Hwang ◽  
R. Ghaffarian
Keyword(s):  
Solder Joint ◽  
Solder Joints ◽  
Calculated Data ◽  
Ball Grid Array ◽  
Substantial Improvement ◽  
Stress Model ◽  
Solder Material ◽  
The Difference ◽  
Free Solder ◽  
Ic Package

Abstract The “head-in-pillow” (HnP) defects in lead-free solder joint interconnections of IC packages with conventional (small) stand-off heights of the solder joints, and particularly in packages with fine pitches, are attributed by many electronic material scientists to the three major causes: 1) attributes of the manufacturing process, 2) solder material properties and 3)design-related issues. The latter are thought to be caused primarily by elevated stresses in the solder material, as well as by the excessive warpage of the PCB-package assembly and particularly to the differences in the thermally induced curvatures of the PCB and the package. In this analysis the stress-and-warpage issue is addressed using an analytical predictive stress model. This model is a modification and an extension of the model developed back in 1980-s by the first author. It is assumed that it is the difference in the post-fabrication deflections of the PCB-package assembly that is the root cause of the solder materials failures and particularly and perhaps the HnP defects. The calculated data based on the developed analytical thermal stress model suggest that the replacement of the conventional ball-grid-array (BGA) designs with designs characterized by elevated stand-off heights of the solder joints could result in significant stress and warpage relief and, hopefully, in a lower propensity of the IC package to HnP defects as well. The general concepts are illustrated by a numerical example, in which the responses to the change in temperature of a conventional design referred to as ball-grid-array (BGA) and a design with solder joints with elevated stand-off heights referred to as column-grid-array (CGA) are compared. The computed data indicated that the effective stress in the solder material is relieved by about 40% and the difference between the maximum deflections of the PCB and the package is reduced by about 60%, when the BGA design is replaced by a CGA system. Although no proof that the use of solder joints with elevated stand-off heights will lessen the package propensity to the HnP defects is provided, the authors think that there is a reason to believe that the application of solder joints with elevated stand-off heights could result in a substantial improvement in the general IC package performance, including, perhaps, its propensity to HnP defects.

Nanoindentation Characterization of Lead-free Solders and Intermetallic Compounds under Thermal Aging

2010 ◽  
Vol 2010 (1) ◽  
pp. 000314-000318
Author(s):  
Tong Jiang ◽  
Fubin Song ◽  
Chaoran Yang ◽  
S. W. Ricky Lee
Keyword(s):  
Mechanical Properties ◽  
Thermal Aging ◽  
Solder Joints ◽  
Lead Free ◽  
Small Range ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Aging Test ◽  
Free Solder ◽  
Lead Free Solders

The enforcement of environmental legislation is pushing electronic products to take lead-free solder alloys as the substitute of traditional lead-tin solder alloys. Applications of such alloys require a better understanding of their mechanical behaviors. The mechanical properties of the lead-free solders and IMC layers are affected by the thermal aging. The lead-free solder joints on the pads subject to thermal aging test lead to IMC growth and cause corresponding reliability concerns. In this paper, the mechanical properties of the lead-free solders and IMCs were characterized by nanoindentation. Both the Sn-rich phase and Ag3Sn + β-Sn phase in the lead-free solder joint exhibit strain rate depended and aging soften effect. When lead-free solder joints were subject to thermal aging, Young's modulus of the (Cu, Ni)6Sn5 IMC and Cu6Sn5 IMC changed in very small range. While the hardness value decreased with the increasing of the thermal aging time.

scholarly journals Effects of Bi2O3 Doping on the Mechanical Properties of PbO Ceramic Pellets Used in Lead-Cooled Fast Reactors

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1948 ◽  
Author(s):  
Yan Ma ◽  
Anxia Yang ◽  
Huiping Zhu ◽  
Arslan Muhammad ◽  
Pengwei Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Eutectic Alloy ◽  
Composite Ceramic ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Oxygen Control ◽  
Fast Reactors ◽  
Future Studies ◽  
X Ray ◽  
Lead Bismuth Eutectic

In this paper, the effects of Bi2O3 doping on the mechanical properties of PbO ceramic pellets were studied. Different ratios of Bi2O3/PbO (i.e., xBi2O3-(1−x) PbO, where x is 0, 1, 3, 5, or 7 wt.%) were fabricated and sintered at 570, 620, and 670 °C. Mechanical properties including density, hardness, flexural strength, and sintering of PbO were studied for each of the aforementioned compositions. Phase composition, microstructure, and the worn surfaces of the composites were characterized by scanning electron microscopy and X-ray diffraction (XRD). The XRD analysis revealed that a solid solution formed in the composite ceramic. The best suited conditions of temperature and doping of Bi2O3 for optimal sintering were found to be 620 °C and 3 wt.%, respectively. The hardness of the 3 wt.% Bi2O3-97 wt.% PbO ceramic was found to be 717 MPa, which is about four times higher than the hardness of pure PbO. In addition, the strength of the composites was found to be 43 MPa, which is two times higher than that of pure PbO. The integrity of the composites was verified using the lead–bismuth eutectic alloy flushing experiment. The results of this research paper are important for future studies of oxygen control in the lead–bismuth eutectic alloy of lead-cooled fast reactors.

The Effects of Electromigration to the Solder Joint Formation: A Comparison Between 99.3Sn-0.7Cu and 96.5Sn-3.0Ag-0.5Cu Lead Free Solder

2012 ◽  
Vol 622-623 ◽  
pp. 195-199 ◽  
Author(s):  
M.A.A. Mohd Salleh ◽  
A.R. Nik Nurhidayatul Suhada ◽  
Flora Somidin ◽  
Rafezi Ahmad Khairel ◽  
C.S. Lee ◽  
...  
Keyword(s):  
Solder Joint ◽  
Room Temperature ◽  
Solder Joints ◽  
Research Work ◽  
Cathode Region ◽  
Lead Free ◽  
Lead Free Solder ◽  
Joint Formation ◽  
Current Stress ◽  
Free Solder

Electromigration effects on the solder joint formation of 99.3Sn-0.7Cu and 96.5Sn-3.0Ag-0.5Cu lead-free solder with Cu electroplated Ni layer wire were investigated. The electromigration effects on the solder joints were studied after current density stressing at 1 x 103 A/cm2 in room temperature for 0 h, 120 h, and 240 h. The research work found that intermetallic compound (IMC) formation on the joint is increases for both solders with longer period of current stress applied. Higher IMC thickness growth in 99.3Sn-0.7Cu solder joint compared to 99.3Sn-0.7Cu is detected and both anode regions of the solder joints show higher IMC thickness growth compared to cathode region. Experimental results show 99.3Sn-0.7Cu solder joint is more prone to failure under current stress compared to 96.5Sn-3.0Ag-0.5Cu solder joint with thicker IMC which translates to higher brittleness.

SAC–xTiO2 nano-reinforced lead-free solder joint characterizations in ultra-fine package assembly

2018 ◽  
Vol 30 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Fakhrozi Che Ani ◽  
Azman Jalar ◽  
Abdullah Aziz Saad ◽  
Chu Yee Khor ◽  
Roslina Ismail ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Solder Joint ◽  
Solder Joints ◽  
Ion Beam ◽  
Lead Free ◽  
Lead Free Solder ◽  
Solder Paste ◽  
Content Type ◽  
X Ray ◽  
Free Solder

Purpose This paper aims to investigate the characteristics of ultra-fine lead-free solder joints reinforced with TiO2 nanoparticles in an electronic assembly. Design/methodology/approach This study focused on the microstructure and quality of solder joints. Various percentages of TiO2 nanoparticles were mixed with a lead-free Sn-3.5Ag-0.7Cu solder paste. This new form of nano-reinforced lead-free solder paste was used to assemble a miniature package consisting of an ultra-fine capacitor on a printed circuit board by means of a reflow soldering process. The microstructure and the fillet height were investigated using a focused ion beam, a high-resolution transmission electron microscope system equipped with an energy dispersive X-ray spectrometer (EDS), and a field emission scanning electron microscope coupled with an EDS and X-ray diffraction machine. Findings The experimental results revealed that the intermetallic compound with the lowest thickness was produced by the nano-reinforced solder with a TiO2 content of 0.05 Wt.%. Increasing the TiO2 content to 0.15 Wt.% led to an improvement in the fillet height. The characteristics of the solder joint fulfilled the reliability requirements of the IPC standards. Practical implications This study provides engineers with a profound understanding of the characteristics of ultra-fine nano-reinforced solder joint packages in the microelectronics industry. Originality/value The findings are expected to provide proper guidelines and references with regard to the manufacture of miniaturized electronic packages. This study also explored the effects of TiO2 on the microstructure and the fillet height of ultra-fine capacitors.

Thermal Cycling Reliability of Chip Resistor Lead Free Solder Joints

2003 ◽  
Author(s):  
N. Islam ◽  
J. C. Suhling ◽  
P. Lall ◽  
T. Shete ◽  
H. S. Gale ◽  
...  
Keyword(s):  
Solder Joint ◽  
Thermal Cycling ◽  
Fatigue Resistance ◽  
Solder Joints ◽  
Lead Free ◽  
Lead Free Solder ◽  
Snagcu Alloy ◽  
Temperature Ranges ◽  
Free Solder

In this study, we have examined the thermal cycling reliability of several lead free chip resistor solder joint configurations. Five sizes of resistors (2512, 1206, 0805, 0603, 0402), 2 temperature ranges (−40 to 125°C and −40 to 150°C), and five different solder types have been examined. The solders include the normal SnAgCu alloy recommended by earlier studies (95.5Sn-3.8Ag-0.7Cu), and several variations that include small percentages of Bismuth and Indium to enhance fatigue resistance. Results have been compared to data for standard 63Sn-37Pb joints.

Deformation Behavior of SAC305 Solder Joints With Multiple Grains

2020 ◽  
Author(s):  
Debabrata Mondal ◽  
Abdullah Fahim ◽  
KM Rafidh Hassan ◽  
Jeffrey C. Suhling ◽  
Pradeep Lall
Keyword(s):  
Grain Size ◽  
Solder Joint ◽  
Deformation Behavior ◽  
Thermal Loading ◽  
Solder Joints ◽  
Lead Free ◽  
External Loading ◽  
Lead Free Solder ◽  
Material Anisotropy ◽  
Free Solder

Abstract Lead-free solder joints are the most widely used interconnects in electronic packaging industries. Usually solder joints in most of the electronic devices are exposed to an environment where variation of temperature exists, which indicates cyclic thermal loading to be a very common type of external loading. Moreover, due to difference in the coefficient of thermal expansion (CTE) among dissimilar contact materials, shear stress develops in junctions under thermal loading, which significantly deteriorates the overall reliability. Hence, characterization of lead-free solder materials under thermal loading is essential to predict the performance and deformation behavior of joints in practical applications. A significant portion of the studies in this field are concerned with thermal loading of lead-free solder interconnects, each of which has a very small diameter, in sub-millimeter range. Although the solder balls have very small dimensions, most of the analyses considered them as a bulk material with homogeneous and isotropic properties. However, with the decrease of specimen dimensions, size effects and material directionality play a significant role in deformation mechanisms. Since a very few grains exist in a small specimen, individual grain properties play a vital role on overall material response. Therefore, modeling from the grain structure and orientation point of view could be an effective and more accurate way to predict solder joint deformation behavior under thermal loading. In this study, the effect of grain size and orientation of SAC305 is investigated for predicting anisotropic behavior of solder joints under thermal load. A simplified three-dimensional model of beach-ball configuration solder joint was generated and simulated using ABAQUS finite element (FE) software. Experimentally obtained directional properties such as elastic modulus and CTE were assigned to the computational geometry to create material anisotropy. The effects of material anisotropy were studied for varying grain size specimens, as well as for specimens with varying grain orientation.

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