Micromechanical Studies of 4n Gold Wire for Fine Pitch Wirebonding

This study focuses towards typical micromechanical properties such as strength, yield point, Young’s Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 μm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the micro-tensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep

Effect of Different S AC Based Nanoparticles Types on the Reflow Soldering Process of Miniaturized Component using Discrete Phase Model Simulation

The wetting formation and nanoparticles dispersion on adding nanoparticles to the lead free solder Sn-3.0Ag-0.5Cu (SAC305) is methodically investigated using Discrete Phase Model (DPM) simulation and applied on a 01005 capacitor component. Different types of nanoparticles, namely titanium dioxide (TiO2), nickle oxide (NiO) and Iron (III) oxide (Fe2O3) with varying weight percentages, 0.01wt%, 0.05wt% and 0.15wt% that is doped in SAC305 are used. The study of two-way interactions between multiphase volume of fluid (VOF) and discrete phase model (DPM) shows excellent capability in tracking the dispersed nanoparticles immersed in the wetted molten solder. In this study, real reflow profile temperature setup will be used to mimic the conventional reflow process. Based on the findings, the fillet height managed to achieve the minimum required height set by IPC standards. As the concentration of the nanoparticles doped in the molten solder increases, higher time is required for the wetting process. In general, the doped NiO nanoparticles at 0.05wt% has the lowest wetting time compared to other cases. The study of the instantaneous nanoparticles trajectory tracking was also conducted on a 3D model and 2D cross sectional view to identify the exact movement of the particles. Additionally, it was also observed that the velocity and pressure distribution increases as the weight percentage of the nanoparticles increases

Thermo-Mechanical And Adhesion Performance Of Silver-Filled Conductive Polymer Composite (SFCP) Using Thermoplastic Polyurethane (TPU) Substrate

Emerging of conductive metal filler in nanoscale like Silver-Filled Conductive Polymer Composite (SFCP) ink is one of the important technology for electronic interconnects future. Among the key challenges in the successful development of such materials are to offer high electrical conductivity and good adhesion in polymer-based substrates without compromising on the mechanical reliability of such devices. This paper discussed the characteristics of Thermoplastic Polyurethane (TPU) based-materials in terms of their sustainability, wettability and SFCP conductivity of thermal effect (room temperature –25°C), 40°C, 60°C and 80°C). The experimental work involved electrical conductivity measurement using a Four-Point Probe, contact angle measurement and surface roughness analysis. Surface morphology analysis was carried out by using Axioscope 2MAT Optical Microscope and Scanning Electron Microscopic (SEM). The results show that sheet resistance of SFCP increased with an increasing strain and decrease with the increasing of temperature. The above results were observed due to the crack formation against strain but the presents of temperature cause the silver (Ag) particle to expand, filled the gap and form network path for electrical conduction even at maximum temperature and strain (80°C at 80%). Moreover, the TPU shows low wettability that exhibits poor adhesion between SFCP and TPU substrate due to reducing in the contact area between adhesive and substrate that cause the surface has low surface energy when exposed to variation of temperature

Surface morphology study on aluminum alloy after treated with silicate-based corrosion inhibitor from paddy residue

Aluminum alloys have extensive applications in engineering structures like aircraft due to their high strength-to-weight ratio. However, these alloys are very reactive and prone to corrosion attack. Paddy waste is one of the beneficial natural sources that have a potential contribution on inhibiting the corrosion attack. At 600°C, silica was obtained from rice husk ash. The chemical reaction between silica powders with concentrated alkali generates formulation of potential silicate-based corrosion inhibitor. The potentiodynamic polarization, optical microscope (OM), infinite focus microscope (IFM) and scanning electron microscopy (SEM) were employed to investigate the corrosion behaviour of Al 6061 through electrochemical and surface study. The electrochemical measurement showed that the existence of silicate-based corrosion inhibitor in 0.5 M hydrochloric acid medium significantly mitigates the corrosion rates. SEM, IFM and OM showed that the morphology of untreated Al 6061 contributes more damage on the sample surface than that of Al 6061 treated with silicate-base corrosion inhibitor. The aim of this study was to attain better understanding of surface study on corrosion behaviour of aluminum alloy in acidic medium after treated and untreated with silicate-based corrosion inhibitor from paddy residue

Surface morphology studies of low carbon steel treated in aqueous lignin

The effect of corrosion inhibition of low carbon steel in water based medium containing lignin was investigated via weight loss method. The evolution of surface morphology has been carried out for 7 to 42 days via optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron microscopy (XPS). Immersion of metal specimen without lignin shows that significant increase in the surface roughness. The longer the immersion time, the more the oxide crust formed. The surface degradation of metal specimen was well protected by immersion in lignin solution. A protective layer containing of lignin was formed on the surface of metal specimens after 7 and 21 days immersion. The corrosion inhibition gives about 13 and 53% inhibition for both 7 and 21 days immersion, respectively. The protective layers were spalling and separated from the metal surface after 42 days immersion in lignin solution possibly due to the increase in corrosion attack after long time immersion according to the increase in dissolved oxygen and may also due to the thermal mismatch between oxide and substrate. The adsorption of protective layer containing lignin was temporary adsorbed on the surface

Effect of substrate pre-soldering temperature on wettability of SAC387 lead-free solder

No Abstract

Review on Corrosion in Electronic Packaging Trends of Collaborative between Academia–Industry

This article reviews corrosion in electronic packaging mainly in the semiconductor industry over the world. The previous study was reviewed scientifically to highlight the significant work on corrosion in electronic packaging. A total of 467 and 762 studies were found in the IEEE Explore and Scopus databases from 2010 to 2020, respectively. After the search was limited to articles and proceedings, the databases showed only 319 from IEEE and 694 from Scopus. The keywords searching for this topic also emphasized corrosion wire bonding, corrosion leadframe, and corrosion solder. When searching for articles and proceedings were divided into three (3) categories such as academia, industry, and collaborative works, the database from collaborative works showed only 57 and 108 results in IEEE and Scopus, respectively. The studies were classified according to the process after some analysis using Microsoft Excel. Most of the previous studies were on corrosion in electronic packaging. From the study, we found that most of the journal articles were published by academia while the proceeding was published by industry. This information was extracted from IEEE Explore and Scopus databases. Since 2010, the trend of collaborative works among the industry and academia showed increased from 13 to 165 total publications in 2020. This review is significant to give an overview of the collaborative works between industry and academia on the corrosion issue in electronic packaging

Review on Corrosion in Electronic Packaging Trends of Collaborative between Academia–Industry

This article reviews corrosion in electronic packaging mainly in the semiconductor industry over the world. The previous study was reviewed scientifically to highlight the significant work on corrosion in electronic packaging. A total of 467 and 762 studies were found in the IEEE Explore and Scopus databases from 2010 to 2020, respectively. After the search was limited to articles and proceedings, the databases showed only 319 from IEEE and 694 from Scopus. The keywords searching for this topic also emphasized corrosion wire bonding, corrosion leadframe, and corrosion solder. When searching for articles and proceedings were divided into three (3) categories such as academia, industry, and collaborative works, the database from collaborative works showed only 57 and 108 results in IEEE and Scopus, respectively. The studies were classified according to the process after some analysis using Microsoft Excel. Most of the previous studies were on corrosion in electronic packaging. From the study, we found that most of the journal articles were published by academia while the proceeding was published by industry. This information was extracted from IEEE Explore and Scopus databases. Since 2010, the trend of collaborative works among the industry and academia showed increased from 13 to 165 total publications in 2020. This review is significant to give an overview of the collaborative works between industry and academia on the corrosion issue in electronic packaging

Micro-structural Studies of Thermosonic Cu-Al Bonding Interface

Thermosonic Copper (Cu) wire interconnection has been under an extensive research and development to replace expensive Gold (Au) wire material in the semiconductor industry. However, a reliability concern is raised due to void formation at the bonding interface of Copper wire-Aluminum bond pad (Cu-Al) after High Temperature Storage (HTS) annealing condition. It is believed that the Intermetallic Compound (IMC) layer growth and evolution lead to a volumetric shrinkage which in turn results in the void formation. Annealing conditions influence the development of the IMC at the bonding interface which is related to the bonding reliability. In this work, the effects of annealing toward the micro-structure and IMC growth at the bonding interface were evaluated using Scanning Transmission Electron Microscope equipped with Energy Dispersive X-ray analysis. In the as-synthesized sample bonded at 100°C, an inhomogeneous IMC formation dominated by grain boundary diffusion was observed. After High Temperature Storage of 1000 hours, the consumption of the Al bond pad resulted in the formation of irregular IMC layers. The variation of phases existed in a localized region was believed due to simultaneous growth of IMC by both grain boundary and volume diffusions. Moreover, the diffusion of Cu into Si was observed. This resulted in the formation of the mixture of Si + η” phases in the affected sea region

Micro-structural Studies of Thermosonic Cu-Al Bonding Interface

Thermosonic Copper (Cu) wire interconnection has been under an extensive research and development with objective to replace expensive Gold (Au) wire material in the semiconductor industry. However, a reliability concern is raised due to void formation at the bonding interface of Copper wire-Aluminum bond pad (Cu-Al) after High Temperature Storage (HTS) annealing condition. It is believed that the Intermetallic Compound (IMC) layer growth and evolution lead to a volumetric shrinkage which in turn results in the void formation. This defect increases the electrical resistance of the micro-chip until a functionality failure occurs. The wire bonding and annealing conditions influence the development of the IMC at the bonding interface which is related to the bonding reliability. In this work, effects of bonding temperature and annealing toward the micro-structure and IMC growth at the bonding interface were evaluated using Scanning Transmission Electron Microscope equipped with Energy Dispersive X-ray facility. From the imaging results of as-bonded Cu wire samples, bonding temperature resulted in a rapid interdiffusion of Cu-Al. This resulted in a thicker and more uniform IMC formation at the bonding interface. After High Temperature Storage of 1000 hours, the consumption of the Al bond pad and diffusion of Cu into Si to form precipitates were observed. The chemical analysis shows multiple phases existed at the bonding interface especially for the sample synthesized with a lower bonding temperature. Moreover, the IMC of the annealed sample synthesized with higher bonding temperature developed in a superlattice-like structure