Copper Wire Bonding: A Review

This paper provides a comprehensive review on copper (Cu) wire bonding. Firstly, it introduces the common types of Cu wire available in the market, including bare Cu wire, coated Cu wire, insulated Cu wire, and alloyed Cu wire. For each type, their characteristics and application areas are discussed. Additionally, we provide detailed insights into the impact of Free Air Ball (FAB) morphology on bonding reliability, including its effect on bond strength and formation mechanisms. Next, the reliability of Cu wire bonding is analyzed, with a focus on the impact of intermetallic compounds and corrosion on bonding reliability. Specifically, the formation, growth, and stability of intermetallic compounds at bonding interfaces are discussed, and their effects on bonding strength and reliability are evaluated. The detrimental mechanisms of corrosion on Cu wire bonding and corrosion inhibition methods are also analyzed. Subsequently, the applications of simulation in Cu wire bonding are presented, including finite element analysis and molecular dynamics simulations, which provide important tools for a deeper understanding of the bonding process and failure mechanisms. Finally, the current development status of Cu wire bonding is summarized, and future research directions are discussed.

Dynamics of chaotic system based on circuit design with Ulam stability through fractal-fractional derivative with power law kernel

In this paper, the newly developed Fractal-Fractional derivative with power law kernel is used to analyse the dynamics of chaotic system based on a circuit design. The problem is modelled in terms of classical order nonlinear, coupled ordinary differential equations which is then generalized through Fractal-Fractional derivative with power law kernel. Furthermore, several theoretical analyses such as model equilibria, existence, uniqueness, and Ulam stability of the system have been calculated. The highly non-linear fractal-fractional order system is then analyzed through a numerical technique using the MATLAB software. The graphical solutions are portrayed in two dimensional graphs and three dimensional phase portraits and explained in detail in the discussion section while some concluding remarks have been drawn from the current study. It is worth noting that fractal-fractional differential operators can fastly converge the dynamics of chaotic system to its static equilibrium by adjusting the fractal and fractional parameters.

Kinetic Analysis of Laminar Combustion Characteristics of a H2/Cl2 Mixture at CO2/N2 Dilution

Garbage and biomass contain more chlorine, which reacts with H₂ to form HCl gas during combustion or gasification, resulting in corrosion of metal walls. In this paper, based on the chlorine mechanism in Ansys Chemkin-Pro, the laminar combustion characteristics of H₂/Cl₂ are simulated with different diluents CO₂/N₂ under an initial temperature of 298 K, equivalence ratio range of 0.6-1.4, and initial pressure of 0.1-0.5 MPa. The results show that the laminar burning velocity of H₂/Cl₂ decreases significantly with the increase of dilution gas ratio, and the effect of diluent CO₂ is more significant than that of N₂. Due to the dilution effect, the fuel and oxidation components are reduced. Through sensitivity analysis, reaction R2: Cl + H₂ = HCl + H is the main reaction of HCl formation. On improving the initial pressure, the laminar burning velocity is slightly lowered, and the thermal diffusivity of the fuel mixture increases with the increase of the initial pressure. According to the sensitivity analysis of the velocity, reactions R2, R9, and R10 are the main reactions that affect the laminar burning velocity, and the product HCl will be generated with a delay with the increase of the initial pressure.

Effect of Indium Addition on the Low-Temperature Selective Catalytic Reduction of NO x by NH3 over MnCeO x Catalysts: The Promotion Effect and Mechanism

A MnCeInO _x catalyst was prepared by a coprecipitation method for denitrification of NH₃-SCR (selective catalytic reduction). The catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller analysis, H₂ temperature-programmed reduction, and NH₃ temperature-programmed desorption. The NH₃-SCR activity and H₂O and SO₂ resistance of the catalysts were evaluated. The test results showed that the SCR and water resistance and sulfur resistance were good in the range of 125-225 °C. The calcination temperature of the Mn₆Ce_0.3In_0.7O _x catalyst preparation was studied. The crystallization of the Mn₆Ce_0.3In_0.7O _x catalyst was poor when calcined at 300 °C; however, the crystallization is excessive at a 500 °C calcination temperature. The influence of space velocity on the performance of the catalyst is great at 100-225 °C. FTIR test results showed that indium distribution on the surface of the catalyst reduced the content of sulfate on the surface, protected the acidic site of MnCe, and improved the sulfur resistance of the catalyst. The excellent performance of the Mn₆Ce_0.3In_0.7O _x catalyst may be due to its high content of Mn⁴⁺, surface adsorbed oxygen species, high specific surface area, redox sites and acid sites on the surface, high turnover frequency, and low apparent activation energy.