Mechanism analysis of microvia filling based on multiphysics coupling

Circuit World ◽  
2018 ◽  
Vol 44 (2) ◽  
pp. 60-68
Author(s):  
Linxian Ji ◽  
Shidong Su ◽  
Hexian Nie ◽  
Shouxu Wang ◽  
Wei He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Growth Period ◽  
Operating Conditions ◽  
Initial Growth ◽  
Copper Electrodeposition ◽  
Copper Plating ◽  
Content Type ◽  
Multiphysics Coupling ◽  
Plating Solution ◽  
Excellent Tool

Purpose Copper electrodeposition acts as a crucial step in the manufacture of high-density interconnect board. The stability of plating solution and the uniformity of copper electrodeposit are the hotspot and difficulty for the research of electrodeposition. Because a large number of factors are included in electrodeposition, experimentally determining all parameters and electrodeposition conditions becomes unmanageable. Therefore, a multiphysics coupling technology was introduced to investigate microvia filling process, and the mechanism of copper electrodeposition was analyzed. The results provide a strong theoretical basis and technical guidance for the actual electroplating experiments. The purpose of this paper is to provide an excellent tool for quickly and cheaply studying the process behavior of copper electrodeposition without actually needing to execute time-consuming and costly experiments. Design/methodology/approach The interactions among additives used in acidic copper plating solution for microvia filling and the effect on the copper deposition potential were characterized through galvanostatic measurement (GM). The adsorption behavior and surface coverage of additives with various concentrations under different rotating speeds of working electrode were investigated using cyclic voltammetry (CV) measurements. Further, a microvia filling model was constructed using multiphysics coupling technology based on the finite element method. Findings GM tests showed that accelerator, inhibitor and leveler affected the potential of copper electrodeposition, and bis(3-sulfopropyl) disulfide (SPS), ethylene oxide-propylene oxide (EO/PO) co-polymer, and self-made leveler were the effective additives in acidic copper plating solution. CV tests showed that EO/PO–Cu+-Cl− complex was adsorbed on the electrode surface by intermolecular forces, thus inhibiting copper electrodeposition. Numerical simulation indicated that the process of microvia filling included initial growth period, the outbreak period and the stable growth period, and modeling result was compared with the measured data, and a good agreement was observed. Research limitations/implications The research is still in progress with the development of high-performance computers. Practical implications A multiphysics coupling platform is an excellent tool for quickly and cheaply studying the electrodeposited process behaviors under a variety of operating conditions. Social implications The numerical simulation method has laid the foundation for mechanism of copper electrodeposition. Originality/value By using multiphysics coupling technology, the authors built a bridge between theoretical and experimental study for microvia filling. This method can help explain the mechanism of copper electrodeposition.

Multiphysics coupling simulation of RDE for PCB manufacturing

Circuit World ◽  
2015 ◽  
Vol 41 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Linxian Ji ◽  
Chong Wang ◽  
Shouxu Wang ◽  
Wei He ◽  
Dingjun Xiao ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Finite Element Method ◽  
Current Density Distribution ◽  
Copper Electrodeposition ◽  
The Finite Element Method ◽  
Content Type ◽  
Multiphysics Coupling ◽  
Pcb Manufacturing ◽  
Electrochemical Model ◽  
Plating Layer

Purpose – The purpose of this paper is to optimize experimental parameters and gain further insights into the plating process in the fabrication of high-density interconnections of printed circuit boards (PCBs) by the rotating disc electrode (RDE) model. Via metallization by copper electrodeposition for interconnection of PCBs has become increasingly important. In this metallization technique, copper is directly filled into the vias using special additives. To investigate electrochemical reaction mechanisms of electrodeposition in aqueous solutions, using experiments on an RDE is common practice. Design/methodology/approach – An electrochemical model is presented to describe the kinetics of copper electrodeposition on an RDE, which builds a bridge between the theoretical and experimental study for non-uniform copper electrodeposition in PCB manufacturing. Comsol Multiphysics, a multiphysics simulation platform, is invited to modeling flow field and potential distribution based on a two-dimensional (2D) axisymmetric physical modeling. The flow pattern in the electrolyte is determined by the 2D Navier–Stokes equations. Primary, secondary and tertiary current distributions are performed by the finite element method of multiphysics coupling. Findings – The ion concentration gradient near the cathode and the thickness of the diffusion layer under different rotating velocities are achieved by the finite element method of multiphysics coupling. The calculated concentration and boundary layer thicknesses agree well with those from the theoretical Levich equation. The effect of fluid flow on the current distribution over the electrode surface is also investigated in this model. The results reveal the impact of flow parameters on the current density distribution and thickness of plating layer, which are most concerned in the production of PCBs. Originality/value – By RDE electrochemical model, we build a bridge between the theoretical and experimental study for control of uniformity of plating layer by concentration boundary layer in PCB manufacturing. By means of a multiphysics coupling platform, we can accurately analyze and forecast the characteristic of the entire electrochemical system. These results reveal theoretical connections of current density distribution and plating thickness, with controlled parameters in the plating process to further help us comprehensively understand the mechanism of copper electrodeposition.

Multi-physics coupling aid uniformity improvement in pattern plating

Circuit World ◽  
2016 ◽  
Vol 42 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Linxian Ji ◽  
Chong Wang ◽  
Shouxu Wang ◽  
Kai Zhu ◽  
Wei He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Current Distribution ◽  
Printed Circuit Boards ◽  
Operating Conditions ◽  
Copper Layer ◽  
Distribution Model ◽  
Plating Bath ◽  
Content Type ◽  
Secondary Current ◽  
Pcb Manufacturing

Purpose The uniformity of electrodeposition is the key to successful application of pattern plating because the quality of electrodeposited copper layer has a huge impact on the performance of printed circuit boards (PCBs). The multi-physics coupling technology was used to accurately analyze and forecast the characteristics of electrochemical system. Further, an optimized plating bath was used to achieve a uniform electrodeposition. Design/methodology/approach A multi-physics coupling numerical simulation based on the finite element method was used to optimize electrodeposition conditions in pattern plating process. The influences of geometric and electrochemical factors on uniformity of current distribution and electrodeposited layer thickness were discussed by multi-physics coupling. Findings The model results showed that the distance between cathode and anode and the insulating shield had a great impact on uniformity of electrodeposition. By numerical simulation, it had been proved that using an auxiliary cathode was an effective and simple way to improve uniformity of electrodeposition due to redistributing of the current. This helped to achieve more uniform surface of the copper patterns by preventing the edge effect and the roughness of the copper layer was reduced to 1 per cent in the secondary current distribution model. Research limitations/implications The research is still in progress with the development of high-performance computers. Practical implications A multi-physics coupling platform is an excellent tool for quickly and cheaply studying the process behaviors under a variety of operating conditions. Social implications The numerical simulation method has laid the foundation for the design and improvement of the plating bath. Originality/value By multi-physics coupling technology, we built a bridge between theoretical and experimental study for control of uniformity of pattern plating in PCB manufacturing. This method can help optimize the design of plating bath and uniformity of pattern plating in PCB manufacturing.

Preparation of electronic-grade CuO for copper electrodeposition of printed circuit boards

Circuit World ◽  
2014 ◽  
Vol 40 (4) ◽  
pp. 127-133
Author(s):  
Jianhui Lin ◽  
Chong Wang ◽  
Yuanming Chen ◽  
Wei He ◽  
Dingjun Xiao ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Printed Circuit Boards ◽  
Open Circuit ◽  
New Method ◽  
Circuit Board ◽  
Dissolution Time ◽  
Copper Electrodeposition ◽  
Content Type ◽  
Printed Circuit ◽  
Plating Solution

Purpose – The purpose of this paper was to present a simple and convenient technology to produce the electronic-grade CuO. The prepared electronic-grade CuO fully meets the demands of industrial production of high density interconnect (HDI). Design/methodology/approach – A new method termed as open-circuit potential-time technology is proposed to measure the dissolution time of CuO in plating solution. X-ray diffraction (XRD) scanning electron microscopy (SEM) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were used to characterize the prepared CuO. Solder shock and reflow tests were carried out to examine the Cu deposits. Findings – All aspects of the prepared CuO meet the demands of printed circuit board (PCB) industry. Originality/value – A simple and convenient technology was presented to produce the electronic-grade CuO. A new method was proposed to determine the dissolution time of CuO in plating solution.

Numerical simulation of gas-solid two-phase reaction flow with multiple moving boundaries

2015 ◽  
Vol 25 (2) ◽  
pp. 375-390 ◽  
Author(s):  
Qiao Luo ◽  
Xiaobing Zhang
Keyword(s):  
Numerical Simulation ◽  
Physical Phenomenon ◽  
Great Influence ◽  
Moving Boundaries ◽  
Charge Weight ◽  
Phase Reaction ◽  
Two Phase ◽  
Content Type ◽  
One Dimensional ◽  
Chamber Volume

Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.

Numerical Simulation of Gas Flow and Heat Transfer in Cross-Wavy Primary Surface Channel for Microtubine Recuperators

2005 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Numerical Study ◽  
High Reliability ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
The Cross

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.

Thermo-structural analysis of a honeycomb-type volumetric absorber for concentrated solar power applications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Masoud Behzad ◽  
Benjamin Herrmann ◽  
Williams R. Calderón-Muñoz ◽  
José M. Cardemil ◽  
Rodrigo Barraza
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Steady State ◽  
Discrete Model ◽  
Continuum Model ◽  
Transient State ◽  
Operating Conditions ◽  
Steady State Condition ◽  
Content Type ◽  
The Continuum

Purpose Volumetric air receivers experience high thermal stress as a consequence of the intense radiation flux they are exposed to when used for heat and/or power generation. This study aims to propose a proper design that is required for the absorber and its holder to ensure efficient heat transfer between the fluid and solid phases and to avoid system failure due to thermal stress. Design/methodology/approach The design and modeling processes are applied to both the absorber and its holder. A multi-channel explicit geometry design and a discrete model is applied to the absorber to investigate the conjugate heat transfer and thermo-mechanical stress levels present in the steady-state condition. The discrete model is used to calibrate the initial state of the continuum model that is then used to investigate the transient operating states representing cloud-passing events. Findings The steady-state results constitute promising findings for operating the system at the desired airflow temperature of 700°C. In addition, we identified regions with high temperatures and high-stress values. Furthermore, the transient state model is capable of capturing the heat transfer and fluid dynamics phenomena, allowing the boundaries to be checked under normal operating conditions. Originality/value Thermal stress analysis of the absorber and the steady/transient-state thermal analysis of the absorber/holder were conducted. Steady-state heat transfer in the explicit model was used to calibrate the initial steady-state of the continuum model.

Numerical simulation of coupled liquid water, stress and heat for frozen soil in the thawing process

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wei Xiao ◽  
Enlong Liu ◽  
Xiao Yin ◽  
Guike Zhang ◽  
Chong Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Water Content ◽  
Coupled Model ◽  
Frozen Soil ◽  
Water Migration ◽  
Overburden Pressure ◽  
Content Type ◽  
Thawing Process ◽  
Sample Water ◽  
The One

PurposeThe purpose of this paper is to perform the thermo-hydro-mechanical (THM) numerical analysis in order to study the thawing process for frozen soil and to predict the thawing settlement.Design/methodology/approachA new one-dimensional multi-field physical coupled model was proposed here to describe the thawing process of saturated frozen soil, whereby the void ratio varied linearly with effective stress (Eq. 10) and hydraulic conductivity (Eq. 27b). The thawing process was simulated with different initial and boundary conditions in an open system with temperature variations. The mechanical behavior and water migration of the representative cases were also investigated.FindingsThe comparisons of representative cases with experimental data demonstrated that the model predicts thawing settlement well. It was found that the larger temperature gradient, higher overburden pressure and higher water content could lead to larger thawing settlement. The temperature was observed that to distribute height linearly in both frozen zone and unfrozen zone of the sample. Water migration forced to a decrease in the water content of the unfrozen zone and an increase in water content at the thawing front.Research limitations/implicationsIn this study, only the one-directional thawing processes along the frozen soil samples were investigated numerically and compared with test results, which can be extended to two-dimensional analysis of thawing process in frozen soil.Originality/valueThis study helps to understand the thawing process of frozen soil by coupled thermo-hydro-mechanical numerical simulation.

A thermodynamic performance analysis on influence parameters of COG-CCHP based on exergy

2018 ◽  
Vol 15 (6) ◽  
pp. 771-785
Author(s):  
Hongbin Zhao ◽  
Yu Cao ◽  
Chang Liu ◽  
Xiang Qi
Keyword(s):  
Energy Consumption ◽  
Energy Loss ◽  
Volume Fraction ◽  
Coke Oven ◽  
Integrated System ◽  
Operating Conditions ◽  
Weak Links ◽  
Coke Oven Gas ◽  
Content Type ◽  
Temperature And Pressure

PurposeThe purpose of this paper is to investigate the performance of coke oven gas (COG)-combined cooling, heating and power (CCHP) system and to mainly focus on studying the influence of the environmental conditions, operating conditions and gas conditions on the performance of the system and on quantifying the distribution of useful energy loss and the saving potential of the integrated system changing with different parameters.Design/methodology/approachThe working process of COG-CCHP was simulated through the establishment of system flow and thermal analysis mathematical model. Using exergy analysis method, the COG-CCHP system’s energy consumption status and the performance changing rules were analyzed.FindingsThe results showed that the combustion chamber has the largest exergy loss among the thermal equipments. Reducing the environmental temperature and pressure can improve the entire system’s reasonable degree of energy. Higher temperature and pressure improved the system’s perfection degree of energy use. Relatively high level of hydrogen and low content of water in COG and an optimal range of CH4volume fraction between 35 per cent and 46 per cent are required to ensure high exergy efficiency of this integration system.Originality/valueThis paper proposed a CCHP system with the utilization of coke oven gas (COG) and quantified the distribution of useful energy loss and the saving potential of the integrated system under different environmental, operating and gas conditions. The weak links of energy consumption within the system were analyzed, and the characteristics of COG in this way of using were illustrated. This study can provide certain guiding basis for further research and development of the CCHP system performance.

Leakage flow analysis in the gas turbine shroud gap

2019 ◽  
Vol 91 (8) ◽  
pp. 1077-1085 ◽  
Author(s):  
Filip Wasilczuk ◽  
Pawel Flaszynski ◽  
Piotr Kaczynski ◽  
Ryszard Szwaba ◽  
Piotr Doerffer ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Mass Flow ◽  
Labyrinth Seal ◽  
Leakage Flow ◽  
Original Design ◽  
Reference Case ◽  
Content Type ◽  
Flow Through ◽  
The Impact

Purpose The purpose of the study is to measure the mass flow in the flow through the labyrinth seal of the gas turbine and compare it to the results of numerical simulation. Moreover the capability of two turbulence models to reflect the phenomenon will be assessed. The studied case will later be used as a reference case for the new, original design of flow control method to limit the leakage flow through the labyrinth seal. Design/methodology/approach Experimental measurements were conducted, measuring the mass flow and the pressure in the model of the labyrinth seal. It was compared to the results of numerical simulation performed in ANSYS/Fluent commercial code for the same geometry. Findings The precise machining of parts was identified as crucial for obtaining correct results in the experiment. The model characteristics were documented, allowing for its future use as the reference case for testing the new labyrinth seal geometry. Experimentally validated numerical model of the flow in the labyrinth seal was developed. Research limitations/implications The research studies the basic case, future research on the case with a new labyrinth seal geometry is planned. Research is conducted on simplified case without rotation and the impact of the turbine main channel. Practical implications Importance of machining accuracy up to 0.01 mm was found to be important for measuring leakage in small gaps and decision making on the optimal configuration selection. Originality/value The research is an important step in the development of original modification of the labyrinth seal, resulting in leakage reduction, by serving as a reference case.

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