Interconnect Reliability Research Articles

Remote Control in Sprinkle Robot

As we see there is enough wind and solar energy globally to satisfy as much as humanity’s energy requirements. vertical axis wind turbines (VAWT) may as efficient as current horizontal axis system, might be practical and significantly cheaper to build and maintain than horizontal axis wind turbine (HAWT). They have other original advantages, like they are always facing the wind, which might make them a significant player in our daily routine for low cost, cleaner renewable sources of lifting water. The growing popularity of solar wind pumps in many rural areas, these areas typically have no access to electricity or shortage of electricity, which creates a problem when it comes to irrigation and watering livestock. VAWT’s might even critical in mitigating grid interconnect stability and reliability issue currently facing electricity producers and pump the water from suppliers. Additionally cheap VAWT’s may provide an alternative to the rain forest destruction for the growing of bio-fuel crops. In this project we attempt to design and fabricate a Savonius water pumping Vertical Axis Wind Turbine. And also we make our model hybrid- solar and wind mill operated water pump. The solar energy gained by the solar panel and convert that electrical energy into mechanical energy which causes to rotate the shaft which is connected to crank plate. The circular motion of crank plate uses to lift the water as it converted in up and down motion using crank mechanism. Keywords: Agriculture; Irrigation; Water Pump; Sprinkler; Pressure Drop; Steel; Lath; Arduino; Microcontroller.

Hybrid-Solar and Wind Power Water Pumping System

As we see there is enough wind and solar energy globally to satisfy as much as humanity’s energy requirements. vertical axis wind turbines (VAWT) may as efficient as current horizontal axis system, might be practical and significantly cheaper to build and maintain than horizontal axis wind turbine (HAWT). They have other original advantages, like they are always facing the wind, which might make them a significant player in our daily routine for low cost, cleaner renewable sources of lifting water. The growing popularity of solar wind pumps in many rural areas, these areas typically have no access to electricity or shortage of electricity, which creates a problem when it comes to irrigation and watering livestock. VAWT’s might even critical in mitigating grid interconnect stability and reliability issue currently facing electricity producers and pump the water from suppliers. Additionally cheap VAWT’s may provide an alternative to the rain forest destruction for the growing of bio-fuel crops. In this project we attempt to design and fabricate a Savonius water pumping Vertical Axis Wind Turbine. And also we make our model hybrid- solar and wind mill operated water pump. The solar energy gained by the solar panel and convert that electrical energy into mechanical energy which causes to rotate the shaft which is connected to crank plate. The circular motion of crank plate uses to lift the water as it converted in up and down motion using crank mechanism. Keywords: Solar panel, Wind Mill, Agriculture, Water Pumping.

Board Level Reliability of Flipchip Package

In the world of electronic materials, solder is a critical material that plays an important role in the first level (silicon to package substrate) and second level (package to printed circuit board) interconnection. As a joining material in electronic assemblies, solder provides electrical and mechanical connections. The increasing need for reliable electronic devices for harsh environment triggers the need for reliable solder joints. This study focuses on reliability of second level interconnections between package and printed circuit boards. Board level temperature cycling and mechanical drop performance of a 15 mm x 15 mm FCBGA test vehicle were evaluated with different package construction (lidded vs non-lidded), and BGA solder alloys (SA1, SA2, and SA3). Daisy chain packages were assembled on 1.0 mm thick PCB. Mounted units were thermally cycled between from -40C to 125C. Additional samples were evaluated in mechanical drop test conditions following JEDEC standards. Results showed that packages with SA2, and SA3 BGA had significantly higher board-level thermal cycling life compared to SA1. The best drop performance was achieved with SA1 solder. The performance trend among different solder alloys was found to be similar between lidded vs non lidded package. However, lidded package showed improved board-level reliability performance compared to a non-lidded package.

Topologically devised flexible bi-aeolotropic conduction Janus-like bi-layer membrane functionalized by red-green bicolor fluorescence

To further advance the development for new-generations of high-performance, miniaturized and flexible electronic devices, it is particularly significant to research new-typed fluorescence-functionalized bi-aeolotropic conduction membrane. Herein, a unique topology optimization design philosophy is proposed, which highly integrates macroscopic with microscopic partitions to manufacture high-performance aeolotropic conduction membrane functionalized by fluorescence. Topologically devised Janus-like bi-layer membrane (JBM) with bi-aeolotropic conduction and red-green bicolor fluorescence is successfully assembled by using a bi-axis electro-spinning. [PANI/PMMA]//[Eu(TTA)3bipy/PMMA] Janus-structured micro-fiber and [PANI/PMMA]//[Tb(acac)3phen/PMMA] Janus-structured micro-fiber was respectively employed as microcosmic constructing unit to align directionally to build first layer (JBM-F) and second layer (JBM-S) of the JBM. Macroscopically, for the JBM, each layer has aeolotropic conduction, and furthermore, the conductive orientations of the two layers are vertical, and the insulated orientations are also vertical, leading in the bi-aeolotropic conduction of the JBM. The strongest conductive aeolotropism for each layer can reach 108 when the PANI/PMMA is 65%. The introduction of the Eu and Tb complexes into the Janus-structured micro-fiber gives the JBM excellent red-green bicolor fluorescence. The fluorescent traits can be employed to visualize the operational state of JBM. The high integration of Janus-structured micro-fiber possessing microcosmic partition with Janus-like bi-layer membrane possessing macrocosmic partition achieves the efficacious separation of electrical and fluorescent fillers to shun the deleterious interferences between two functions to obtain superior fluorescence and bi-aeolotropic conduction. Interestingly, the prepared flexible JBM can be applied as a reliable microcircuit interconnection, providing a basis for practical applications.

Remarkable Conductive Anisotropy of Ag-Coated Glass Microbeads/UV Adhesive Composites Made by Electric Field Induced Alignment

We successfully prepared highly anisotropic conductive composites (ACCs) made of Ag-coated glass microbeads/UV adhesive via electric field-induced alignment, which was achieved using custom patterned microelectrode arrays. An optimized AC electric field (2 kV/cm, 1 kHz) with pole-plate spacing (50 μm) was utilized to effectively assemble the microbeads into chain arrays, which were precisely positioned on the microelectrode arrays to construct ordered conductive channels. In this case, tangling and cross-connection of the assembled microchains could be reduced, resulting in enhanced performance of the ACCs with high conductivity as well as excellent anisotropy. With a minor loading (3 wt %), the conductivity in the alignment direction could reach ∼24.9 S/m, which was the highest among the reported ACCs to the best of our knowledge, and it could also be 6 orders of magnitude higher than that within the plane. Besides, the samples exhibited high reliability in wire connections with low resistances. Due to these fascinating properties, the ACCs demonstrate promising applications for reliable electrical interconnects and integrated circuits.

Reinforcement in electromigration reliability of Cu interconnects by alloying of extremely dilute MnO

Nonconformal high-aspect-ratio trenches/vias filling has limited the use of conventional sputtered Ta/TaN liner/barrier for Cu metallization on nanoscaled technology nodes. The self-forming alloyed metallization could offer an alternative barrier-layer/capping-layer thinning scheme for the downsizing Cu interconnects. This study reports an entire-wet process involving trench-filling of electroless plating Cu interconnects alloyed with and without an extremely dilute MnO content of 0.10%. The electromigration (EM) reliability and thermal stability of the Cu(MnO) metallization were evaluated for interconnect applications in integrated circuits. Incorporating the diluted MnO can significantly enhance the EM reliability by a factor of nine by shifting the failure mechanism towards void growth. The failure mode is thoroughly evaluated through analysis of the activation energies and current-density scale factors obtained from Black’s equation. The proposed scheme has promised the application for the nanoscaled technology nodes. The reinforcement in EM reliability by self-forming Cu(MnO) will be elucidated.

Extracting and Analyzing the S-Parameters of Vertical Interconnection Structures in 3D Glass Packaging

In order to effectively employ through-glass vias (TGVs) for high-frequency software package design, it is crucial to accurately characterize the S-parameters of vertical interconnection structures in 3D glass packaging. A methodology is proposed for the extraction of precise S-parameters using the transmission matrix (T-matrix) to analyze and evaluate the insertion loss (IL) and reliability of TGV interconnections. The method presented herein enables the handling of a diverse range of vertical interconnections, encompassing micro-bumps, bond-wires, and a variety of pads. Additionally, a test structure for coplanar waveguide (CPW) TGVs is constructed, accompanied by a comprehensive description of the equations and measurement procedure employed. The outcomes of the investigation demonstrate a favorable concurrence between the simulated and measured results, with analyses and measurements conducted up to 40 GHz.

Wavelet multiscale principal components and traveling waves enabled machine learning technique for protection of MT-HVDC systems

The interconnection of renewable energy sources to conventional power grids is widely recognized and promoted by the deployment of high voltage direct current (HVDC) technology. One of the biggest challenges associated with the HVDC systems is the rapid rate of rising DC fault currents, resulting in the immediate collapse of the converter stations. Conventional schemes of AC protection and low-speed DC protection are not worthy and mature because of the abrupt rising characteristics of DC currents. Therefore, protection techniques are being developed for reliable bulk power transfer and interconnection of unsynchronized grids via DC links. Timely identification, classification, and determination of location are the most fundamental characteristics of any protection scheme. This research paper proposes a machine learning-based protection method that establishes a rapid and reliable solution addressing the drawbacks of existing protection schemes. A multi-terminal high voltage direct current (MT-HVDC) test system is designed in Matlab/Simulink. Pole-to-ground and pole-to-pole faults are applied at different fault locations to assess the validity of the proposed algorithm. For this, DC voltages and currents are measured and analyzed. Power spectral analysis of traveling waves and Wavelet multiscale principal components analysis are employed for the extraction of featured data to classify and locate the DC faults. This reduced dimensional featured data is utilized for training and testing the support vector machine learning algorithm to analyze the accuracy of the proposed protection technique. Simulation results confirm the accuracy of rapid identification, classification, and location of DC faults.

Graded Mxene-Doped Liquid Metal as Adhesion Interface Aiming for Conductivity Enhancement of Hybrid Rigid-Soft Interconnection.

Hybrid rigid-soft electronic system combines the biocompatibility of stretchable electronics and the computing capacity of silicon-based chips, which has a chance to realize a comprehensive stretchable electronic system with perception, control, and algorithm in near future. However, a reliable rigid-soft interconnection interface is urgently required to ensure both the conductivity and stretchability under a large strain. To settle this demand, this paper proposes a graded Mxene-doped liquid metal (LM) method to achieve a stable solid-liquid composite interconnect (SLCI) between the rigid chip and stretchable interconnect lines. To overcome the surface tension of LM, a high-conductive Mxene is doped for the balance between adhesion and liquidity of LM. And the high-concentration doping could prevent the contact failure with chip pins, while the low-concentration doping tends to maintain the stretchability. Based on this dosage-graded interface structure, the solid light-emitting diode (LED) and other devices integrated into the stretchable hybrid electronic system could achieve an excellent conductivity insensitive to the exerted tensile strain. In addition, the hybrid electronic system is demonstrated for skin-mounted and tire-mounted temperature-test applications under the tensile strain up to 100%. This Mxene-doped LM method aims to obtain a robust interface between rigid components and flexible interconnects by attenuating the inherent Young's modulus mismatch between rigid and flexible systems and makes it a promising candidate for effective interconnection between solid electronics and soft electronics.

Optimal design of thermo-compression bonder via ANN-based surrogate modeling under uncertainty

The miniaturisation of electronic devices demands advanced microelectronics packaging systems dominated by interconnection reliability. Thermo-compression bonding (TCB) is a promising approach to improve bonding quality by applying heat and pressure onto the chip. However, TCB has prompted severe mechanical warpage and electrical shortage when the diminutive interconnection is randomly shaped, which yields non-uniform stress and thermal distribution in bonding. Moreover, the mechanism is interpreted by excessive multi-physics simulations or experiments, which impedes computational cost-efficiency. Therefore, this research develops an optimised TCB design via a machine learning-based surrogate model to predict complex TCB behaviour, by certifying its best performance. First, a framework is proposed to extract and propagate the multivariate geometric uncertainties of the interconnection. The framework realistically represents the existing packaging system and predicts TCB behaviour through ANN, which enriches the accuracy and efficiency of the prediction model. Second, an optimal TCB is designed to minimise the warpage and electrical short. With the surrogate model, the optimisation attempts to find the best location and magnitude of a structural pressure, which derives uniform stress concentration or restricted interconnection deformation. The efficacy of the proposed framework is demonstrated with a practical example of an advanced packaging system utilised in actual commercial products.

Development of novel single-die hybridisation processes for small-pitch pixel detectors

Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, especially for small-scale applications, such interconnect technologies need to be suitable for the assembly of single dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25 µm and 55 µm are presented in this contribution — an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing using support wafers, as well as a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The fine-pitch bump-bonding process is qualified with hybrid assemblies from a recent bonding campaign at Frauenhofer IZM. Individual CLICpix2 ASICs with 25 µm pixel pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50 µm to 130 µm. The device characterisation was conducted in the laboratory as well as during a beam test campaign at the CERN SPS beam-line, demonstrating an interconnect yield of about 99.7%. The ACF interconnect technology replaces the solder bumps by conductive micro-particles embedded in an epoxy film. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACF using a flip-chip device bonder. The required pixel pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) plating process. This newly developed ACF hybridisation process is first qualified with the Timepix3 ASICs and sensors with 55 µm pixel pitch. The technology can be also used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the two interconnect processes and presents preliminary hybridisation results with CLICpix2 and Timepix3 sensors and ASICs.

Photovoltaics literature survey (no. 182)

Photovoltaics literature survey (no. 182)

Analisis Destruction Test Tower Sutet dibandingkan dengan Software Ms Tower dan SAP 2000

The transmission line system which is currently growing rapidly in Sumatra, requires a reliable interconnection network to meet the electricity demand for the West Sumatra region. PT. PLN as a provider of electricity businesses in Indonesia conducted planning and destruction tests to design a new model Extra High Voltage Transmission Line (SUTET) tower with specification of 66.6 meters height, slim type tower, 275 kV, lattice BB+15, quadrapole zebra (435/55 mm2) 2 cct. This research aims to study tower collapse behavior caused by working loads, analyze and compare the suitability level of tower deformation and natural frequency among MS Tower, SAP 2000 space truss analysis, SAP 2000 space frame analysis with destruction test results. SAP 2000 space frame deformation analysis shows that the tower is unstable in the Leg section. The analysis of natural frequency and the mode shape in the SAP 2000 space frame analysis is close to the value of the natural frequency destruction test with a deviation of 30%. The tower collapse occurred due to imperfection geometry on the legs section, resulting in a global collapse. Improvements in the form of adding equal angle to the hip bracing were carried out, the result was able to withstand a load case load of 9870 up to 100%. Space frame analysis on SAP 2000 is closer to MS Tower, this can be seen from the deformation and natural frequency values that approach each other from the two analyses.

Phase field modelling combined with data-driven approach to unravel the orientation influenced growth of interfacial Cu6Sn5 intermetallics under electric current stressing

Microstructure of interfacial intermetallics plays an important role in determining the service performance and reliability of interconnects especially due to the anisotropic properties of intermetallic grains, preferential growth of intermetallics induced by the electric current is observed in experiments, but the exact mechanisms for this have not been understood completely. For this endeavor, a phase field model considering the free energy arisen from the applied electric current is developed to tackle the intermetallic grain growth behavior in Sn/Cu interconnects, the focus falls on the influence of anisotropic electric conductivity. Simulation results show that electric current stressing preferentially accelerates the intermetallic growth, and the orientation effects are more pronounced with higher value of electric current density. Due to the competitive growth of multiple Cu6Sn5 grains in the presence of electric current, most region of the intermetallic layer is occupied by the grains whose c-axis is along the direction of the electric current. The intermetallic grain with higher electric conductivity along the electron flow holds smaller current field, while the phase boundaries own higher electric field. It is found that the higher local electric field concentrating at phase boundary drives faster phase boundary migration. The data generated from physics-based phase field simulations are utilized to train a neural network model that functionally maps the area of a particular grain with the applied current density, simulation time, grain identification, orientation of the grain and its neighboring grains. The prediction model reveals that that electric current stressing preferentially accelerates the intermetallic growth, and the orientation effects are more pronounced with higher value of electric current density. The results from phase field simulation and physically informed machine learning model further deepen understandings of the microstructure evolution and selective intermetallic growth in the context of electric current, and shed light on the in-silico studies and design route of interconnects under other types of loadings.

Use of Rotary Ultrasonic Plastic Welding as a Continuous Interconnection Technology for Large-Area e-Textiles

For textile-based electronic systems with multiple contacts distributed over a large area, it is very complex to create reliable electrical and mechanical interconnections. In this work, we report for the first time on the use of rotating ultrasonic polymer welding for the continuous integration and interconnection of highly conductive ribbons with textile-integrated conductive tracks. For this purpose, the conductive ribbons are prelaminated on the bottom side with a thermoplastic film, which serves as an adhesion agent to the textile carrier, and another thermoplastic film is laminated on the top side, which serves as an electrical insulation layer. Experimental tests are used to investigate the optimum welding process parameters for each material combination. The interconnects are initially electrically measured and then tested by thermal cycling, moisture aging, buckling and washing tests, followed by electrical and optical analyses. The interconnects obtained are very low ohmic across the materials tested, with resulting contact resistances between 1 and 5 mOhm. Material-dependent results were observed in the reliability tests, with climatic and mechanical tests performing better than the wash tests for all materials. In addition, the development of a heated functional prototype demonstrates a first industrial application.

Effects of interface cracks on reliability of surface mount technology interconnection in service environment

PurposeSurface mount technology (SMT) is widely used and plays an important role in electronic equipment. The purpose of this paper is to reveal the effects of interface cracks on the fatigue life of SMT solder joint under service load and to provide some valuable reference information for improving service reliability of SMT packages.Design/methodology/approachA 3D geometric model of SMT package is established. The mechanical properties of SMT solder joint under thermal cycling load and random vibration load were solved by 3D finite element analysis. The fatigue life of SMT solder joint under different loads can be calculated by using the modified Coffin–Manson model and high-cycle fatigue model.FindingsThe results revealed that cracks at different locations and propagation directions have different effect on the fatigue life of the SMT solder joint. From the location of the cracks, Crack 1 has the most significant impact on the thermal fatigue life of the solder joint. Under the same thermal cycling conditions, its life has decreased by 46.98%, followed by Crack 2, Crack 4 and Crack 3. On the other hand, under the same random vibration load, Crack 4 has the most significant impact on the solder joint fatigue life, reducing its life by 81.39%, followed by Crack 1, Crack 3 and Crack 2. From the crack propagation direction, with the increase of crack depth, the thermal fatigue life of the SMT solder joint decreases sharply at first and then continues to decline almost linearly. The random vibration fatigue life of the solder joint decreases continuously with the increase of crack depth. From the crack depth of 0.01 mm to 0.05 mm, the random vibration fatigue life decreases by 86.75%. When the crack width increases, the thermal and random vibration fatigue life of the solder joint decreases almost linearly.Originality/valueThis paper investigates the effects of interface cracks on the fatigue life and provides useful information on the reliability of SMT packages.

Structure connectivity and substructure connectivity of data center network

<abstract><p>The structure connectivity $ \kappa(G; H) $ and substructure connectivity $ \kappa^s(G; H) $ are important indicators to measure interconnection network's fault tolerance and reliability. The data center network, denoted by $ D_{k, n} $, have been proposed for data centers as a server-centric interconnection network structure, which can support millions of servers with high network capacity by only using commodity switches. In this paper, we obtain $ \kappa(D_{k, n}; S_m) $ and $ \kappa^s(D_{k, n}; S_m) $ when $ k\geq2 $, $ n\geq4 $ and $ 1\leq m\leq n+k-2 $. Furthermore, we obtain both $ \kappa(D_{k, n}; S_{23}) $ and $ \kappa^s(D_{k, n}; S_{23}) $ for $ k\geq8 $ and $ n\geq8 $.</p></abstract>

Pixel detector hybridisation with anisotropic conductive films

Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, and in general for small-scale applications, such interconnect technologies need to be suitable for the assembly of single-dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. This contribution presents recent results of a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The ACF interconnect technology replaces the solder bumps with conductive particles embedded in an adhesive film. The electro-mechanical connection between the sensor and the read-out chip is achieved via thermo-compression of the ACF using a flip-chip device bonder. A specific pad topology is required to enable the connection via conductive particles and create cavities into which excess epoxy can flow. This pixel-pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) plating process that is also under development within the project. The ENIG and ACF processes are qualified with the Timepix3 ASIC and sensors, with 55 µm pixel pitch and 14 µm pad diameter. The ACF technology can also be used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the ENIG plating and ACF processes and presents recent results on Timepix3 hybrid assemblies.

An analytical thermal model for the 3-D integrated circuit with new-type through silicon via

Through silicon via technology is a promising and preferred way to realize the reliable interconnection for 3-D integrated circuit (3-D IC), which can transfer heat from multiple dies to the heat sink in vertical direction. In this paper, a new gen?eral model of the through-silicon via (TSV) is proposed to investigate the thermal performance of the 3-D IC. The heat transfer characteristics of conical-annular TSV are studied for the first time. The impacts of different sidewall inclination angles and insulating layer thicknesses of TSV on the heat dissipation of 3-D IC were compared and analyzed in detail. As expected, our proposed model is in good agreement with the results of the existing models, which shows that the proposed model considering the lateral heat transfer and TSV structures can predict the distribution of temperature more efficiently and accurately. Furthermore, it is found that conical-annular TSV has more excellent heat dissipation performance.

Improvement in the reliability of crystalline silicon solar cell interconnection by using Nickel Micro-Plating Bonding (NMPB) technology

It is popular to research promoting the light conversion efficiency of crystalline silicon solar cell photovoltaic (PV) modules. However, excellent light conversion efficiency does not mean it could maintain initial performance after long-term running. Long-term reliability of interconnection to assemble crystalline silicon solar cells in PV modules is critical to ensure that the device performs continually for up to 20 years. It is reported that most crystalline PV modules fail from corrosion and breakage of the interconnector with the solder joint. As a result, improvement of interconnection technology is highly necessary. Nickel (Ni) Micro-Plating Bonding (NMPB) is an innovative interconnection technology for crystalline silicon solar cells: copper ribbons bonded with lead or lead-free solder are replaced by copper wires bonded with Ni electroplating film. The NMPB interconnection provides key advantages: low temperature (55 °C) process, enhancement of reliability from strain and stress caused by high temperature, and coefficient of thermal expansion (CTE) mismatch between metal and silicon. Furthermore, the material of NMPB, Ni, possesses excellent corrosion resistance. High reliability was confirmed with about 1.9% degradation of output power for up to 1000 thermal cycling tests and 3.8% for 1000 h of damp heat tests in bare NMPB solar cells, while 64.7% degradation in thermal cycling tests and 23.0% in damp heat tests were confirmed in solder bonding solder cells.