bluuebunny/crossref_metadata_2025_split huggingface dataset:
Internal Bump Cracking Risk Assessment for Flip Chip Ball Grid Array Package During Board Level Reliability Test Through Finite Element Analysis
Authors: Li Guangxu , Gurrum Siva , Jiang Li , Murugan Rajen 
Published: March 2024

The performance of semiconductor devices during board-level reliability (BLR) thermal cycling tests continues to be a concern in different applications. The primary focus of those BLR tests is to evaluate the fatigue life of external solder joints between the package and printed circuit board (PCB). For flip-chip ball grid array (FCBGA) package technology, internal solder bumps can also crack and result in open electrical failure. This type of BLR failure has yet to be widely reported in the literature. This article presents failures due to internal solder bump cracks during the BLR test. Failure analysis (FA) clearly shows the cracking location strongly depends on bump density. Finite Element Analysis (FEA) based simulation is performed to understand the failure mechanism. Unlike the standard BLR modeling approach, which focuses on predicting external solder joint fatigue life with correlated data, simulation here has to capture the entire internal bump pattern in the global BLR model. The need to capture the entirety of the bump scheme poses a significant challenge to managing the global model size with a reasonable meshing count and running time. Therefore, a customized post-process approach is developed to analyze bump density impact and enable design optimization.
Cost Analysis of Fan-out Processes for Chiplet Packaging
Authors: Lujan Amy Palesko 
Published: March 2024

When building a design around chiplets, there are many factors to consider: industry standards, availability of chiplets within the supply chain, size requirements, and cost, to name a few. The cost of chiplet packaging is a particularly important factor that must be understood, because even if all design requirements can be met, the chiplet package will not come to fruition if the total cost is too high. The basic tradeoff between a monolithic die and a series of chiplets is a reduction in silicon costs countered by an increase in packaging costs. This analysis will compare a monolithic die flip chip package to two fan-out processes that support chiplet packaging. In the first scenario, a two-chiplet chip-last fan-out on substrate package will be compared to a standard flip chip package. For the second comparison, a monolithic flip chip package will be compared to a four-chiplet fan-out package that utilizes embedded silicon for additional interconnect. For both scenarios, a detailed cost comparison will be provided. Activity based cost modeling will be used for this analysis. In addition to looking at the direct costs of the substrated and assembly processes, yield considerations and the prices of the incoming silicon (which varies by node) will be included. The goal of this analsysis is to evaluate the cost of monolithic flip chip package versus a chiplet scenario for two designs, and to highlight the cost drivers of the fan-out chiplet packaging processes.
A Jettable and Dispensable Liquid Metal Paste as a Thermal Interface Material
Authors: Lazic Milos 
Published: March 2024

Metal thermal interface materials (TIMs) have been used in the electronics industry for over 20 years. The thermal performance of any TIMs is defined by their thermal conductivity, bondline thickness, and interfacial resistance. Generally, metal TIMs have very high thermal conductivity and they can be applied in a thin layer. Most of the metals are hard and stiff, making interfacial resistance the biggest obstacle for metal TIMs to overcome. Over the years, many metal TIMs have been developed and used in applications to improve the performance of the components. Recently, liquid metal TIMs are getting more attention, especially in gaming and high-performance applications. They are excellent in terms of accommodating imperfections of the materials they are connecting, but their physical properties can make application risky. To overcome this challenge, a new metal TIMs material - liquid metal paste (LMP) TIM – has been developed. This paper will examine this new material’s thermal conductivity, viscosity, jetting, and dispensing performance compared with other existing metal TIMs, such as liquid metal. The application in mass manufacturing will be studied, with a solution to prevent leakage and provide higher thermal cycling performance (-40°C / +125°C) for LMP.
A Thermally Enhanced Film Adhesive for Assembling High Power Density Electronic Devices
Authors: Zhao Yuan , Katze Doug , Pre Ana , Wyatt Derek , Sherwood Josh , Virdi Jaskaran 
Published: March 2024

Assembly adhesives play a crucial role in packaging and thermal management design for microelectronics devices. The main function of the adhesives is attaching multiple components together to deliver designed functionalities and ensure integrity and reliability of the device. As requirements for performance and functionality increase, heat generated from these devices increases exponentially. For example, local heat flux can easily exceed 50 W/cm2 for IGBT power modules while it may reach several hundred W/cm2 at active areas for Gallium Nitride (GaN) power amplifiers. However, intrinsic thermal conductivity of polymer-based adhesives is around 0.2 W/mK, which increasingly becomes a thermal bottleneck in high power density electronics devices, especially those used in defense and aerospace systems. Effectively and safely dissipating the high heat and ensuring device reliability have become one of the critical tasks in the development of modern aerospace and defense systems. This paper presents an adhesive film that uses non-electrically conductive particles with high thermal conductivity as fillers in the adhesive to enhance thermal transport. The adhesive film offers an effective thermal conductivity around 0.7 W/mK, which is more than a 3X improvement over conventional assembly adhesives. In addition, the film adhesive has a long work life at ambient conditions with significantly improved processability and controllability, such as bondline thickness control and uniformity, no voids/air pockets, no or minimum resin bleed, etc. They can also be easily converted into preforms with complicated shapes/geometries with typical tolerances less than 10 mil to facilitate assembly processes and ensure a clean and waste free environment.
Wafer Level Chip Size Package Integration of an Aero-acoustic MEMS Microphone into a Thin and Flexible Substrate
Authors: Erbacher Kolja , Marques Joao Alves , Mackowiak Piotr 
Published: March 2024

This publication describes a novel combination of a chip-scale-package-approach for micro-electromechanical systems with flush surface chip embedding in thermal Polyurethane. The concept enables the fabrication of thin and flexible substrates in which sensor chips with fragile membranes are integrated. The presented sensor array can be used for applications like sound source localization in streams of passenger airplanes whilst test-flights.
Stereolithographic Process for Embedding of Electronic Components into Multi-material Flexible and Stretchable Polymer Substrate to Reduce Stress During Stretching
Authors: Tiedje Tobias , Bräuer Christoph , Luniak Marco , Nieweglowski Krzysztof , Bock Karlheinz 
Published: March 2024

The integration of rigid electronic components into stretchable materials is a complex challenge due to contrary material properties. This paper shows a novel approach for the embedding of electronic components into flexible and stretchable polymer substrates using a stereolithographic process that leads to stress reduction during stretching. The key factor is the multi-material printing with various elastic material properties. The paper shows a miniaturized packaged component (e.g. 0201 LED) in a flexible and stretchable substrate based on three different materials. The first material has rigid properties (stiffness 42.25 N/mm) and surrounds a small area of the LED with about 500 μm peripheral frame. The main purpose of this material is to round up the sharp edges of the LED to the next material. The second material is more elastic (stiffness 0.11 N/mm) and surrounds the first embedded LED. The purpose of the implementation of the second intermediate material is to spread the load between the LED and stretchable substrate caused by stretching. The third material has even higher elastic properties (stiffness 0.05 N/mm) and builds up the main part of the stretchable substrate (size of (4.5x34) mm2). After the fabrication of the multi-material substrate with the embedded LED, horseshoe conductive traces are screen printed with conductive paste. Finally, the embedded LED substrate with the conductive traces is cured at 125 °C. The final stretchable substrate with the embedded LED was able to stretch up to about 25 % for 30 cycles without disturbing the electrical function.
Automotive Grade WLCSP for Radar Applications
Authors: Lakhera Nishant , Carpenter Burt , Lau Teck Beng , Mawer Andrew J. 
Published: March 2024

Wafer-Level Chip Scale Packages (WLCSPs) are becoming commonplace in the industry due to their small form factor. Applications include industrial and automotive which demand high reliability performance. Additionally, WLCSPs may be superior in some implementations to other package options for RF performance in the mmWave spectrum, which is desired for automotive radar application. In this study the industry’s first auto grade 1 capable large WLCSP package. (~ 72 mm2 body size, 18x15 BGA array, 0.5 mm pitch) will be presented. It will be demonstrated how extensive design enhancements, predictive simulations, careful package materials and process selection and assembly process optimization studies are required to develop a robust package solution. Multiple assembly process experiments and corner studies were conducted to demonstrate robustness of WLCSP package solution to meet automotive grade quality and reliability requirements. Both component/unit level and board level reliability was evaluated as per AECQ100 standards. Robustness margins were confirmed through reliability testing performed up to 2-3x reliability requirements.
Development of Wafer Level Package Platform for High Reliability Crossover MCUs
Authors: Sharma Gaurav , Su Meng Yao , Thukral Varun , Beddingfield Craig , Lakhera Nishant 
Published: March 2024

Fan in and fan out wafer level packages are primarily used in the industry for applications in handheld consumer electronic products. The key benefits of wafer level package (WLP) are small form factor, reduced cost, improved electrical and thermal performance. WLP investigated in this study are directly surface mounted on PCB and have no intermediate substrate. Direct mount of package on PCB, leads to significant CTE mismatch between the package and board which stresses the package solder joint, leading to cyclic fatigue induced solder joint cracking. To overcome the solder joint cracking, stiffer solder alloys have been evaluated. However, higher stiffness of the solder alloy shifts the cyclic stress induced failure, from the solder joint to the package metal interconnect layers. Moreover, WLP on advanced silicon node have fragile low-k and extremely low-k back end of line dielectric layers that also crack or delaminate in cyclic fatigue. In this work extensive WLP platform development has been done with following DOE variables; multi-layer package routing, dielectric materials, solder alloys, solder ball pitch and diameter. Developed packages passed and outperformed the following product reliability qualification conditions: high temperature storage life (150°C, 2000 hours), highly accelerated stress test (110°C / 85%RH / Bias, 528 hours), application level temperature cycling ((-40 °C to 125 °C, 600 cycles), board level temperature cycling (-40 °C to 125 °C, 500 cycles) and board level drop test (1500g/0.5ms, 30 drops). Excellent reliability, functional performance, and successful chip package integration was achieved for WLP for crossover MCU products.
Tata Memorial Centre Evidence Based Management of Breast cancer
Authors: Wadasadawala Tabassum , Joshi Shalaka , Rath Sushmita , Popat Palak , Sahay Ayushi , Gulia Seema , Bhargava Prabhat , Krishnamurthy Revathy , Hoysal Dileep , Shah Jessicka , Engineer Mitchelle , Bajpai Jyoti , Kothari Bhavika , Pathak Rima , Jaiswal Dushyant , Desai Sangeeta , Shet Tanuja , Patil Asawari , Pai Trupti , Haria Purvi , Katdare Aparna , Chauhan Sonal , Siddique Shabina , Vanmali Vaibhav , Hawaldar Rohini , Gupta Sudeep , Sarin Rajiv , Badwe Rajendra 
Published: March 2024

Abstract
The incidence of breast cancer is increasing rapidly in urban India due to the changing lifestyle and exposure to risk factors. Diagnosis at an advanced stage and in younger women are the most concerning issues of breast cancer in India. Lack of awareness and social taboos related to cancer diagnosis make women feel hesitant to seek timely medical advice. As almost half of women develop breast cancer at an age younger than 50 years, breast cancer diagnosis poses a huge financial burden on the household and impacts the entire family. Moreover, inaccessibility, unaffordability, and high out-of-pocket expenditure make this situation grimmer. Women find it difficult to get quality cancer care closer to their homes and end up traveling long distances for seeking treatment. Significant differences in the cancer epidemiology compared to the west make the adoption of western breast cancer management guidelines challenging for Indian women. In this article, we intend to provide a comprehensive review of the management of breast cancer from diagnosis to treatment for both early and advanced stages from the perspective of low-middle-income countries. Starting with a brief introduction to epidemiology and guidelines for diagnostic modalities (imaging and pathology), treatment has been discussed for early breast cancer (EBC), locally advanced, and MBC. In-depth information on loco-regional and systemic therapy has been provided focusing on standard treatment protocols as well as scenarios where treatment can be de-escalated or escalated.
Vascularization of choroidal melanomas as a prognostic factor: Comparative analysis between color Doppler and histopathological aspects of tumors
Authors: Costa Marcio Augusto Nogueira , Allemann Norma , Nehemy Andrea , Burnier Miguel Noel Nascente 
Published: March 2024

Objectives:
The objective of the study was to correlate color Doppler with the vascularization of choroidal melanoma (CM) observed in histopathological sections and also to analyze the vascular histopathological prognostic factors of these tumors.

Patients, Materials, and Methods:
This was an experimental, cross-sectional, and analytical study carried out at Escola Paulista de Medicina - UNIFESP (São Paulo) and at the Ocular Pathology and Translational Research Laboratory of McGill University (Montreal/Canada). Twenty-five enucleated eyes of patients with CM were studied, 10 patients studied at UNIFESP and 15 patients studied at McGill University. The first 10 patients (Brazil), before enucleation, were submitted to color Doppler, all performed at UNIFESP. The resistance index (RI) and maximum systolic velocity of each tumor were calculated. The inclusion criteria of this study were as follows: CMs >8 mm in thickness, enucleation as primary treatment, histopathological blocks sufficient for hematoxylin–eosin staining, periodic acid–Schiff, and CD34 immunohistochemistry. Exclusion criteria included tumors smaller than 8 mm and/or previous treatments such as laser or brachytherapy. Regarding the histopathology of each CM, cell-type classification, vessel diameter measurements, count of the number of mitoses, and vascular clefts were carried out. The latter are considered vessels because they are lined by endothelium (CD34 positive) and surrounded by melanoma cells.

Results:
There was a statistical correlation between RI and cell type (P < 0.05). Tumors with a better prognosis (spindle cell) showed higher RI compared to epithelioid tumors, with a worse prognosis. The number of mitoses and vascular clefts correlated with the cell type, with a statistically significant difference (P < 0.001). Tumors of worse prognosis (epithelioid) showed an increase in the number of mitoses and in the number of vascular clefts. There was no difference between vessel diameter and cell type.

Conclusions:
The number of vascular clefts has a positive prognostic correlation with the malignancy of CM. Doppler RI showed a positive prognostic correlation with CM malignancy. For the first time, the usefulness of vascular clefts as prognostic factors was proven, and a new classification of the vascular network in CMs was proposed.
Transitioning to a Hydrogen Future: Analyzing Demand and Supply Dynamics in New Zealand's Transportation Sector
Authors: Sheng Mingyue Selena , Wen Le , Tan Beryl , Poletti Stephen 
Published: March 2024

This study conducts a comprehensive literature review, analysing academic articles, government documents, and reports from international organisations to discern trends in hydrogen fuel deployment for heavy transportation in New Zealand. It specifically assesses the current state-of-the-art technology, economic policies, and the impact of hydrogen fuel and fuel-cell vehicles on decarbonisation efforts and economic growth, acknowledging the influence of consumer preferences, diesel prices, and technological advancements on market demand. While recognising the cost-competitiveness challenges these vehicles face, the research highlights the necessity of significant investments in infrastructure development. Methodologically, the study integrates economies of scale and technological learning rates to evaluate hydrogen fuel investment returns. Furthermore, this paper employs the Castalia-MBIE model for scenario analysis, revealing two key insights. First, it underscores the criticality of maintaining a favourable equilibrium between domestic and international production costs alongside hydrogen fuel consumption to bolster New Zealand's competitiveness on the global stage. Second, it highlights the pronounced vulnerability of fuel-cell electric vehicles to supply-side influences as compared to demand-related variables. These insights contribute scientifically to understanding the economic dynamics of hydrogen fuel adoption and its implications for New Zealand's transport sector.

Received: 18 July 2023 | Revised: 30 January 2024 | Accepted: 26 February 2024

Conflicts of Interest
The authors declare that they have no conflicts of interest to this work.

Data Availability Statement
The data that support the findings of this study are openly available in the New Zealand Wind Energy Association at https://www.windenergy.org.nz/generation#:&sim;:text=On%20an%20annual%20basis%2C%20New,the%20highest%20in%20the%20world.

Author Contribution Statement
Mingyue Selena Sheng: Conceptualization, Formal analysis, Investigation, Data curation, Writing - review & editing, Supervision, Funding acquisition. Le Wen: Conceptualization, Methodology, Formal analysis, Investigation, Resources, Writing - review & editing, Supervision, Project administration, Funding acquisition. Beryl Tan: Methodology, Software, Validation, Formal analysis, Investigation, Writing - original draft, Visualization. Stephen Poletti: Conceptualization, Writing - review & editing.
Pumping Station Design with an Analysis of Variability of Demand and Considering Techno-Economic and Environmental Criteria through the AHP Method
Authors: Briceño-León Christian Xavier , Iglesias-Rey Pedro Luis , Martínez-Solano Francisco Javier , Creaco Enrico 
Published: March 2024

Pumping stations costs including, capital and operational costs are some of the highest costs in urban water distribution system. A proper pumping station design could be defined as the solution with the minimum life cycle cost and satisfying extreme scenarios in water distribution system. These costs are associated with investment, operational and maintenance costs. However, there are some important aspects to consider un a pumping station design, such as the feasibility of infrastructure construction, the size of the infrastructure, and the complexity of operation in the pumping station. These aspects are associated with technical criteria. In a classical pumping station design, the number of pumps is determined in arbitrary form according to the criteria of the engineer, and the pump model is selected according to the maximum requirements of flow and pressure of the network. In summary, these variables in a pumping station design are not usually analyzed deeply. In addition, global warming acceleration in the last decades has gained momentum to be considered in engineering problems to mitigate the environmental impact. Hence, it is imperative to consider environmental aspects, such as greenhouse emission, energetic efficiency of the pump in modern pumping systems of water distribution networks. Finally, the most suitable solution is determined only by analyzing economic aspects. Therefore, this work proposed a methodology to design pumping stations in urban water networks considering technical, environmental, and economic criteria and link them together through the Analytic Hierarchy Process (AHP) method. The propose of this method is to determine the importance priority of these aspects to assess the possible solutions and determine the most suitable solution in the pumping station design. In addition, this work considers the variability of demand pattern. This work analyses several scenarios of demand patterns from the minimum possible demand to the maximum possible demand in a water distribution network and the respective probabilities of occurrence of scenario. It allows that the pumping station design be more robust. This methodology has been applied in different case studies to analyze how affects to determine the most suitable solution when the characteristics of the network change.
A decision-making approach to assess and prioritise intervention solutions in water distribution systems
Authors: Cabral Marta , Loureiro Dália , Covas Dídia 
Published: March 2024

The present paper aims at proposing and demonstrating the application of a decision-making approach for the identification, assessment, comparison and prioritisation of different intervention solutions. Infrastructural, financial, performance and economic perspectives are considered in the study. The proposed approach is composed of three main modules: 1) Analysis planning and database construction; 2) Infrastructure, asset or component diagnosis and prioritisation; and 3) Study of intervention solutions for priority assets or components. Three assessment levels – macro, meso and micro – are proposed, and the decision-making approach is adapted to each level. A water distribution system located in Portugal is used to demonstrate the proposed approach. This case study comprises five water subsystems, including different assets, such as water storage tanks, pumping and booster stations and water distribution pipes. Five intervention solutions are defined by identifying the main problems associated with the priority subsystem and the respective causes. The intervention solutions are compared considering the financial metrics and performance indicators, such as standardised energy consumption, energy in excess per unit of the authorised consumption, infrastructure value index and non-revenue water. New metrics regarding the assets’ physical condition are also incorporated in the assessment system. Results have shown the influence of considering different assessment criteria and performance indicators in the solutions' prioritisation, highlighting that the solution with the lowest capital cost does not always correspond to the solution with the highest overall performance.