bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Cu Sintering and Its Role on Corrosion Behaviour for High-Temperature Microelectronic Application
Authors: Kotadia Hiren R. , Ahuir-Torres Juan Ignacio , Bhogaraju Sri Krishna , West Geoff , Elger Gordon 
Published: March 2024

There has been a significant rise in interest from academic and industry communities on copper nano and micro-particles-based sinter pastes for harsh environment die attach. However, sintering these particles is a complex process which is affected by many parameters, such as (i) particles size, shape, and distribution, (ii) sintering temperature, pressure, environment, and (iii) organic compounds used for the paste formulation. In literature, various research groups demonstrated that sintered copper layer can achieve good electrical conductivity and high strength. In our previous research [1, 2], we explained that microscale etched flakes are also capable of shear strength >30Mpa while sintering with 10 MPa bonding pressure at 275°C for just 1 minute with negligible paste cost (in comparison to silver paste). However, very limited knowledge exists on literature about corrosion behaviour in sintered copper interconnects. This, from experience in the industry with silver sintering has proven to be critical to applications. For examples in high power LED headlamp applications, minor exposure to residual Sulphur emerging from vulcanized rubber seals has been observed to cause corrosion in silver sintered interconnects. Therefore, corrosion and its impact on performance and reliability must be considered, especially for safety critical applications. For this reason, we have studied the relationship between copper sintered samples and corresponding corrosion behaviours and compared again to pure copper (conventionally produced). The corrosion resistance of the samples in salt water was assessed via various electrochemical analysis techniques and correlated with sintered microstructure. Sample produced better corrosion resistance when fabricated with higher density (less porosity). However, in case of the microscale copper flakes-based interconnects, a pitting behaviour was observed. The sintered copper paste samples showed to be nobler than commercial copper. In addition, copper oxide and its role in accelerating/preventing oxidation is also studied.
Thermal Design of Stacked Power Modules for Electric Drive Applications
Authors: Li Jianfeng , Du Yuekang , Wang Xingzhi , Liu Liangjie , Pang Yong , Liu Feixiang 
Published: March 2024

This paper reports the thermal design of a stacked arrangement inserting four IGBT modules between five heat sinks to achieve good cooling performance while enabling them to be installed into the limited space. Such stacked four IGBT modules can be used for a variable voltage converter (VVC), a three-phase motor inverter (M-INV) and a three-phase generator inverter (G-INV) of one electric control system in one electric vehicle or hybrid electric vehicle. Work presented in this paper are the thermally related structure design and thermalelectric and computational fluid dynamics coupled simulation, while the prototyping and thermal test of the stacked arrangement are still ongoing. The simulation results indicate that the stacked arrangement can be designed into a compact 121 mm × 94.7 mm × 90.8 mm structure while achieving the maximum virtual junction temperature below 150°C under the coolant feed temperature of 70°C, flow rate of 10 L/min and pressure drop of 0.16 bar for the VVC delivering 150 kW, the M-INV delivering 100 kW and the G-INV delivering 50 kW. If validated with the ongoing work, the stacked arrangement can be employed to increase power density and improve electrical and thermal performance of the power modules in the electric control systems with multiple converters/inverters.
MEMS Mirror in Hermetic Package for Enhanced Performances
Authors: Maggi Luca , Del Sarto Marco , Maierna Amedeo , Shaw Mark , Carminati Roberto , Mendicino Gianluca , Rotta Davide , Chiesa Marco , Rodrigo Aina Serrano , Bogoni Antonella 
Published: March 2024

Ceramic substrate coupled to metal lid has been selected for realizing hermetic package for MEMS mirror. The component passed the fine and gross leak tests and show good performance with improved Q-factor.
Integration of Multi-Lithography Technologies for the Fabrication of Flexible Optical Link
Authors: Mistry Akash , Nieweglowski Krzysztof , Bock Karlheinz 
Published: March 2024

The advancement in demand for high bandwidth energy-efficient communication in the data centre and edge cloud servers needs a viable optical interconnection solution to cope with the demands. Therefore, the presented study describes the concept of flexible multi-mode waveguides (MMWGs) as an optical link for co-packaged optics. It evaluates three lithography technologies; UV-lithography, 2 photon polymerization direct laser writing process (2PP-DLW), and nano-imprint lithography (NIL) for the fabrication of flexible MM-WGs. The UV-lithography and 2PP-DLW process were evaluated for the fabrication of MM-WGs and micro-mirrors, respectively, for the master pattern of the NIL stamp. The NIL evaluates the imprinting of the MM-WGs with micro-mirrors at either end on the flexible and transparent PEN substrates with a low-loss OrmoClad lower cladding layer. There are five different crosssections from 10x10 μm2 to 50x50 μm2 of MM-WGs with micromirrors were imprinted. Additionally, it presents the importance of integrating multi-lithography technologies to fabricate flexible optical links where a 2PP-DLW process shows the best results for printing μm-scale optical components. On the other side, UV-lithography with SU-8 gives the foremost definition of the master for the polymeric MM-WGs. Furthermore, NIL offers the industrial mass-production option alongside prototyping.
Effect of Surface Microstructure on Joints Using Nanoporous Cu Sheet for Power Devices
Authors: Nishikawa Hiroshi , Park Byungho , Saito Mikiko , Mizuno Jun 
Published: March 2024

Wide-bandgap (WBG) semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) are being developed as promising replacements for Si-based semiconductors. The operating temperature of SiC semiconductor is expected to be much higher. The replacement of soldering with new bonding process has been needed for WBG semiconductor devices. We have proposed a solid-state bonding process using nanoporous metal sheet, as a die-attach bonding method for WBG semiconductor devices. In this study, the bonding process using nanoporous Cu sheet as an insert metal was investigated to achieve a Cu disk/Cu disk bonding without solvent and flux. The shear strength of the joint using nanoporous Cu sheet at 350 and 300°C in formic acid atmosphere exceeded the shear strength of conventional Pb–5Sn solder joints which was approximately 18 MPa.
From MEMS Strip to MEMS Unit: a Comprehensive Simulation Approach to Warpage
Authors: Ratti Andrea , Simoncini Daniele , Adolfo Annabel , Del Sarto Marco , Gritti Alex , Fedeli Patrick , Maggi Luca , Napolitano Teresa , Shaw Mark Andrew , Talledo Jefferson 
Published: March 2024

The paper suggests a simulation flow methodology suitable for MEMS package designers that can help R&D teams to develop industrially feasible products by achieving consistent warpage prediction results, both at unit and strip levels. Striplevel- wise, one of the most important findings of this activity is the direct impact of raw material selection. Unit-level-wise, it allows checking a priori and in different conditions (inside the socket or mounted on a PCB for example) stress distribution on different elements of the assembled MEMS unit.
Adhesion Copper/Molding Compound: Modeling and Characterization
Authors: Rovitto Marco , Zalaffi Samuele , Passagrilli Carlo , Villa Claudio Maria , Andena Luca , Mariani Stefano 
Published: March 2024

Delamination at the resin-copper interface is fully characterized during operative conditions by adopting a combined experimental and numerical approach. Peeling and four-point bending fracture tests are used along with cohesive zone models to reach this purpose. The promising findings are beneficial to analyze the crack propagation at the interface during package-oriented reliability tests, and may therefore be employed to enhance these interfaces in microelectronic plastic packages.
An Innovative Conformal Electronically Scanned Array Antenna for full 360° Steerability in the Ka-band
Authors: Uhlig Peter , Friedrich Aline , Krengel Markus , Simon Winfried , Litschke Oliver 
Published: March 2024

A novel approach to constructing an omnidirectional 5G/6G Ka-band Tx/Rx frontend module using an Active Electronically Steerable Array (AESA) will be presented. The 5G standard includes a number of mmWave frequency bands that provide the bandwidth for high data rates. However, up to now 5G still transmits primarily in the sub-6 GHz frequency range. Small cells like micro or pico cells operated in the mmWave range are capable to increase network capacity in densely populated areas. Efficient beam-based communications using directional antenna arrays can overcome the limitations imposed by propagation loss at high frequencies. These and a number of further requirements have been taken into account in the design of the antenna module presented here, making it a fundamental component for the cellular infra— structure of future 5G/6G mmWave networks. The dualpolarised module is using 2 x 96 elements to scan 360° in azimuth and ±45° in elevation. The operation frequency range is 24.25 GHz to 29.5 GHz, covering n258, n257, and n261 3GPP bands. Additionally, the module is capable to control up to four beams simultaneously.
An Experimental Investigation of a Flexible Sintered Silver Joint for Micro-Joining Based on a Design of Experiments
Authors: Vivet Laurent , Benabou Lahouari , Simon Olivier 
Published: March 2024

The increasing electrification of vehicles requires the use of ever higher voltages and electrical power. The thermal stresses to which the assembly joints of electronic chips are subjected are becoming increasingly severe. As a result, thermal stresses acting on the electronic assembly, and particularly on the electrical interconnections, are becoming increasingly severe. The objective of this study is to create, characterize and optimize the structure and properties of a porous silver sintered joint using the design of experiments (DoE) method. Joints consisting of a porous network of silver particles are obtained, showing remarkable flexibility allowing for thermal stresses accommodation and having sufficient tensile strength to ensure a correct bonding of the components. Depending on the selected levels for the sintering process parameters, the microscopy analysis shows a transition of the mode of rupture from the silver layer to the intermetallic compounds forming at the interface with the substrate.
Hybrid Lithography Fabrication of Single Mode Optics for Signal Redistribution and Coupling
Authors: Weyers David , Nieweglowski Krzysztof , Bock Karlheinz 
Published: March 2024

This paper describes advances in hybrid-lithography process, combining UV-lithography for planar, single mode redistribution layer (RDL) and 2-photon- polymerization direct-laserwriting (2PP-DLW) for micro-mirrors inside RDL-opening. Improvements to multi-layer direct patterning of OrmoCore/-Clad material system using UV- ithography and need for broadband UV-LED source are presented. Near square core cross sections and smooth sidewalls are achieved. Openings in full stack with steep sidewalls without residual layer are patterned. To optimize 2PP-DLW-process processing window for both OrmoComp and IP-DIP is thoroughly characterized. Roughness measurements prove feasibility even of coarsely printed structure as reflective μ-mirror for 1550 nm wavelength. Finally these results are applied to periscope probe for wafer-level-testing of edge emitting lasers and proof of concept is shown. Outlook to further research on UV-lithography of multi-layer waveguide stack and alignment with μ-mirror printing is given.
Research of Chip Placement Accuracy for Fan-Out WLP using A Novel Self-Assembly Stage
Authors: Yamada Tadatomo , Takano Ken , Menjo Toshiaki , Takyu Shinya 
Published: March 2024

This paper discusses the alignment accuracy after self-assembly using a novel self- assembly method with a uniquely developed porous stage. In a preceding paper, we have introduced our process that combines tape expansion technology and self-assembly technology. By using this process and machine device, it is possible to significantly improve the throughput of pick and place process for FO-WLP. Furthermore, it is indicated that our self-assembly method using the porous chuck stage enables achievement of high precision chip alignment and high throughput. In this study, two factors are evaluated to clarify the impact on the chip accuracy after self-assembly; 1) the influence of chip position before self-assembly, 2) the relationship between stage size of self-assembly area and chip size. As a result of evaluation, if the chip size is the same as the porous stage size, the alignment accuracy after self-assembly is within 5 μm or less even with varied chip positions before self-assembly. On the other hand, when the porous stage size and chip size are different, the chip position before self-assembly has an impact on the alignment accuracy after self-assembly. Based on the results obtained in this study, further development of machine device and process will be pursued to improve the alignment accuracy after selfassembly.
20 μm Copper Micro-Bump Bonding Through a Silver Metallization for Advanced Packaging Under a Low Pressure Condition
Authors: Zhang Zheng , Hsieh Ming-Chun , Suetake Aiji , Yoshida Hiroshi , Okumuara Rieko , Kagami Noriko , Okamoto Kazamasa , Chen Chuantong , Hashizume Kei , Hasegawa Norihiko , Yoshida Ryuji , Homma Hidekazu , Suganuma Katsuaki 
Published: March 2024

In this work, we proposed a copper (Cu) microbump bonding strategy by using a silver (Ag) metallization layer as an interconnect bridge. Si chips with 20 μm Cu-Ag bumps were bonded under a low pressure (0.4 MPa) and atmospheric conditions at 250 °C. By investigating the surface morphology evolution of the Cu-Ag bump, it is found that severe surface deformation caused by Ag abnormal grain growth and hillock generation plays a critical role in the Cu-Ag bump bonding, which facilitates the approach and bonding of top and bottom Ag surface of the bump structure. Moreover, this bonding strategy is expected to be particularly advantageous for finepitch interconnect applications. It not only mitigates the severe bonding condition requirements that are used in thermal compression bonding and hybrid bonding, but also provides higher quality bonding structures for advanced packaging.
Ceramic Embedding of SiC-Semiconductor Using Cofiring Technology
Authors: Ziesche Steffen , Reinhardt Kathrin , Varghese Jobin , Manhica Birgit , Schletz Andreas 
Published: March 2024

The presented work demonstrates our current state in embedding of SiC power electronic dies using Ceramic Multilayer Technology. The novelty of the approach presented includes the cofiring of a semiconductor element with ceramic base material, which demands for a reduced sintering temperature of ceramics (using LTCC or ULTCC based ceramics) in combination with an increased temperature stability of the semiconductor.
As Milky as It Can Get; Chyluria: A Case Report and Review of Literature
Authors: Mahapatra Debasish , Jha Vijoy Kumar , Nair Nithya 
Published: March 2024

Abstract
Filariasis is an important public health problem in India. Extralymphatic manifestation of filariasis includes chyluria or passage of intestinal lymph or chyle into urine imparting a milky-white color, is an important manifestation of renal involvement. A young woman residing in a filaria endemic region, presented with persistent chyluria of 3-month duration. She did not have any features of nephrotic or nephritic syndrome or features of connective tissue disease. After routine hematological, biochemical, serological, and urinalysis, nephrotic range proteinuria and lipiduria were confirmed, and kidney biopsy was performed. Kidney biopsy showed an elongated parasitic sheathed structure with multiple basophilic nuclei spread along the length of the tail, suggestive of microfilaria, in capillaries of a single glomerulus; immunofluorescence was negative for immunoglobulin (Ig) A, IgM, IgG, C3, C1q, kappa, and lambda. She was given antifilarial drug and chyluria promptly subsided. The complex evaluation and management of chyluria have been discussed.
Generalizing the German Tank Problem
Authors: Anthony Lee  , Steven Miller  
Published: March 2024

The German Tank Problem dates back to World War II when the Allies used a statistical approach to estimate the number of enemy tanks produced or on the field from observed serial numbers after battles. Assuming that the tanks are labeled consecutively starting from 1, if we observe k tanks from a total of N tanks with the maximum observed tank being m, then the best estimate for N is m(1 + 1/k) - 1. We refer to an estimate as "best" when the estimate is closest to the actual number of tanks. We explore many generalizations; first, we looked at the discrete and continuous one-dimensional case. We attempted to improve the original formula by using different estimators such as the second largest and Lth largest tank, and applied motivation from portfolio theory by seeing if a weighted average of different estimators would produce less variance; however, the original formula, using the largest tank proved to be the best; the continuous case was similar. Then, we looked at the discrete and continuous square and circle variants where we pick pairs instead of points, which were more complex as we dealt with problems in geometry and number theory, such as dealing with curvature issues in the circle, and the problem that not every number is representable as a sum of two squares. In some cases, when we could not derive precise formulas, we derived approximate formulas. For the discrete and continuous square, we tested various statistics, but found that the largest observed component of our pairs is the best statistic to look at; the scaling factor for both cases is (2k+1)/2k. For the circle we used motivation from the equation of a circle; for the continuous case, we looked at the square root of X2+Y2 and for the discrete case, we looked at X2+Y2 and took a square root at the end to estimate for r. Interestingly, the scaling factors, a number, generally a little greater than 1, that we multiplied to scale up to get our estimation, were different for the cases. Lastly, we generalized the problem into L-dimensional squares and circles. The discrete and continuous square proved to be similar to the two-dimensional square problem. However, for the Lth dimensional circle, we had to use formulas for the volume of the L-ball, and had to approximate the number of lattice points inside it. The discrete circle formula was particularly interesting, as there was no L dependence in the formula.
On Prime Labelings of Uniform Cycle Snake Graphs
Authors: Bedi Agam , Ollis Matt , Ramesh Samiksha 
Published: March 2024

A prime labeling of a graph of order n is an assignment of the integers 1, 2, ... , n to the vertices such that each pair of adjacent vertices has coprime labels. For positive integers m, k, q with k ≥ 3 and 1 ≤ q ≤ ⌊k/2⌋ , the uniform cycle snake graph Cmk,q is constructed by taking a path with m edges and replacing each edge by a k-cycle by identifying two vertices at distance q in the cycle with the vertices of the original path edge. We construct prime labelings for Cmk,q for many pairs (k,q) and, in each case, all m. These include: all cases with k ≤ 9 or k = 11; all cases with q = 2 when k ≡ 3 (mod 4); all cases with q = 3 when k has the form 2a − 1, 3a + 1 or 3b + 3 for all a and all odd b; all cases with q = 4 when k is even; and all cases with q = k/2 when q is a prime congruent to 1 (mod 3).
Fears, Beliefs and Practices of Pregnant Women in Saudi Arabia regarding their Sexual Health during Pregnancy and after Birth
Authors:   Department of Obstetrics and Gynecology, College of Medicine, King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia, Othman Aldakhil Lateefa , Alobaid Saleh ,   Alfaisal University, Riyadh, Saudi Arabia
Published: March 2024

Background: A woman’s sexual life during pregnancy is subject to many physiological and psychological changes. In this regard, there are inconsistencies in some aspects, while some are yet to be explored. This study aimed to obtain a detailed account of the fears, beliefs and practices of pregnant women and their associated factors in Saudi Arabia regarding their sexual life during pregnancy and after birth. Methods: A convenience sample of pregnant women (n=439) attending antenatal clinics at purposefully selected hospitals completed a self-report questionnaire of her fears, beliefs and practices regarding her sexual life during pregnancy. This was a cross-sectional study performed by a team of researchers at King Khalid University Hospital from August 2021 to August 2022. Results The majority of the pregnant women recorded •	A decrease in libido •	That Kegel exercises improved sexual function •	That vaginoplasty is important after vaginal delivery •	Fear of dyspareunia, vaginal laxity, and changes in the sexual relationship •	Dependence on unverified sources for information regarding female sexual issues. A large proportion of the participants •	Thought that delivery-related vaginal laxity needed medical consultation •	Thought that vaginal laxity was associated with episiotomy •	Relied on traditional herbs for managing sexual health issues. Among pregnant women in Saudi Arabia, sexual health-related fears, attitudes and practices were associated with age, marital status and educational level, and participants relied on past experience and social media for information. Conclusion: Decreased libido and painful intercourse are common among pregnant women regardless of parity. Sexual health concerns and education should be part of antenatal care visits.
Diyet Lifleri: Tanımı, Türleri ve Gıda Endüstrisinde Kullanımları
Authors: YILMAZ Mahir Serdar 
Published: March 2024

Diyet lifi, sindirim enzimlerine dirençli olan ve esas olarak tahıllarda, meyvelerde ve sebzelerde bulunan bir gıda bileşenleri grubudur. İnsan sindirim sistemi içinde ince bağırsakta sindirilemeyen fakat kolonda kısmen sindirilebilen diyet lifi, suda çözünen ve suda çözünmeyen olmak üzere iki grupta incelenir. Diyet lif tüketiminin insan sağlığı açısından oldukça önemli etkileri vardır. Bu nedenle tüketiminin teşvik edilmesi ve çeşitli gıda ürünlerine fonksiyonel özellikler kazandırma amacıyla katkı maddesi olarak eklenmesi yaygınlaşmaya başlamıştır. Gıda endüstrisinde özellikle et, süt ve unlu mamullerin üretimlerinde kullanılmaktadırlar.
Bu çalışmada, diyet lifleri tanımlanmış, türleri belirtilmiş ve gıda ürünlerinde diyet lifi kullanımına dair bazı bilimsel çalışmalar özetlenerek derlenmiştir.