scholarly journals Core-Shell Sr2CeO4@SiO2 Filled COC‑Based Composites with Low Dielectric Loss for High-Frequency Substrates

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4006
Author(s):  
Qinlong Wang ◽  
Hao Wang ◽  
Caixia Zhang ◽  
Qilong Zhang ◽  
Hui Yang
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Loss ◽  
High Frequency ◽  
High Speed ◽  
Heat Dissipation ◽  
Coefficient Of Thermal Expansion ◽  
Signal Transmission ◽  
Sol Gel ◽  
Normal Operation ◽  
Core Shell

High-frequency communication equipment urgently needs substrate materials with lower dielectric loss, better heat dissipation, and higher stability, to ensure real-time low-loss and high-speed signal transmission. The core-shell structure of Sr2CeO4@SiO2 was prepared by the sol-gel method, and the modified powders with different volume contents were introduced into the cyclic olefin copolymer (COC) to prepare hydrocarbon resin-based composites. Due to the protective effect of the SiO2 shell, the stability of the powders is significantly improved, and the moisture barrier and corrosion resistance of the composites are enhanced, which is conducive to the normal operation of electronic equipment in harsh and complex environments. When the filler content is 20 vol%, the composite has a dielectric loss of 0.0023 at 10 GHz, a dielectric constant of 3.5, a thermal conductivity of 0.9 W·m−1·K−1, a water absorption of 0.32% and a coefficient of thermal expansion of 37.7 ppm/℃. The COC/Sr2CeO4@SiO2 composites exhibit excellent dielectric properties and thermal conductivity, while maintaining good moisture resistance and dimensional stability, which shows potential application prospects in the field of high-frequency substrates.

scholarly journals MPPE/SEBS Composites with Low Dielectric Loss for High-Frequency Copper Clad Laminates Applications

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1875
Author(s):  
Jianming Guo ◽  
Hao Wang ◽  
Caixia Zhang ◽  
Qilong Zhang ◽  
Hui Yang
Keyword(s):  
Dielectric Loss ◽  
High Frequency ◽  
Composite Laminates ◽  
Printed Circuit Boards ◽  
Coefficient Of Thermal Expansion ◽  
Weight Ratio ◽  
Resin Matrix ◽  
Ceramic Powders ◽  
Low Dielectric ◽  
Low Dissipation

Copper clad laminates (CCLs) with low dissipation factor (Df) are urgently needed in the fields of high-frequency communications devices. A novel resin matrix of modified poly (2,6-dimethyl-1,4-phenylene ether) (MPPE) and styrene-ethylene/butylene-styrene (SEBS) was employed in the fabrication of high-frequency copper clad laminates (CCLs). The composites were reinforced by E-glass fabrics, which were modified with phenyltriethoxysilane (PhTES). The composite laminates obtained exhibited impressive dielectric loss of 0.0027 at 10 GHz when the weight ratio of MPPE to SEBS was 5:1. In order to modify the dielectric constant (Dk), coefficient of thermal expansion (CTE) and other performances of laminates, Li2TiO3 (LT) ceramic powders were introduced into the resin matrix. The composite laminates showed low dielectric loss of 0.0026 at 10 GHz and relatively high flexural strength of 125 MPa when the mass ratio of LT fillers to resin is 0.4. Moreover, the composite laminates all maintain low water uptake (<0.5%). The microstructure and thermal properties of composite laminates filled with LT ceramic powders were also tested. These results show that copper clad laminates prepared with modified polyphenylene ether (MPPE)/SEBS and LT ceramic fillers have strong competitiveness to fabricate printed circuit boards (PCBs) for high-frequency and high-speed applications.

scholarly journals Improved Properties of PTFE Composites Filled with Glass Fiber Modified by Sol-Gel Method

2021 ◽  
Author(s):  
Qiuying Li ◽  
Pengying Liu ◽  
Kashif Mahmood ◽  
Ning Zhang ◽  
Yanchao Che
Keyword(s):  
Thermal Conductivity ◽  
Glass Fiber ◽  
Coefficient Of Thermal Expansion ◽  
Sol Gel ◽  
Circuit Board ◽  
Organic Precursor ◽  
Gel Method ◽  
Sol Gel Method ◽  
Bending Modulus ◽  
Ptfe Composites

Abstract Tetraethyl orthosilicate (TEOS) was used as the silicon source, and polydimethylsiloxane (PDMS) was the organic precursor to modify the surface of glass fiber (GF) through the sol-gel method. The modified GF noted T-GF was filled in PTFE to prepare PTFE/T-GF composites. SEM, FTIR, XPS, and contact angle confirmed that organic-inorganic hybrids were successfully loaded on GF's surface. Compared with PTFE/GF and the conventional coupling agent modified GF filled PTFE composites, the properties of PTFE/T-GF composites, including dielectric properties, mechanical properties, moisture absorption, thermal conductivity, and coefficient of thermal expansion (CTE), enhanced significantly for the improvement of compatibility of PTFE and GF. Moreover, the PTFE/T-GF exhibited improved dielectric constant (2.305), decreased dielectric loss (9.08E-4), higher bending strength (21.45 MPa) and bending modulus (522 MPa), better thermal conductivity (0.268 W/m*K) and lower CTE (70 ppm/℃), making it has promising application as the substrate materials for printed circuit board.

High Speed Signal Transmission using Through-Si Vias and Coplanar Waveguides in a 3D IC Test Structure

2013 ◽  
Vol 2013 (1) ◽  
pp. 000228-000232
Author(s):  
Min Xu ◽  
Robert Geer ◽  
Pavel Kabos ◽  
Thomas Wallis
Keyword(s):  
Integrated Circuits ◽  
High Frequency ◽  
High Speed ◽  
Signal Transmission ◽  
Coplanar Waveguides ◽  
Scattering Parameter ◽  
High Frequency Signal ◽  
3D Integrated Circuits ◽  
High Bandwidth ◽  
Silicon Vias

High frequency signal transmission through silicon substrates is critical for 3D heterogeneous integration. This paper presented fabrication, testing, and simulation of high-frequency interconnects based on through-silicon vias (TSVs) and coplanar waveguides (CPWs) for stacked 3D integrated circuits (3D ICs). Our simulation results showed that adding ground TSVs can improve signal transmission by 6× at 50GHz. We further investigated signal/ground TSV (1SXG) configurations for high-bandwidth signal transmission links. Scattering parameter measurements of fabricated 1SXG TSV structures for frequencies from 100MHz to 50GHz show low insertion loss (S21 less than −1dB up to 50GHz) and return loss (S11 lower than −15dB). These results indicate that these vertical interconnects exhibit good performance for high speed signal transmission. To understand the RF signal transmission in 3D interconnects, we used full wave electromagnetic simulation to investigate the electromagnetic field distribution associated with the ground TSV placement. We observed that the ground TSVs induced substantial overall field confinement, consistent with the experimental observation of improved signal transmission. Simulations also provided design guidance with respect to the substrate conductivity's impact on EM confinement and signal transmission.

scholarly journals Synthesis And Characterization of Cobalt-Zinc Spinel Ferrites For High Frequency Applications

2021 ◽  
Author(s):  
Salma Aman ◽  
Tahani I. Al-Muhimeed ◽  
Zaki Ismail Zaki ◽  
Zeinhom M. El-Bahy ◽  
Abeer A. AlObaid ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
High Frequency ◽  
Sol Gel ◽  
Secondary Phase ◽  
Spinel Ferrites ◽  
Dc Resistivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Dielectric

Abstract Spinel ferrites are attractive for high frequency applications due to their larger direct current (dc) resistivity and low dielectric loss. In the present work, Co0.6Zn0.4HoxFe2-xO4 (x = 0.00 and 0.1) spinel ferrites were prepared by sol-gel method. The X-ray diffraction pattern showed that both samples had cubic spinel structure, while in sample (x = 0.1), the secondary phase (HoFeO3) was also observed. The dc resistivity was increased with the addition of holmium ions. As the temperature increased, the dc resistivity was decreased by proving their semiconducting nature. The dielectric properties were also measured as a function of temperature and frequency. The sample which was composed by the substitution of holmium ions contained low value of dielectric loss. The magnetic properties were also experimentally measured by applying the field up to 2000 oersted. The small area covered by hysteresis loop proved that both samples possessed soft nature of magnetic materials.

scholarly journals Aluminum/Stainless Steel Clad Materials Fabricated via Spark Plasma Sintering

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 239 ◽  
Author(s):  
Kwangjae Park ◽  
Dasom Kim ◽  
Kyungju Kim ◽  
Hansang Kwon
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Thermal Expansion ◽  
Spark Plasma Sintering ◽  
Heat Dissipation ◽  
Coefficient Of Thermal Expansion ◽  
Laser Flash ◽  
High Heat ◽  
Plasma Sintering ◽  
Spark Plasma

Aluminum (Al)/stainless steel (SUS) clad materials were fabricated via the process of spark plasma sintering (SPS) using Al powder/bulk and an SUS sheet. Three Al/SUS clad types were fabricated: powder/bulk (P/B), bulk/bulk (B/B), and bulk/powder/bulk (B/P/B). During the SPS, Al and SUS reacted with each other, and intermetallic compounds were created in the clads. The thermal conductivity and thermal-expansion coefficient were measured using a laser flash analyzer and dynamic mechanical analyzer, respectively. The Al/SUS (P/B) clad had a thermal conductivity of 159.5 W/mK and coefficient of thermal expansion of 15.3 × 10−6/°C. To analyze the mechanical properties, Vickers hardness and three-point bending tests were conducted. The Al/SUS (P/B) clad had a flexural strength of about 204 MPa. The Al/SUS clads fabricated via SPS in this study are suitable for use in applications in various engineering fields requiring materials with high heat dissipation and high heat resistance.

Build-up Electrical Insulation Material with Low-Dielectric Loss Tangent, Low-CTE and Low-Surface Roughness

2011 ◽  
Vol 2011 (1) ◽  
pp. 000813-000819
Author(s):  
Eita HORIKI ◽  
Isao SUZUKI ◽  
Toshiaki TANAKA ◽  
Akihiro UENISHI ◽  
Hiroshi KOUYANAGI
Keyword(s):  
Surface Roughness ◽  
Dielectric Loss ◽  
Loss Tangent ◽  
Dielectric Loss Tangent ◽  
High Frequency ◽  
Transmission Loss ◽  
Coefficient Of Thermal Expansion ◽  
Electrical Insulation ◽  
Insulation Material ◽  
Low Dielectric

With the increasing speed of information and communication equipments in recent years, together with the high-speed signal processing of LSIs, there is a requirement for build-up electrical insulation materials (used in IC package substrates) to have low-dielectric loss tangent which reduces dielectric loss so as to achieve low transmission loss in the high-frequency GHz bands. At the same time, there is an increasing need for materials to have low-CTEs (Coefficient of Thermal Expansion) so as to ensure highly reliable substrates. With ou formulation technology, we have developed a next-generation film-shaped build-up electrical insulation material compatible with high-frequency signal transmission by using a composition of practical thermosetting epoxy resin, which has realized both a low-dielectric loss tangent and at the same time, a low-CTE. In addition, this material can show a low-surface roughness after the film desmear process. It is thus expected to help reduce not only dielectric loss by means of a low-dielectric loss tangent, but also conductor loss caused by the skin effect, and will promote fine line formation by means of SAP (Semi Additive Process).

Effect of Additives on Thermal Conductivity of Si3N4 Ceramics

2021 ◽  
Vol 1036 ◽  
pp. 185-195
Author(s):  
Zi Hao Chen ◽  
Qiang Gu ◽  
Wei Kui Ma ◽  
Guo Qi Liu
Keyword(s):  
Thermal Conductivity ◽  
High Speed ◽  
Heat Dissipation ◽  
High Strength ◽  
High Thermal Conductivity ◽  
Raw Material ◽  
Β Phase ◽  
Sealing Material ◽  
Strong Current ◽  
High Oxidation Resistance

Compared with traditional ceramics, Si3N4 ceramics have the characteristics of high theoretical thermal conductivity, high thermal shock resistance, high oxidation resistance, high strength, and strong current carrying capacity. It is a potential high-speed circuit and high-power device for heat dissipation and heat dissipation. Sealing material. For applications in 5these fields, β-Si3N4 with a relatively stable structure and high thermal conductivity is an ideal material. However, β-Si3N4 powder is difficult to sinter as a raw material. Therefore, the prepared Si3N4 generally has a low density, and there are various defects in the crystal. The existence of these defects will cause interference and scattering of heat in the transfer process. Limits the application of β-Si3N4 ceramics. Studies have shown that the introduction of different additives can form a liquid phase at high temperatures, which can effectively reduce the firing temperature of the sample and increase the density. At the same time, it can also remove lattice oxygen, weaken the intercrystalline phase, and promote the α→β phase transition. Thereby improving the thermal conductivity and sintering performance of Si3N4 ceramics. Therefore, this article reviews the types of additives and their effects on the properties of Si3N4 ceramics and their mechanism. Trying to find an additive system for the preparation of high thermal conductivity Si3N4 ceramics with excellent comprehensive performance, hoping to provide help for the work and researchers engaged in the research on the thermal conductivity of Si3N4 ceramics.

scholarly journals Thermal Properties of Copper Matrix-Ceramic Filler Composite Prepared by Polymer Solution Method

2022 ◽  
Vol 60 (1) ◽  
pp. 68-75
Author(s):  
Bok-Hyun Oh ◽  
Chung-Il Ma ◽  
Ji-Yeon Kwak ◽  
Heon Kong ◽  
Sang-Jin Lee
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Heat Dissipation ◽  
Coefficient Of Thermal Expansion ◽  
High Thermal Conductivity ◽  
Ceramic Filler ◽  
Aqueous Solvent ◽  
Significant Difference

A copper (Cu) metal-ceramic filler composite with high thermal conductivity and a suitable thermal expansion coefficient was designed for application as a high-performance heat dissipation material. The purpose of the designed material was to utilize the high thermal conductivity of Cu while lowering its high coefficient of thermal expansion by using a ceramic filler. In this study, a Cu-sol containing a certain amount of AlN or SiC ceramic filler was prepared using a non-aqueous solvent. A complex was produced by applying a PVB polymer to prepare a homogeneous precursor. The composite sintered without pressure in a reducing atmosphere showed low thermal conductivity due to residual pores, but the hot press sintered composite exhibited improved thermal conductivity. The Cu composite with 30 wt% AlN filler added exhibited a thermal conductivity of 290 W/m·K and a thermal expansion coefficient of 9.2 × 10-6/oC. Due to the pores in the composite, the thermal conductivity showed some difference from the theoretical value calculated from the rule of mixture. However, the thermal expansion coefficient did not show any significant difference.

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