scholarly journals Benzoxazine-modified BMI Heat-resistant Resin with Low Dielectric Properties

2021 ◽  
Vol 14 (0) ◽  
pp. E20-016-1-E20-016-14
Author(s):  
Pitao Kuo ◽  
Hitoshi Habuka
Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1646
Author(s):  
Corneliu Hamciuc ◽  
Mihai Asandulesa ◽  
Elena Hamciuc ◽  
Tiberiu Roman ◽  
Marius Andrei Olariu ◽  
...  

Heat-resistant magnetic polymer composites were prepared by incorporating cerium-doped copper-nickel ferrite particles, having the general formula Ni1-xCuxFe1.92Ce0.08O4 (x: 0.0, 0.3, 0.6, 1.0), into a polyimide matrix. The effects of particle type and concentration on the thermal, magnetic, and electrical properties of the resulting composites were investigated. The samples were characterized by FTIR, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, differential scanning calorimetry, vibrating sample magnetometer, and broadband dielectric spectroscopy. The composites exhibited high thermal stability, having initial decomposition temperatures between 495 and 509 °C. Saturation magnetization (Ms), magnetic remanence (Mr), and coercivity (Hc) were found in range of 2.37–10.90 emu g−1, 0.45–2.84 emu g−1, and 32–244 Oe, respectively. The study of dielectric properties revealed dielectric constant values of 3.0–4.3 and low dielectric losses of 0.016–0.197 at room temperature and a frequency of 1 Hz.


RSC Advances ◽  
2016 ◽  
Vol 6 (26) ◽  
pp. 21662-21671 ◽  
Author(s):  
Weibing Dong ◽  
Yue Guan ◽  
Dejing Shang

To acquire low dielectric constant polyimide films with good mechanical and thermal properties and low CTE applied in microelectronic fields, three novel polyimides containing pyridine and –C(CF3)2– groups were firstly designed and synthesized.


2012 ◽  
Vol 512-515 ◽  
pp. 828-831 ◽  
Author(s):  
Wei Dong ◽  
Chang An Wang ◽  
Lei Yu ◽  
Shi Xi Ouyang

Porous Si3N4/SiO2/BN composite ceramics with high strength and low dielectric constant were prepared by dry-pressing process and pressureless sintering at 1750°C for 1.5 h in flow nitrogen. The influences of BN content on microstructure, porosity, mechanical and dielectric properties of the porous Si3N4/SiO2/BN composite ceramics were discussed. The results showed that the porous Si3N4/SiO2/BN composite ceramics with porosity ranging from 29% to 48% were fabricated by adjusting the content of BN. The flexural strength of the porous Si3N4/SiO2/BN composite ceramics was 78215 MPa. The dielectric constant of the porous Si3N4/SiO2/BN composite ceramics was 3.9~5 at 1 MHz.


2020 ◽  
Author(s):  
Eduardo Araújo ◽  
Marcelo Silva ◽  
Mauricio Pereira ◽  
Antonio Sombra ◽  
Igor Vasconcelos ◽  
...  

Abstract Molybdates from A2Mo3O12 family have been widely investigated due to its low sintering temperature, low thermal expansion coefficient, and low dielectric loss. Fe2Mo3O12 (FMO) is an oxide from this family and widely used in the catalytic field. The aim of this work is to evaluate the influence of the Bi2O3-B2O3 as a sintering aid in the microstructure and dielectric properties of FMO. The diffraction results showed that the FMO with the monoclinic structure phase was obtained after the calcination process (650 °C). Mössbauer spectroscopy showed the formation of Fe2O3 after the sintering process at 800 °C. The scanning electron-microscopic demonstrates an increase of the grain as a function of sintering aid concentration. The samples were analyzed by using the impedance spectroscopy at radiofrequency with temperature variation. The Nyquist diagram obtained in this temperature range was fitted from an equivalent circuit with three R-CPE associations, corresponding to the morphology of the electroceramics. For dielectric properties in the microwave, all the samples showed values of εr lower than 10. Values of Q x f above 14132.35 GHz were achieved. The thermal stability was evaluated by the temperature coefficient of resonant frequency (τf). The lowest τf values of -6.55 ppm/°C and -4.35 ppm/°C (near-zero) were measured to FMO and FMO mixed with 7.5 wt% Bi2O3-B2O3, respectively. Based on these results, FMO can be used to low permittivity ceramic for low temperature co-fired ceramics (LTCC) applications, antenna substrate, and millimeter-wave range.


2018 ◽  
Vol 9 (21) ◽  
pp. 2913-2925 ◽  
Author(s):  
Ming Zeng ◽  
Jiangbing Chen ◽  
Qingyu Xu ◽  
Yiwan Huang ◽  
Zijian Feng ◽  
...  

The effects of the reaction solvent on the preparation, polymerization kinetics, and high-frequency dielectric properties of aliphatic main-chain benzoxazine copolymers were investigated.


2018 ◽  
Vol 2018 (1) ◽  
pp. 000476-000482 ◽  
Author(s):  
Masao Tomikawa ◽  
Hitoshi Araki ◽  
Yohei Kiuchi ◽  
Akira Shimada

Abstract Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.


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