Oxidation bonding of porous silicon nitride ceramics with high strength and low dielectric constant

2007 ◽  
Vol 61 (11-12) ◽  
pp. 2277-2280 ◽  
Author(s):  
Shuqiang Ding ◽  
Yu-Ping Zeng ◽  
Dongliang Jiang
Keyword(s):  
Dielectric Constant ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
High Strength ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Nitride Ceramics

Preparation of Low Dielectric Constant Porous Silicon Nitride Ceramics for Radome Application

2018 ◽  
Vol 281 ◽  
pp. 610-615
Author(s):  
Ling Li ◽  
Bao Xin Zhu ◽  
Hong Sheng Wang ◽  
Jie Zhang
Keyword(s):  
Dielectric Constant ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Flexural Strength ◽  
Dielectric Material ◽  
Core Layer ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Dielectric Constant And Loss ◽  
Nitride Ceramics

The porous silicon nitride ceramics with low dielectric constant and high flexural strength were obtained by adding pore-forming agent through partial sintering technique. The effects of pore-forming agent amount on the properties of porous silicon nitride ceramics were investigated. Microstructure was analyzed by means of scanning electron microscopy. The results show that the porous structure is formed by the overlap of pillar β-Si3N4 with high length diameter ratio. The porosity of samples rises with the increase of pore-forming agent content, which leads to the decrease of the dielectric constant and loss, but the decrease of flexural strength. When the pore-forming agent of PMMA with mass fraction of 20% was added, the volume density, porosity, dielectric constant and loss of porous silicon nitride ceramics were 1.17g/cm3, 66.5%, 2.33 and 0.8×10-3 respectively, with higher flexural strength of 75MPa which is satisfactory as low dielectric material for core layer of broadband radome.

Preparation and Properties of Porous Si3N4/SiO2/BN Composite Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 828-831 ◽  
Author(s):  
Wei Dong ◽  
Chang An Wang ◽  
Lei Yu ◽  
Shi Xi Ouyang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
High Strength ◽  
Low Dielectric Constant ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Porous Si ◽  
Low Dielectric ◽  
Dry Pressing ◽  
Porous Si3n4

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.

Microwave Dielectric Property of Porous Silicon Nitride Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 307-309 ◽  
Author(s):  
Jun Qi Li ◽  
Fa Luo ◽  
Dong Mei Zhu ◽  
Wan Cheng Zhou
Keyword(s):  
Dielectric Constant ◽  
Silicon Nitride ◽  
Dielectric Property ◽  
Porous Silicon ◽  
Microwave Dielectric Property ◽  
Volume Fraction ◽  
Silicon Powder ◽  
Dense Matrix ◽  
Microwave Dielectric ◽  
Nitride Ceramics

This paper presents the microwave dielectric property of porous silicon nitride ceramics at a frequency of 9360 MHz, which were fabricated by the nitridation of silicon powder. The porous ceramics with different volume fraction of porosity from 18.6% to 56.2% were produced by adding different amount of the pore-forming agent into the initial silicon powder. Microstructural analysis revealed a dense matrix containing large pores and cavities with needle-shaped and flaky β-Si3N4 grains distributing in it. The results showed that the dielectric constant of the ceramics reduces with the porosity increases. With the addition of α-Si3N4 powder in the raw silicon powder, the nitridation rate is raised, and the dielectric constant and the dielectric loss of the ceramics decrease notablely.

scholarly journals BN Nanoparticles/Si3N4Wave-Transparent Composites with High Strength and Low Dielectric Constant

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Dongliang Zhao ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Baoxin Zhu ◽  
Xiaoyu Zhang
Keyword(s):  
Mechanical Properties ◽  
Dielectric Constant ◽  
Volume Content ◽  
Bending Strength ◽  
High Strength ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
Transparent Composites ◽  
Gas Pressure Sintering ◽  
Dielectric And Mechanical Properties

Si3N4wave-transparent composites with different volume content of BN nanoparticles (BNnp/Si3N4) were prepared by gas pressure sintering at 1800°C in N2atmosphere. The effects of BN nanoparticles on the dielectric and mechanical properties of BNnp/Si3N4composites were investigated. The results showed that the addition of the BN nanoparticles improved the dielectric properties of BNnp/Si3N4composites effectively and decreased the mechanical properties. When the volume content of BN nanoparticles was 10%, the dielectric constant and dielectric loss tangent were 4.31 and 0.006, respectively, and the bending strength and fracture toughness still reached 198.9 MPa and 3.36 MPa·m1/2. The high mechanical properties of BNnp/Si3N4composites with 10% BN nanoparticles were attributed to homogeneously dispersed BN nanoparticles which were embedded in the pores formed by the rod-likeβ-Si3N4.

High Strength Low Dielectric Constant Aromatic Thermosets

2005 ◽  
Vol 863 ◽  
Author(s):  
Yongqing Huang ◽  
James Economy
Keyword(s):  
Thermal Stability ◽  
Dielectric Constant ◽  
Young’S Modulus ◽  
Breakdown Strength ◽  
Young's Modulus ◽  
Chemical Vapor ◽  
High Strength ◽  
Low Dielectric Constant ◽  
Crosstalk Noise ◽  
Low Dielectric

AbstractContinuing miniaturization of microelectronic devices requires development of low dielectric constant materials to lower the RC delay, power dissipation and crosstalk noise. Although spin-on polymer dielectrics usually have better potential for extendibility to lower dielectric constant (k) values compared to chemical-vapor-deposited dielectrics, their low mechanical properties prevent them from being successfully integrated with copper metal lines.Recent evaluation of a new thermosetting oligomer shows high thermal stability, low moisture pick-up and low dielectric constant. Techniques to optimize the solubility and spin coating characteristics of the oligomer have been developed. The thermally cured polymer displayed a thermal stability up to 480°C in nitrogen and 400°C in air. The cured polymer displayed a dielectric constant of 2.7 at 1 MHz and a breakdown strength larger than 230 V/μm. Nanoindentation testing showed that it had an extraordinarily high Young's modulus of 16.8 GPa and a hardness of 3.5 GPa. By use of porogens, a dielectric constant as low as 1.85 was obtained while still maintaining an acceptable high Young's modulus of 7.7 GPa and hardness of 2.0 GPa. Nanoscratch testing indicated that this material had good adhesion to the Si substrate, and Ta which is a diffusion barrier for copper. These results appear unique compared to all commercially available low-k candidates.

scholarly journals A multilayer model for describing hardness variations of aged porous silicon low-dielectric-constant thin films

2009 ◽  
Vol 518 (1) ◽  
pp. 213-221 ◽  
Author(s):  
K. Rahmoun ◽  
A. Iost ◽  
V. Keryvin ◽  
G. Guillemot ◽  
N.E. Chabane Sari
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Porous Silicon ◽  
Low Dielectric Constant ◽  
Multilayer Model ◽  
Low Dielectric

Fabrication of High-Porosity Silicon Nitride Ceramics with Excellent Mechanical Properties

2011 ◽  
Vol 284-286 ◽  
pp. 1339-1342
Author(s):  
Shao Yun Shan ◽  
Qing Ming Jia ◽  
Ya Ming Wang ◽  
Jin Hui Peng
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
Porous Silicon ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
High Strength ◽  
High Porosity ◽  
Microstructure And Mechanical Properties ◽  
Nitride Ceramics ◽  
Sintering Conditions

High-porosity silicon nitride ceramics with excellent mechanical properties were fabricated by the carbothermal reduction of SiO2. The influences of sintering conditions on microstructure and mechanical properties were studied. The results showed that microstructure and mechanical properties of porous silicon nitride ceramics were dependent mostly on the sintering conditions. The sintered porous silicon nitride ceramics exhibited the formation of fibrous microstructure with submicrometer-sized, high-aspect ratio b-Si3N4 grains, and uniform pore structure. Porous Si3N4 ceramics with a porosity of about 70%, and a flexural strength of about 70 MPa were obtained by sintering at 1750°C, with lower rate of temperature rise and no retaining time. The high strength was attributed to fine, high-aspect ratio b-Si3N4 grains and uniform pores between grains.

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