Thermal conductivity of beryllium oxide ceramic

Акишин, Г. П.; Turnaev, S. K.; Vaispapir, V. Ya.; Gorbunova, M. A.; Makurin, Yu. N.; Кийко, В. С.; Ivanovskiĭ, A. L.

doi:10.1007/s11148-010-9239-z

Cited by 71 publications

(43 citation statements)

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“…This has included cooling integrated into baseplates (32) and ceramic substrates (33,34) and even directly cooling the backside of the packaged devices (35). A number of other investigators have pursued alternative substrate (beryllium oxide [BeO] [36]) and composite heat sink materials (aluminumSiC (37), aluminum-carbon (38), etc.) to decrease total conduction resistance while reducing weight and mechanical package stresses.…”

Section: Electronics Cooling -Technology Optionsmentioning

confidence: 99%

Thermal Management as a Force Multiplier within the Research, Development, and Engineering Command (RDECOM)

Odom¹,

Jankowski²,

Morgan³

2012

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Section: Electronics Cooling -Technology Optionsmentioning

confidence: 99%

Thermal Management as a Force Multiplier within the Research, Development, and Engineering Command (RDECOM)

Odom¹,

Jankowski²,

Morgan³

2012

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“…In this case the effect of BeO-ceramic color on thermal conductivity and ultrasound propagation rate was not established [11,12].…”

Section: Composition Of Beryllium Oxide Ceramics 379mentioning

confidence: 99%

Composition of beryllium oxide ceramics

Акишин¹,

Turnaev²,

Vaispapir³

et al. 2011

Refract Ind Ceram

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The physicochemical and electrophysical properties of ceramics based on BeO without impregnation and after impregnation with an aqueous solution of sodium carbonate Na 2 CO 3 are studied. It is established that impregnation leads to preparation of ceramic specimens with a white color, which develop increased porosity, lower amount of impurities and smaller average microcrystal size, although it has little effect on their electrophysical properties. In order to improve these properties considerably it is necessary to increase ceramic density by increasing its sintering temperature by 20 -40 K. Values of electrical permittivity e and dielectric loss tangent tg d are determined for a series of BeO ceramic specimens (732 pieces), having identical geometric dimensions, but prepared from original BeO powder of different batches. Studies show considerable scatter in the distribution of these parameters, which points to a requirement for further improvement of BeO-ceramic preparation technology.One of the most important tasks is improving the quality of beryllium oxide ceramics, used in radio electronic devices and other areas of technology, and special instrument building. Previously the effect has been established for some impurities on the physicochemical properties of BeO-ceramic prepared by normal ceramic technology (methods of semidry compaction and slip casting), and high-temperature compaction [1 -10]. It has been established that introduction into the BeO-ceramic composition of an admixture of TiO 2 and sintering specimens in a reducing atmosphere made it possible to increase to a considerable extent their electrical conductivity and capacity for absorbing UHF-radiation [8 -10]. Impurity phases of iron have a defining effect on the change in electrophysical properties of BeO-ceramic, which limits its use in objects for electronic technology [1 -7].In order to reduce the unfavorable effect of primarily iron impurity and partly other admixtures on color, microstructure and electrophysical properties of BeO-ceramic objects, production operations have been proposed previously for impregnating porous ceramic preforms, after burning off the organic binder, in aqueous solutions of lithium carbonate Li 2 CO 3 [1, 6, 7]. As a result of this stabilization of microcrystal dimensions is achieved, coloring of the surface and volume of an object is suppressed, and there is also a reduction in values of dielectric permittivity e and dielectric loss tangent tg d. We have considered features of the impurity states of lithium and sodium in .The effect of impregnating BeO-ceramic in a solution of sodium carbonate on its properties has not been studied entirely. In view of this it is important to study the change in physicochemical properties of BeO-ceramic without impregnation and after it in aqueous sodium carbonate Na 2 CO 3 solution. In the present work comprehensive study is attempted for a number of most important functional properties of BeO-ceramic (mechanical strength, linear thermal expansion coefficient, volumetric elect...

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“…Beryllium oxide (BeO) is the only alkaline‐earth mono‐oxide that crystallizes in a wurtzite (hexagonal) structure rather than a halite (cubic) structure (MgO, CaO, SrO, and BaO), and it is the lightest among the wurtzite‐structured materials . BeO exhibits unique physicochemical properties, such as high electrical resistivity, high bulk modulus (212 GPa, the hardest known material), high‐energy bandgap (10.6 eV, direct), high melting point (2532 ± 10°C), low dielectric losses, and transparency for ultraviolet/infrared/X‐ray light . One of the most important properties of BeO is its high thermal conductivity (330 W/m·K) .…”

Section: Introductionmentioning

confidence: 99%

Domain epitaxy of crystalline BeO films on GaN and ZnO substrates

et al. 2018

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We demonstrated the growth of wurtzite‐crystalline beryllium oxide (BeO) thin films on GaN and ZnO substrates using atomic layer deposition (ALD). Single‐crystalline BeO were epitaxially grown on GaN. Despite the inherently large lattice mismatch of BeO and GaN atoms, the 6/5 and 7/6 domain‐matched structures dramatically reduced the residual strain in BeO thin films. On the other hand, the lattice mismatch of BeO and ZnO was not effectively accommodated in the mixed domains. X‐ray diffraction (XRD) confirmed the in‐plane crystallization of BeO‐on‐substrates in the (002){102}BeO||(002){102}Sub orientation and relaxation degrees of 20.8% (GaN), 100% (ZnO). The theoretical critical thicknesses of BeO for strain relaxation were 2.2 μm (GaN) and 1.6 nm (ZnO), calculated using a total film energy model. Transmission electron microscopy (TEM) and Fourier‐filtered imaging supported the bonding configuration and crystallinity of wurtzite BeO thin films on GaN and ZnO substrates.

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Thermal conductivity of beryllium oxide ceramic

Cited by 71 publications

References 1 publication

Thermal Management as a Force Multiplier within the Research, Development, and Engineering Command (RDECOM)

Thermal Management as a Force Multiplier within the Research, Development, and Engineering Command (RDECOM)

Composition of beryllium oxide ceramics

Domain epitaxy of crystalline BeO films on GaN and ZnO substrates

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