Properties and Reliability of Silicon Nitride Substrates with AMB Copper Conductor

This paper focuses on the properties of Si3N4 substrate material with AMB (active metal brazing) copper conductor. A recently developed type of tape casted, gas pressure sintered silicon nitride ceramic with a three times higher thermal conductivity than known from typical standard silicon nitride materials and with good flexural strength was applied. The increase of thermal conductivity is the result of using different species of sintering aids and the optimization of their ratio in the material. The high bending strength allows creating a thinner substrate compared to other standard ceramic materials for power electronics, e.g. aluminum nitride. This reduction in thickness leads to a decrease of the total thermal resistance of the substrate which improves heat dissipation. For the AMB process a silver based active brazing solder composition optimized for Silicon Nitride was used. This optimization could be obtained by an investigation of the physical and chemical interactions between the brazing and the base material. A void free joint without short circuits between adjacent structures could be formed. The copper surface can be coated on demand with Nickel or Nickel/Gold for improved solderability and wire bondability as well as for corrosion protection. The silicon nitride substrate with AMB copper conductor lines and fully covered back side ground shows a higher reliability than comparable substrates made out of common, well known ceramic materials. The heat dissipation is comparable with conventional AMB substrates made of high thermal conductive ceramic such as Aluminum Nitride, but thermal cycling behavior exceeds the limits well known from AlN-AMB or AlN-DCB.

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Ceramic-Based Planar Heat Pipe (Plate) for Passive Electronics Cooling

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-2011-wa12 ◽

2011 ◽

Vol 2011 (CICMT) ◽

pp. 000159-000165

Author(s):

M. Wilson ◽

H. Anderson ◽

J. Fellows ◽

C. Lewinsohn

Keyword(s):

Integrated Circuits ◽

Phase Change ◽

Heat Dissipation ◽

Thermal Contact ◽

Three Dimensional ◽

Electronics Cooling ◽

Ceramic Materials ◽

Back Side ◽

Dimensional Network ◽

Internal Networks

Heat dissipation has become a major hurdle for the electronics industry, especially as higher performance integrated circuits are being developed for the power industry. Two of the primary hurdles in dissipating this heat are:The thermal contact resistance between the IC and the cooling device.The ability to effectively spread the heat, such that traditional cooling technologies can be effective.By selecting ceramic materials that are thermo-mechanically matched (CTE) to IC materials, the proposed heat plate can be directly bonded by typical solder or braze techniques to the back-side of the IC. This eliminates thermal resistances due to contact and thermal interface materials. Within these heat plates, a three dimensional network of gas channels and fluid wicks spread the high-flux heat loads from localized hot spots to the surrounding regions via phase change fluids and mass transport. Like traditional heat pipes, these heat plates operate at nearly uniform temperature due to the phase change. The internal networks provide for multidimensional heat and mass flow, increasing their dissipating capability. By using matched ceramic materials, and the inclusion of a heat plate, these primary hurdles for heat dissipation can be mitigated. The performance of prototypical planar heat plates will be presented.

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Improvement in Thermal Conductivity of Silicon Nitride Ceramics via Microstructural Control and Their Application to Heat Dissipation Substrates

Journal of the Japan Society of Powder and Powder Metallurgy ◽

10.2497/jjspm.64.439 ◽

2017 ◽

Vol 64 (8) ◽

pp. 439-444

Author(s):

Kiyoshi HIRAO ◽

You ZHOU ◽

Hiroyuki MIYAZAKI ◽

Hideki HYUGA

Keyword(s):

Thermal Conductivity ◽

Silicon Nitride ◽

Heat Dissipation ◽

Nitride Ceramics ◽

Microstructural Control

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Examination of Fracture Interfaces in Silicon Nitride

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100113925 ◽

1975 ◽

Vol 33 ◽

pp. 60-61

Author(s):

Nancy J. Tighe

Keyword(s):

Silicon Nitride ◽

Grain Boundary ◽

Crack Growth ◽

Subcritical Crack Growth ◽

Slow Crack Growth ◽

Ceramic Materials ◽

Grain Boundary Sliding ◽

Boundary Phase ◽

Turbine Engines ◽

Boundary Sliding

Silicon nitride is one of the ceramic materials being considered for the components in gas turbine engines which will be exposed to temperatures of 1000 to 1400°C. Test specimens from hot-pressed billets exhibit flexural strengths of approximately 50 MN/m2 at 1000°C. However, the strength degrades rapidly to less than 20 MN/m2 at 1400°C. The strength degradition is attributed to subcritical crack growth phenomena evidenced by a stress rate dependence of the flexural strength and the stress intensity factor. This phenomena is termed slow crack growth and is associated with the onset of plastic deformation at the crack tip. Lange attributed the subcritical crack growth tb a glassy silicate grain boundary phase which decreased in viscosity with increased temperature and permitted a form of grain boundary sliding to occur.

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Ceramic Materials. Effects of Fracture Origin and Microstructure on Bending Strength of High-Strength Si3N4.

Journal of the Society of Materials Science Japan ◽

10.2472/jsms.43.599 ◽

1994 ◽

Vol 43 (489) ◽

pp. 599-605 ◽

Cited By ~ 1

Author(s):

Akira YAMAKAWA ◽

Takehisa YAMAMOTO ◽

Tomoyuki AWAZU ◽

Kenji MATSUNUMA ◽

Takao NISHIOKA

Keyword(s):

Bending Strength ◽

High Strength ◽

Ceramic Materials ◽

Fracture Origin

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Effective thermal conductivity of open-pore metal foams as a function of the base material

Materials Testing ◽

10.3139/120.110784 ◽

2015 ◽

Vol 57 (10) ◽

pp. 825-836 ◽

Cited By ~ 5

Author(s):

Alexander Martin Matz ◽

Bettina Stefanie Mocker ◽

Norbert Jost ◽

Peter Krug

Keyword(s):

Thermal Conductivity ◽

Effective Thermal Conductivity ◽

Base Material ◽

Metal Foams

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Layer thickness optimization of ceramic composite for body armor by considering volume, weight, and cost

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211015791 ◽

2021 ◽

pp. 095440622110157

Author(s):

Yuksel Palaci ◽

Mustafa M Arikan

Keyword(s):

Silicon Nitride ◽

Boron Carbide ◽

Layer Thickness ◽

Ceramic Composite ◽

Material Selection ◽

Composite Layer ◽

Ceramic Materials ◽

Ternary Diagram ◽

Body Armor ◽

Volume Weight

This study investigates visualization of optimized layer thickness with a ternary diagram by considering Volume, Weight, and Cost priorities to determine the composite structure of alternative ceramics to use in body armor application by using the Digital Logic Method (DLM). Three criterion priorities (volume, weight, cost) have been investigated to help designers decide on optimum ceramic material for their applications. Alumina (Al2O3), silicon carbide (SiC), silicon nitride (Si3N4), and boron carbide (B4C) were analyzed and ranked to decide for material selection based on priorities. The analysis results showed that silicon nitride (Si3N4) had the maximum performance index (PI) point (80.0) based on the volume priority. On the other hand, while boron carbide (B4C) had the maximum PI point (76.4) in terms of the weight priority, alumina (Al2O3) was determined to be the best material according to the cost priority. PI point of alumina (Al2O3) was calculated as 100. A ternary diagram was developed for decision-makers to visualize material selection performances. The optimization of the ceramic composite layer thickness of the alternative ceramic materials is visualized by considering three criteria.

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Design of Thermal Insulation Materials with Different Geometries of Channels

Polymers ◽

10.3390/polym13132217 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2217

Author(s):

Daniela Șova ◽

Mariana Domnica Stanciu ◽

Sergiu Valeriu Georgescu

Keyword(s):

Thermal Conductivity ◽

Porous Structure ◽

Base Material ◽

Cost Effective ◽

Heat Radiation ◽

Average Temperature ◽

Temperature Regimes ◽

The Face ◽

Inclined Channels ◽

Air Channels

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.

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Thermal, Physical and Mechanical Performance of Orange Peel Boards: A New Recycled Material for Building Application

Sustainability ◽

10.3390/su13147945 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7945

Author(s):

Matteo Vitale ◽

María del Mar Barbero-Barrera ◽

Santi Maria Cascone

Keyword(s):

Thermal Conductivity ◽

Bending Strength ◽

Mechanical Performance ◽

Orange Peel ◽

Insulation Material ◽

Orange Peels ◽

Orange Fruit ◽

Citrus Waste ◽

Absorption Thickness ◽

Loss Of Strength

More than 124 million tons of oranges are consumed in the world annually. Transformation of orange fruit generates a huge quantity of waste, largely composed of peels. Some attempts to reuse by-products derived from citrus waste have been proposed for energy production, nutrient source or pharmaceutical, food and cosmetic industries. However, their use in the building sector had not been researched. In this study, orange peels, in five different ratios, from 100% of wet peels to 75% and from 0% of dry peels to 25%, were submitted to a thermo-compression procedure. They were evaluated according to their physical (bulk density, water absorption, thickness swelling, surface soundness and thermal conductivity) and mechanical properties (bending strength and modulus of elasticity). The results showed that orange peels can be used as thermal insulation material. The addition of dried peels makes the structure of the board heterogeneous and thus increases its porosity and causes the loss of strength. Hence, the board with the sole use of wet peel, whose thermal conductivity is 0.065 W/mK while flexural strength is 0.09 MPa, is recommended.

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Improvement of thermal conductivity of rigid polyurethane foams with aluminum nitride filler

Cellular Polymers ◽

10.1177/0262489321988970 ◽

2021 ◽

pp. 026248932198897

Author(s):

Serife Akkoyun ◽

Meral Akkoyun

Keyword(s):

Thermal Conductivity ◽

Aluminum Nitride ◽

Polyurethane Foams ◽

Thermal Transitions ◽

Rigid Polyurethane Foams ◽

Noticeable Increase ◽

Polyurethane Composite ◽

Composite Foams ◽

Step Procedure ◽

Electrical Conductivities

The aim of this work is the fabrication of electrically insulating composite rigid polyurethane foams with improved thermal conductivity. Therefore, this study is focused on the effect of aluminum nitride (AlN) on the thermal and electrical conductivities of rigid polyurethane foams. For this purpose, aluminum nitride/rigid polyurethane composite foams were prepared using a three-step procedure. The electrical and thermal conductivities of the foams were characterized. The thermal transitions, mechanical properties and morphology of the foams were also examined. The results reveal that AlN induces an increase of the thermal conductivity of rigid polyurethane foam of 24% which seems to be a relatively noticeable increase in polymeric foams. The low electrical conductivity of the foams is preserved.

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