• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.149-153
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• 2019

The technology of electronic packaging among semiconductor technologies is evolving as an axis of the market in its own field beyond the simple assembly process of the past. In the field of electronic packaging technology, the packaging of power modules plays an important role for green electric vehicles. In this power module packaging, the thermal reliability is an important factor, and silicon nitride plays an important part of package substrates, Silicon nitride is a compound that is not found in nature and is made by chemical reaction between silicon and nitrogen. In this study, this core material, silicon nitride, was fabricated by reaction bonded silicon nitride. The fabricated silicon nitride was studied for thermo-mechanical properties, and through this, the structure of power module packaging was made using reaction bonded silicon nitride. And the characteristics of stress were evaluated using finite element analysis conditions. Through this, it was confirmed that reaction bonded silicon nitride could replace the silicon nitride as a package substrate.

• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.67-74
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• 1986

To investigate the effects of unreacted silicon on the $\alpha$/$\beta$transfornation variation of morphology and mechanical strength of Sintered Reaction Bonded Silicon Nitride the mixtures of $\alpha$-$Si_3N_4$ and Si powder and Reaction Bonded Silicon Nitride were heat treated. The heat-treatments were performed in Ar atmosphere in order to inhibit the nitridation of silicon. In the mixtures heat-trated at 1$700^{\circ}C$ the amount of $\beta$-TEX>$Si_3N_4$transformed from $\alpha$-TEX>$Si_3N_4$was sigmoidally increased and the equiaxed $\alpha$-TEX>$Si_3N_4$grains elongated with the amount of silicon and heat treating time. And large $\beta$-TEX>$Si_3N_4$grains grown into silicon were observed. On the other hand there was no change in the heat-treatment of pure $\alpha$-TEX>$Si_3N_4$In case of the heat-treatment of RBSN the same phenomena due to the silicon appearing from the decomposition of $\alpha$-Smatte and needle were observed. From the three point bending test the strength of the sintered specimens with the and without 5wt% silicon addition had 53Kg/$mm^2$ and 73Kg/$mm^2$ respectively.

• Journal of the Korean Ceramic Society
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• v.21 no.1
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• pp.51-59
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• 1984

In this paper mechanical properties of reaction-bonded silicon nitride are studied with the variation of initial nitrogen partial pressure. At 1, 25$0^{\circ}C$ the amount of nitridation and the nucleation of nitride increase linearly with the nitrogen partial pressure increase. After the nitridation is completed the density of nitride and modulus of rupture at room temperature are increased with the amount of nitridation. When the partial pressure of nitrogen is 0.5 atm the specimen show the optimum properties that is the highest density of nitride and modulus of rupture. Also the microstructure of $\alpha$-matte is deveoped very well at that pressure of nitrogen which contributes to the strength development of specimen. It is shown that with proper control of initial partial pressure of nitrogen high strength silicon nitride body can be manufactured for dynamic applications.

• Journal of the Korean Ceramic Society
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• v.22 no.1
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• pp.53-59
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• 1985

Experiments related to nitriding silicon with addition of $Si_3N_4$ have provided information on the effects of such inclusion on the phase relationships of Reaction Bonded Silicon Nitride. In the current work specimens containing 0-25wt% Si3N4 which have 55.5wt% $\alpha$ 4.5wt% $eta$, 40wt% amorphous phase were nitrided for 7-20 hours at 1300-135$0^{\circ}C$ The evaluation of nitridation was per-formed by means of $\alpha$-and $\beta$-phase contents determination in nitrided specimens, In order to observe nitrided region between silicon and silicon nitride scanning electron microscopy was used to study reacted region between silicon and silicon nitride particle. For this purpose semiconductor-grade silicon wafer single crystal was used as a silicon source. The incorporation of small amount of $Si_3N_4$ powder is contributed to enhancing the rate of formation of $\alpha$-phase.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.435-440
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• 2015

It is a challenge from an industrial point of view to fabricate silicon nitride substrates with high thermal conductivity and good mechanical properties for power devices from high-purity Si scrap powder by means of thick film processes such as tape casting. We characterize the residual carbon and oxygen content after the binder burnout followed by nitridation as a function of the temperature in the temperature range of $300^{\circ}C-700^{\circ}C$ and the atmosphere in a green tape sample which consists of high-purity Si powder and polymer binders such as polyvinyl butyral and dioctyl phthalate. The optimum condition of binder burnout is suggested in terms of the binder removal temperature and atmosphere. If considering nitridation, the burnout of the organic binder in air compared to that in a nitrogen atmosphere could offer an advantage when fabricating reaction-bonded $Si_3N_4$ substrates for power devices to enable low carbon and oxygen contents in green tape samples.

• Journal of the Korean Ceramic Society
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• v.39 no.1
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• pp.45-50
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• 2002

Effect of sintering additives on the densification behavior of reaction-bonded silicon nitride prepared by using coarse Si powders is discussed. Sintering additives such as 6 wt% $Y_2O_3$+1wt% $A1_2O_3$ (6YlA) did not give rise to full densification, while full densification was obtained by using the sintering additives such as 6wt% $Y_2O_3$+3 wt% $A1_2O_3$+ 2wt% $SiO_2$ (6Y3A2S) and 9wt% $Y_2O_3$+ 1.5wt% $A1_2O_3$+ 3wt% $SiO_2$ (9Yl.5A3S). In the case of 6Y3A2S addition, high fracture strength of 960 MPa and the fracture toughness of $6.5 MPa.m^{1/2}$ were obtained.

• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.218-225
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• 2013

The densification behavior and strength of sintered reaction bonded silicon nitrides (SRBSN) that contain $Lu_2O_3-SiO_2$ additives were improved by the addition of fine Si powder. Dense specimens (relative density: 99.5%) were obtained by gas-pressure sintering (GPS) at $1850^{\circ}C$ through the addition of fine Si. In contrast, the densification of conventional specimens did not complete at $1950^{\circ}C$. The fine Si decreased the onset temperature of shrinkage and increased the shrinkage rate because the additive helped the compaction of green bodies and induced the formation of fine $Si_3N_4$ particles after nitridation and sintering at and above $1600^{\circ}C$. The amount of residual $SiO_2$ within the specimens was not strongly affected by adding fine Si powder because most of the $SiO_2$ layer that had formed on the fine Si particles decomposed during nitridation. The maximum strength and fracture toughness of the specimens were 991 MPa and $8.0MPa{\cdot}m^{1/2}$, respectively.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.206.2-206
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• 2000

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.62.1-62
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• 2003

• Journal of the Korean Ceramic Society
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• v.37 no.5
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• pp.505-510
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• 2000

In this investigation, we fabricated RBSN (Reaction Bonded Silicon Nitride) using the static nitriding system which could be advantageous for commercialization. Firstly, Si compacts of different sizes were made, and then nitridation rates were investigated as a function of added static gas pressure. The reaction schedule was obtained by pre-experiments. In case of small samples, the variation of ${\alpha}$, ${\beta}$ phases between the inside and the outside region of the specimens was examined after the samples were nitrided under 1 bar and 1.5 bar reaction pressure. On the other hand, large samples of Si compact with the size of 36 mm for diameter and 23 mm for thickness were nitrided for 26 hours of the total nitridation time, which showed a complete and homogeneous nitriding reaction from the outside to the inside of the samples, although the time was considerably shorter than that needed for convertional nitridation. Nitridation rates obtained at the early stage of reaction were proportional to the reaction gas pressures. The sequences of the nitridation reaction with the thickness were as follows 1) the outside, 2) the inside and 3) the intermediate area of the specimen. These results wer eobtained from the coloration of cross sectioned specimens that had various nitridation rates. Total nitriding reaction kinetics was controlled by chemical reaction, not by diffusion of the nitrogen gas.