• Journal of the Korean Ceramic Society
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• v.40 no.9
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• pp.832-836
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• 2003

Multi-layer ceramic composites were prepared by tape casting followed by hot pressing using silicon nitride layer with silicon nitride whiskers, silicon nitride layer with silicon carbide particles and boron nitride-alumina layer. The whiskers were aligned during the casting. As the whisker content of the silicon nitride layer was increased up to 10 wt％, the flexural strength of the multi-layer composite was increased. However, further increase of the whisker content in the layer resulted in a rapid decrease of the strength of the composite. The results suggest that the strength of multi-layer ceramic composite showing non-catastrophic failure behavior can be significantly improved by incorporating the aligned whiskers in the layers.

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.901-908
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• 1995

In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder used as polymeric processing additives on the silicon nitride particle surface was studied to identify the effect of these processing polymeric additives on the ceramic powder processing. The adsoprtion isotherm study of anionic organic molecule as dispersant and nonionic organic molecules as binder of silicon nitricde was studied to investigate the effect of these processing organic additives on the physicochemical properties of silicon nitride particles. As anionic molecule adsorbed onto silicon nitrice surface, the IEP of silicon nitride shifted toward acidic pH and changed the stability of silicon nitride particle. However, the adsorption of binder as nonionic organic molecule onto silicon nitride surface did not changed the IEP but caused the decrease of electrostatic potentials of silicon nitride. These distinctive adsorption behaviors of organic additives on silicon nitride particles can be closely correlated to the stability of silicon nitride particles suspended in aqueous media.

• Tribology and Lubricants
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• v.11 no.5
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• pp.20-25
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• 1995

Diamond films were prepared by a hot filament vapor deposition onto polycrystal silicon nitride substrates. Different kinds of silicon nitride containing CaO and $Fe_{2}O_{3}$ were manufactured to investigate the impurity effect of substrate on the morphology of diamond films and their wear behaviors. Nucleation rates and morphologies of diamond films deposited on various kinds of silicon nitride were compared. The highest nucleation rate was observed in a substrate containing 1% of CaO. Wear tests were performed with a silicon nitride ball on the disk geometry to investigate the tribological behavior of diamond film against silicon nitride. This study demonstrated that different morphologies of diamond film due to substrate impurities produced different wear behavior against silicon nitride.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06b
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• pp.129-153
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• 1996

In aqueous slurry processing of silicon nitride, the interaction of dispersant and binder on the surface of particles was studied to identify the effect of these additives on ceramic powder processing. Polymethacrylic acid (PMAA) and polyvinyl alcohol (PVA) were used as dispersant and binder, respectively. the adsorption isotherms of PMAA and PVA for the silicon nitride suspension were determined, while the adsorption of PMAA was differentiated in the mixed additive system by ultraviolet spectroscopy. These experiments were done in order to investigate the effect of these organic additives on the physicochemical properties of silicon nitride suspensions. The electrokinetic behavior of silicon nitride was subsequently measured by electrokinetic sonic amplitude (ESA). As PMAA adsorbed onto silicon nitride, the isoelectric point (pHicp) shifted from pH=6.7 to acidic pH, depending on the surface coverage of PMAA. However, adsorption of PVA did not change the pHicp of suspensions, but did decrease the surface potential of silicon nitride moderately. The rheological behavior of silicon nitride suspensions was measured to assess the stability of particles in aqueous media, and was correlated with the electrokinetic behavior and adsorption isotherm data for silicon nitride.

• Transactions on Electrical and Electronic Materials
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• v.9 no.6
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• pp.231-236
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• 2008

B, P, and Cs ions were implanted with various parameters into silicon nitride layers prepared by LPCVD. In order to get the maximum impurity concentration at the silicon nitride surface, a high temperature oxide (HTO) buffer layers was deposited prior to the implantation. Alkali ion and pH sensing properties of the layers were investigated with an electrolyte-insulator-silicon (EIS) structure using high frequency capacitance-voltage (HF-CV) measurements. The ion sensing properties of implanted silicon nitrides were compared to those of as-deposited silicon nitride. Band Cs co-implanted silicon nitrides showed a pronounced difference in pH and alkali ion sensing properties compared to those of as-deposited silicon nitride. B or P implanted silicon nitrides in contrast showed similar ion sensitivities like those of as-deposited silicon nitride.

• 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.35 no.2
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• pp.115-122
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• 1998

The effect of sintering conditions on the sinterability for silicon nitride has been studied by many in-vestigators. However the effect of sintering conditions on the machinability which is the major barrier to the field applications of the ceramic components has not been fully studied. In this study the sintering con-ditions such as temperature gas pressure and time in silicon nitride were varied. The physical and mechan-ical properties of the gas pressure sintered (GPS) silicon nitride were measured. The optimum mi-crostructure of silicon nitride with the excellent machinability was investigated by MFG(magnetic-fluid grinding) technique. An attempt was made to figure out how the mechanical properties influence upon the machinability of silicon nitride ball.

• Journal of Welding and Joining
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• v.20 no.3
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• pp.116-121
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• 2002

For the accumulation of a fundamental knowledge about the behavior of glass solder during the joining of ceramics, the wettability of solder on silicon nitride have been measured by sessile drop method. $SiO_2-MgO-Al_2O_3$ g1ass solder and oxynitride glass solders were selected as examples while silicon nitride which were used as substrates. Contact angle of solder on silicon nitride didn't decrease with time at high nitrogen content in the solder, but low nitrogen content in solders have the time-dependent property. Reason which contact angle of low nitrogen content in solders decrease on silicon nitride was that diffusion of nitrogen take place between solder and silicon nitride.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.56.1-56.1
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• 2010

결정질 실리콘 태양전지의 표면 ARC(Anti-reflection Coating)layer는 반사도를 줄여 광 흡수율을 증가시키고, passivation 효과를 통하여 표면 재결합을 감소 시켜 태양전지의 효율을 높이는 중요한 역할을 한다. Silicon nitride 박막은 외부 stress 요인에 대해 안정성을 담보할 수 있어야한다. 따라서, 본 연구에서는 굴절률 가변에 따른 silicon nitride 박막을 PECVD를 이용하여 증착하고, 항온/항습 stability test를 통해 박막의 안정성을 확인하였다. Silicon nitride 증착을 위해 PECVD를 이용하였고, 공정압력 0.8Torr, 증착온도 $450^{\circ}C$, 증착파워 300W에서 실험을 진행하였다 박막의 굴절률은 1.9~2.3의 범위로 가변하였다. 항온/항습에 대한 신뢰성을 test 하기 위하여 5시간동안의 test를 1cycle로 하여 20회 동안 실험을 실시하였다. 증착된 silicon nitride 박막의 lifetime은 firing 이후 57.8us로 가장 높았으며, 항온/항습 test 이후에도 유사한 경향을 확인 할 수 있었다. 또한, 100h 동안의 항온/항습 test 결과 silicon nitride 박막의 lifetme 감소는 8.5%에 불과했다. 본 연구를 통하여 온도와 습도의 변화에 따른 결정질 실리콘 태양전지의 SiNx 박막의 증착 공정 조건에 대한 신뢰성을 확인 할 수 있었다.

• Journal of Welding and Joining
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• v.28 no.6
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• pp.40-44
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• 2010

Laser assisted machining (LAM) has been researched in order to machine the silicon nitride ceramics economically and effectively. LAM is an effective machining method by local heating of the cutting part to the softening temperature of the silicon nitride using laser beam. When silicon nitride ceramics is heated using a laser beam, the surface of silicon nitride ceramic is softened, oxidized and decomposed. And then surface hardness is decreased. Through machining in low viscosity and hardness conditions, silicon nitride was machined effectively and the life span of tool was increased. The plastic deformation was occurred due to softening of amorphous YSiAlON above $ 1,000^{\circ}C$. Transgranular fracture of ${\beta}-Si_3N_4$ was occurred when YSiAlON was not softened, but mostly intergranular fracture was occurred by the plastic deformation of softened YSiAlON.