摘要:
Disclosed are a silicon-containing compound, a liquid crystal composition comprising the same compound, and a liquid crystal display device comprising a liquid crystal layer prepared from the liquid crystal composition. The silicon-containing compound, which forms the liquid crystal composition, has low viscosity and high positive dielectric anisotropy. Therefore, it is possible to provide a liquid crystal display device, which has a fast response time and can be driven at a low voltage.
摘要:
Disclosed are a silicon derivative, a liquid crystal composition comprising the same, and a compensation film for a liquid crystal display device using the same liquid crystal composition. More particularly, the silicon derivative is a liquid crystal material of a high-quality view angle compensation film, which improves a contrast ratio measured at a tilt angle when compared to a contrast ratio measured from the front surface and minimizes color variations in a black state depending on view angles.
摘要:
Disclosed are a vinylsulfone derivative, a liquid crystal composition comprising the same, and a compensation film for a liquid crystal display device using the same liquid crystal composition. More particularly, the vinylsulfone derivative is a liquid crystal material of a high-quality view angle compensation film, which improves a contrast ratio measured at a tilt angle when compared to a contrast ratio measured from the front surface and minimizes color variations in a black state depending on view angles.
摘要:
Disclosed are a silicon-containing compound, a liquid crystal composition comprising the same compound, and a liquid crystal display device comprising a liquid crystal layer prepared from the liquid crystal composition. The silicon-containing compound, which forms the liquid crystal composition, has low viscosity and high negative (−) dielectric anisotropy. Therefore, it is possible to provide a liquid crystal display device, which has a fast response time and can be driven at a low voltage.
摘要:
Described is a radially multi-branched polymer represented by the following formula (I): ABi (I), which includes a central molecule (A) to which side-branches (B) are bonded in at least three positions (i≧3). Also described are methods for preparing a multi-branched polymer as well as a porous insulating film including a multi-branched polymer.
摘要:
Disclosed herein is a polymer-ceramic dielectric composition. The dielectric composition comprises a polymer and a ceramic dispersed in the polymer wherein the ceramic is composed of a material having a perovskite structure represented by ABO3 and a metal oxide dopant and has an electrically charged surface. According to the dielectric composition, the surface of the ceramic is electrically charged to induce space-charge polarization (or interfacial polarization) at the polymer/ceramic interface, resulting in an increase in dielectric constant. Since the dielectric composition has a high dielectric constant particularly in a low-frequency range, it can be suitably used to produce decoupling capacitors. Further disclosed are a capacitor and a printed circuit board that use the dielectric composition.
摘要:
Disclosed herein is a composite dielectric composition having a small variation of capacitance with temperature, comprising a combination of a polymer matrix exhibiting a positive or negative variation of capacitance with temperature and a ceramic filler exhibiting a negative or positive variation of capacitance with temperature which is reciprocal to that of the polymer matrix; and a signal-matching embedded capacitor prepared by using the same composition. Particularly, the present invention provides a composite dielectric composition comprising a polymer matrix exhibiting a positive or negative variation of capacitance with temperature and a ceramic filler exhibiting a variation of capacitance which is reciprocal to that of the polymer matrix; and a signal-matching embedded capacitor formed of the same composition and having a variation of capacitance with temperature, Δ C/C×100(%), of not more than 5%. The composite dielectric composition of the present invention can be used in preparation of the signal-matching embedded capacitor due to a small variation of capacitance with temperature.
摘要:
A method of manufacturing a thin film capacitor includes steps of: performing recrystallization heat treatment on a metal foil; forming a dielectric layer on a top surface of the recrystallized metal foil; heat treating the metal foil and the dielectric layer; and forming an upper electrode on a top surface of the heat-treated dielectric layer. The recrystallization heat treatment prevents the oxidation of a metal foil, by which a dielectric layer can be heat treated at a high temperature, thereby improving electric properties of a thin film capacitor and the reliability of a product.
摘要:
Disclosed herein is a resin composition and ceramic/polymer composite for dielectric layers of embedded capacitors having a high dielectric constant, a dielectric layer of a capacitor manufactured therefrom, and a printed circuit board including the dielectric layer. In addition, a method of increasing temperature stability and a dielectric constant of the ceramic/polymer composite for dielectric layers of embedded capacitors is also provided. The resin composition for embedded capacitors includes 5-30 wt % of at least one resin selected from the group consisting of bisphenol-A epoxy resins, bisphenol-F epoxy resins and combinations thereof, 60-85 wt % of at least one resin selected from the group consisting of novolac-type epoxy resins, polyimides, cyanate esters and combinations thereof, and 10-30 wt % of a multi-functional epoxy resin, and the ceramic/polymer composite includes such a resin composition. Further, the dielectric layer of a capacitor formed of the ceramic/polymer composite of the current invention is provided along with the printed circuit board including the dielectric layer.
摘要:
A cerium oxide powder for one-component CMP slurry, which has a specific surface area of 5 m2/g or more, and a ratio of volume fraction of pores with a diameter of 3 nm or more to that of pores with a diameter less than 3 nm of 8:2˜2:8. A method for preparing the same, a one-component CMP slurry comprising the same as an abrasive material, and a method of shallow trench isolation using the one-component CMP slurry are also disclosed. The CMP slurry causes no precipitation of the cerium oxide powder even if it is provided as a one-component CMP slurry, because the CMP slurry uses, as an abrasive material, cerium oxide powder that is obtained via a low-temperature calcination step, optionally a pulverization step, and a high-temperature calcination step and has a high pore fraction and low strength.