National Central University

Industrial Technology Research Institute

Jyh-Chen Chen

Gwo-Jiun Sheu

Yeeu-Chang Lee

Farn-Shiun Hwu

Ming-Te Lin

Kuang-Yu Tai

Cheng-Wei Chien

Shen-Hang Tu

Ying-Yang Teng

Chang-Hung Chiang

Jenq Yang Chang

Chung-Wei Lu

Bing-Jung Chen

Hsueh-I Chen

The present invention relates to a gas flow guiding device for use in a crystal-growing furnace. The gas flow guiding device has an insulation layer enclosing a crucible, a gas inlet mounted in the upper insulation layer, and a gas exit formed in the lateral insulation layer. A plurality of guide plates are radially arranged around the opening of the gas inlet, so that the free surface of the melt is blown by the guided gas flow in such a manner that the gas flow takes the impurity away from the free surface efficiently. As a result, the crystal ingot obtained by solidifying the melt will exhibit a reduced concentration of impurities and an improved crystal quality.

Gas flow guiding device for use in crystal-growing furnace

The present invention provides a method for measuring the PN-junction temperature of a light-emitting diode (LED), which uses a reference voltage to establish the function of current, real power, power factor, or driving-time interval on temperature. The initial and thermal-equilibrium values of current, real power, power factor, or driving-time interval are measured, and hence the variations thereof are calculated. Referring to the pre-established function, the temperature change is given. By the temperature change and the initial temperature, the PN-junction temperature of the LED is thereby deduced.

Method for measuring PN-junction temperature of light-emitting diode (LED)

Providing a fabrication method of a periodic domain inversion structure. A nonlinear optical ferroelectric material substrate is provided. A photoresist layer is formed on the upper and the lower surface of the substrate, and periodic gratings formed by interference of two laser beams are employed to expose the photoresist layer on the upper surface. Meanwhile, the two laser beams pass through the substrate, so the periodic gratings are used to expose the photoresist layer on the lower surface. A development process is performed to form a periodic photoresist pattern on the two surfaces of the substrate. A conductive layer is formed above the substrate for covering the photoresist pattern and the surface of the exposed substrate. The photoresist pattern and a portion of the conductive layer thereon are removed by lift-off. A voltage is applied to the substrate via the remaining conductive layer to polarize parts of the substrate.

Method of fabricating periodic domain inversion structure

An mold having a sub-micron, or even nano, structure is fabricated. The mold is a porous aluminum oxide mold. With the mold, a sub-micron pattern is easily imprinted on a large surface of a substrate or a LED. No expensive equipment is necessary. The fabricating process is fast and cheap and thus meets the needs of producers.

Method of fabricating porous aluminum oxide mold having sub-micron structure and methods of imprinting to make LEDS using the mold

A heat shield and a crystal growth equipment are provided, in which the length-adjustable and hybrid-angle heat shield is provided for the crystal growth equipments. The heat shield is adapted for not only guiding the inert gas flow but also speeding up the flow rate of the gas and the cooling rate of the crystal so as to raise the axial temperature gradient at the solid-molten interface, the growth rate of the crystal and the productivity. The heat shield further can also reduce the possibility of microdefect nucleation to improve the quality of crystal at the same time. In addition, the length of heat shield can be adjusted according to the distance between the heat shield and the semiconductor material melt in different crucibles in case that the crucibles are made by different factories. This can reduce the cost of the heat shield manufacturing.

Heat shield and crystal growth equipment

A method of producing lithium aluminosilicate (LAS) ceramics, which uses a mixing powder of lithium carbonate, aluminum oxide, and silicon oxide as a raw material powder. After being mixed by ball milling and baked dry, the raw material powder is processed with a calcinations process such that the raw material powder becomes a precursor. The precursor is then pressed into the green ceramic. Significantly, the high heat conducting metal sheets are tightly attached above and below the surfaces of the ceramic during sinter and heat-treatment processes. A solid-state sinter process is performed with the green ceramic. Next, the ceramic is treated with a proper heat-treatment process. Since the top and bottom surfaces of the ceramic are capped with the high heat conducting metal, the ceramics are uniformly heated during all the heating processes. The ceramics of this invention exhibit more uniform properties and stable structure, which allow them to be used as temperature compensation components and athermal products.

Growing community of inventors

Taoyuan, Taiwan

Jyh-Chen Chen