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Patent Issued for Method of Manufacturing Semiconductor Light Emitting Device

July 2, 2014



By a News Reporter-Staff News Editor at Journal of Engineering -- A patent by the inventors Tsutsui, Tsuyoshi (Gyeonggi-do, KR); Kim, Shin Kun (Gyeonggi-do, KR); Hong, Seong Jae (Gyeonggi-do, KR); Park, Il Woo (Gyeonggi-do, KR), filed on July 3, 2012, was published online on June 17, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8753908 is assigned to Samsung Electronics Co., Ltd. (Suwon-Si, Gyeonggi-Do, KR).

The following quote was obtained by the news editors from the background information supplied by the inventors: "The present invention relates to a method of manufacturing a semiconductor light emitting device and a paste application apparatus used for the same.

"In general, a light emitting diode is a device used in transmitting a signal formed by converting electrical energy into light, such as infrared light or light within the visible spectrum, by using the characteristics of a compound semiconductor. A light emitting diode utilizes electroluminescence (EL), and currently, a light emitting diode using a group III-.quadrature. compound semiconductor has been practically used. A group III nitride compound semiconductor, a direct transition type semiconductor, may be more stably operated in high temperature conditions than a device using other semiconductors, and thus has been widely used in a light emitting device, such as a light emitting diode (LED), a laser diode (LD) or the like.

"The respective chips configuring the light emitting device maybe formed by growing a semiconductor layer on a single wafer and then separating the wafer into unit chips through a cutting process. A process of forming a fluorescent layer including fluorescent substance particles for wavelength conversion on an upper surface of each separated unit chip is separately undertaken. In this case, the process of forming a fluorescent layer on an upper surface of each unit chip may be performed through screen printing, compression molding, spin coating, spray coating, a deposition operation, or the like. Precision in the process of forming a fluorescent layer may significantly affect light uniformity of a semiconductor light emitting device."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventors' summary information for this patent: "An aspect of the present invention provides a method of manufacturing a semiconductor light emitting device having improved chromaticity and light uniformity.

"An aspect of the present invention also provides a method of manufacturing a semiconductor light emitting device having improved processing efficiency.

"An aspect of the present invention also provides a paste application apparatus capable of manufacturing the semiconductor light emitting device having improved chromaticity and light uniformity.

"According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor light emitting device, the method including: preparing a light emitting structure including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; disposing a mask including an opening exposing a part of the light emitting structure on the light emitting structure; applying a paste including a wavelength conversion material to the light emitting structure through the opening of the mask, by using a pressure means; and planarizing the applied paste by using a roller.

"In the applying of the paste, the pressure means may be a squeegee pushing the paste horizontally.

"In the applying of the paste and the planarizing of the applied paste, the pressure means and the roller may move horizontally on the light emitting structure in opposite directions.

"The roller may include prominences and depressions formed on a surface thereof, and in the planarizing of the applied paste, prominences and depressions may be formed on a surface of the applied paste by the prominences and depressions formed on the surface of the roller.

"The prominences and depressions formed on the surface of the roller may have a size of several nanometers (nm) to several micrometers (.mu.m).

"A radius r of the roller may satisfy

".gtoreq..times..pi. ##EQU00001## provided that a radius of the roller is r and a maximum width of an upper surface of the light emitting structure to which the paste is applied is 1.

"The opening may be provided in plural, and unit device areas formed by a separation of the light emitting structure may be exposed through the plurality of openings.

"The applying of the paste may be performed by a screen printing method.

"The method may further include forming the light emitting structure by sequentially stacking the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer on a wafer.

"The method may further include separating the light emitting structure into unit devices to generate a plurality of light emitting devices.

"In this case, the separating of the light emitting structure into unit devices to generate a plurality of light emitting devices, may be performed before the applying of the paste or after the applying of the paste.

"The paste maybe exposed through sides of the plurality of light emitting devices generated by separating the light emitting structure into unit devices.

"The paste may include at least one of fluorescent substance particles and quantum dots.

"According to another aspect of the present invention, there is provided a paste application apparatus, including: a supporting means having a light emitting structure disposed on an upper surface thereof; a movement means disposed above the supporting means to be spaced apart therefrom and moving horizontally on the light emitting structure; a pressure means connected to the movement means and pushing a paste applied to the light emitting structure horizontally; and a roller connected to the movement means and rotatably-moving horizontally to thereby planarize the paste applied to the light emitting structure.

"The pressure means and the roller may be positioned at different heights from the light emitting structure when the pressure means and the roller move horizontally by the movement means.

"The roller may include prominences and depressions formed on a surface thereof. In this case, the prominences and depressions formed on the surface of the roller may have a size of several nanometers (nm) to several micrometers (.mu.m).

"A radius r of the roller may satisfy

".gtoreq..times..pi. ##EQU00002## provided that a radius of the roller is r and a maximum width of an upper surface of the light emitting structure to which the paste is applied is 1.

"The paste application apparatus may further include a paste supplying means provided under the movement means.

"The paste application apparatus may further include a mask disposed on the light emitting structure and including an opening defining a paste application area.

"The pressure means may be a squeegee pushing the paste horizontally."

URL and more information on this patent, see: Tsutsui, Tsuyoshi; Kim, Shin Kun; Hong, Seong Jae; Park, Il Woo. Method of Manufacturing Semiconductor Light Emitting Device. U.S. Patent Number 8753908, filed July 3, 2012, and published online on June 17, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8753908.PN.&OS=PN/8753908RS=PN/8753908

Keywords for this news article include: Semiconductor, Light-emitting Diode, Samsung Electronics Co. Ltd..

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Source: Journal of Engineering


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