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Researchers Submit Patent Application, "Light Emitting Diode Chip Having Wavelength Converting Layer and Method of Fabricating the Same, and Package...

June 25, 2014



Researchers Submit Patent Application, "Light Emitting Diode Chip Having Wavelength Converting Layer and Method of Fabricating the Same, and Package Having the Light Emitting Diode Chip and Method of

By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors JUNG, Jung Hwa (Ansan-si, KR); KIM, Bang Hyun (Ansan-si, KR), filed on February 5, 2014, was made available online on June 12, 2014.

The patent's assignee is Seoul Semiconductor Co., Ltd.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention relates to a light emitting diode (LED) chip and a method of fabricating the same, and a package having the LED chip and a method of fabricating the same, and more particularly, to an LED chip having a wavelength converting layer and a method of fabricating the same, and a package having the LED chip and a method of fabricating the same.

"LEDs are currently used as backlight sources in various types of display devices including cellular phones and the like. LEDs may be light, thin, and small, and may have energy-saving and long-lifespan characteristics. Since light emitting devices having LEDs mounted therein, i.e., LED packages, may implement white light with a high color rendering property, LED packages may be used for general illumination while substituting for white light sources such as fluorescent lamps.

"Meanwhile, there are a variety of methods for implementing white light using LEDs, and a method may be used, in which white light is implemented through the combination of an InGaN LED to emit blue light of 430 nm to 470 nm and a phosphor to covert the blue light into light of a longer wavelength. For example, white light may be implemented through the combination of a blue LED and a yellow phosphor to be excited by the blue LED, the yellow phosphor to emit yellow light or through the combination of a blue LED, a green phosphor and a red phosphor.

"A white light emitting device may be formed by applying a resin containing a phosphor in a recess region of a package having an LED mounted therein. However, as the resin is applied in the package, the phosphor may not be uniformly distributed in the resin, and it may be difficult to form the resin having a uniform thickness.

"Accordingly, a method of attaching a wavelength converting sheet onto an LED has been researched. For example, the wavelength converting sheet may be formed by mixing a phosphor into glass or the like. The wavelength converting sheet may be attached on a top surface of the LED, so that white light can be implemented at a chip level.

"However, since the wavelength converting sheet is attached on the top surface of the LED, it may be limited to implement white light in an LED in which light is configured to be mostly emitted through the top surface of the LED. Further, the wavelength conversion using the wavelength converting sheet may not be suitable in an LED in which a considerable amount of light is configured to be emitted through side surfaces of the LED, e.g., to side surfaces of a growth substrate.

"Meanwhile, when a resin containing a phosphor is applied in a package, a wire may be bonded to an LED, and the resin is then applied thereto. Hence, it may not matter even if an electrode of the LED is covered with the resin containing the phosphor. However, when a wavelength converting layer is formed at the chip level, it may be necessary to bond the wire to the LED after the wavelength converting layer is formed."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "Exemplary embodiments of the present invention provide a light emitting diode (LED) chip and a method of fabricating the same capable of performing light conversion such as wavelength conversion at a chip level.

"Exemplary embodiments of the present invention also provide an LED chip and a method of fabricating the same capable of performing wavelength conversion with respect to light emitted through side surfaces of a substrate.

"Exemplary embodiments of the present invention also provide an LED chip and a method of fabricating the same capable of performing light conversion such as wavelength conversion and performing wire bonding.

"Exemplary embodiments of the present invention provide an LED chip capable of preventing light converted in a wavelength converting layer from being incident into the LED chip.

"Exemplary embodiments of the present invention provide an LED chip capable of preventing a wavelength converting layer from being damaged by light.

"Additional features of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.

"An exemplary embodiment of the present invention discloses an LED chip including a substrate, a GaN-based compound semiconductor stacked structure arranged on the substrate, an electrode electrically connected to the semiconductor stacked structure, and a wavelength converting layer covering an upper portion of the semiconductor stacked structure. In the LED chip, the additional electrode passes through the wavelength converting layer. The semiconductor stacked structure including a first conductivity-type semiconductor layer, an active layer and a second conductivity-type semiconductor layer.

"An exemplary embodiment of the present invention also discloses an LED chip including a substrate, a plurality of semiconductor stacked structures arranged on the substrate, a first electrode electrically connected to a first semiconductor stacked structure, a second electrode electrically connected to a second semiconductor stacked structure, and a wavelength converting layer covering a portion of each of the plurality of semiconductor stacked structures. In the LED chip, the first electrode and the second electrode pass through the wavelength converting layer. The plurality of semiconductor stacked structures each includes a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer.

"An exemplary embodiment of the present invention also discloses an LED package including a lead terminal, an LED chip as described above, and a bonding wire connecting the lead terminal and the LED chip. In the LED chip, the bonding wire connects the electrode and the lead terminal.

"An exemplary embodiment of the present invention also discloses a method of fabricating an LED chip, the method including arranging a plurality of bare chips on a support substrate, wherein each of the bare chips includes a substrate, a GaN-based compound semiconductor stacked structure positioned on the substrate, and an electrode electrically connected to the semiconductor stacked structure, forming a transparent coating layer covering the plurality of bare chips and the electrodes on the support substrate, removing a portion of the transparent coating layer to expose the electrodes, removing the support substrate, and separating the plurality of bare chips into individual LED chips. The semiconductor stacked structure includes a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer.

"An exemplary embodiment of the present invention also discloses an LED package including a submount substrate, a bare chip mounted on the submount substrate, the bare chip including a first conductivity-type semiconductor layer, an active layer, a second conductivity-type semiconductor layer, a first electrode electrically connected to the first conductivity-type semiconductor layer, and a second electrode electrically connected to the second conductivity-type semiconductor layer, the bare chip having at least one of the first electrode and the second electrode arranged on a top surface thereof, and a wavelength converting layer exposing the at least one of the first electrode and the second electrode, the wavelength converting layer covering a top surface and side surfaces of the bare chip, and covering at least a portion of a top surface of the submount substrate.

"An exemplary embodiment of the present invention also discloses a method of fabricating an LED package, the method including mounting a plurality of bare chips on a substrate, each of the plurality of bare chips including a first conductivity-type semiconductor layer, an active layer, and a second conductivity-type semiconductor layer, forming a first electrode electrically connected to the first conductivity-type semiconductor layer and forming a second electrode electrically connected to the second conductivity-type semiconductor layer, and forming a wavelength converting layer exposing at least one of the first electrode and the second electrode, the wavelength converting layer covering a top surface and side surfaces of each of the bare chips, and covering at least a portion of a top surface of the substrate.

"It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

"The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

"FIG. 1 is a sectional view illustrating a light emitting diode (LED) chip according to an exemplary embodiment of the present invention.

"FIG. 2 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 3 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 4 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 5 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 6 is a sectional view illustrating an LED chip according to a an exemplary embodiment of the present invention.

"FIG. 7 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 8 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 9 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 10 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 11 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 12 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 13 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 14 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 15 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 16 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 17 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 18 is a sectional view illustrating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 19 is a sectional view illustrating an LED package having an LED chip mounted therein according to an exemplary embodiment of the present invention.

"FIG. 20 shows sectional views illustrating a method of fabricating an LED chip according to an exemplary embodiment of the present invention.

"FIG. 21 is a top plan view illustrating an LED according to an exemplary embodiment of the present invention.

"FIG. 22 is a sectional view of the LED taken along line C-C' of FIG. 21.

"FIG. 23 is a view showing a submount substrate having a plurality of LEDs formed thereon according to an exemplary embodiment of the present invention.

"FIG. 24 is an enlarged view of a region indicated by a circle in FIG. 23.

"FIG. 25 is a flowchart illustrating a method of fabricating an LED package according to an exemplary embodiment of the present invention.

"FIG. 26 shows sectional views sequentially illustrating processes of fabricating the LED package according to an exemplary embodiment of the present invention.

"FIG. 27 is a sectional view illustrating the LED package having the LED mounted therein according to an exemplary embodiment of the present invention.

"FIG. 28 is a sectional view illustrating an LED according to an exemplary embodiment of the present invention."

For additional information on this patent application, see: JUNG, Jung Hwa; KIM, Bang Hyun. Light Emitting Diode Chip Having Wavelength Converting Layer and Method of Fabricating the Same, and Package Having the Light Emitting Diode Chip and Method of Fabricating the Same. Filed February 5, 2014 and posted June 12, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5839&p=117&f=G&l=50&d=PG01&S1=20140605.PD.&OS=PD/20140605&RS=PD/20140605

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

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Source: Electronics Newsweekly


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