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`US009112121B2
`
`c12) United States Patent
`Jung et al.
`
`(IO) Patent No.:
`(45) Date of Patent:
`
`US 9,112,121 B2
`Aug. 18, 2015
`
`(54) LIGHT EMITTING DEVICE HAVING
`WAVELENGTH CONVERTING LAYER
`
`(75)
`
`Inventors: Jung Hwa Jung, Ansan-si (KR); Jung
`Doo Kim, Ansan-si (KR); Seoung Ho
`Jung, Ansan-si (KR); Min Hye Kim,
`Ansan-si (KR); Yoo Jin Kim, Ansan-si
`(KR)
`
`(73) Assignee: Seoul Semiconductor Co., Ltd.,
`Ansan-si (KR)
`
`( *) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by O days.
`
`(21) Appl. No.:
`
`13/984,154
`
`(22) PCT Filed:
`
`Jan.31,2012
`
`(86) PCT No.:
`
`PCT /KR2012/000728
`
`§ 371 (c)(l),
`(2), ( 4) Date: Aug. 7, 2013
`
`(87) PCT Pub. No.: W02012/108636
`
`PCT Pub. Date: Aug. 16, 2012
`
`(65)
`
`Prior Publication Data
`
`US 2013/0313585 Al
`
`Nov. 28, 2013
`
`(30)
`
`Foreign Application Priority Data
`
`Feb. 9, 2011
`Dec. 20, 2011
`
`(KR) ........................ 10-2011-0011298
`(KR) ........................ 10-2011-0138520
`
`(51)
`
`Int. Cl.
`HOJL29/06
`HOJL31/00
`
`(2006.01)
`(2006.01)
`(Continued)
`
`(52) U.S. Cl.
`CPC ............ HOJL 33/50 (2013.01); HOJL 2510753
`(2013.01); HOJL 33/508 (2013.01); HOJL 33/62
`(2013.01); HOJL 2224/48091 (2013.01)
`
`(58) Field of Classification Search
`CPC . HOlL 2224/00; HOlL 2924/00; H01L 33/00;
`HOlL 25/00
`USPC ............... 257/13, E33.012, E33.061, E33.03,
`257/E33.065, E33.066, E33.069, 89
`See application file for complete search history.
`References Cited
`
`(56)
`
`U.S. PATENT DOCUMENTS
`
`8,664,635 B2 *
`2001/0024460 Al*
`
`3/2014 Jung et al. ....................... 257/13
`9/2001 Yamamoto et al. ............. 372/36
`(Continued)
`
`FOREIGN PATENT DOCUMENTS
`
`JP
`KR
`
`10/2009
`2009-239116
`8/2006
`10-2006-0095271
`(Continued)
`OTHER PUBLICATIONS
`International Search Report issued on Aug. 22, 2012 in International
`Application No. PCT/KR2012/000728.
`(Continued)
`
`Primary Examiner - Telly Green
`(74) Attorney, Agent, or Firm - H.C. Park & Associates,
`PLC
`ABSTRACT
`(57)
`Disclosed is a light emitting device having a wavelength
`converting layer. The light emitting device comprises a plu(cid:173)
`rality of semiconductor stacked structures; connectors for
`electrically connecting
`the plurality of semiconductor
`stacked structures to one another; a single wavelength con(cid:173)
`verting layer for covering the plurality of semiconductor
`stacked structures; an electrode electrically connected to at
`least one of the semiconductor stacked structures; and at least
`one additional electrode positioned on the electrode, passing
`through the wavelength converting layer to be exposed to the
`outside, and forming a current input terminal to the light
`emitting device or a current output terminal from the light
`emitting device. Since the single wavelength converting layer
`covers the plurality of semiconductor stacked structures, the
`plurality of semiconductor stacked structures can be inte(cid:173)
`grally mounted on a chip mounting member such as a package
`or a module.
`
`22 Claims, 8 Drawing Sheets
`
`42
`
`21
`
`Seoul
`Exhibit 2011
`Satco v. Seoul
`IPR2020-00704
`
`Ex. 2011-001
`
`

`

`US 9,112,121 B2
`Page 2
`
`(51)
`
`Int. Cl.
`HOJL33/50
`HOJL25/075
`HOJL 33/62
`
`(2010.01)
`(2006.01)
`(2010.01)
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`7 /2008 Chitnis et al.
`2008/0173884 Al
`2009/0159915 Al*
`6/2009 Branchevsky .................. 257/98
`4/2010 Chen et al.
`2010/0105156 Al
`2011/0284822 Al* 11/2011 Jung et al ........................ 257/13
`
`2011/0284884 Al * 11/2011 Lee et al.
`........................ 257 /88
`6/2014 Jung et al. ....................... 257/13
`2014/0151633 Al*
`
`FOREIGN PATENT DOCUMENTS
`
`KR
`KR
`
`1020060095271
`10-2011-0011171
`
`* 8/2006
`2/2011
`
`.............. HO lL 33/00
`
`OTHER PUBLICATIONS
`
`Written Opinion issued on Aug. 22, 2012 in International Application
`No.PCT/KR2012/000728.
`
`* cited by examiner
`
`Ex. 2011-002
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 1 of 8
`
`US 9,112,121 B2
`
`Figure 1
`
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`
`44
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`
`Ex. 2011-003
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 2 of 8
`
`US 9,112,121 B2
`
`Figure 3
`
`33
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`
`Ex. 2011-004
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 3 of 8
`
`US 9,112,121 B2
`
`Figure 6
`
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`
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`
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`
`21
`
`Ex. 2011-005
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 4 of 8
`
`US 9,112,121 B2
`
`Figure 8
`
`41 4~
`
`33
`
`50
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`57
`53
`51
`
`44
`
`42
`
`Ex. 2011-006
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 5 of 8
`
`US 9,112,121 B2
`
`Figure 10
`
`73a
`\
`
`R2
`
`71
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`
`Ex. 2011-007
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 6 of 8
`
`US 9,112,121 B2
`
`Figure 13
`
`97
`
`91
`
`93b
`
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`
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`
`42 31 81 85
`J
`
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`
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`
`Ex. 2011-008
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 7 of 8
`
`US 9,112,121 B2
`
`Figure 15
`
`173b
`
`R1
`
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`
`r A
`
`R4
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`
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`171
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`
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`
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`173a
`
`RB
`I
`
`I I
`
`173a
`
`Ex. 2011-009
`
`

`

`U.S. Patent
`
`Aug. 18, 2015
`
`Sheet 8 of 8
`
`US 9,112,121 B2
`
`Figure 18
`
`Figure 19
`
`Figure 20
`
`100
`
`100
`
`200
`
`/
`
`197
`
`I
`
`210
`
`/
`
`191
`
`191
`
`Ex. 2011-010
`
`

`

`US 9,112,121 B2
`
`2
`SUMMARY
`
`1
`LIGHT EMITTING DEVICE HAVING
`WAVELENGTH CONVERTING LAYER
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This application is the National Stage entry oflnternational
`Application PCT/KR2012/000728, filed on Jan. 31, 2012,
`and claims priority from and the benefit of Korean Patent
`Application Nos. 10-2011-0011298, filed on Feb. 9, 2011, 10
`and 10-2011-0138520, filed on Dec. 20, 2011, which are
`incorporated herein by reference for all purposes as if fully set
`forth herein.
`
`BACKGROUND
`
`1. Field
`The present invention relates to a light emitting device, and
`more particularly, to a light emitting device having a wave(cid:173)
`length converting layer.
`2. Discussion of the Background
`Current light emitting diodes (LEDs) can be made to be
`light in weight, thin in thickness and small in size, and have
`advantages of energy reduction and long lifetime. Accord(cid:173)
`ingly, the LEDs are used as backlight sources for various
`types of display devices including cellular phones, and the
`like. Since an LED package having an LED mounted therein
`can implement white light having a high color rendering
`property, it is expected that the LED package will be applied
`to general illumination while substituting for white light
`sources such as fluorescent lamps.
`Meanwhile, there are various methods of implementing
`white light using LEDs. Among others, a method is generally
`used in which white light is implemented by combining an
`InGaN LED that emits blue light of 430 to 470 nm and a
`phosphor that can convert the blue light into light with a long
`wavelength. For example, the white light may be imple(cid:173)
`mented by combining a blue LED and a yellow phosphor
`excited by the blue LED so as to emit yellow light or by
`combining a blue LED and green and red phosphors.
`Conventionally, white LED packages have been formed by
`encapsulating an LED chip with a resin containing a phos(cid:173)
`phor at a package level. However, the phosphor is not uni(cid:173)
`formly distributed in the resin, and it is difficult to form the
`resin with a uniform thickness.
`Accordingly, studies have been conducted to develop a
`technique for providing an individual LED chip having a
`wavelength converting layer with a uniform thickness by
`forming a uniform phosphor layer at a wafer level or a chip
`level. The LED chip having the wavelength converting layer
`with a uniform thickness is provided at the wafer level or the
`chip level, so that a process of forming the wavelength con(cid:173)
`verting layer can be omitted at a package level. Further, since
`the wavelength converting layer with the uniform thickness is
`used, it is possible to prevent color variations which could be
`generated due to orientation angles.
`However, in the technique as described above, the indi(cid:173)
`vidual LED chip has the wavelength converting layer, so that,
`when a plurality of LED chips are required, for example, in a 60
`high-power LED package, each of the LED chips should be
`individually mounted and subjected to wire bonding at the
`package level. Therefore, there is a limitation in simplifying a
`packaging process. Further, since a plurality of LED chips
`should be mounted, the size of the package is increased, and 65
`it is difficult to provide a light source which may be consid(cid:173)
`ered as a point light source.
`
`5
`
`Accordingly, the present invention is conceived to solve the
`aforementioned problems. An object of the present invention
`is to provide a light emitting device having a wavelength
`converting layer, which can simplify a mounting process
`and/or a wire bonding process of a plurality of chips, per(cid:173)
`formed at a package level or a module level, and decrease the
`size of a light source.
`Another object of the present invention is to provide a light
`emitting device capable of preventing light converted in a
`wavelength converting layer from being again incident into
`the inside of an LED chip to be resultantly lost.
`Still another object of the present invention is to provide a
`15 light emitting device capable of reducing the damage of a
`wavelength converting layer by light.
`According to an aspect of the present invention, there is
`provided a light emitting device having a wavelength convert(cid:173)
`ing layer, comprising: a plurality of semiconductor stacked
`20 structures electrically connected to one another; a wavelength
`converting layer for covering the plurality of semiconductor
`stacked structures; an electrode electrically connected to at
`least one of the semiconductor stacked structures; and at least
`one additional electrode positioned on the electrode and pass-
`25 ing through the wavelength converting layer to be exposed to
`the outside. Since the plurality of semiconductor stacked
`structures are electrically connected to one another, the addi(cid:173)
`tional electrode passing through the wavelength converting
`layer can be disposed only at a current input terminal and/or
`30 a current output terminal, so that it is possible to simplify a
`wire to bonding process at a package level or a module level.
`The plurality of semiconductor stacked structures may be
`electrically connected to one another by means of connectors.
`The wavelength converting layer may cover the connectors.
`35 For example, a single wavelength converting layer may cover
`the plurality of semiconductor stacked structures. Since the
`single wavelength converting layer covers the is plurality of
`semiconductor stacked structures, the plurality of semicon(cid:173)
`ductor stacked structures can be integrally mounted on a chip
`40 mounting member such as a package or a module.
`The additional electrode may comprise a first additional
`electrode through which current is outputted from the light
`emitting device, and a second additional electrode through
`which current is inputted to the light emitting device. Further,
`45 the light emitting device may have a plurality of first addi(cid:173)
`tional electrodes and a plurality of second additional elec(cid:173)
`trodes, or may have a single first additional electrode and a
`single second additional electrode.
`At least one of the plurality of semiconductor stacked
`50 structures comprise a plurality oflight emitting cells, and the
`plurality oflight emitting cells may be electrically connected
`to one another by wires.
`In some embodiments, the wavelength converting layer
`may maintain a spatial relation between the plurality of semi-
`55 conductor stacked structures. That is, a support substrate for
`supporting the entire of the plurality of semiconductor
`stacked structures may not separately exist, and only the
`wavelength converting layer may combine the plurality of
`semiconductor stacked structure.
`In other embodiments, the support substrate may maintain
`a spatial relation between the plurality of semiconductor
`stacked structures. The wavelength converting layer may
`cover the plurality of semiconductor stacked structures on the
`support substrate.
`The plurality of semiconductor stacked structures may
`comprise a first semiconductor stacked structure for emitting
`light of a first wavelength, and a second semiconductor
`
`Ex. 2011-011
`
`

`

`US 9,112,121 B2
`
`4
`Accordingly, since the light emitting device is connected to
`an external power source using the first and second lead
`electrodes, the additional electrode can be omitted.
`In some embodiments, the plurality of LED chips may
`5 comprise a first LED chip for emitting light of a first wave(cid:173)
`length, and a second LED chip for emitting light of a second
`wavelength longer than the first wavelength.
`Although the plurality of LED chips may be connected to
`one another in series between the first and second lead elec(cid:173)
`trodes, the present invention is not limited thereto, and the
`plurality of LED chips may be connected to one another in
`various manners. The plurality of LED chips may be electri(cid:173)
`cally connected to one another by means of bonding wires.
`Alternatively, the LED chips are flip-bonded onto the support
`substrate so as to be electrically connected to one another.
`According to still another aspect of the present invention,
`there are provided a light emitting module and a lighting
`assembly. The light emitting module may comprise the light
`emitting device as described above and a printed circuit board
`on which the light emitting device is mounted. The lighting
`assembly may comprise the light emitting module.
`According to the present invention, since a plurality of
`semiconductor stacked structures are electrically connected
`to one another, an additional electrode passing through a
`wavelength converting layer is disposed only at a current
`input terminal and/or a current output terminal, or lead elec-
`trodes passing through a support substrate is employed, so
`that it is possible to simplify a wire bonding process at a
`package level or a module level. Further, since the plurality of
`30 semiconductor stacked structures are covered using the single
`wavelength converting layer, the plurality of semiconductor
`stacked structures can be integrally mounted on a chip mount(cid:173)
`ing member such as a package or a module. Further, a spacer
`layer is employed, so that it is possible to prevent a phosphor
`35 in the wavelength converting layer from being damaged by
`light emitted from the semiconductor stacked structure. Fur(cid:173)
`ther, the spacer layer comprises a DBR, so that it is possible to
`prevent light converted in the wavelength converting layer
`from being again incident into the inside of the semiconduc-
`40 tor stacked structure, thereby improving light efficiency.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`3
`stacked structure for emitting light of a second wavelength
`longer than the first wavelength.
`The light emitting device may comprise a plurality of LED
`chips. Here, the respective LED chips may comprise a sub(cid:173)
`strate and the semiconductor stacked structures positioned on
`the substrate. The plurality of LED chips may emit light of the
`same wavelength, but the present invention is not limited
`thereto. The plurality of LED chips may comprise LED chips
`for emitting light of different wavelengths, respectively. Fur(cid:173)
`ther, at least one of the plurality of LED chips may have a 10
`plurality of light emitting cells.
`The connectors are not particularly limited, but may com(cid:173)
`prise bonding wires. The additional electrode may be formed
`using a ball bonding process of the wires. In this case, the 15
`bonding wires may be formed together with the additional
`electrode in the same process.
`In some embodiments, the plurality of LED chips may be
`arranged on the support substrate so as to be supported by the
`support substrate. The light emitting device may further com- 20
`prise a bonding pattern formed on the support substrate. A
`wire may be bonded to the bonding pattern. Thus, the plural-
`ity of LED chips can be easily connected to one another using
`the bonding wires with the help of the bonding pattern.
`The light emitting device may further comprise a spacer 25
`layer interposed between the wavelength converting layer and
`the at least one of the semiconductor stacked structures. The
`spacer layer is formed of an insulating layer. The spacer layer
`may comprise a distributed Bragg reflector (DBR), and may
`further comprise a stress relief layer interposed between the
`DBR and the semiconductor stacked structure.
`The spacer layer is interposed between the wavelength
`converting layer and the semiconductor stacked structure so
`that the wavelength converting layer is spaced apart from the
`semiconductor stacked structure. The spacer layer prevents
`the yellowing of a phosphor in the wavelength converting
`layer, which might be caused by light emitted from the semi(cid:173)
`conductor stacked structure.
`The DBR may be formed by alternately laminating insu(cid:173)
`lating layers with different refractive indices, e.g., Si0iTi02
`or Si0iNb20s- By adjusting the optical thicknesses of the
`insulating layers with different refractive indices, the DBR
`may be configured to transmit light generated in an active
`layer and reflect light converted in the wavelength converting 45
`layer.
`The stress relief layer relieves a stress which might be
`caused in the DBR, so that it is possible to prevent the DBR
`from being exfoliated from a layer formed under the DBR,
`e.g., the semiconductor stacked structure. The stress relief 50
`layer may be formed of spin-on-glass (SOG) or porous silicon
`oxide.
`The additional electrode may have a width narrower than
`that of the electrode. The width of the additional electrode
`may become narrower as the additional electrode is further
`apart from the electrode. Accordingly, the additional elec(cid:173)
`trode can be stably attached to the electrode, and it is possible
`to ensure the reliability of a subsequent process of bonding
`Wifes.
`According to another aspect of the present invention, there
`is provided a light emitting device comprising: a support
`substrate having first and second lead electrodes; a plurality
`of LED chips mounted on the support substrate; and a single
`wavelength converting layer for covering the plurality of
`LED chips. Here, the first and second lead electrodes pass 65
`through the support substrate to extend to a bottom of the
`support substrate.
`
`FIG. 1 is a schematic plan view illustrating a light emitting
`device according to an embodiment of the present invention.
`FIG. 2 is a sectional view taken along line A-A of FIG. 1,
`illustrating the light emitting device according to the embodi(cid:173)
`ment of the present invention.
`FIG. 3 is a sectional view illustrating a light emitting device
`according to another embodiment of the present invention.
`FIG. 4 is a sectional view illustrating a light emitting device
`according to still another embodiment of the present inven(cid:173)
`tion.
`FIG. 5 is a sectional view illustrating a light emitting device
`55 according to still another embodiment of the present inven(cid:173)
`tion.
`FIG. 6 is a plan view illustrating the light emitting device of
`FIG. 5.
`FIG. 7 is a sectional view illustrating a light emitting device
`60 according to still another embodiment of the present inven(cid:173)
`tion.
`FIG. 8 is a sectional view illustrating a light emitting device
`according to still another embodiment of the present inven(cid:173)
`tion.
`FIG. 9 is a sectional view illustrating a light emitting device
`according to still another embodiment of the present inven-
`tion.
`
`Ex. 2011-012
`
`

`

`US 9,112,121 B2
`
`5
`FIG. 10 is a schematic plan view illustrating a light emit(cid:173)
`ting device according to still another embodiment of the
`present invention.
`FIG. 11 is a sectional view illustrating the light emitting
`device of FIG. 10.
`FIG. 12 is a sectional view illustrating a light emitting
`device according to still another embodiment of the present
`invention.
`FIG. 13 is a sectional view illustrating an LED package in
`which a light emitting device of the present invention is
`mounted.
`FIG. 14 is a sectional view illustrating an LED chip having
`a plurality of light emitting cells according to the present
`invention.
`FIG. 15 is a schematic plan view illustrating a light emit(cid:173)
`ting device according to still another embodiment of the
`present invention.
`FIG.16 isa sectional viewtakenalonglineA-AofFIG.15.
`FIG. 17 is a schematic sectional view illustrating a light
`emitting device according to still another embodiment of the
`present invention.
`FIG. 18 is a schematic sectional view illustrating a light
`emitting module having a light emitting device mounted
`therein according to an embodiment of the present invention.
`FIG. 19 is a schematic sectional view illustrating a light
`emitting module having a light emitting device mounted
`therein according to another embodiment of the present
`invention.
`FIG. 20 is a schematic sectional view illustrating a lighting
`assembly having a light emitting module mounted therein
`according to an embodiment of the present invention.
`
`DETAILED DESCRIPTION OF THE
`ILLUSTRATED EMBODIMENTS
`
`Hereinafter, preferred embodiments of the present inven(cid:173)
`tion will be described in detail with reference to the accom(cid:173)
`panying drawings. The following embodiments are provided
`only for illustrative purposes so that those skilled in the art can
`fully understand the spirit of the present invention. Therefore,
`the present invention is not limited to the following embodi(cid:173)
`ments but may be implemented in other forms. In the draw(cid:173)
`ings, the widths, lengths, thicknesses and the like of elements
`are exaggerated for convenience of illustration. Like refer(cid:173)
`ence numerals indicate like elements throughout the specifi(cid:173)
`cation and drawings.
`FIG. 1 is a schematic plan view illustrating a light emitting
`device according to an embodiment of the present invention.
`FIG. 2 is a sectional view taken along line A-A of FIG. 1,
`illustrating the light emitting device according to the embodi- 50
`ment of the present invention.
`Referring to FIGS. 1 and 2, the light emitting device
`includes a substrate 21, a plurality of semiconductor stacked
`structures Sl, S2, S3 and S4, first electrodes 41, second elec(cid:173)
`trodes 42, a first additional electrode 43, a second additional 55
`electrode 44, connectors 45 for electrically connecting the
`plurality of semiconductor stacked structures to one another,
`and a wavelength converting layer 50. The respective semi(cid:173)
`conductor stacked structures Sl, S2, S3 and S4 is formed of a
`plurality ofGaN-based semiconductor stacked structures 30 60
`including a first conductive-type semiconductor layer 25, an
`active layer 27 and a second conductive-type semiconductor
`layer 29. A buffer layer 23 may be interposed between the first
`conductive-type semiconductor layer 25 and the substrate 21,
`and a spacer layer 33 may be interposed between the wave- 65
`length converting layer 50 and each of the semiconductor
`stacked structures 3 0.
`
`6
`The substrate 21 is not particularly limited, and may be a
`substrate capable of growing nitride semiconductor layers
`thereon, e.g., a sapphire substrate, a silicon carbide substrate,
`a spine! substrate, a silicon substrate, or the like. The substrate
`5 21 may be relatively thicker than the semiconductor stacked
`structure.
`The active layer 27 and the first and second conductive(cid:173)
`type semiconductor layers 25 and 29 may be formed of a
`III-N-based compound semiconductor, e.g., an (Al, Ga, In)N
`10 semiconductor. Each of the first and second conductive-type
`semiconductor layers 25 and 29 may have a single- or multi(cid:173)
`layered structure. For example, the first conductive-type
`semiconductor layer 25 and/or the second conductive-type
`semiconductor layer 29 may comprise a contact layer and a
`15 clad layer, and may further comprise a superlattice layer. In
`addition, the active layer 27 may have a single or multiple
`quantum well structure. For example, the first and second
`conductive-type semiconductor layers may be n-type and
`p-type semiconductor layers, respectively, but the present
`20 invention is not limited thereto. That is, the first and second
`conductive-type semiconductor layers may be p-type and
`n-type semiconductor layers, respectively. The buffer layer
`23 decreases the defect density generated in the semiconduc(cid:173)
`tor layers 25, 27 and 29 by reducing the lattice mismatch
`25 between the substrate 21 and the first conductive-type semi(cid:173)
`conductor layer 25.
`Meanwhile, the first electrode 41 is electrically connected
`to the first conductive-type semiconductor layer 25 by com(cid:173)
`ing in contact with an exposed surface of the first conductive-
`30 type semiconductor layer 25. The second electrode 42 may be
`positioned on a top of the second conductive-type semicon(cid:173)
`ductor layer 29 so as to be electrically connected to the second
`conductive-type semiconductor layer 29. The first and second
`electrodes 41 and 42 may be formed on each of the semicon-
`35 ductor stacked structures Sl, S2, S3 and S4. The first and
`second electrodes 41 and 42 may comprise, for example, Ti,
`Cu, Ni, Al, Au or Cr, and may be formed of two or more
`materials thereof. A transparent conductive layer 31 such as
`Ni/ Au, ITO, IZO or ZnO may be formed on the second
`40 conductive-type semiconductor layer 29 for the purpose of
`current distribution, and the second electrode 42 may be
`connected to the transparent conductive layer.
`The first additional electrode 43 forms a current output
`terminal of the light emitting device, and is positioned on the
`45 first electrode 41 of the semiconductor stacked structure S4.
`The second additional electrode 44 forms a current input
`terminal of the light emitting device, and is positioned on the
`second electrode 42 of the semiconductor stacked structure
`Sl. Since the first and second additional electrodes form the
`current output terminal and the current input terminal, respec(cid:173)
`tively, the light emitting device may have only the two addi(cid:173)
`tional electrodes. The first and second additional electrodes
`43 and 44 may have widths narrower than those of the first and
`second electrodes 41 and 42, respectively. That is, the first and
`second additional electrodes are confined to tops of the first
`and second electrodes, respectively. The first and second
`additional electrodes 43 and 44 may have shapes in which the
`widths of the first and second additional electrodes become
`narrower as the first and second additional electrodes are
`further apart from the first and second electrodes 41 and 42,
`respectively. Accordingly, the shapes as described above may
`cause the first and second additional electrodes 43 and 44 to
`be stably attached and maintained to the respective first and
`second electrodes 41 and 42, which may be advantageous in
`a subsequent process such as a wire bonding process.
`The connectors 45 electrically connect the semiconductor
`stacked structures Sl, S2, S3 and S4 to one another.As shown
`
`Ex. 2011-013
`
`

`

`US 9,112,121 B2
`
`7
`in FIG. 1, the semiconductor stacked structures may be con(cid:173)
`nected in series by the connectors 45. However, the present
`invention is not limited thereto, and the semiconductor
`stacked structures Sl, S2, S3 and S4 may be electrically
`connected in various manners including in series, in parallel, 5
`in series-parallel, in reverse parallel, and the like.
`The connectors 45 may be particularly bonding wires, and
`may be formed together with the first and second additional
`electrodes 43 and 44 using a wire bonding process. Since the
`semiconductor stacked structures Sl, S2, S3 and S4 are 10
`arranged on the substrate 21 with a high degree of precision,
`the wire bonding process can be very precisely performed.
`The single wavelength converting layer 50 may cover sides
`and tops of the plurality of semiconductor stacked structures 15
`30. The wavelength converting layer 50 may also cover the
`connectors 45 such as bonding wires.
`The single wavelength converting layer 50 may be formed
`of a phosphor contained in epoxy or silicon, or may be formed
`only of a phosphor. For example, before a chip is partitioned 20
`at a wafer level, the wavelength converting layer 50 may be
`formed of resin, e.g., epoxy or silicon, containing a phosphor
`therein so to have a uniform thickness using squeezing. At this
`time, the resin covering the first and second additional elec(cid:173)
`trodes 43 and 44 is removed using grinding or the like, so that 25
`top surfaces of the first and second additional electrodes 43
`and 44 can be exposed. Accordingly, the wavelength convert(cid:173)
`ing layer 50 having a flat top surface can be formed, and the
`first and second additional electrodes 43 and 44 pass through
`the wavelength converting layer 50 to be exposed to the 30
`outside of the light emitting device.
`Further, the wavelength converting layer 50 may have a
`refractive index, for example, within a range from 1.4 to 2.0,
`and powder made of Ti02 , Si02 , Y20 3 or the like may be 35
`mixed in the wavelength converting layer 50 so as to control
`the refractive index.
`Although not particularly limited, the top surface of the
`first additional electrode 43 may be positioned at a height
`identical to that of the second additional electrode 44. There- 40
`fore, when portions of the second conductive-type semicon(cid:173)
`ductor layer 29 and the active layer 27 are removed to expose
`the first conductive-type semiconductor layer 25, the first
`additional electrode 43 may be longer than the second addi(cid:173)
`tional electrode 44, as shown in FIG. 2.
`The spacer layer 33 is interposed between each of the
`semiconductor stacked structures 30 and the wavelength con(cid:173)
`verting layer 50 so that the wavelength converting layer 50 is
`spaced apart from the semiconductor stacked structure 30.
`The spacer layer 33 may cover tops of the semiconductor
`stacked structure 30 and the transparent conductive layer 31.
`The spacer layer 33 may be formed of, for example, transpar(cid:173)
`ent resin, silicon nitride or silicon oxide. As the wavelength
`converting layer 50 is spaced apart from the semiconductor
`stacked structure 30 by the spacer layer 33, it is possible to 55
`prevent the yellowing of the wavelength converting layer 50.
`According to this embodiment, the second additional elec(cid:173)
`trode 44 of the semiconductor stacked structure Sl forms a
`current input terminal so that current can be inputted from the
`outside to the light emitting device through the current input 60
`terminal, and the first additional electrode 43 of the semicon(cid:173)
`ductor stacked structure S4 forms a current output terminal so
`that current can be outputted from the light emitting device to
`the outside through the current output terminal. Meanwhile,
`current is inputted/outputted to/from the semiconductor
`stacked structures S2 and S3 by means of the connectors 45.
`Thus, the semiconductor stacked structures S2 and S3 can be
`
`8
`fully buried in the wavelength converting layer 50, so that
`additional electrodes need not be added on the semiconductor
`stacked structures S2 and S3.
`Similarly to the conventional method of fabricati