Organization
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`International Bureau
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`=z
`Soe=\
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`AMCTATA RNA
`
`(10) International Publication Number
`WO 2013/118072 A2
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`(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY(PCT)
`(19) World Intellectual Property
`=
`
`(43) International Publication Date
`15 August 2013 (15.08.2013) WIPO! PCT
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`(51)
`
`International Patent Classification:
`
`HOIL 33/00 (2010.01)
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`(21)
`
`International Application Number:
`
`PCT/IB2013/051009
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`(22)
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`International Filing Date:
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`(25)
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`Filing Language:
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`7 February 2013 (07.02.2013)
`English
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`(26)
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`(30)
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`(71)
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`(72)
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`(74)
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`(81)
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`Publication Language:
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`English
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`Priority Data:
`61/597,358
`
`10 February 2012 (10.02.2012)
`
`US
`
`[NL/NL];
`Applicant: KONINKLIJKE PHILIPS N.V.
`High Tech Campus 5, NL-5656 AE Eindhoven (NL).
`
`Inventor: BIERHUIZEN, Serge Joel Armand; c/o High
`Tech Campus, Building 44, NL-5656 AE Eindhoven (NL).
`
`Agents: VAN EEUWLJK, Alexander Henricus Walterus
`et al.; High Tech Campus, Building 44, NL-5656 AE Eind-
`hoven (NL).
`
`Designated States (unless otherwise indicated, for every
`kind of national protection available). AE, AG, AL, AM,
`AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY,
`BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM,
`DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM,GT,
`HN, HR, HU, ID, IL, IN, IS, JP, KE, KG, KM, KN, KP,
`
`KR, KZ, LA, LC, LK, LR, LS, LT, LU, LY, MA, MD,
`ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI,
`NO, NZ, OM,PA, PE, PG, PH, PL, PT, QA, RO, RS, RU,
`RW, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH,TJ,
`TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA,
`ZM,ZW.
`
`(84)
`
`Designated States (unless otherwise indicated, for every
`kind of regional protection available): ARIPO (BW, GH,
`GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, SZ, TZ,
`UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU,TJ,
`TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK,
`EE, ES, FI, FR, GB, GR, HR, HU,IE,IS, IT, LT, LU, LV,
`MC, MK,MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM,
`TR), OAPI (BF, BJ, CF, CG, CL, CM, GA, GN, GQ, GW,
`ML, MR,NE, SN, TD, TG).
`Declarations under Rule 4.17:
`
`as to applicant's entitlement to apply for and be granted a
`patent (Rule 4.17(ii))
`
`as to the applicant's entitlement to claim the priority of the
`earlier application (Rule 4.17(iii))
`Published:
`
`without international search report and to be republished
`upon receipt of that report (Rule 48.2(g))
`
`(54) Title: WAVELENGTH CONVERTED LIGHT EMITTING DEVICE
`
`(57) Abstract: Embodiments of the invention include a semiconductor structure comprising a light emitting layer. The semiconduct-
`or structure is attached to a support such that the semiconductor structure and the support are mechanically self-supporting. A
`wavelength converting material extends over the sides of the semiconductor structure and the support, wherein the wavelength con-
`verting material has a substantially uniform thickness over the top and sides of the semiconductorstructure and the support.
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`IKEA Supply AG
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`WAVELENGTH CONVERTED LIGHT EMITTING DEVICE
`
`BACKGROUND
`
`FIELD OF INVENTION
`
`[0001]
`
`The present invention relates to a wavelength-converted semiconductorlight emitting
`
`device on a chip-scale package.
`
`DESCRIPTION OF RELATED ART
`
`[0002]
`
`Semiconductorlight-emitting devices including light emitting diodes (LEDs),
`
`resonant cavity light emitting diodes (RCLEDs), vertical cavity laser diodes such as surface-
`
`emitting lasers (VCSELs), and edge emitting lasers are among the mostefficient light sources
`
`currently available. Materials systems currently of interest in the manufacture of high-brightness
`
`light emitting devices capable of operation across the visible spectrum include Group III-V
`
`semiconductors, particularly binary, ternary, and quaternary alloys of gallium, aluminum,
`
`indium, and nitrogen,also referred to as III-nitride materials. Typically, [I-nitride light emitting
`
`devices are fabricated by epitaxially growing a stack of semiconductorlayers of different
`
`compositions and dopant concentrations on a sapphire, silicon carbide, III-nitride, or other
`
`suitable substrate by metal-organic chemical vapor deposition (MOCVD), molecular beam
`
`epitaxy (MBE), or other epitaxial techniques. The stack often includes one or more n-type layers
`
`doped with, for example, Si, formed over the substrate, one or more light emitting layers in an
`
`active region formedover the n-type layer or layers, and one or more p-type layers doped with,
`
`for example, Mg, formed overthe active region. Electrical contacts are formed on the n- and p-
`
`type regions.
`
`[0003]
`
`Il]-nitride light emitting devices often emit blue or UV light. To form an LEDthat
`
`emits white light, one or more wavelength converting materials such as phosphorsare often
`
`disposed in the path of the blue or UV light emitted from the LED. For example, for an LED that
`
`emits blue light, a single phosphorthat emits yellow light may be used, or two phosphorsthat
`
`emit green andred light may be used. Someofthe light emitted by the LED is wavelength-
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`converted by the phosphor. The wavelength-converted light emitted by the phosphor mixes with
`
`unconverted light emitted by the LED suchthat the overall appearance of light from the deviceis
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`white.
`
`[0004]
`
`Fig. | illustrates a process for forming a wavelength-converted light emitting device
`
`mounted on a chip-scale package, described in more detail in US 2010/0279437. A chip-scale
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`packagerefers to a packageforthe light emitting device that is attached to the semiconductor
`
`light emitting device structure in a wafer-scale process. In process 102 of Fig. 1, LEDs are
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`formed on a growth wafer. In process 104, a carrier wafer is temporarily bondedto the device
`
`wafer. A removable adhesiveisfirst applied over the top of the device wafer then a carrier wafer
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`is bondedto the top of the device wafer. In process 106, the device waferis flipped over and the
`
`growth wafer is removed. In process 108, the n-type layer exposed by removing the growth
`
`wafer is roughened to improve light extraction. In process 110, a window waferis bonded to the
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`device wafer. The window wafer provides mechanical strength to the device wafer for
`
`subsequent processing. The window wafer may include a wavelength converting structure for
`
`modifying the emission spectrum to provide a desired color such as amberforsignallights or
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`multiple colors for a white light emitter. The structure may be a ceramic phosphor, a suitable
`
`transparent substrate or carrier such as a sapphireorglass layer, or a filter such as a distributed
`
`Bragg reflector. In process 112, the carrier wafer is removed from the device wafer.
`
`In process
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`114, the device wafer is mounted from the bottom side to a stretch film. The stretch film may be
`
`a blue tape, a white tape, a UV tape, or other suitable materials that allows adhesionto a flexible
`
`(expandable) substrate. In process 116, the LEDsin the device wafer are singulated into
`
`individualdice, for example usingalaser, a scribe, ora saw. The LED dice may have edge
`
`emission that degrades color-over-angle uniformity. In process 118, the stretch film is expanded
`
`to laterally separate the LED dice to create the spaces between neighboring dice. In process 120,
`
`a reflective coating is applied over the tops of the LEDs andin the spaces between them. In
`
`process 122, the reflective coating in the spaces between the LED diceis optionally broken or
`
`weakened (e.g., cleaved). In process 124, the stretch film is expanded again to furtherlaterally
`
`separate the LED dice. In process 126, portions of the reflective coating on the top of the LED
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`dice is removed. Afterwards only portionsof the reflective coating on the sides of the LED dice
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`remains. Portions of the reflective coating on the sides of the LED dice may control edge
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`emission, improve color-over-angle uniformity, and improve brightness. In process 128, the
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`LEDsareflipped over and transferred to anotherstretch film to expose n-type bond padsand p-
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`type bond pads on the LEDdicefor testing in process 130.
`
`SUMMARY
`
`[0005]
`
`It is an object of the invention to provide a wavelength converted light emitting device
`
`where leakage of unconverted light from the sides of the light emitting device is reduced or
`
`eliminated.
`
`[0006]
`
`Embodiments of the invention include a semiconductorstructure comprising a light
`
`emitting layer. The semiconductorstructure is attached to a support such that the semiconductor
`
`structure and the support are mechanically self-supporting. A wavelength converting material
`
`extends overthe sides of the semiconductorstructure and the support. In some embodiments, the
`
`thickness of the wavelength converting material varies less than 20% over the top and sides of
`
`the semiconductorstructure and the support.
`
`[0007]
`
`A method according to embodiments of the invention includes attaching a plurality of
`
`light emitting devices to a substrate. Each light emitting device includes a support attached to a
`
`semiconductorstructure comprising a light emitting layer. Each light emitting device is
`
`mechanically self-supporting. Neighboring devices are spaced apart on the substrate. A
`
`wavelength converting material is disposed overthe plurality of light emitting devices. The
`
`wavelength converting material extends over the sides of each semiconductorstructure and
`
`support.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0008]
`
`Fig. | illustrates a method of forming a wavelength-converted LED.
`
`[0009]
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`Fig. 2 illustrates a method of forming a wavelength-converted light emitting device
`
`according to embodiments of the invention.
`
`[0010]
`
`Fig. 3 is a cross sectional view of a semiconductorstructure attached to a support.
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`[0011]
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`Fig. 4 is a plan view of a reconstituted wafer.
`
`[0012]
`
`Fig. 5 is a cross sectional view of a wavelength-converted light emitting device
`
`according to embodiments of the invention.
`
`DETAILED DESCRIPTION
`
`[0013]
`
`In a structure formed by the method illustrated in Fig. 1, leakage of unconverted light
`
`from the sides ofa chip-scale packaged light emitting device is prevented or reduced by forming
`
`a reflective material on the sides of the light emitting device. In embodiments of the invention,
`
`wavelength converting material rather than a reflective material is formed on the sides of a chip-
`
`scale packaged light emitting device.
`
`[0014]
`
`Fig. 2 illustrates a method of forming a wavelength-converted semiconductorlight
`
`emitting device according to embodiments of the invention. Thoughin the discussion below the
`
`semiconductorlight emitting devices are III-nitride LEDs that emit blue or UV light,
`
`semiconductor light emitting devices besides LEDssuchaslaser diodes and semiconductorlight
`
`emitting devices madefrom other materials systems such as other III-V materials, [I-phosphide,
`
`Il-arsenide, II-VI materials, ZnO, or Si-based materials may be used.
`
`[0015]
`
`In stage 10, a wafer of semiconductor devices attached to a mechanical support is
`
`prepared. Fig. 3 is a cross sectional view of a portion of a wafer of semiconductorlight emitting
`
`devices attached to a support. To form the structure of Fig. 3, a semiconductorstructure 20 is
`
`first grown on a growth substrate (not shownin Fig. 3) as is knownin the art. The growth
`
`substrate may be anysuitable substrate such as, for example, sapphire, SiC, Si, GaN,or
`
`composite substrates. The semiconductorstructure 20 includes a light emitting or active region
`
`sandwiched between n- and p-type regions. An n-type region may be grownfirst and may
`
`include multiple layers of different compositions and dopant concentration including, for
`
`example, preparation layers such as buffer layers or nucleation layers, and/or layers designed to
`
`facilitate removal of the growth substrate, which may be n-typeornot intentionally doped, and n-
`
`or even p-type device layers designedfor particular optical, material, or electrical properties
`
`desirable for the light emitting region to efficiently emit light. A light emitting or active region is
`
`grown overthe n-type region. Examples of suitable light emitting regions include a single thick
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`or thin light emitting layer, or a multiple quantum well light emitting region including multiple
`
`thin orthick light emitting layers separated by barrier layers. A p-type region may then be grown
`
`overthe light emitting region. Like the n-type region, the p-type region may include multiple
`
`layers of different composition, thickness, and dopant concentration, including layers that are not
`
`intentionally doped, or n-type layers. The total thickness of all the semiconductor materialin the
`
`deviceis less than 10 um in some embodiments andless than 6 um in some embodiments.
`
`[0016]
`
`A metal p-contact is formed on the p-type region. If a majority oflight is directed out
`
`of the semiconductorstructure through a surface opposite the p-contact, such as in a flip chip
`
`device, the p-contact may bereflective. A flip chip device may be formed by patterning the
`
`semiconductorstructure by standard photolithographic operations and etching the semiconductor
`
`structure to removea portion of the entire thickness of the p-type region and a portion of the
`
`entire thickness of the light emitting region, to form a mesa whichreveals a surface of the n-type
`
`region on which a metal n-contact is formed. The mesa and p- and n-contacts may be formed in
`
`any suitable manner. Forming the mesa and p- and n-contacts is well knownto a person of skill
`
`in the art andis notillustrated in Fig. 3. In the regions between devices, the semiconductor
`
`structure 20 is etched downto an insulating layer, which maybe an insulating semiconductor
`
`layerthat is part of the semiconductorstructure 20, or the growth substrate.
`
`[0017]
`
`The p- and n-contacts may beredistributed by a stack of insulating layers and metals
`
`as is knowninthe art to form at least two large electrical pads. Oneof the electrical padsis
`
`electrically connected to the p-type region of the semiconductorstructure 20 and the other of the
`
`electrical padsis electrically connected to the n-type region of the semiconductorstructure 20.
`
`Electrical pads may be any suitable conductive material including, for example, copper, gold, and
`
`alloys. The electrical padsare electrically isolated from each other by a gap which maybefilled
`
`with an insulating material such as a dielectric, air, or other ambient gas. The p- and n-contacts,
`
`the metal/dielectric stack to redistribute the contacts, and the electrical pads are well known in
`
`the art andare illustrated in Fig. 3 as electrical connection structure 22.
`
`[0018]
`
`The semiconductorstructure 20 is connected to a support 24 throughelectrical
`
`connection structure 22. Support 24 is a structure that mechanically supports semiconductor
`
`structure 20 andthat is diced at the same time as semiconductor structure 20, when the wafer of
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`devicesis divided into individual or groups of devices. Support 24 is attached to semiconductor
`
`structure 20 on a wafer scale. In some embodiments, support 24 is a self-supporting structure
`
`suitable to attach the semiconductorlight emitting device to a substrate such as a PC board. For
`
`example, the surface of support 24 opposite semiconductorstructure 20 (the bottom surface of
`
`support 24 in Fig. 3) may be reflow-solderable. Any suitable support may be used. Examples of
`
`suitable supports 24 include (1) an insulating or semi-insulating wafer with conductive vias for
`
`forming electrical connectionsto the electrical connection structure 22, such asa silicon wafer,
`
`which may be attached to the semiconductorstructure by, for example, gold-gold interconnects,
`
`(2) thick metal bonding pads formed onelectrical connection structure 22, for example by
`
`plating, or (3) any other suitable mount.
`
`[0019]
`
`In stage 12 of Fig. 2, the individual semiconductor devices on the wafer illustrated in
`
`Fig. 3 are tested to identify good devices, and optionally to identify characteristics of each
`
`device, such as the peak emission wavelength, brightness, etc. The wafer including the
`
`semiconductorstructure 20, electrical connection structure 22, and support 24 is then diced, to
`
`divide the wafer into individual devices or groups of devices. In some embodiments, the growth
`
`substrate is removed from the semiconductorstructure before dicing, as is knownin the art. In
`
`some embodiments, the growth substrate remains part of the final structure andis therefore diced
`
`at the same time as the semiconductorstructure. In some embodiments, the semiconductor
`
`structure is diced with the growth substrate still attached, then the growth substrate is later
`
`removedat a die-level rather than a wafer level. Dicing can be performedby anysuitable
`
`method such as scribe-and-break with a laser scribe or sawing andis well knowninthe art.
`
`Since the semiconductorstructure 20, connection structure 22 and support 24 are diced at the
`
`same time, support 24 is substantially the same width as the semiconductorstructure 20 for each
`
`device or group of devices, as illustrated below in Fig. 5. The device may have substantially
`
`vertical sidewalls, as illustrated in Fig. 5.
`
`[0020]
`
`In stage 14, a reconstituted wafer of devices is formed. A reconstituted waferis
`
`illustrated in Fig. 4. Individual devices or groups of devices 26 diced in stage 12 are connected
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`to a substrate 28. Substrate 28 can be any suitable structure that supports devices 26, such as an
`
`inflexible structure such as a board ora flexible structure such as wafer handling tape, for
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`example. In some embodiments, only knowngood devices, based on the test described above in
`
`reference to stage 12, are connected to substrate 28 in the reconstituted wafer. Since device
`
`testing is done before wavelength converting material is applied in stage 16 and only good
`
`devices are used, no wavelength converting material is wasted on bad devices(i.e. nonfunctional
`
`or non-light-emitting devices), which may reduce cost. In some embodiments, based on thetest
`
`described abovein reference to stage 12, only devices that emit light within the same peak
`
`wavelength range are connected to substrate 28 in the reconstituted wafer, suchthat the
`
`wavelength converting material can be matched to the peak emission wavelength of the devices,
`
`which may improve yield. For example, a suitable peak wavelength range may be as narrow as 5
`
`nm in some embodiments. In some embodiments, the wafer of devices is attached to handling
`
`tape, diced while attached to the handling tape, then the reconstituted wafer is formed by
`
`stretching the handling tape to separate the devicesafter dicing.
`
`[0021]
`
`In some embodiments, the spacing 30 between devices 26 on the reconstituted wafer
`
`is at least as wide as required to cleave the wavelength converting material formed over the
`
`wafer, described below. In some embodiments, the spacing may be wide enoughto create an
`
`overhang 38 (illustrated in Fig. 5) of wavelength converting material on the sides of the devices.
`
`The overhang may be, for example, at least as thick as the wavelength converting materiallayer,
`
`or it may be wider or narrower. The dotted lines 32 on Fig. 4 show where the wavelength
`
`converting material layer is cleaved to separate the devices on the reconstituted wafer, described
`
`below in stage 18. In one example, the wavelength converting material layer is 50 um thick.
`
`The spacing 30 between devices 26 may beat least 100 um, such that the overhang of
`
`wavelength converting material on the sides of each device 26 is at least 50 um. In some
`
`embodiments, the devices are spaced such that no overhang38 is created.
`
`[0022]
`
`In some embodiments, the aspect ratio of the reconstituted wafer is selected to match
`
`the shape of a pre-fabricated wavelength converting film. For example, the wafer whichis diced
`
`in stage 12 is typically a round wafer. The reconstituted wafer formed in stage 14 may be
`
`rectangular, sized to match a rectangular sheet of pre-fabricated wavelength-converting film.
`
`[0023]
`
`In stage 16 of Fig. 2, a wavelength-converting material is applied over the devices 26
`
`on the reconstituted wafer. The wavelength converting material may be formed such that all or
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`only a portion of the light emitted by the light emitting device and incident on the wavelength
`
`converting material may be converted by the wavelength converting material. Unconverted light
`
`emitted by the light emitting device maybepart of the final spectrum of light, though it need not
`
`be. Examples of common combinations include a blue-emitting LED combinedwith a yellow-
`
`emitting wavelength converting material, a blue-emitting LED combined with green- and red-
`
`emitting wavelength converting materials, a UV-emitting LED combinedwith blue- and yellow-
`
`emitting wavelength converting material, and a UV-emitting LED combined with blue-, green-,
`
`and red-emitting wavelength converting materials. Wavelength converting materials emitting
`
`other colors of light may be addedto tailor the spectrum oflight emitted from the device. The
`
`wavelength converting material may be conventional phosphorparticles, organic
`
`semiconductors, I-VI or II-V semiconductors, II-VI or II-V semiconductor quantum dots or
`
`nanocrystals, dyes, polymers, or materials such as GaN that luminesce. Phosphorparticles may
`
`have an average diameter between 5 and 50 um insome embodiments. Any suitable phosphor
`
`may beused,including but not limited to garnet-based phosphors such as Y3Als012:Ce (YAG),
`
`Lu3Al50 12:Ce (LUAG), Y3Als.,.Ga,O12:Ce (YAIGaG), (BayxSrx)Si03:Eu (BOSE), and nitride-
`
`based phosphorssuch as (Ca,Sr)AISiN3:Eu and (Ca,Sr,Ba)oSisNg:Eu.
`
`[0024]
`
`The wavelength converting material is formed to conformally coat devices 26 on the
`
`reconstituted wafer with a substantially uniform thickness. For example, the thickness of the
`
`wavelength converting material over the top and sides of each device and between devices may
`
`vary less than 50% in some embodiments, less than 20% in some embodiments, and less than
`
`10% in some embodiments. One example of a wavelength converting material is a luminescent
`
`film, formed as follows: one or more conventional powder phosphors are mixed with a binder
`
`such as acrylic or silicone to achieve a target phosphor density. The phosphor/bindersheetis
`
`formedto havea target thickness, for example by spinning the mixture onaflat surface or
`
`molding the phosphor sheet. Phosphor may be mixed with a binderin liquid form whichis then
`
`cured or dried to form a flexible luminescent film. The luminescentfilm is pressed over the
`
`reconstituted wafer in stage 16. In some embodiments, wavelength converting materialis
`
`molded over devices 26, for example by placing a mold overdevices 26, filling the mold with
`
`phosphor mixed with binder material, curing the binder material, then removing the mold.
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`[0025]
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`Other optional materials suchasfilters, dichroics, optics, or lenses may be formed
`
`over devices 26 on the reconstituted wafer, before or after the wavelength converting material is
`
`formed over devices 26.
`
`[0026]
`
`In stage 18 of Fig. 2, the wavelength converting material formed overthe
`
`reconstituted wafer is cleaved to separate the devices or groups of devices 26. Fig. 5 illustrates a
`
`single device after being separated from the reconstituted wafer in stage 18. Wavelength
`
`converting material 34 covers the top and sides of semiconductorstructure 20 and support 24 to
`
`prevent leakage of unconvertedlight from the sides of semiconductorstructure 20. The width of
`
`optional overhang 38 on the sides of device 26 depends on the spacing on the reconstituted
`
`wafer, as described above.
`
`[0027]
`
`The embodiments described above may have advantages over the methodillustrated
`
`in Fig. 1. Cleaving a wavelength converting material in stage 18 of Fig. 2 (such as a 50 um thick
`
`phosphorandsilicone film for example)is easier than cleaving a semiconductor wafer, carrier
`
`wafer, and ceramic phosphoras described abovein process 116 of Fig. 1. In addition, in
`
`embodiments of the invention only known good die are covered with wavelength converting
`
`material. Ease of cleaving and using only known good devices may improveyield and reduce
`
`cost.
`
`[0028]
`
`Having described the invention in detail, those skilled in the art will appreciate that,
`
`given the present disclosure, modifications may be madeto the invention without departing from
`
`the spirit of the inventive concept described herein. Therefore, it is not intended that the scope of
`
`the invention be limited to the specific embodiments illustrated and described.
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`10
`
`CLAIMS
`
`Whatis being claimed is:
`
`1.
`
`A device comprising:
`
`a semiconductor structure comprising a light emitting layer disposed between an n-type
`
`region and a p-type region;
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`a metal n-contact disposed on the n-type region and a metal p-contact disposed on p-type
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`region;
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`a support, wherein the semiconductorstructure is attached to the support throughat least
`
`one of the n-contact and the p-contact such that the semiconductorstructure and the support are
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`mechanically self-supporting; and
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`a wavelength converting material extending overthe sides of the semiconductorstructure
`
`and the support.
`
`2.
`
`The device of claim 1 wherein a thickness of the wavelength converting material
`
`varies less than 20% over the top and sides of the semiconductorstructure and the support.
`
`3.
`
`The device of claim | wherein the n-contact and the p-contact are formed on the
`
`sameside of the semiconductorstructure.
`
`4.
`
`The device of claim | wherein the support comprises thick metal pads disposed on
`
`the semiconductorstructure.
`
`5.
`
`6.
`
`The device of claim 1 wherein the support comprises a silicon wafer.
`
`The device of claim 1 wherein a structure comprising the semiconductorstructure
`
`and the support has substantially vertical sidewalls.
`
`7.
`
`The device of claim | wherein the wavelength converting material is a phosphor
`
`powder mixedwith a transparent binder material in a pre-fabricated sheet.
`
`8.
`
`The device of claim 7 wherein the wavelength converting sheet extends outward
`
`from a bottom of the support.
`
`9.
`
`A method comprising:
`
`attaching a plurality of light emitting devices to a substrate, each light emitting device
`
`comprising a support attached to a semiconductorstructure comprising a light emitting layer,
`
`wherein each light emitting device is mechanically self-supporting and neighboring devices are
`
`spaced apart on the substrate;
`
`IKEA Supply AG
`Exhibit 1022 Page 11 of 15
`
`IKEA Supply AG
`Exhibit 1022 Page 11 of 15
`
`

`

`WO2013/118072
`
`PCT/IB2013/051009
`
`11
`
`disposing a wavelength converting material over the plurality of light emitting devices,
`
`wherein the wavelength converting material extends overthe sides of each semiconductor
`
`structure and support.
`
`10.
`
`The method of claim 9 wherein each light emitting device has substantially
`
`vertical sidewalls.
`
`11.
`
`The method of claim 9 further comprising:
`
`attaching supports to a wafer of semiconductorstructures to form a wafer of light emitting
`
`devices;
`
`testing each light emitting device on the wafer of light emitting devices; and
`
`dicing the waferof light emitting devices.
`
`12.|The method of claim 11 wherein attaching a plurality of light emitting devices to a
`
`substrate comprises attaching only light emitting devices that meet a predeterminedcriterion.
`
`13.
`
`The method of claim 12 wherein the predeterminedcriterion is peak emission
`
`wavelength range and disposing a wavelength converting material comprises disposing a
`
`wavelength converting material that is matched to the peak emission wavelength range.
`
`14.
`
`The method of claim 9 wherein attaching a plurality of light emitting devices to a
`
`substrate comprises:
`
`attaching a wafer of light emitting devices to handling tape;
`
`dicing the waferinto a plurality of light emitting devices; and
`
`stretching the handling tape to space the plurality of light emitting devices apart before
`
`disposing the wavelength converting material over the plurality of light emitting devices.
`
`15.|The method of claim 9 wherein disposing a wavelength converting material over
`
`the plurality of light emitting devices comprises molding wavelength converting material over
`
`each light emitting device.
`
`16.|The method of claim 9 wherein disposing a wavelength converting material over
`
`the plurality of light emitting devices comprises pressing a pre-fabricated sheet of phosphor
`
`disposed in transparent binder material overthe plurality of light emitting devices.
`
`17.|The method of claim 9 wherein disposing a wavelength converting material over
`
`the plurality of light emitting devices comprises forming a wavelength converting material with a
`
`substantially uniform thickness over the top and sides of the semiconductorstructure and the
`
`support.
`
`IKEA Supply AG
`Exhibit 1022 Page 12 of 15
`
`IKEA Supply AG
`Exhibit 1022 Page 12 of 15
`
`

`

`WO2013/118072
`
`PCT/IB2013/051009
`
`1/3
`
`pent 2
`
`— \
`
`Form LED dies on growth wafer
`
`Pam 1092
`
`Bond carrier wafer to device waler
`
`Frommeemmnn 1 4
`
`Remove the growth wafer
`
`- mrmmm TOG
`
`Roughen n layer
`
`pom 108
`
`Bond windowwaferto the device wafer
`
`I wom F10
`
`Remove the carrier wafer
`
`I. aommme FID
`
`Mount the device wafer onto tacky tape
`
`| mcrae, TL
`
`Singulate the LED dies
`
`pm 116
`
`Expand tacky tape fo separate the LED dies b mm 118
`
`Apply reflective coating
`
`Break or weaken reflective coating
`
`between the LED dies
`
`Expand tacky fape again to further
`separate the LED dies
`
`b womme 12
`
`L —~ 122
`
`L 124
`
`Remove reflective coating from top
`
`of the LED dies
`
`Lo 126
`
`Transfer the LED dies to another tacky tape = om 178
`
`pnonpqRNNBIB0N000000TesttheindividualLEDdeson«dL __ 130
`the tacky tape
`
`FTG 1
`
`IKEA Supply AG
`Exhibit 1022 Page 13 of 15
`
`IKEA Supply AG
`Exhibit 1022 Page 13 of 15
`
`

`

`WO2013/118072
`
`PCT/IB2013/051009
`
`2/3
`
`~i0
`
`Prepare wafer of semiconductor
`
`devices and support
`
`IKEA Supply AG
`Exhibit 1022 Page 14 of 15
`
`IKEA Supply AG
`Exhibit 1022 Page 14 of 15
`
`

`

`WO2013/118072
`
`PCT/IB2013/051009
`
`3/3
`
`
`
`22
`
`2426
`
`22
`
`24
`
`«26
`
`IKEA Supply AG
`Exhibit 1022 Page 15 of 15
`
`IKEA Supply AG
`Exhibit 1022 Page 15 of 15
`
`