BRINK INTERNATIONAL
`
`P-119
`United Slules District [‘oun
`Eastem |Jis1|ict ui'Michlgun
`No.
`l2-L‘\'-i[HH-t‘..—\|I:\1K!\1I
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`Ei'w'h'gh: Iffam'onic: r Nichin Corp.
`
`Merrill Brink Internationai Corporation
`
`1345 Avenue of the Americas, 17th Floor
`New York, NY 10105 ' (212} 620 5600
`
`State of New York
`
`CountyofKings
`
`\n-JNJV
`
`ss:
`
`Certificate of Accuracx
`
`This is to certify that the attached:
`
`ELIGHT00001486 - ELIGHT00001499
`
`originally written in the German language is, to the best of our knowledge and belief, a true,
`accurate and complete translation into the English language.
`
`Dated: March 5, 2015
`
`
`
`y erations Manager, Legal
`erriil Brink International
`
`ansIations
`
`mama.m
`mmmmwmm
`No.01MA5057911
`Qualified In ram-3W
`Commission ExpirasAprfl 1. $13
`
`.
`
`Sworn to and signed before
`.. __ "11.1.93, this
`5th
`day of
`E March
`2015
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`OFFICES [N MAJOR CITIES THROUGHOUT THE WORLD
`A020352
`Merrill is an Equal Fmploymemgm'g and Nii-matiw: Action Employm
`
`TCL 1019, Page 1
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`LOWES 1 0 1 9 Page 1
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`LOWES 1019, Page 1
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`HIIHFIlllfltllllllllllflilifllttflitItIlllllltltltllitllitlllli
`
`(19) FEDERAL REPUBLIC
`OF GERMANY
`(12) Patent Application
`* (10} DE 196 38 667 A 1
`1'
`196 38 567.5
`(21) File number:
`GERMAN PATENT
`{22} Application date:
`sizorsa
`OFFICE
`(43) Disclosure date:
`4721’98
`
`(51} "11.01.“:
`H 01 L 33100
`
`G02F2IO2
`
`
`
`(71) Appiicant:
`Siemens AG, 30333 Munich, DE
`
`(72) Inventors:
`
`Schlotter, Peter, 79112 Freiburg, DE; Schmidt,
`Holt, 79279 Vérstetten, DE; Schneider, Jiirgen,
`Dr., 79199 Kirchzarten, DE
`
`(56) Citations:
`33 15 575 C2
`DE
`38 04 293 A1
`DE
`DE—OS 20 59 909
`Abstract of JP 07175 274 A;
`"Appl. Phys. Let." 69 (Aug. 12, 1966} 889-900;
`
`A request for examination is submitted pursuant to § 44 PatG
`
`(54) Light-emitting semiconductor element with a luminescence-converting element
`
`(57) A blended color light-emitting semiconductor ele-
`ment with radiation emitting semiconductor body (1}
`and a luminescence-converting element (4, 5). The
`semiconductor body (1) emits radiation having a
`wavelength
`A
`s
`520
`nm and
`the
`lumines—
`cence-converting element (4. 5) converts a part of
`this radiation into radiation having a higher wave-
`length.
`This makes it possible to produce light
`emitting diodes that emit multicotored light. in partic-
`ular white light. The luminescence-converting ele-
`
`ment (4. 5] contains a luminescent organic substance
`
`The lollowing intormation is taken trom documents submitted by the applicant
`BUNDESDFIUGKEHE] [Federal Priming Otlice] 02.98 802 0147138
`
`16f23
`
`DE19638667A1
`
`TRW%E'ON
`A020353
`
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`

`

`DE196 36 667 A]
`
`Description
`The invention concerns a semiconductor element
`
`that emits a mixture of colors, in particular, white light.
`There is an increasing demand in many poten—
`tial areas of application for light etnitting diodes with
`which it is possible to produce multicolored light, par—
`ticularly white light, such as, for example,
`in display
`elements, vehicle dashboards, illumination in airplanes
`and cars and in full color LED displays. So far it has only
`been possible to produce white
`”LED"
`ligltt with
`so-called multi LEDs, in which three light emitting di-
`odcs emitting different colors (in general a red, a green
`and a blue one) or two complementary-colored light
`emitting diodes tag, a blue and a yellow one) are used.
`Aside front increased assembly costs, such multi—LEDs
`require expensive control electronics, since the different
`types of diodes
`require different driving voltages.
`Long—term stability regarding the wavelength and inten-
`sity is additionally intpacted by the different aging be—
`havior of the different
`light emitting diodes and also
`because of the different driving voltages and the operat-
`ing currents resulting therefrom. An additional disad-
`vantage of the Multi-LEDs is that component miniatur-
`ization is strongly limited.
`It is the task of the present invention to develop a
`semiconductor elentent of the aforesaid kind, by means
`of which, in a technically simple manner and with as little
`use of components as possible, multicolored light,
`in
`particular white light, can be produced.
`This task is accomplished by means of a semi-
`conductor element according to Claim I. Additional
`advantageous embodiments are the objects of the de‘
`pendent claims 2 to 30. The dependent Claims 31 to 34
`disclose possible preferred applications of the semicon—
`ductor element of this invention.
`
`According to this invention, a radiation—emitting
`semiconductor body is provided with at least a firstand at
`least a second electrical contact, which is electrically
`connected to the semiconductor body, to which a lumi‘
`nescence-converting element is attached. The semicon-
`ductor has a layer sequence which emits electromagnetic
`radiation at wavelengths 3. E 520 nm. It particularly has a
`layer sequence with an active layer of Ga,Inl.,N or
`Ga,All.,N. The lumineseence—cmiverting element trans—
`forms radiation in a first wavelength range of the radia~
`tion out of a first wavelength range emitted by the sem—
`iconductor body into a second wavelength range such
`that
`the semiconductor component emits in at least a
`second spectral subrange of the first wavelength range
`and radiation in the second wavelength range. The Iu-
`minescenee—converting element
`is,
`for
`this purpose,
`provided with an inorganic luminescent compound, in
`particular a phosphor. This means, for example, that the
`luminescence—converting elelnent selectively speetrally
`absorbs a part of the radiation emitted by the semicon~
`ductor body and emits it in a longer wavelength range (in
`the second wavelength range). The radiation entitted by
`the semiconductor body ideally has a wavelength ll. 5 520
`nm at an intensity maximum.
`In an advantageous additional configuration of the
`semiconductor element according to this invention, tlte
`luminescencc—converting element consists at least in part
`
`of a transparent epoxy resin to which the organic lumi-
`nescent material
`is added. It is in fact advantageously
`possible to incorporate inorganic luminescent substanc—
`es,
`in particular phosphors,
`such
`as YAG: Ce
`{Y3A150.3:Ce+3) in the epoxy resin in a simple manner.
`Other suitable luminescent substances are other garnets
`doped with rare earths, such as YjGa50.3:Ce‘3, as well as
`alkali earth sulfides doped with rare earths, such as
`SrS:Ce+3, Na, Srs:Ce*-‘,
`(:1, SrS:CeCl_~., canoe” and
`SrSe:Cc+".
`Tbiogsallates doped with with rare earths, such as
`(IaGa:S.cCe+3 and Srfiagsifle"3 as well as aluminates
`doped with
`rare
`earths,
`such
`as YAlO3:Ce+“,
`YGa03:Ce+3, and orthosilicates doped with rare earths.
`such as
`l'\/l_sSiO_t,:Ce+3
`(M: Sc, Y, Sc),
`such as
`Y38i05:Ce+3, are capable of producing light of blended
`colors. The yttrium in all of the yttrium compounds can
`in principle be replaced by scandium or lanthanum.
`It is likewise advantageously possible, in the case
`of the semiconductor component according to this in-
`vention, to convert a nulnber {one or more) of first spec—
`tral ranges deriving from the first spectral range into
`several second wavelength ranges.
`It
`is thus advanta—
`geously possible to produce various color mixtures and
`color temperatures.
`The semiconductor element of this invention has
`
`the particular advantage that the wavelength spectrum
`produced by wavelength conversion and thus the result—
`ing color of the emitted light does not depend on the
`magnitude of the operating current passing through the
`semiconductor body. This is of particularly great
`iln—
`portance if the ambient temperature of the semiconductor
`element, and thus, as is well—known, the operating cur—
`rent, varies considerably. Light emitting diodes with a
`semiconductor body based on GaN are particularly sen—
`sitive in this regard.
`Contrary to the ntulti-LEDs mentioned above, the
`semiconductor element of this invention additionally
`needs only one driving voltage and thus only one control
`circuit, whereby the component cost cart be kept very
`low.
`
`A particularly preferred embodiment of the invert—
`tion makes use of a partially transparent, i.e., partially
`transparent
`to
`the
`radiation emitted by the
`radia~
`[ion—emitting
`semiconductor
`body,
`luntines—
`cence-converting element. To ensure a uniform color of
`the emitted light, the luminescence-converting layer can
`advantageously be designed so that
`it has a constant
`thickness throughout. According to this additional
`im-
`provement, it is a particular advantage of die semicon—
`ductor element according to this invention that a high
`reproducibility can be achieved in a simple manner,
`which is of great significance for mass production. A
`lacquer or synthetic resin layer can, for instance, be used
`as a luminescence—converting layer.
`Another preferred embodiment of the semicon-
`ductor element of this invention has a partially trans~
`parent
`luminescence-converting casing as a lumines-
`cence-converting element, which casing encloses at least
`a part of the semiconductor body (and possibly portions
`of the electrical connectors) and can be used as a
`
`museum
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`DE196 36 667 Al
`
`component casing {housing} at the same time. The ad-
`vantage of a semiconductor element according to this
`embodiment is essentially that it is possible to use pro
`duction lines that are conventionally used for producing
`conventional
`light entitling diodes (cg,
`radial
`light
`emitting diodes} to produce it. The material of the lu-
`minescence conversion casing is used as the component
`casing in place of the transparent plastic used for colt—
`vcntional light emitting diodes.
`In advantageous implementations of the semicon—
`ductor element of this invention and of aforementioned
`
`|uminescence~converting
`the
`preferred embodiments,
`layer or the luminescence—converting casing consists of a
`transparent material (e.g., a polymer such as an epoxy
`resin) to which at
`least one luminescent dye is added
`[examples of suitable polymers are provided below).
`Luminescence-comening elements can be produced
`particularly economically in this way. The process steps
`needed for this can in fact be integrated into conventional
`production lines for light emitting diodes without much
`expense.
`In a particularly preferred other implementation of
`this invention andJ'or of the aforesaid embodiments, the
`second wavelength rangets) are at least partly at a longer
`wavelength than the first wavelength range.
`It
`is in particular ensured that a second spectral
`subrange of the first wavelength range and the second
`wavelength range are complementary to each other. This
`particularly makes it possible to produce multicolored
`light, in particular white light, by means of a single—color
`light source, particularly by way ofa light emitting diode
`with a light-emitting semiconductor that only emits blue
`or green light. For example, to produce white light with a
`light emitting semiconductor body that only emits blue
`light, a portion of the spectral range emitted by the sem—
`iconductor body is converted into the yellow spectral
`range. In the process, the color temperature of the white
`light can be varied by way of a suitable selection of the
`luminescent substance and a suitable design of the lu—
`minescence—converting element
`(e.g., concerning its
`thickness and the concentration of the luminescent sub-
`
`stance). In addition, these strucmres advantageously also
`offer the possibility of using luminescent dye mixtures
`whereby the desired color tone can be readily adjusted in
`a very precise manner.
`lumineSm
`produce
`to
`It
`is
`also
`possible
`cence—converting elements in an inhomogeneous way,
`e.g., with an inhomogeneous luminescent dye distribu—
`tion. In the process, different wavelengths of the light
`produced by the luminescence—converting element can be
`compensated for in an advantageous manner.
`In a further preferred embodiment of the lumines~
`cence-converting semiconductor of this invention,
`the
`luminescence-converting elentent or another component
`easing contains one or more dyes that do not perform any
`wavelength conversion. Dyes used for the production of
`conventional
`light
`emitting
`diodes,
`e.g.,
`azo,
`anthraquinonc or perinone dyes can be used for this
`purpose as usual.
`In an advantageous furdter improvement of the
`semiconductor element according to this invention, at
`least a part of the surface of the semiconductor body is
`covered with a first transparent coating, e.g., made of a
`
`polymer, to which the luminescence-converting layer is
`applied. This reduces the radiation intensity in the luv
`minescence-converting element and thus its radiation
`exposure, which has a positive effect on the life span of
`the luminescence-converting element depending on the
`materials used.
`
`A particularly preferred further improvement of
`the invention as well as the aforementioned embodiments
`
`make use of a semiconductor body, e.g., a light emitting
`or a laser diode, in which the spectrum of the emitted
`radiation has a luminescence maximum at a wavelength
`between 420 not and 460 nm,
`in particular at 430 nm
`{e.g., semiconductor bodies based on Ga,Al._,N) or 450
`nm. (e.g., scnticonductor bodies based on Ga_,ln,_,N).
`By using such a semiconductor element according to this
`invention it is possible to produce nearly all colors and
`color combinations of the CUE color palette.
`In another particularly preferred implementation of
`the invention and its embodiments,
`the luminescence
`—converting casing andfor the luminescence—converting
`layer consists of a lacquer or a polymer, such as silicone,
`thermoplastic or
`thermosetting material
`(epoxy and
`acrylate resins) used as the casing of optoelectronic el—
`entents.
`It is furthermore possible to use covering ele-
`ments, e.g., made of thermoplastic, as
`a
`lumines-
`cence—converting layer. All aforementioned materials
`can be added to one or more luminescing materials in a
`simple manner.
`A semiconductor element according to this inven—
`tion can be realized in a particularly simple manner if the
`semiconductor body is placed in a recess of a possibly
`prefabricated housing according to a preferred imple-
`mentation and if the recess is equipped with a covering
`element with a luminescence-converting layer. Such a
`semiconductor element can be mass produced in large
`numbers in conventional production lines. To accomplish
`this, it is simply necessary for the covering element, e.g.,
`a layer of lacquer or casting resin or a prefabricated
`covering made of a thermoplastic, to be mounted on the
`housing after the semiconductor body is installed. The
`recess in the housing can optionally be filled with a
`transparent material, for exampie, a transparent polymer,
`which, e.g., does not alter the wavelength of the light
`emitted by the semiconductor body or else can, ifdesired,
`be designed to be luminescence converting. In the latter
`case, the covering element can also be omitted.
`Advantageous materials for producing the afore—
`said luminescence—coaverting layer andlor the lumines—
`cence~converting
`casing
`are,
`for
`example,
`polymethylmethacrylate (PMMA) or an epoxy resin to
`which one or more luminescing materials are added.
`In a particularly advantageous embodiment of the
`semiconductor element aCcording to this invention, at
`least all of the components of the casing through which
`light passes, i.e., the luminescence converting casing or
`layer as well, are made of purely inorganic materials. The
`luminescence converting element
`thus consists of an
`inorganic luminescent material, which is embedded in an
`inorganic material that is temperature—stable, transparent
`or partially transparent. The luminescence
`converting
`element particularly consists of an inorganic phosphor
`which is embedded in a preferably inorganic glass that
`melts at a low temperature (e.g., a silicate glass). A pre—
`
`matriarch!
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`ferred method for producing such a luminescence con-
`verting layer is the sol-gel method, by means of which
`the entire luminescence converting layer, i.c., both the
`inorganic luminescent material and the material in which
`it is embedded, can be produced in one production step.
`To improve the mixing of the radiation of the first
`wavelength range emitted by the semiconductor body
`with the radiation of the second wavelength range ob—
`tained by luminescence conversion and thus the color
`constancy of the emitted light,
`it
`is possible, in an ad—
`vantageous development of the semiconductor element
`according to the invention, to also add to the lumines-
`cence casing andl'or the luminescence conversion layer a
`dye that
`luminesces in the blue, which weakens the
`so-called directionality of the radiation emitted by the
`semiconductor body. Directionality is understood to
`signify that the radiation emitted by the semiconductor
`body has a preferred beam direction.
`In a further advantageous development of the
`semiconductor component according to dtis invention, an
`inorganic luminescent material in the form of a powder is
`used, which does not dissolve in the enveloping material
`(matrix). The inorganic luminescent material and the
`material
`in which it
`is enveloped also have different
`indexes of refraction. This advantageously causes a
`fraction of the light that is not absorbed by the lumincs‘
`cent material, depending on the grain size, to be scat-
`tered. This efficiently weakens the directionality of the
`radiation emitted by the semiconductor body so that
`unabsorbed radiation and the radiation deriving from
`luminescence conversion can be homogeneously blend—
`ed, which leads to a spatially homogeneous color im-
`pression. This is, for example, the case when YAG:Ce
`having a grain size of 4 — l3 pm is embedded in epoxy
`resin.
`
`A semiconductor element that emits white light
`can, for example, be made by mixing the inorganic lu—
`minescent material Y3A15012:Ce+3 into an epoxy resin
`used to produce the luminescence convening casing or
`layer. A portion of the blue radiation emitted by the
`semiconductor body is shifted to the yellow wavelength
`range
`by
`the
`inorganic
`luminescent material
`YgAl50,2:Ce+3 and thus into a complimentary wave-
`length region. The color tone (chromaticity coordinate in
`the CD3 Color Pallet} of the white light can then be varied
`through an appropriate choice of dye luixturc and cons
`centration.
`
`The inorganic phosphor YAG:Ce has the particular
`advantage among others that
`this concerns insoluble
`pigments (a particle size of e.g., 10 pm) with an index of
`refraction of approx. LS4. As a result a scattering effect
`takes place in addition to wave length conversion, which
`leads to a good blending of the blue diode emission and
`the yellow converter emission.
`In a further preferred implementation of a semi—
`conductor element of this invention andl'or of the aforem
`
`said advantageous embodiments, light scattering parti—
`cles, so—called diffusers, are added to the luminescence
`converting element or some other light
`transmitting
`component of the component casing. This allows the
`color impression and the directional characteristics of the
`semiconductor element to be optimized in an advanta—
`
`DE196 36 667 A]
`genus way.
`It is of particular advantage for the excitation effi—
`cicncy of white light emitting semiconductor elements of
`this invention andlor of the aforesaid embodiments to be
`
`increased considerably, as compared with the excitation
`efficiency of a light bulb, by way of a blue light emitting
`semiconductor body essentially based on GaN. The
`reason for this is that, on the one hand,
`the external
`quantum yield of such semiconductor bodies is a few
`percent and, on me other hand, the luminescence yield of
`inorganic dye molecules is often about 90%. The setu—
`iconductor element of this invention furthermore has an
`
`extremely long lifespan in comparison with a light bulb,
`it is more robust and it operates at a lower voltage.
`[I is furthermore advantageous that the brightness
`of the semiconductor element of this invention that is
`
`perceptible to the human eye as compared with a senti-
`conductor elentent that is not fitted with a luminescence
`
`is otherwise identical, can be
`converting element, but
`increased considerably because the eye‘s sensitivity in—
`creases at longer wavelengths. It is furthermore possible
`to convert ultraviolet light to visible light.
`The concept of luminescence conversion with the
`blue light of a semiconductor body presented here can
`also be advantageously extended to multiple-stage lu-
`minescence conversion elements
`according to
`the
`scheme ultraviolet —r blue —r green —~ yellow —> red. [n
`this case a number of spectrally selectively emitting
`luminescence conversion elements are disposed one
`behind the other relative to the semiconductor body.
`It is also advantageously possible to jointly embed
`several
`inorganic luminescent materials that emit in a
`spectrally selective manner in a transparent polymer of a
`luminescence-convcrting element. This makes it possible
`to produce a very wide color spectrum.
`The semiconductor elements of this invention can
`
`be employed particularly advantageously in, e.g., full
`color LED displays or for putposes of illumination in
`airplanes, motor vehicles, etc.
`A particular advantage of the white light emitting
`semiconductor elements of this
`invention based on
`
`Ce«doped phosphors, particularly Ce—doped garnets, such
`as YAG:CE, as luminescing materials is that, upon ex—
`citation with blue light,
`these luminescing materials
`effectuate a spectral shift of about 100 nm between ab—
`sorption and emission. This leads to a considerable re-
`duction in the reabsorption of the light emitted by the
`luminescent material and thus to a higher light yield.
`Such inorganic luminescing materials additionally, ad—
`vantageously and generally have a higher thermal and
`photochemical (cg, UV) stability (considerably higher
`than organic luminescent materials), so that it is possible
`to produce white light emitting diodes for exterior ap-
`plications andfor higher temperature ranges.
`Semiconductor elements of this invention can most
`
`advantageously be used for purposes of illuminating
`motor vehicle interiors and airplane cabins as well as for
`displays, such as such as motor vehicle dashboards or
`liquid crystal displays, particularly because of their low
`power consumption in full color LED displays.
`
`TRaaaasION
`A020356
`
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`

`DE196 36 667 A]
`
`Further characteristics, advantages and expediencies of
`the invention are provided via the following description
`of nine example embodiments in connection with Figs.
`l
`to IE, which show:
`Fig. I a schematic cutaway view of a first example em—
`bodiment of a semiconductor element of this invention;
`Fig. 2 a schematic cutaway view of a second example
`embodiment of a semiconductor element of this inven—
`tion;
`Fig. 3 a schematic cutaway view of a third example
`embodiment of a semiconductor element of this inven-
`tion;
`Fig. 4 a schematic cutaway view of a fourth example
`embodiment of a semiconductor element of this inven-
`tion;
`Fig. 5 a schematic cutaway view of a fifth example em-
`bodiment of a semiconductor element of this invention;
`Fig. 6 a schematic cutaway view of a sixth example
`embodiment of a semiconductor element of this inven—
`tion;
`Fig. 7 a schematic representation of an emission spec-
`trum of a blue light emitting semiconductor body with a
`layer sequence based on GaN;
`Fig. 8 a schematic representation of the emission spectra
`of two semiconductor elements of this invention, which
`emit white light;
`Fig. 9 a schematic sectional view of a semiconductor
`body, which emits blue light;
`Fig. 10 a schematic cutaway view of a seventh example
`embodiment of a semiconductor element of this inven—
`tion;
`Fig. I] a schematic cutaway view of a eighth example
`embodiment of a semiconductor element of this inven-
`tion; and
`Fig. 12 a schematic cutaway view of a ninth example
`embodiment of a semiconductor element of this inven—
`
`tion; and
`Equivalent andlor equivalent acting parts are a]—
`ways assigned the same reference symbols in the dif—
`ferent figures.
`In the case of the light emitting semiconductor
`element shown in Fig. l. a semiconductor body I, e.g., a
`light emitting diode or a laser diode, has a back side
`contact 11, a front side contact 12 and of a sequence of
`layers 7 consisting of a number of different layers having
`at least one radiation emitting [e.g., ultraviolet, blue or
`green light emitting) active zone.
`An example of a suitable sequence of layers 7 of
`this and all embodiments described hereinafter is shown
`
`in Fig. 9. In this case. a sequence of layers consisting of
`an AIN or a GaN layer l9, an n—conducting GaN layer 20,
`an n-conducting Ga,Al._xN or a Ga,[n._xN layer 21. an
`additional n-conducting GaN or Ga,[11._,N layer 22, a
`p—conducting Ga,Al|_XN 01' Ga,In;_XN layer 23 and a
`p-conducting GaN layer 24 is deposited on a principal
`substrate 18 consisting of, for example. SiC. A contact
`metallization 27, 28 made of a material conventionally
`used for electrical contacts in semiconductor technology
`is deposited on the top surface 25 of the p—conducting
`GaN layer 24 and the top surface 26 of the substrate l8.
`It is however possible to use any other semicon—
`
`ductor body, which an expert considers to be suitable, as
`the semiconductor element of this invention. This also
`
`applies to all embodiments described hereafter.
`In the example embodiment of Fig. I. the semi-
`conductor body 1 is fastened by way of its back side
`contact 11 to a first electrical contact 2 by means of an
`electrically conducting connecting device, e.g., a metallic
`solder or an adhesive. The front side contact 12 is con—
`
`nected with a second electrical contact 3 by means of a
`bond wire 14.
`
`The semiconductor body 1 and portions of the
`electrical contacts 2 and 3 are entirely enclosed in a
`luminescence conversion casing 5. The latter, for exam-
`ple, consists of a transparent polymer that is usable for
`transparent light emitting diode casings (cg, epoxy resin
`or polymethyimetacrylate) or an inorganic glass that
`melts at a low temperature,
`into which an inorganic
`phosphor 6, e.g., Y_;A150|2:Ce+3{YAG:Ce) is admixed in
`order to produce a white light emitting semiconductor
`element.
`
`The example embodiment of a semiconductor
`element of this invention shown in Fig. 2 differs from
`that in Fig. l in that the semiconductor body I and por-
`tions of the electrical contacts 2 and 3 are enclosed in a
`
`transparent casing 15 instead of a luminescence conver—
`sion casing. This transparent casing 15 does not cause the
`wavelength of the radiation emitted by the semiconductor
`body 1 to change and consists, for example, of an epoxy,
`silicone or acrylate resin or another suitable material,
`such as inorganic glass.
`A luminescence converting layer 4, which covers
`the entire surface of the transparent casing 15 as shown in
`Fig. 2, is applied onto this casing 15. It is also conceiv-
`able for the luminescence converting layer 4 to cover
`only a portion of this surface. The luminescence con-
`vetting layer 4 again, for example, consists of a traits—
`parent
`polymer
`{e.g.,
`epoxy
`resin,
`lacquer
`or
`polymethyimetacrylate) or of an inorganic glass to which
`an inorganic phosphor 6 is added. In this case, as well, a
`suitable phosphor for a white light emitting semicon-
`ductor element is, for example, YAG:Ce.
`the previously
`This example embodiment has
`mentioned particular advantage that the wavelength of
`the radiation emitted by the semiconductor body in
`passing through the radiation-converting element is ap-
`proximately the same. This plays a particularly important
`role if, as it is often the case, the exact color shade of the
`light emitted by the semiconductor element depends on
`this wavelength.
`A lens-shaped cover 29 {shown by a dashed line).
`which reduces total reflection of the radiation within the
`
`luminescence-converting layer, can be installed on a side
`surface of the component for purposes of improved de-
`coupling of the light from the luminescence—converting
`layer 4 of Fig. 2. This lens-shaped cover 29 can consist of
`transparent plastic or glass and can, for example, be
`glued onto the luminescence converting layer 4 or it can
`be made to be an intimate component of the lumines—
`cence converting layer 4.
`In the example embodiment shown in Fig. 3, the
`first and second electrical contacts 2, 3 are embedded in
`
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`DE196 36 667 A]
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`an opaque possibly prefabricated basic housing 8 with a
`recess 9. The word "prefabricated" is to be understood
`to mean that the basic housing 8 has been previously
`molded onto the contacts 2, 3, e.g., by injection molding,
`before the semiconductor body is mounted onto the
`contact 2. The basic housing 8 can, for example, be
`made of an intransparent polymer and the recess 9 is
`configured as a reflector17{possibly by way of a suitable
`coating of the inner walls of the recess 9). Such basic
`housings 8 have been used for some tinte, in particular in
`surface—mountable
`light
`emitting
`diodes
`(SMD
`TOPLEDs), and are therefore not described in greater
`detail here. They are mounted on a conducting strip
`(leadframe) having the electric contacts 2, 3 prior to the
`installation of the semiconductor bodies.
`
`lumincsm
`a
`by
`covered
`is
`9
`recess
`The
`cence-converting layer 4, for example, a cover plate I?
`made of a polymer, which is produced separately and is
`fastened onto the basic housing 8. Suitable materials for
`the luminescence converting layer 4 are again the poly—
`mers mentioned above in the general description or an
`inorganic glass along with the inorganic phosphors
`mentioned there. The recess 9 can be filled with a
`
`transparent polymer, an inorganic glass or with gas and
`evacuated.
`
`As in the example embodiment according to Fig. 2,
`a lens-shaped cover 29 (shown by a dashed line), which
`reduces the total reflection of the radiation within the
`
`luminescence converting layer 4, can be provided here as
`well for purposes of improved decoupling of the light
`from the luminescence converting layer 4. This cover 29
`can also be made of a transparent polymer or inorganic
`glass and can be glued onto the lumineseonce—converting
`layer or it can be an integral part of the luminescence
`converting layer 4.
`It is also possible to till the recess 9 with a polymer
`or glass containing an inorganic phosphor 6, as shown in
`Fig. 10, i.e., containing a luminescence casing 5, which
`forms the luminescence conversion element. A cover
`
`plate 17 andfor a lens—shaped cover 29 can then also be
`left out. In addition, the first electric contact 2 is option-
`ally configured as a reflecting trough 34, which is filled
`with a luminescence-converting casing 5, by for exam-
`ple. embossing in the area of the semiconductor body 1 as
`shown in Fig. 11.
`Fig. 4 shows a so-called radial diode as another
`example etnbodintent.
`In this case the semiconductor
`body is fastened to a part 16 of the electrical contact 2
`forming a reflector by e.g., soldering or gluing it on. Such
`housing designs are also well—known in light emitting
`diode technology and therefore require no further ex-
`planation.
`In the example embodiment of Fig. 4 the semi-
`conductor body 1
`is enveloped by a transparent casing
`15, which does not effectuate a change in the wavelength
`of the radiation etnitted by the semiconductor body 1 as
`in the second example embodiment (Fig 2) and which
`can be tirade of an epoxy resin or an inorganic glass
`conventionally used in light emitting diode technology.
`A luminescence—eonverting layer is applied onto
`this transparent casing 15. Suitable materials for this are,
`for example, the polymers mentioned in connection with
`the foregoing example embodiments or inorganic glass
`
`together with the aforesaid phosphors.
`The entire structure, consisting of a semiconductor
`body 1, subdomains of the electrical contacts 2, 3, a
`transparent casing 15 is enclosed in a further transparent
`casing, which does not cause the wavelength of the light
`passing through the luminescence converting layer 4 to
`change. It is, for example, again made of a transparent
`epoxy resin 01' glass conventionally used in light emitting
`diode technology.
`The example embodiment shown in Fig. 5 essen—
`tially differs front that in Fig. 4 in that the free surfaces of
`the semiconductor body 1 are directly covered by a lu-
`minescence—converting easing 5, which is in turn en—
`veloped by a further transparent casing 10. Fig. 5 fur-
`thermore shows an example of a semiconductor body 1 in
`which’ instead of the back side contact 11, an additional
`contact is affixed to the semiconductor layer sequence 7,
`which contact is connected to the associated electrical
`
`contact 2 or 3 by means of a second bond wire 14. Such
`semiconductor bodies 1 are of