By:
`
`P-119
`United States District Court
`Eastem District of Michigan
`No. 12-C'V-11758-GADXMEM)
`
`Everlight Electronics v. Nichia Corp.
`
`Date Admitted:
`
`MERRILL
`BRINK INTERNATIONAL
`Merrill Brink International Corporation
`
`1345 Avenue of the Americas, 17th Floor
`New York, NY 10105 * (212) 620 5600
`
`State of New York
`
`County of Kings
`
`Smee”eeeee”
`
`$s:
`
`Certificate of Accuracy
`
`This is to certify that the attached:
`
`ELIGHT00001486 - ELIGHT00001499
`
`originally written in the German languageis, to the best of our knowledge andbelief, a true,
`accurate and complete translation into the English language.
`
`Dated: March 5, 2015
`
`
`
`jiCperrl Brink International
`
`Sworn to and signed before
`si:this
`chi
`day of
`Cc JA
`+ March
`2015
`3ga
`NotaryPublic, State ofNewYork. - rp
`
`
`Notary Public
`
`ROBERTJ.MAZZA
`Gone
`
`Kings County
`Commission ExpiresApril 1, 2018
`
`OFFICES IN MAJOR CITIES THROUGHOUT THE WORLD
`Merrill is an Equal Employmeng@apg'g.5and Atfirmative Action Employer
`A020352
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`9
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`

`

`S
`
`mw
`
`S
`S
`wo
`os
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`oa
`
`a L
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`u a
`
`cc
`
`(19) FEDERAL REPUBLIC
`
`OF GERMANY
`oR
`*
`GERMAN PATENT
`OFFICE
`
`«2) Patent Application
`io) DE 196 38 667 A 1
`(21) File number:
`196 38 667.5
`(22) Application date: 9/20/96
`(43) Disclosure date:
`4/2/98
`
`(51)
`
`Int. Cl.°:
`H 01 L 33/00
`
`G 02 F 2/02
`
`
`
`(71) Applicant:
`Siemens AG, 80333 Munich, DE
`
`(72) Inventors:
`
`Schlotter, Peter, 79112 Freiburg, DE; Schmidt,
`Rolf, 79279 Vorstetten, DE; Schneider, Jurgen,
`Dr., 79199 Kirchzarten, DE
`
`(56) Citations:
`33 15 675 C2
`DE
`38 04 293 Al
`DE
`DE-OS 2059909
`Abstract of JP 07 175 274 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
`
`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 the_lumines-A s 520 nm and
`
`
`
`
`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 multicolored light, in partic-
`ular white light. The luminescence-converting ele-
`
`(57)
`
`ment (4, 5) contains a luminescent organic substance
`
`DE19638667Al
`
`The following information is taken from documents submitted by the applicant
`BUNDESDRUCKERE!I [Federal Printing Office] 02.98 802 014/138
`
`16/23
`
`TRANSbSSBION
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`DE 196 36 667 Al
`
`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 emitting 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"
`light with
`so-called multi LEDs, in which three light emitting di-
`odes emitting different colors (in general a red, a green
`and a blue one) or two complementary-colored light
`emitting diodes (e.g., a blue and a yellow one) are used.
`Aside from increased assembly costs, such multi-LEDs
`require expensive control electronics, since the different
`types of diodes
`require different driving voltages.
`Long-termstability regarding the wavelength and inten-
`sity is additionally impacted 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 element of the aforesaid kind, by means
`of which, in a technically simple mannerand with aslittle
`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 1. 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 first and 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 4 <520 nm. It particularly has a
`layer sequence with an active layer of Ga,In,,.N_
`or
`Ga,Al,..N. The luminescence-converting 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 lu-
`minescence-converting element
`is,
`for
`this purpose,
`provided with an inorganic luminescent compound, in
`particular a phosphor. This means, for example, that the
`luminescence-converting element selectively spectrally
`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 emitted by
`the semiconductor body ideally has a wavelength 4 < 520
`nm at an intensity maximum.
`In an advantageous additional configuration of the
`semiconductor element according to this invention, the
`luminescence-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 substane-
`es,
`in particular phosphors,
`such
`as YAG: Ce
`(Y3A1;0)9:Ce*) in the epoxy resin in a simple manner.
`Other suitable luminescent substances are other garnets
`doped with rare earths, such as Y,Ga;O)9:Ce™, as well as
`alkali earth sulfides doped with rare earths, such as
`SrS:Ce"’, Na, SrS:Ce**, Cl, SrS:CeCl;, CaS:Ce** and
`SrSe:Ce™.
`Thiogsallates doped with with rare earths, such as
`CaGapS.Ce* and SrGa,S4:Ce** as well as aluminates
`doped with
`rare
`earths,
`such
`as YAIO,:Ce™,
`YGaO;:Ce™*, and orthosilicates doped with rare earths,
`such as M,SiO.:Ce* (M: Se, Y, Sc),
`such as
`Y,SiOs:Ce™, 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 number(one or more) offirst 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
`im-
`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 multi-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 can be kept very
`low.
`
`A particularly preferred embodiment of the inven-
`tion makes use of a partially transparent, i.e., partially
`transparent
`to
`the
`radiation emitted by the
`radia-
`tion-emitting
`semiconductor
`body,
`lumines-
`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 the 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
`
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`DE 196 36 667 Al
`component casing (housing) at the same time. The ad-
`polymer, to which the luminescence-converting layer is
`applied. This reduces the radiation intensity in the lu-
`vantage of a semiconductor element according to this
`embodiment is essentially that it is possible to use pro-
`minescence-converting element and thus its radiation
`duction lines that are conventionally used for producing
`exposure, which has a positive effect on the life span of
`conventional
`light emitting diodes (e.g.,
`radial
`light
`the luminescence-converting element depending on the
`materials used.
`emitting diodes) to produce it. The material of the lu-
`minescence conversion casing is used as the component
`A particularly preferred further improvement of
`the invention as well as the aforementioned embodiments
`casing in place of the transparent plastic used for con-
`ventional light emitting diodes.
`make use of a semiconductor body, e.g., a light emitting
`In advantageous implementations of the semicon-
`or a laser diode, in which the spectrum of the emitted
`ductor element of this invention and of aforementioned
`radiation has a luminescence maximumat a wavelength
`preferred embodiments,
`the
`luminescence-converting
`between 420 nm and 460 nm,
`in particular at 430 nm
`layer or the luminescence-converting casing consists of a
`(e.g., semiconductor bodies based on Ga,Al,_,.N) or 450
`transparent material (e.g., a polymer such as an epoxy
`nm. (e.g., semiconductor bodies based on Ga,In,..N).
`resin) to which at
`least one luminescent dye is added
`By using such a semiconductor element accordingto this
`(examples of suitable polymers are provided below).
`invention it is possible to produce nearly all colors and
`Luminescence-converting elements can be produced
`color combinations of the CIE color palette.
`particularly economically in this way. The process steps
`In anotherparticularly preferred implementation of
`the invention and its embodiments,
`the luminescence
`needed for this can in fact be integrated into conventional
`production lines for light emitting diodes without much
`-converting casing and/or the luminescence-converting
`expense.
`layer consists of a lacquer or a polymer, such as silicone,
`In a particularly preferred other implementation of
`thermoplastic or
`thermosetting material
`(epoxy and
`this invention and/or of the aforesaid embodiments, the
`acrylate resins) used as the casing of optoelectronic el-
`second wavelength range(s) are at least partly at a longer
`ements.
`It is furthermore possible to use covering ele-
`wavelengththan the first wavelength range.
`ments, e.g., made of thermoplastic, as
`a
`lumines-
`It
`is in particular ensured that a second spectral
`cence-converting layer. All aforementioned materials
`subrange of the first wavelength range and the second
`can be added to one or more luminescing materials in a
`wavelength range are complementary to each other. This
`simple manner.
`particularly makes it possible to produce multicolored
`A semiconductor element according to this inven-
`tion can be realized in a particularly simple manner if the
`light, in particular white light, by means of a single-color
`semiconductor body is placed in a recess of a possibly
`light source, particularly by way ofa light emitting diode
`with a light-emitting semiconductor that only emits blue
`prefabricated housing according to a preferred imple-
`or green light. For example, to produce white light with a
`mentation and if the recess is equipped with a covering
`light emitting semiconductor body that only emits blue
`element with a luminescence-converting layer. Such a
`light, a portion of the spectral range emitted by the sem-
`semiconductor element can be mass produced in large
`iconductor body is converted into the yellow spectral
`numbers in conventional production lines. To accomplish
`range. In the process, the color temperature of the white
`this, it is simply necessary for the covering element, e.g.,
`light can be varied by way of a suitable selection of the
`a layer of lacquer or casting resin or a prefabricated
`luminescent substance and a suitable design of the lu-
`covering made of a thermoplastic, to be mounted on the
`minescence-converting element
`(e.g., concerning its
`housing after the semiconductor body is installed. The
`thickness and the concentration of the luminescent sub-
`recess in the housing can optionally be filled with a
`stance). In addition, these structures advantageously also
`transparent material, for example, a transparent polymer,
`offer the possibility of using luminescent dye mixtures
`which, e.g., does not alter the wavelength of the light
`whereby the desired color tone can be readily adjusted in
`emitted by the semiconductor body orelse can, if desired,
`a very precise manner.
`be designed to be luminescence converting. [n the latter
` lumines-
`produce
`to
`It
`is
`also
`possible
`case, the covering element can also be omitted.
`cence-converting elements in an inhomogeneous way,
`Advantageous materials for producing the afore-
`e.g., with an inhomogeneous luminescent dye distribu-
`said luminescence-converting layer and/or the lumines-
`tion. In the process, different wavelengths of the light
`cence-converting
`casing
`are,
`for
`example,
`produced by the luminescence-converting element can be
`polymethylmethacrylate (PMMA) or an epoxy resin to
`compensatedfor in an advantageous manner.
`which one or more luminescing materials are added.
`In a further preferred embodiment of the lumines-
`In a particularly advantageous embodiment of the
`cence-converting semiconductor of this invention,
`the
`semiconductor element according to this invention, at
`luminescence-converting element or another component
`least all of the components of the casing through which
`casing contains one or more dyes that do not perform any
`light passes, i.e., the luminescence converting casing or
`wavelength conversion. Dyes used for the production of
`layer as well, are made of purely inorganic materials. The
`luminescence converting element
`thus consists of an
`conventional
`light
`emitting
`diodes,
`e.g.,
`azo,
`anthraquinone or perinone dyes can be used for this
`inorganic luminescent material, which is embedded in an
`inorganic material that is temperature-stable, transparent
`purpose as usual.
`In an advantageous further improvement of the
`or partially transparent. The luminescence
`converting
`semiconductor element according to this invention, at
`element particularly consists of an inorganic phosphor
`which is embedded in a preferably inorganic glass that
`least a part of the surface of the semiconductor body is
`covered with a first transparent coating, e.g., made of a
`melts at a low temperature (e.g., a silicate glass). A pre-
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`DE 196 36 667 Al
`geous way.
`ferred method for producing such a luminescence con-
`It is of particular advantage for the excitation effi-
`verting layer is the sol-gel method, by means of which
`the entire luminescence converting layer, i.e., both the
`ciency of white light emitting semiconductor elements of
`this invention and/or of the aforesaid embodiments to be
`inorganic luminescent material and the material in which
`it is embedded, can be produced in one productionstep.
`increased considerably, as compared with the excitation
`To improve the mixing of the radiation of thefirst
`efficiency of a light bulb, by way ofa blue light emitting
`wavelength range emitted by the semiconductor body
`semiconductor body essentially based on GaN. The
`reason for this is that, on the one hand,
`the external
`with the radiation of the second wavelength range ob-
`tained by luminescence conversion and thus the color
`quantum yield of such semiconductor bodies is a few
`constancy of the emitted light,
`it
`is possible, in an ad-
`percent and, on the other hand, the luminescence yield of
`vantageous development of the semiconductor element
`inorganic dye molecules is often about 90%. The sem-
`iconductor element of this invention furthermore has an
`according to the invention, to also add to the lumines-
`cence casing and/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 beamdirection.
`In a further advantageous development of the
`semiconductor component according to this invention, an
`inorganic luminescent material in the form of a powderis
`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 lightthat is not absorbed by the lumines-
`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 - 13 umis embedded in epoxy
`resin.
`
`extremely long lifespan in comparison with a light bulb,
`it is more robust and it operates at a lower voltage.
`[t is furthermore advantageous that the brightness
`of the semiconductor element of this invention that is
`perceptible to the human eye as compared with a semi-
`conductor element thatis not fitted with a luminescence
`converting element, but
`is otherwise identical, can be
`increased considerably because the eye's sensitivity in-
`creases at longer wavelengths. It is furthermore possible
`to convertultraviolet 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
`schemeultraviolet — blue — green — yellow — red. In
`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 mannerin a transparent polymer of a
`luminescence-converting element. This makes it possible
`to produce a very wide color spectrum.
`The semiconductor elements of this invention can
`
`A semiconductor element that emits white light
`can, for example, be made by mixing the inorganic lu-
`minescent material Y»Al;Oy:Ce™ into an epoxy resin
`used to produce the luminescence converting 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
`Y,A1,O,5:Ce** and thus into a complimentary wave-
`length region. The color tone (chromaticity coordinate in
`the CIE ColorPallet) of the white light can then be varied
`through an appropriate choice of dye mixture and con-
`centration.
`
`The inorganic phosphor YAG:Cehasthe particular
`advantage among others that
`this concerns insoluble
`pigments (a particle size of e.g., 10 um) with an index of
`refraction of approx. 1.84. 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 and/or ofthe afore-
`
`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-
`
`be employed particularly advantageously in, e.g., full
`color LED displays or for purposes 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 (e.g., UV) stability (considerably higher
`than organic luminescent materials), so that it is possible
`to produce white light emitting diodes for exterior ap-
`plications and/or 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.
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`DE 196 36 667 Al
`
`Further characteristics, advantages and expediencies of
`the invention are provided via the following description
`of nine example embodiments in connection with Figs.
`|
`to 12, which show:
`Fig. 1 a schematic cutaway view ofa first example em-
`bodiment of a semiconductor clementof 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 elementof 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. 11 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 and/or equivalent acting parts are al-
`ways assigned the same reference symbols in the dif-
`ferent figures.
`In the case of the light emitting semiconductor
`element shown in Fig. 1, a semiconductor body 1, ¢.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 numberofdifferent 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 ora GaNlayer 19, an n-conducting GaN layer 20,
`an n-conducting Ga,Al,_xN or a Ga,Inj,N layer 21, an
`additional n-conducting GaN or Ga,In),.N layer 22, a
`p-conducting Ga,Al,,N or Ga,Inj,N 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 18.
`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. 1, the semi-
`conductor body I 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 I 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
`transparentlight emitting diode casings (e.g., epoxy resin
`or polymethylmetacrylate) or an inorganic glass that
`melts at a low temperature,
`into which an inorganic
`phosphor6, e.g., Y3Al;0)9:Ce*™ (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. 1 in that the semiconductor body 1 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-
`verting layer 4 again, for example, consists of a trans-
`parent
`polymer
`(e.g.,
`epoxy
`resin,
`lacquer
`or
`polymethylmetacrylate) 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 dashedline),
`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 ofthe 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 secondelectrical contacts 2, 3 are embedded in
`
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`LOWES 1019, Page 6
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`DE 196 36 667 Al
`an opaque possibly prefabricated basic housing 8 with a
`together with the aforesaid phosphors.
`recess 9. The word “prefabricated” is to be understood
`The entire structure, consisting of a semiconductor
`to mean that the basic housing 8 has been previously
`body 1, subdomains of the electrical contacts 2, 3, a
`molded onto the contacts 2, 3, e.g., by injection molding,
`transparent casing 15 is enclosed in a further transparent
`casing, which does not cause the wavelength ofthe light
`before the semiconductor body is mounted onto the
`contact 2. The basic housing 8 can, for example, be
`passing through the luminescence converting layer 4 to
`made of an intransparent polymer and the recess 9 is
`change. It is, for example, again made of a transparent
`epoxy resin or glass conventionally used in light emitting
`configured as a reflector 17 (possibly by way of a suitable
`coating of the inner walls of the recess 9). Such basic
`diode technology.
`housings 8 have been used for sometime, in particular in
`The example embodiment shown in Fig. 5 essen-
`surface-mountable
`light
`emitting
`diodes
`(SMD
`tially differs fromthat in Fig. 4 in that the free surfaces of
`TOPLEDs), and are therefore not described in greater
`the semiconductor body 1 are directly covered by a lu-
`detail here. They are mounted on a conducting strip
`minescence-converting casing 5, which is in turn en-
`(leadframe) having the electric contacts 2, 3 prior to the
`veloped by a further transparent casing 10. Fig. 5 fur-
`installation of the semiconductor bodies.
`thermore shows an example of a semiconductor body 1 in
`lumines-
`a_
`The
`recess
`9
`is
`covered
`by
`which, instead ofthe back side contact 11, an additional
`cence-converting layer 4, for example, a cover plate 17
`contact is affixed to the semiconductor layer sequence 7,
`which contact is connected to the associated electrical
`made of a polymer, which is produced separately and is
`fastened onto the basic housing 8. Suitable materials for
`contact 2 or 3 by means of a second bond wire 14. Such
`the luminescence converting layer 4 are again the poly-
`semiconductor bodies 1 are of course also employable in
`mers mentioned above in the general description or an
`all
`the other example embodiments described herein.
`inorganic glass along with the inorganic phosphors
`Conversely,
`it is naturally also possible to employ a
`mentioned there. The recess 9 can be filled with a
`semiconductor body 1 in accordance with the aforemen-
`tioned example embodiments in the example embodi-
`mentof Fig. 5.
`it should also be
`For the sake of completeness,
`mentioned here that,
`in the case of the configuration
`according to Fig. 5, it is naturally also possible to use a
`one-piece luminescence conversion casing 5, whichthen,
`in analogy with the example embodimentof Fig 1, takes
`the place of the combination consisting of the lumines-
`cence conversion casing 5 and a further transparent cas-
`ing 10.
`In the example embodiment of Fig. 6, a lumines-
`cence-converting layer 4 (possible materials as indicated
`above) is applied directly to the semiconductor body 1.
`The latter and portions of the electrical contacts 2, 3 are
`enveloped in an additional transparent casing 10, which
`does not cause the wavelength of light passing through
`the luminescence converting layer 4 to change and which
`is, for instance, made of a transparent epoxy resin or glass
`usable in light emitting diode technology.
`Such semiconductor bodies 1 without a casing
`provided with a luminescence-converting layer 4 can
`naturally be used advantageously in all kinds of housings
`(e.g., SMD housings, radial housings (see Fig. 5)) known
`in light emitting technology.
`In the example embodiment of a semiconductor
`component of this invention shown in Fig. 12, a trans-
`parent trough-shaped part 35 is located on the semicon-
`ductor body 1, which forms a trough 36 over the semi-
`conductor body 1. The trough-shapedpart is, for exam-
`ple, made of transparent epoxy resin or inorganic glass
`and is for example, made by insert molding around the
`electrical contacts 2, 3, including the semiconductor body
`1. This trough contains a luminescence converting layer
`4, which is for example, again made of epoxy resin
`and/or inorganic glass in which particles 37 made of one
`of the aforesaid inorganic phosphors are embedded. This
`design makes it possible to ensure in a very simple way
`that
`the phosphor does not accumulate in unexpected
`places, e.g., near the semiconductor body, during the
`production of the semicondu