CN1983651A - Light-emitting semiconductor device and device containing the same - Google Patents

Abstract

The present invention relates to a light emitting semiconductor device and a device including the light emitting semiconductor device. To improve the light-emitting semiconductor device, according to the invention, it has a semiconductor multilayer structure which is suitable for emitting electromagnetic radiation in the first wavelength range during operation of the semiconductor device. The luminescence conversion element converts the ray from the first wavelength band into the ray of the second wavelength band different from the first wavelength band and emits the ray, so that the semiconductor device emits visible electromagnetic radiation including the first wavelength band. The mixed color light of the ray and the visible electromagnetic ray of the second wavelength band. The radiation emitted by the semiconductor body has a relative intensity maximum at a wavelength λ≤520nm, and the wavelength range spectrally selectively absorbed by the luminescence conversion element lies outside the intensity maximum. Therefore, a simple process method can be adopted for mass production, and the reproducibility characteristics of the device can be guaranteed to the greatest extent.

Description

Light-emitting semiconductor device and device including the light-emitting semiconductor device

This application is a divisional application of the invention patent application with the application number 200510091728.0, the application date is June 26, 1997, and the invention title is "radiation-emitting semiconductor chip and device including the semiconductor chip".

technical field

The present invention relates to a light emitting semiconductor device, a display device using the light emitting semiconductor device, and an application of the light emitting semiconductor device in an aircraft cabin.

Background technique

Semiconductor devices of this type are known, for example, from DE 38 04 293 of the open document. The structure of an electrically excited light emitting diode or laser diode is described. In this structure, the entire emission spectrum emitted by the diode is shifted towards larger wavelengths by a plastic element doped with a fluorescent light-changing organic dye. As a result of this measure, the structure emits light of a different color than the light-emitting diode. By mixing different kinds of dyes in the plastic, the same light-emitting diode can be used to make light-emitting diode structures that emit light of different colors.

In DE-OS 2 347 289 an infrared (IR) solid-state lamp is disclosed, in which a luminescent material is coated on the edge of an IR diode so that the IR radiation emitted there is converted into visible light. The purpose of this measure is to convert the smallest possible fraction of the IR radiation emitted by the diode into visible light while reducing the intensity of the IR radiation emitted by the diode as little as possible for control purposes.

In addition, a light-emitting diode has been published in EP 486 052, wherein at least one semiconductor photoluminescent layer is arranged between the substrate and a layer of active electroluminescent layer, and the emission from the active layer toward the substrate The light of the first wavelength band is converted into the light of the second wavelength band, so that the light-emitting diode emits light of various different wavelength bands in total.

Strict requirements are placed on light-emitting diodes in many promising areas of application, such as display elements on Kfz instrument panels, interior lighting of aircraft and automobiles, and in light-emitting diode displays capable of emitting full-color light , enabling it to produce mixed light, especially white light.

Introduced in JP-07 176 794-A a kind of planar light source that emits white light, two light-emitting diodes that emit blue light are arranged at the front end of one of the transparent plates, and emit light to the inside of the transparent plate. One of the two main surfaces of the transparent plate facing oppositely is coated with a coating of luminescent substance, which emits light when it is excited by the blue light of the diode. The light emitted by the luminescent substance has a different wavelength than the blue light emitted by the diode. However, it is difficult to coat the fluorescent substance which can make the light source emit uniform white light in this way with the element of this known structure. In addition to this, reproducibility in mass production has become a big problem, since even slight variations in the thickness of the phosphor layer, e.g. due to uneven surfaces of the transparent plate, can lead to variations in the white hue of the emitted light .

Contents of the invention

The basic task of the invention is to provide a semiconductor chip in the manner described at the outset, which emits mixed colors uniformly, which can be produced in large quantities using simple technological methods and which ensures maximum reproducibility of the device. sexual characteristics.

According to one aspect of the present invention, there is provided a light emitting semiconductor device comprising: a semiconductor body emitting electromagnetic radiation when said semiconductor device is in operation; at least one first and at least one second conductive lead connected to said The semiconductor body is electrically conductively connected to; and a luminescence conversion element comprising at least one luminescent material. The semiconductor body has a semiconductor multilayer structure which is suitable for emitting electromagnetic radiation in a first wavelength range during operation of the semiconductor component. The luminescence conversion element converts the ray from the first wavelength band into the ray of the second wavelength band different from the first wavelength band and emits the ray, so that the semiconductor device emits light including the first wavelength band. The mixed color light of the visible electromagnetic ray in the wavelength band and the visible electromagnetic ray in the second wavelength band. The radiation emitted by the semiconductor body has a relative intensity maximum at a wavelength λ≤520 nm, and the wavelength range spectrally selectively absorbed by the luminescence conversion element lies outside the intensity maximum.

According to a further aspect of the invention, an aircraft cabin interior lighting is provided, in which the radiation-emitting semiconductor chip described above is used.

According to still another aspect of the present invention, a display device is provided, which includes a plurality of said semiconductor chips, and said semiconductor chips are arranged to illuminate a display of the display device.

According to yet another aspect of the present invention, a full-color LED display device is provided, including a plurality of the above-mentioned semiconductor chips emitting rays.

According to the provisions of the present invention, the light-emitting semiconductor body is a multilayer structure, in particular an active semiconductor multilayer structure made of _{GaxIn1 -xN} or _{GaxAl1 -xN} , in the semiconductor When the device works, it emits an electromagnetic ray of a first wavelength band consisting of ultraviolet, blue and/or green spectral bands. The luminescence conversion element converts a part of the radiation from the first wavelength band into a second wavelength band of radiation in the following manner, that is, the polychromatic radiation is emitted by the semiconductor device, especially the radiation from the first wavelength band and the second wavelength band The mixed color light composed of rays. That is to say, for example, the luminescence conversion element preferentially selects only one spectral segment in the first wavelength range from the radiation emitted by the semiconductor body for selective absorption, and then emits in a longer wavelength range (in the second wavelength range). It is preferred to select a relative intensity maximum in the radiation emitted by the semiconductor body with a wavelength of λ≤520nm, while the wavelength range in the spectrum selectively absorbed by the luminescence conversion element is outside this intensity maximum.

Another advantage of using according to the invention is that several (one or more) first spectral bands from the first wavelength band can be transformed into a plurality of second wavelength bands. Advantages of multiple color mixing and color temperature are thus also possible.

The semiconductor component according to the invention has the particular advantage that the wavelength spectrum produced by the luminescence conversion and thus the emitted light color is independent of the magnitude of the operating current flowing through the semiconductor body. This advantage is of particular significance when the ambient temperature of the semiconductor component changes, and thus the well-known severe changes in the operating current intensity. In particular a light-emitting diode based on a GaN-based semiconductor body is sensitive in this respect.

In addition, the semiconductor device according to the invention requires only one single control voltage and thus also only one single control voltage configuration, so that the setup outlay required for the control circuit of the semiconductor device is kept to a minimum.

In a particularly preferred embodiment according to the invention, a partially transparent luminescence conversion layer is arranged on or on the semiconductor body, that is to say a partially transparent luminescence conversion layer for the radiation emission of the radiation-emitting semiconductor body . In order to ensure that the emitted light must have a uniform color, it is preferred to make the luminescence conversion layer into a structure with such a constant transmission path, which has a particularly good advantage, so that the light emitted by the semiconductor body in all emission directions can pass through. The path length through the luminescence conversion layer is almost constant. This can only be achieved if the semiconductor device emits the same light in all directions. A further particularly advantageous advantage of a semiconductor component according to the invention according to the improved structure is that a high degree of reproducibility can be achieved with simple methods, which is important for efficient mass production. As the luminescence conversion layer, for example, a varnish layer or a resin layer doped with a luminescent material can be used.

Another preferred embodiment according to the invention is a luminescence conversion element made of a partially transparent luminescence conversion envelope, which encloses at least a part of the semiconductor body (sometimes also a part of the conductive lead), and It is also used as a structural cladding (shell). The advantage of a semiconductor component of this type is essentially that production lines customary for the production of light-emitting diodes (for example radial light-emitting diodes) can be used conventionally for this production. The structural component of the envelope is to replace the transparent plastic used by ordinary diodes with the material of the light-emitting transformation envelope.

With other advantageous configurations of the semiconductor device according to the invention and the two preferred configurations mentioned above, the luminescence conversion layer or the luminescence conversion envelope is made of a transparent material doped with at least one luminescent material, such as plastic, preferably is an epoxy resin (see below for preferred plastics and luminescent materials). When this method is adopted, the manufacturing cost of the luminescence conversion element is the most economical. The manufacturing process used for this does not require additional expenditure compared with a production line for light-emitting diodes.

When adopting the particularly preferred improved structure of the present invention or the above-mentioned structural forms, it needs to be considered in advance that the wavelength of the present wavelength band or the second wavelength band is far greater than the wavelength of the first wavelength band.

In particular, it should be considered that a second spectral segment of the first wavelength segment and a second wavelength segment are complementary to each other. In this way, mixed light, in particular white light, can be generated from a uniform colored light source, in particular from a uniform blue-emitting semiconductor body. For example, in order to produce white light from a blue-emitting semiconductor body, a part of the radiation emitted by the semiconductor body in the blue spectral range is converted into the yellow spectral range which compensates for the blue color. In this way, the color temperature or color position of white light can be changed by selecting a suitable luminescence conversion element, in particular by selecting a suitable luminescent material, particle size and concentration of the luminescent material. Among other things, this structure advantageously offers the possibility of using mixed luminescent materials, which facilitates the adjustment of the color tone to a very precise degree. Even so, inhomogeneous emission of the luminescence conversion element can still occur, for example due to an inhomogeneous distribution of the luminescent material. Through the above measures, it can be beneficial to compensate for the different lengths of the paths of light passing through the luminescence conversion element.

Due to the preferred embodiment of the semiconductor component according to the invention, the luminescence conversion element or other components in the component envelope can be adapted to one or more dyes without affecting the wavelength conversion. The dyes customary for conventional diodes, such as azo dyes, anthraquinone dyes or perinon dyes, can be used for this purpose.

In order to prevent the luminescence conversion element from being affected by an excessively high radiation dose, at least part of the surface of the semiconductor body is covered by a transparent housing, for example made of plastic, through an advantageous modification of the semiconductor device, or through the above-mentioned preferred structural form. The luminescence conversion layer is coated on the surface, so as to reduce the radiation density of the luminescence conversion element, thereby reducing its radiation dose, which has a good influence on the service life of the luminescence conversion element according to the different materials used.

In a particularly preferred measure according to the invention and its construction, a semiconductor body which emits radiation is used which emits an emission spectrum with a wavelength between 420 nm and 460 nm, in particular at 430 nm (for example in the form of Ga _x Al _1-x N-based semiconductor hosts), or an intensity maximum occurs at 450 nm (such as Ga _x In _1-x N-based semiconductor hosts). With such a semiconductor device according to the invention, it is advantageous to produce almost all colors and mixed colors in the CIE color table. The radiation-emitting semiconductor body here is made of the above-listed mainly electroluminescent semiconductor material, but can also be made of another electroluminescent material, for example a polymer material.

In a further particularly preferred development of the invention and in its construction, the luminescence conversion envelope or the luminescence conversion layer is made of a varnish or plastic, for example with a Silicone, thermoplastic or duroplastic materials (epoxy and acrylic). It is also possible, for example, to make the cover element from thermoplastic for the purpose of the luminescence conversion envelope. The materials listed above can be incorporated into one or more luminescent materials in a simple manner.

The semiconductor device according to the invention can be realized particularly simply when the semiconductor body is arranged in a recess, or in a prefabricated housing, and the recess is covered with a cover coated with a luminescence conversion layer. . Such a semiconductor device can be mass-produced on an ordinary production line. All that has to be done for this is to install the semiconductor body in the housing and then install it on the housing, for example with a covering element made of a layer of varnish or molded resin, or covered with a prefabricated cover made of thermoplastic. It is also possible to use a gap in the shell of a transparent material, such as filling it with a transparent plastic, so that the wavelength of the light emitted from the semiconductor body will not be changed; if desired, a light-emitting conversion structure can also be made in advance.

For reasons of particular ease of implementation, a particularly preferred modified structure of the semiconductor device according to the invention is that the semiconductor body is arranged in a prefabricated or leadframed housing, and the housing is molded with at least partially transparent molding resin. Filled, pre-doped with luminescent material before pouring the gap. Since the semiconductor body is casted with a potting material doped with luminescent materials, epoxy resin doped with one or more luminescent materials is preferably used as a material for light-emitting semiconductor devices with luminescence conversion elements. Polymethyl methacrylate (PMMA) can also be used instead of epoxy resin.

Organic dyes can be incorporated into PMMA in a simple manner. To produce green-, yellow- and red-emitting semiconductor devices according to the invention it is possible to use, for example, dye molecules based on perylen. Semiconductor devices that emit UV, visible light, or infrared light can also be manufactured by doping tetravalent metal organic compounds. Red-emitting semiconductor components according to the invention can be realized in particular by the incorporation of Eu ³⁺ -based metal-organic chelates (λ≈620 nm). Red-emitting semiconductor components according to the invention, in particular blue-emitting semiconductor bodies, can be produced by doping chelate complexes of 4-valent sapphire or by doping sapphire predoped with Ti ⁺³ for mixing.

The manufacture of white light-emitting semiconductor bodies according to the invention is facilitated in such a way that the blue light emitted by the semiconductor body is converted into the wavelength bands of complementary colors, in particular the blue and yellow color bands, or into superimposed Three-color light, such as blue, green, and red light. This produces yellow light, or green and red light, through the luminescent material. The resulting white shade (hue in the CIE-color chart) can be varied by the appropriate selection of the dyes used for mixing and their concentrations.

The luminescent materials suitable for emitting white light and according to the semiconductor device of the present invention are, for example, BASF Lumogen F 083 for green light, BASF Lumogen F 240 for yellow light, and BASF Lumogen F 300 for red light. Pericene luminescent material. These luminescent materials can be incorporated in a simple manner, for example into transparent resins.

A preferred method of using a blue-emitting semiconductor body to produce a green-emitting semiconductor device is to replace the UO ₂ ⁺⁺ in the luminescence conversion element with borosilicate glass.

Another preferred modification of the structure of the semiconductor device according to the invention and of the above-mentioned advantageous structural forms is the additional doping of so-called diffusing agents in the luminescence conversion element or other transmissive components of the structural envelope. Light scattering particles. This approach can help to optimize the colorability and emissivity of the semiconductor device.

A particularly advantageous embodiment of the semiconductor component according to the invention consists in the incorporation of a phosphor into at least part of the transparent epoxy resin of the luminescence conversion element. The most advantageous approach is also to compound the phosphor with epoxy resin in a simple manner. A particularly preferred phosphor for producing white-emitting semiconductor components is phosphorous YAG:Ce (Y ₃ Al ₅ O ₁₂ :Ce ³⁺ ). Such phosphors can be mixed in a particularly simple manner with transparent epoxy resins customary in LED technology. Other garnets doped with rare earth elements that can be considered as luminescent materials, such as Y ₃ Ga ₅ O ₁₂ :Ce ³⁺ , Y(Al,Ga) ₅ O ₁₂ :Ce ³⁺ , Y(Al,Ga) ₅ O ₁₂ :Tb ³⁺ and sulfides of alkaline earth metals doped with rare earth elements such as SrS:Ce ³⁺ , Na, SrS:Ce ³⁺ , Cl, SrS:CeCl ₃ , CaS:Ce ³⁺ and SrSe:Ce ³⁺ .

In addition, thiogallates doped with rare earth elements, such as CaGa ₂ S ₄ :Ce ³⁺ , SrGa ₂ S ₄ :Ce ³⁺ are particularly suitable for generating different types of mixed shades of light. Aluminates doped with rare earth elements can also be considered, such as YAlO ₃ :Ce ³⁺ , YGaO ₃ :Ce ³⁺ , Y(Al,Ga)O ₃ :Ce ³⁺ and orthosilicates doped with rare earth elements M ₂ SiO ₅ :Ce ³⁺ (M:Sc, Y, Sc) such as Y ₂ SiO ₅ Ce ³⁺ . All yttrium compounds can in principle be replaced by scandium or lanthanum.

Another possible embodiment of the semiconductor component according to the invention is a luminous component with at least an envelope made of purely inorganic material, that is to say a luminescence conversion envelope or luminescence conversion layer made of purely inorganic material. The luminescence conversion element is thus produced with a temperature-stable transparent or partially transparent material doped with phosphors. In particular, it is made by doping an inorganic phosphorus in an inorganic glass with a low melting temperature (such as silica glass) in an advantageous manner. A preferred method of producing such a luminescence conversion layer is the Sol-Gel technology, with which the entire luminescence conversion layer, not only the phosphor but also the doped materials, can be carried out in one process step.

In order to improve the mixing of the radiation of the first wavelength range emitted by the semiconductor body and the radiation of the second wavelength range after the luminescence conversion, as well as the color uniformity of the emitted light, advantageous measures are adopted in the semiconductor device according to the invention. A blue-emitting dye is additionally incorporated into the envelope or the luminescence conversion layer and/or into other elements of the structural envelope in order to reduce the so-called orientation characteristic of the radiation emitted by the semiconductor body. Orientation is characterized by causing the radiation emitted by the semiconductor body to assume a preferred emission direction.

In a preferred embodiment of the semiconductor component according to the invention, the above-mentioned object is achieved by using powders of organic phosphors which do not dissolve in their surrounding material (substrate). In addition, the refractive index of the organic light-emitting material and its surrounding materials are different from each other. This adds an advantage that the part of the light not absorbed by the luminescent material will not be scattered due to the constraints of the particle size of the luminescent material. This greatly reduces the orientation characteristics of the radiation emitted by the semiconductor body, so that the non-absorbed radiation and the radiation transformed radiation can be mixed uniformly, resulting in a three-dimensional uniform color pressure.

Due to the intermixing of the epoxy resin used for the manufacture of the luminescence conversion envelope or the luminescence conversion layer with the phosphor (Y ₃ Al ₅ O ₁₂ :Ce ³⁺ ), a semiconductor device according to the invention which emits white light can be used in particular The preferred way to achieve. A part of the blue radiation emitted by the semiconductor body is shifted by the phosphor into the yellow spectral band and thus into a wavelength band complementary to blue. The hue (color position in the CIE color chart) of white light can be changed by proper selection of the mixing concentration of the dyes.

Another advantage of the phosphor YAG:Ce is that it can become an insoluble pigment with a refractive index of about 1.84 (particle size within 10 μm). This produces, in addition to the wavelength conversion, a scattering effect which results in a good mixing of the radiation from the blue-emitting diode and the converted yellow emission.

In another preferred development of the semiconductor device according to the invention, as well as in the above-mentioned advantageous form of manufacture, a further radiation-transparent component of the luminescence conversion element or of the structural envelope is additionally doped with a so-called diffusing agent light scattering particles. Adopting such a method is beneficial to the further optimization of the color pressure and the emission performance of the semiconductor device.

A particularly advantageous advantage is that the luminous efficiency of the white-emitting semiconductor component according to the invention and its blue-emitting semiconductor body of the above-described design, which is mainly based on GaN, is comparable to that of an incandescent light bulb. The reason is that the external quantum output of this semiconductor body is only a few percent, while the luminous efficiency of organic dye molecules is often above 90%. In addition, the semiconductor device according to the invention has a particularly long service life, is very robust, and has a lower operating voltage than an incandescent bulb.

Another advantage is that since the sensitivity of the naked eye increases with the increase of the wavelength, the human eye's resolution ability for the brightness of the semiconductor device of the present invention is compared with that of the non-luminous conversion element, even if it is equipped with the same semiconductor devices, but it can be significantly improved for the former.

Additionally, it is advantageous in accordance with the principles of the present invention when a semiconductor body can be modified to emit visible light in addition to ultraviolet radiation. The brightness of the light emitted by the semiconductor body is thus significantly increased.

The concept of making the semiconductor body emit blue light through luminescence conversion can also be extended by using multi-level luminescence conversion elements in the order of ultraviolet → blue → green → yellow → red. In this case, the luminescence conversion elements for selective emission of various spectrums should be arranged sequentially behind the semiconductor body.

It is also advantageously possible to incorporate several different spectrally selective emitting dye molecules together into the transparent plastic of the luminescence conversion element. This enables a wide color spectrum to be produced.

A particular advantage of white-emitting semiconductor components according to the invention using exclusively YAG:Ce as luminescence-converting dye is that excitation of this luminescent material by blue light produces a shift of approximately 100 nm between absorption and emission of the spectrum. This leads to a greatly reduced back-absorption of the light emitted by the luminescent material, resulting in an increase in luminous efficiency. In addition, YAG:Ce has favorable thermal and photochemical (such as UV-) high stability (mainly higher than organic light-emitting materials), so it is suitable for manufacturing white light-emitting diodes used outdoors and in high-temperature ranges.

So far, YAG:Ce is clearly one of the most suitable luminescent materials in terms of anti-absorption, light efficiency, photochemical stability, and fabrication and processing. And it is considered that it can also be used in Ce-doped phosphorus, especially Ce-doped garnet.

It is particularly advantageous according to the present invention that it is particularly suitable for full-color LED display with low power consumption, suitable for lighting in Kfz cars or aircraft cabins, and used in display devices such as Kfz instrument panels or in the lighting of liquid crystal displays.

Description of drawings

For further features, advantages and practicalities according to the present invention, please refer to the description of the following nine embodiments in conjunction with FIGS. 1 to 14 .

1 is a schematic cross-sectional view of a first embodiment of a semiconductor device according to the present invention;

2 is a schematic cross-sectional view of a second embodiment of a semiconductor device according to the present invention;

3 is a schematic cross-sectional view of a third embodiment of a semiconductor device according to the present invention;

4 is a schematic cross-sectional view of a fourth embodiment of a semiconductor device according to the present invention;

5 is a schematic cross-sectional view of a fifth embodiment of a semiconductor device according to the present invention;

6 is a schematic cross-sectional view of a sixth embodiment of a semiconductor device according to the present invention;

7 is a schematic diagram of the emission spectrum of a blue-emitting semiconductor body having a GaN-based multilayer structure;

8 is a schematic diagram of emission spectra of two semiconductor devices emitting white light according to the present invention;

9 is a schematic cross-sectional view of a semiconductor body emitting blue light;

10 is a schematic cross-sectional view of a seventh embodiment of a semiconductor device according to the present invention;

Figure 11 is a schematic diagram of the emission spectrum of a semiconductor device emitting mixed red light according to the present invention;

12 is a schematic diagram of emission spectra of other semiconductor devices emitting white light according to the present invention;

13 is a schematic cross-sectional view of an eighth embodiment of a semiconductor device according to the present invention;

Fig. 14 is a schematic sectional view of a ninth embodiment of a semiconductor device according to the present invention.

Parts that are the same or have the same effect in each figure are marked with the same reference numerals.

Detailed ways

The light-emitting semiconductor device shown in FIG. 1 has a semiconductor body 1, a rear contact 11, a front contact 12 and a multilayer structure 7 of different laminates, one of which is in the operating state of the semiconductor device. Active region that emits at least one type of radiation (eg ultraviolet, blue or green).

FIG. 9 shows an example of a multilayer structure 7 suitable as such an element and as an element in all embodiments described hereinafter. In the figure, on a substrate 18 made of SiC, a layer coated with AlN- or GaN-layer 19, a layer of n-conducting GaN-layer 20, a layer of n-conducting Ga _x Al _{1- x} N- or Ga _x In _1-x N-layer 21, a further n-conducting GaN- or a Ga _x In _1-x N-layer 22, a p-conducting Ga _x Al _{1 -} a multilayer structure of an x N-layer or a _{GaxIn 1-x} N-layer 23 and a p-conducting GaN-layer 24 . On a main surface 25 of the GaN-layer 24, and on a main surface 26 of the substrate 18, a metal contact 27, 28 is respectively arranged, this is to adopt the material used in the conductive contact of customary light-emitting semiconductor technology made.

Other semiconductor bodies may also be used as semiconductor components according to the invention which are considered suitable by other persons skilled in the art. The same applies to all the embodiments described below.

In the embodiment of FIG. 1 , the semiconductor body uses a conductive adhesive, such as a metal solder or an adhesive material, to fix its bottom contact 11 on the first conductive lead 2 . The front contact 12 is connected to a second conductive lead 3 by means of a bonding wire 14 .

The unoccupied surface of the semiconductor body 1 and part of the conductor lines 2 and 3 are directly enclosed by a luminescence conversion envelope 5 . This cladding is preferably a kind of transparent plastic that is mixed with light-emitting material 6 used in transparent light-emitting diodes, preferably mixed with organic light-emitting materials (preferred epoxy resin or polymethyl methacrylate) ) is made; white light-emitting devices are preferably doped with Y ₃ Al ₅ O ₁₂ :Ce ³⁺ (YAG:Ce).

An embodiment of a semiconductor component according to the invention shown in FIG. 2 differs from FIG. 1 in that the semiconductor body 1 and the partial line segments of the conductor leads 2 and 3 are not made of a luminescence conversion material but of a Transparent cladding 15 encloses. This cladding will not change the wavelength of the ray emitted by the semiconductor body 1; it is made of a kind of epoxy resin or acrylate resin commonly used in light-emitting diode technology, or another material that can transmit light, such as Made of inorganic glass.

Coat one deck luminescence conversion layer 4 on this transparent cladding 15, as shown in Figure 2, enclose the whole surface of cladding 15, also can only enclose a part of this surface with luminescence conversion layer 4. The luminescence conversion layer 4 is again made, for example, of a transparent plastic material (for example epoxy resin, varnish or methyl methacrylate) which has been doped with a luminescence material 6 . Such white light-emitting semiconductor devices also preferably use YAG:Ce as the light-emitting material.

A particular advantage of this embodiment is that the path lengths of the radiation emitted by the semiconductor body through the luminescence conversion element are approximately equal. This length plays a particularly important role when, as often happens, the exact hue of the light emitted by the semiconductor device depends on the length of this path.

In order to improve the outcoupling of the light emitted by the luminescence conversion layer 4 in FIG. Total internal reflection. This lenticular cover 29 can be produced from transparent plastic or glass and then, for example, glued to the luminescence conversion layer 4 or directly formed as an integral structure as a component of the luminescence conversion layer 4 .

In the embodiment shown in FIG. 3 , the first and second leads 2 , 3 are pre-buried in a light-transmitting or prefabricated base 8 with a gap 9 opened therein. The so-called "prefabricated" refers to the finished structure formed by pre-connecting the base 8 to the leads 2, 3 by using, for example, injection molding method, before mounting the semiconductor body on the leads 2. The base 8 is, for example, made of a light-transmitting plastic, and the notch 9 is shaped as a reflector (sometimes through suitable fittings on the inner wall of the notch 9) to reflect the rays emitted during the operation of the semiconductor body. coating). Such a base 8 serves as a conductive plate for the light-emitting diodes mounted thereon. Prior to the mounting of the semiconductor body, the base is mounted on the conductor strips (lead frame) of the conductor leads 2 , 3 , for example by injection molding.

The notch 9 is covered by a cover plate 17 made of plastic that is manufactured separately from the luminescence conversion layer 4 and fixed on the base 8 . Suitable materials for the luminescence conversion layer 4 are again the plastics or inorganic glasses listed in the general part of the above description, doped with the relevant luminescent materials listed therein. The opening 9 can be filled with a plastic, with an inorganic glass or with a gas, and can also be evacuated.

Just like the embodiment in FIG. 2 , in order to improve the light coupling from the luminescence conversion layer 4 , a lens-shaped covering body 29 (indicated by a dotted line) can also be arranged above it here to attenuate the light in the luminescence conversion layer 4 . Total reflection of emitted light. Such a cover can be made of transparent plastic and glued, for example, onto the luminescence conversion layer 4, or can be formed together with the luminescence conversion layer 4 as an integral structure.

As shown in FIG. 10, in a particularly preferred manufacturing form, the gap 9 is filled with an epoxy resin containing a luminescent material, that is to say with a luminescent envelope 5, to form the structure of the luminescence conversion element. In this case, a cover plate 17 and/or a lenticular covering 29 can be omitted. In addition, there is another method as shown in FIG. 13 , for example, the first conductive lead 2 is stamped within the scope of the semiconductor body 1 to form a reflector 34 structure, and the middle is filled with a light-emitting conversion envelope 5 .

Figure 4 shows an example of an alternative fabrication method known as a radial diode. In the figure, the semiconductor body 1 is fixed in a reflector structure part 16 made of first conductive leads 2, for example by soldering or bonding. The shell-shaped structure is a conventional shape in the light-emitting diode technology, so it will not be described in detail here.

The semiconductor body 1 in the embodiment of Fig. 4 is surrounded by a kind of transparent cladding 15, as shown in the above-mentioned second embodiment (Fig. 2), the wavelength of the ray emitted by the semiconductor body 1 will not be changed, It can be produced, for example, from transparent epoxy resins or from glass, which are customary in light-emitting diode technology.

A luminescence conversion layer 4 is applied to this transparent envelope 15 . The materials used for this purpose can still be the plastics or inorganic glass used in the above-described embodiments, plus the relevant dyes listed here.

The entire structure consisting of the semiconductor body 1 , parts of the conductor leads 2 , 3 , the transparent encapsulation 15 and the luminescence conversion layer 4 is directly enclosed by another transparent encapsulation 10 . The wavelength of the radiation emitted through the luminescence conversion layer 4 will not be changed. Such encapsulations are still produced, for example, from transparent epoxy resins or inorganic glasses customary in light-emitting diode technology.

The embodiment shown in FIG. 5 differs substantially from that in FIG. 4 in that the unoccupied surface of the semiconductor body 1 is directly surrounded by a luminescence conversion envelope 5 and then by another transparent envelope 10 . In FIG. 5, a semiconductor body 1 is also shown as an example in which instead of the lower edge as a contact, the other contact area of the semiconductor multilayer structure 7 is used as a contact, the latter with a second connecting wire 14 is connected to its associated conductive lead 2 or 3 . It goes without saying that such a semiconductor body 1 can also be replaced by other exemplary embodiments described here. Conversely, it is of course also possible to use the embodiment in FIG. 5 in the preceding embodiments.

It is also necessary to explain this self-evident situation here. It is also possible to compare the structural shape used in FIG. 5 with the method of the embodiment in FIG. 5 is used in combination with another transparent casing 10.

In the embodiment of FIG. 6 , a layer of luminescence conversion layer 4 (the materials listed above can be used) is coated directly on the semiconductor body 1 . The semiconductor body 1 and some conductive leads 2, 3 are covered by another transparent envelope 10, so that the wavelength of the radiation emitted through the luminescence conversion layer 4 will not be changed. Such encapsulations are still produced, for example, from transparent epoxy resins or inorganic glasses customary in light-emitting diode technology.

Such a semiconductor body 1 with a luminescence conversion layer 4 but without an encapsulation is of course also advantageous in adopting the housing shapes customary in semiconductor technology (eg SMD housings, radial housings (see FIG. 5 )).

The embodiment shown in FIG. 14 is a semiconductor component according to the invention, on which a transparent groove-shaped part 35 is arranged on the semiconductor body 1 , which is a groove 36 outside the semiconductor body 1 . The trough part 35 is made, for example, of transparent epoxy resin or inorganic glass, and is made by encapsulating the conductive leads 2 , 3 together with the semiconductor body 1 , for example by means of injection molding. In such a pocket 36 there is contained a luminescence conversion layer 4 , again made of epoxy resin or inorganic glass, coated with a luminescence conversion layer 4 in which the phosphor particles 37 listed above are doped. The advantage of using this structure is that it can ensure a very simple structure, and that the luminescent material will not accumulate at places not previously considered, for example near the semiconductor body, during the manufacturing process of the semiconductor device. Of course, the trough-shaped part 35 can also be manufactured separately, or it can also be used instead, for example, the method of covering the semiconductor body 1 is fixed on a shell member.

In all the above-described embodiments, in order to optimize the degree of color intervening in the emitted light, in order to make it suitable for the luminescence conversion element (luminescence conversion envelope 5 or luminescence conversion layer 4), it is sometimes necessary The shell 15, and/or the transparent envelope 10 incorporates light scattering particles, most advantageously a diffusing agent. Examples of such diffusing agents are mineral fillers, in particular CaF ₂ , TiO ₂ , SiO ₂ , CaCO ₃ or BaSO ₄ , or also organic pigments. These materials can be incorporated into the plastics mentioned above in a simple manner.

Figures 7, 8 and 12 show the emission spectrum (Fig. 7) of a blue light emitted by a semiconductor body (luminescence maximum at λ=430nm) or a white light emission made of such a semiconductor body, according to the invention The emission spectrum of the semiconductor device (Figure 8 and Figure 12). On the abscissa, the wavelength λ is marked in nm, respectively; on the ordinate, a relative electroluminescence (EL) intensity is marked respectively.

The radiation emitted by the semiconductor body shown in FIG. 7 is only partially converted into a longer wavelength range, so that mixed-color white light is produced. Curve 30 represented by a dotted line in FIG. 8 is the emission spectrum of a semiconductor device according to the present invention. This ray is formed by two auxiliary wavelength bands (blue and yellow), and the overall emission is white light. The spectrum in the figure shows a maximum between approximately 400 and 430 nm (blue) and between approximately 550 and 580 nm (yellow). The entire curve 31 represents the emission spectrum of a semiconductor device according to the present invention, the white color is formed by mixing three wavelength bands (superimposed three colors composed of blue, green and red). The emission spectra in the figure each have a maximum at, for example, around 430 nm (blue), around 500 nm (green) and around 615 nm (red).

Furthermore, FIG. 11 shows the emission spectrum of a semiconductor component according to the invention which emits a mixed light consisting of blue light (a wavelength with a maximum of about 470 nm) and red light (a wavelength with a maximum of about 620 nm). The total color pressure of the emitted light to the human eye is magenta. Here again the emission spectrum emitted by the semiconductor body corresponds to that shown in FIG. 7 .

FIG. 12 shows a white-emitting semiconductor device according to the invention with a semiconductor body emitting the emission spectrum shown in FIG. 7, wherein the luminescent material used is YAG:Ce. Of the radiation emitted by the semiconductor body, only a small fraction is converted into the longer wavelength range, thus producing mixed white light. Curves 31 to 33 plotted with different dashed lines in FIG. 8 represent the emission spectra of the semiconductor device according to the present invention. A luminescence conversion element, wherein the luminescence conversion element is made of epoxy resin and contains different concentrations of YAG:Ce. Each emission spectrum has an intensity maximum between λ=420nm and λ=430 in the blue spectrum and between λ=520 and λ=545 in the green spectrum, which contains a longer wavelength maximum intensity A large part of the emission band of values is in the yellow spectral region. It is evident from the graph in FIG. 12 that with the semiconductor device according to the invention it is possible to vary the CIE color point in white light simply by varying the concentration of the luminescent material in the epoxy resin.

Alternatively, Ce-doped garnet, thiogallic acid, and alkaline earth metal-sulfide aluminates can be directly coated on semiconductor hosts without having to disperse them in epoxy or glass.

A further special advantage of the above-mentioned phosphors is that the concentration of the phosphors in, for example, epoxy resins is not subject to solubility constraints as is the case with organic phosphors. Therefore, it is not necessary to use a very thick luminescence conversion element.

The description of the semiconductor component according to the invention with the aid of the above exemplary embodiments does not, of course, limit the invention to these exemplary embodiments. In the example, a light-emitting diode chip or a laser diode chip is used as an example of the semiconductor body, which can also be understood as, for example, a polymer LED emitting a corresponding spectrum.

Claims (32)

1. luminous semiconductor device,

Have a semiconductor body (1), it is the emission electromagnetic radiation when described semiconductor device is worked,

Have at least one first and at least one second conductive lead wire (2,3), it is connected conductively with described semiconductor body (1), and

Have a luminous inverting element that includes at least a luminescent material,

It is characterized in that:

Described semiconductor body (1) has a semiconductor multilayer structure (7), and it is suitable for launching the electromagnetic radiation of first wavelength period when described semiconductor device is worked, and

The ray that described luminous inverting element will come from described first wavelength period is transformed into the ray of second wavelength period that is different from this first wavelength period and will reads ray and send, make this semiconductor device launch to comprise the mixed-color light of visible electromagnetic radiation of the visible electromagnetic radiation of described first wavelength period and described second wavelength period

Wherein the ray that is sent by described semiconductor body has the relative intensity maximum when wavelength X≤520nm, and the wavelength period that is selectively absorbed by described luminous inverting element spectrum is positioned at outside this maximum of intensity.

2. luminous semiconductor device as claimed in claim 1 is characterized in that, described relative intensity maximum is positioned at blue spectral range.

3. as the luminous semiconductor device of one of claim 1-2, it is characterized in that the ray that is sent by described semiconductor body (1) has the relative luminous intensity maximum during wavelength between 420nm and 460nm in blue spectral range.

4. as the luminous semiconductor device of one of claim 1-3, it is characterized in that, described luminous inverting element is transformed into the ray of a plurality of second wavelength period of being made up of different spectrum subarea mutually with the ray of described first wavelength period, makes this semiconductor device launch to send the mixed-color light of visible electromagnetic radiation of the visible electromagnetic radiation of described first wavelength period and described second wavelength period.

5. as the luminous semiconductor device of one of claim 1-4, it is characterized in that from the main transmit direction of described semiconductor device, described luminous inverting element is disposed in described semiconductor body (1) afterwards.

6. as the luminous semiconductor device of one of claim 1-5, it is characterized in that, the top of described semiconductor body (1) or above at least one luminous transform layer (4) is set as luminous inverting element.

7. as the luminous semiconductor device of one of claim 1-5, it is characterized in that, be provided with luminous conversion involucrum (5) as luminous inverting element, this luminous conversion involucrum surrounds at least a portion of described semiconductor body (1) and the subregion of described conductive lead wire (2,3).

8. as the luminous semiconductor device of one of claim 1-7, it is characterized in that described second wavelength period has the wavelength X greater than first wavelength period at least in part.

9. as the luminous semiconductor device of one of claim 1-8, it is characterized in that first wavelength period and second wavelength period of described mixed-color light are arranged in the complementary colours SPECTRAL REGION at least in part, make to produce white light.

10. as the luminous semiconductor device of one of claim 1-8, it is characterized in that first wavelength period and two second wavelength period of being sent by described semiconductor body form stack three looks, make when this semiconductor device work from this semiconductor device emission white light.

11. the luminous semiconductor device as one of claim 1-10 is characterized in that, described semiconductor body (1) is disposed in the breach (9) of base (8), and described breach (9) is equipped with the cover layer with luminous transform layer (4).

12. the luminous semiconductor device as one of claim 1-10 is characterized in that, described semiconductor body (1) is disposed in the breach (9) of base (8), and described breach (9) is filled by described luminous inverting element at least in part.

13. the luminous semiconductor device as one of claim 1-12 is characterized in that, described luminous inverting element comprises a plurality of layers with different wavelength conversion characteristics.

14. the luminous semiconductor device as one of claim 1-13 is characterized in that, described luminous inverting element (4,5) has at least a phosphor (6).

15. luminous semiconductor device as claim 14, it is characterized in that, described phosphor is to select from a group, and this group has rare earth doped garnet, is mixed with the alkaline earth sulfide of rare earth, is mixed with the sulfo-gallate of rare earth, the orthosilicate that is mixed with the aluminate of rare earth and is mixed with rare earth.

16. the luminous semiconductor device as one of claim 14-15 is characterized in that, described luminescent material comes from garnet group that Ce mixes.

17. the luminous semiconductor device as one of claim 14-16 is characterized in that, described phosphor is YAG:Ce.

18. the luminous semiconductor device as one of claim 14-17 is characterized in that, described phosphor is embedded in the matrix of being formed by thermoplastic material or hard plastics, as epoxy resin and acrylic acid resin.

19. the luminous semiconductor device as one of claim 14-17 is characterized in that, described phosphor is embedded in the matrix of being made up of the low melting point unorganic glass.

20. the luminous semiconductor device as one of claim 14-17 is characterized in that, described phosphor is embedded in the matrix of being made up of silicon materials.

21. the luminous semiconductor device as one of claim 14-17 is characterized in that, described phosphor directly is coated on the described semiconductor body (1).

22. the luminous semiconductor device as one of claim 14-21 is characterized in that, it is the particle mean size of 10 μ m that described phosphor has.

23. the luminous semiconductor device as one of claim 1-22 is characterized in that, described luminous inverting element is provided with multiple different organic or inorganic or organic and phosphor (6).

24. luminous semiconductor device as one of claim 1-23, it is characterized in that, described luminous inverting element has organic or inorganic or the organic and inorganic dyestuff molecule that has the wavelength conversion effect, and described luminous inverting element has the not organic or inorganic or the organic and inorganic dyestuff molecule of bandgap wavelength change action.

25. luminous semiconductor device as one of claim 1-24, it is characterized in that, additional transparent involucrum of setting up (10,15) of described luminous inverting element or one or described luminous inverting element and additional transparent involucrum of setting up have the particle of scattered light.

26. the luminous semiconductor device as one of claim 1-25 is characterized in that, described luminous inverting element is furnished with one or more 4 luminous valency metallo-organic compounds.

27. the luminous semiconductor device as one of claim 1-26 is characterized in that, a described luminous inverting element or a transparent involucrum (10,15) or described luminous inverting element and transparent involucrum are provided with the luminescent material of at least a blue light-emitting.

28.LED display unit comprises a plurality of as the described luminous semiconductor device of one of claim 1-27.

29. lighting device comprises a plurality of as the described luminous semiconductor device of one of claim 1-27.

30. the luminaire of liquid crystal display comprises that at least one is as the described luminous semiconductor device of one of claim 1-27.

31. panchromatic LED display unit comprises a plurality of as the described luminous semiconductor device of one of claim 1-27.

32. the endo-illuminator of aircraft cabin comprises a plurality of as the described luminous semiconductor device of one of claim 1-27.

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