CN202259406U - LED (Light-emitting Diode) displayer - Google Patents

Abstract

The utility model relates to an LED (Light-emitting Diode) displayer which comprises a plurality of LED packages, wherein the plurality of LED packages comprise plastic shells, LED chips arranged in the shells and optical converting materials arranged in reflection cups. The optical switching materials convert at least a plurality of light emitted from the LED chips, and the plurality of LED packages emit the packaging light from the optical converting materials or emit the combinations of the packaging light from the optical converting materials and the light from the LED chips; the LED packages further comprise contrast regions; the contrast regions are arranged outside reflection regions and have colors forming contrast with the packaging light. The LED displayer has excellent contrast ratio between different pixels; meanwhile, the luminous flux or brightness sensed by the displayer cannot be reduced.

Description

Light-emitting diode display

Technical field

The utility model relates to light-emitting diode (LED) and encapsulates and utilize the display of LED package as its light source.

Background technology

Light-emitting diode (LED or LEDs) is the solid state device that converts electrical energy into light, and it comprises one or more active layer that is clipped in the semi-conducting material between the opposite doped layer usually.When the above-mentioned doped layer of leap applied bias voltage, hole and electronics were injected into active layer, and hole and electron recombination are to produce light there.Light is launched from all surface of active layer and LED.

At last decade or more over a long time, scientific and technological progress has made LED have littler taking up room (footprint), the emission effciency that improves and the cost of reduction.Than other reflector, LED also has the working life of prolongation.For example, the working life of LED can surpass 50,000 hours, and the working life of incandescent lamp bulb is approximately 2,000 hours.LED is also can be than other light source more sturdy and durable and consume still less energy.Owing to these and other reason, LED is more popular and in the traditional field of increasing white heat, fluorescence, halogen and other reflector is used, use at present.

In order in conventional use, to use led chip, be known that with led chip pack into the encapsulation in so that environment and/or mechanical protection, color selection, optically focused etc. to be provided.LED encapsulation also comprises and is used to be electrically connected electrical lead, contact or the trace that LED is packaged into external circuit.In the two pin LED encapsulation/parts 10 of typical case shown in Figure 1, single led chip 12 is installed on the reflector 13 through solder bonds or conductive epoxy resin.The ohmic contact that or more closing lines (wire bond) 11 connects led chips 12 is to 15A and/or the 15B of going between, and lead-in wire 15A and/or 15B can be attached to reflector 13 or integrated with reflector 13.Reflector 13 can be filled and can be included in the led chip top or be included in the sealant such as the material for transformation of wave length of phosphor by sealant material 16.Phosphor can absorb LED emission first wavelength light and spontaneously launch the light of second wavelength.So whole assembly can be installed in the transparency protected resin 14, it can be molded to the light that lens shape is launched from led chip 12 with guiding or setting.

Traditional LED encapsulation 20 shown in Figure 2 possibly be more suitable for producing the high power operation of more heats.In LED encapsulation 20, one or more led chips 22 are installed on the carrier, like printed circuit board (PCB) (PCB) carrier, substrate or base station (submount) 23.The solid metal reflector 24 that is installed on the base station 23 leaves encapsulation 20 around led chip 22 and with the light reflection of led chip 22 emissions.Reflector 24 also provides mechanical protection for led chip 22.One or more multi-thread joint connect 21 and are produced between ohmic contact and the electric trace 25A on the base station 23 on the led chip 22, the 25B.Then, cover mounted LEDs chip 22 with sealant 26, it can also serve as lens simultaneously for chip provides environment and mechanical protection.Typically, engage, solid metal reflector 24 is attached to carrier through scolder or epoxy resin.

Different LED encapsulation, those shown in Fig. 1 and 2, no matter large or small, can use as the light source of billboard and display.In many indoor and outdoor occasions, for example in the stadium, horse-racing ground, concert and in large-scale public area, like the Times Square of New York City, the LED-based display of large-screen (often being called huge screen) becomes more general.In these displays or the screen some can be that 60 feet high and 60 feet wide that kind are big.Along with technological progress, the screen that the expectation exploitation is bigger.

These screens can comprise thousands of " pixels " or " picture element module ", its each can comprise a plurality of LED.Picture element module can use high efficiency, high-brightness LED, these LED allow displays from remote relatively be visible, even daytime is under the condition of daylight.In some billboards; Each pixel can have single led chip; And picture element module can have LED few as 3 or 4 (ruddiness, a green glow and a blue light), and this allows pixel from the combination of red, green and/or blue light, to launch the light of many different colours.In the huge screen of maximum, each picture element module can have tens LED.These picture element modules are set to rectangular mesh.In one type display, this grid can be 640 wide and 480 module height of module, and the size of screen depends on the actual size of picture element module.

An importance of traditional LED-based display is the contrast between the pixel in the display, and for good picture quality, the contrast between the pixel should be maximized.Often, the contrast between the increase pixel possibly cause total emissive porwer reduction of reflector in the pixel, the result, and total emissive porwer of light-emitting diode display reduces.

In order to improve the contrast of light-emitting diode display, developed the LED encapsulation, these encapsulation have the surf zone around led chip, and it comprises the color that forms contrast with the light from the led chip emission.Yet red-light LED, green light LED and the blue-ray LED light source as them is only used in these encapsulation.It has been generally acknowledged that, adopt the light of the LED encapsulation emission of this layout can comprise the light of led chip and the light of transition material (for example white light), and adopt the unacceptable luminance loss of the light that this layout can cause launching.What paid close attention to is that contrast surf zone around led chip can absorb encapsulation light, therefore, and the total brightness that has reduced encapsulation and utilized the billboard or the display of these encapsulation.

The utility model content

What the utility model was directed against is the reflector encapsulation, more particularly, encapsulates and utilize LED encapsulated LED display to LED.Adopt led chip and the transition material of conversion according to the LED encapsulation of the utility model from least some light of led chip.

An embodiment according to the LED of the utility model encapsulation comprises led chip and is arranged as the transition material of conversion from least some light of led chip emission.This encapsulation is launched from the light of transition material or is launched the combination from the light of transition material and led chip.Around led chip, comprise reflector space, it fully reflects encapsulation light, and comprises that outside reflector space contrast areas, this contrast areas have the color that forms contrast with encapsulation light.

Comprise according to an embodiment of the light-emitting diode display of the utility model and to install with being relative to each other to produce a plurality of LED encapsulation of message or image.In the LED encapsulation at least some comprise led chip and are arranged in the transition material in the reflector that the transition material conversion is from least some light of led chip emission.The LED encapsulation is launched from the encapsulation light of transition material or is launched the combination from the light of transition material and led chip.Reflector space fully reflects encapsulation light, and this encapsulation further comprises contrast areas, and it is outside reflector space and have and encapsulate the color that light forms contrast.

Another embodiment according to the LED of the utility model encapsulation comprises led chip and is arranged as absorption from the light of led chip and with the radiative again transition material of different wave length.This encapsulation emission encapsulation light, it comprises the light of emission again or comprises from the light of led chip and combination of light emitted again.Led chip is installed in the reflector, and this reflector has the upper surface of the color of the light formation contrast that has and launch from led chip.

Another embodiment according to the LED of the utility model encapsulation comprises a plurality of led chips of electric coupling in single loop.Directly the surface around led chip comprises reflector space, and it fully reflects from the light of led chip emission.Comprise contrast areas, it is outside reflector space and have and form from the light of led chip emission a color of contrast.

The utility model provides a kind of LED encapsulation, and it comprises: plastic casing; Be arranged in the said shell led chip be set for the transition material of conversion from least some light of said led chip emission, said LED encapsulation emission is from the encapsulation light of said transition material or the emission combination from the light of the encapsulation light of said transition material and said led chip; Around the reflector space of said led chip, said reflector space fully reflects said encapsulation light; And the contrast areas outside said reflector space, said contrast areas has the color that forms contrast with said encapsulation light.

Further, said encapsulation light comprises the blue shift gold-tinted.

Further, said encapsulation light comprises white light.

Further, said led chip is electrically coupled to said lead frame.

Further, said LED encapsulation further comprises shell, and wherein said reflector space comprises the cavity in the said shell, and said led chip is installed in the said cavity.

Further, said cavity forms the reflector around said led chip.

Further, said LED encapsulation comprises surface mounted device.

Further, said reflector space comprises reflector.

Further, said contrast areas is a black.

Further, said contrast areas is around said reflector space.

Further, said contrast areas is in the level on the said led chip.

Further, said contrast areas and said led chip are arranged such that said LED light is from said encapsulation emission and directly do not launch on said contrast areas.

The utility model provides a kind of LED display; It comprises: a plurality of LED encapsulation; In the said LED encapsulation some comprise plastic casing, are arranged on the led chip in the shell and are arranged in the light-converting material in the reflector, and said light-converting material conversion is from some light of said led chip emission; Some LED encapsulation emission is from the encapsulation light of said light-converting material or the emission combination from the light of the encapsulation light of said light-converting material and said led chip; Reflector space fully reflects said encapsulation light, and said encapsulation further comprises contrast areas, and said contrast areas is outside said reflector space and have a color that forms contrast with said encapsulation light.

Further, than having the unmatchful same light-emitting diode display that encapsulates than the LED in zone, said light-emitting diode display comprises higher pixel contrast.

Further, the said reflector space of each in more said LED encapsulation comprises the reflector around said led chip.

Further, each in more said LED encapsulation comprises surface mounted device (SMD).

Further, each emission white light in more said LED encapsulation.

Further, the yellow BSY light of each emission blue shift in more said LED encapsulation.

Further, the said contrast areas in each in more said LED encapsulation is a black.

Further, the said contrast areas in each in more said LED encapsulation is around said reflector space.

Further, the said contrast areas in each in more said LED encapsulation is in the level on the said led chip.

Further, be arranged such that in said contrast areas each in more said LED encapsulation that LED light directly is not transmitted on the said contrast areas from said encapsulation emission.

The utility model provides a kind of LED encapsulation; It comprises: plastic casing; Be arranged in the said housing led chip be set for absorption from the lay equal stress on transition material of light of new emission different wave length of the light of said led chip; Said LED encapsulation emission encapsulation light, said encapsulation light comprises the said light of emission again or the light and the said combination of light emitted again of said led chip, said led chip is installed in the reflector; This reflector has colored upper surface, and this color forms contrast with the light of launching from said led chip.

Further, said encapsulation light is fully reflected on the surface of said reflector.

Further, the surface of said reflector is a white.

Further, said upper surface is a black.

Further, said LED encapsulation comprises surface mounted device.

Further, said upper surface and said led chip are arranged such that LED light directly is not transmitted on the said upper surface from said encapsulation emission.

The utility model provides a kind of LED encapsulation, and it comprises: plastic casing; Be arranged in the said housing and be electrically coupled to a plurality of led chips in the single loop; Wherein direct surface around said led chip comprises reflector space and contrast areas; Said reflector space fully reflects from the light of said led chip emission, and it is outer and have with light from said led chip emission and form the color that contrasts that said contrast areas is positioned at said reflector space.

Further, said single loop comprises single anode and the single negative electrode that is used for the signal of telecommunication is applied to said led chip.

Further, the emission of at least some in said led chip white light.

Further, the emission of at least some in said led chip blue shift gold-tinted.

Further, said reflector space comprises the cavity in the said shell, and said led chip is installed in the said cavity.

Further, said cavity forms the reflector around said led chip.

Further, said LED encapsulation comprises surface mounted device (SMD).

Further, said reflector space comprises reflector.

Further, said contrast areas is a black.

Further, said contrast areas is around said reflector space.

Further, said contrast areas is in the level on the said led chip.

The light-emitting diode display that the utility model is special, wherein the LED encapsulation provides the good contrast between the different pixels in LED billboard and the display, does not reduce the luminous flux or the brightness of the perception of display simultaneously.

These of the utility model and others and advantage will be from subsequently to become obvious the detailed description of the characteristic of the utility model of Examples set and the accompanying drawing.

Description of drawings

Fig. 1 is the end view of traditional LED package;

Fig. 2 is the perspective view of another traditional LED package;

Fig. 3 is the perspective view according to an embodiment of the LED encapsulation of the utility model;

Fig. 4 is the top view of LED encapsulation shown in Figure 3;

Fig. 5 is the cutaway view of LED encapsulation shown in Figure 4 along hatching 5-5;

Fig. 6 is the end view according to an embodiment of the light-emitting diode display of the utility model;

Fig. 7 is the perspective view according to another LED encapsulation of the utility model;

Fig. 8 is the top view of LED encapsulation shown in Figure 7; And

Fig. 9 is the interconnective sketch map that illustrates according between the led chip among the embodiment of the LED of the utility model encapsulation.

Embodiment

What the utility model was directed against is LED encapsulation and employing LED encapsulated LED display, and wherein the LED encapsulation comprises different layouts to improve the emission contrast between the adjacent LED encapsulation in the display.These encapsulation can comprise one or more led chips and transition material, and led chip is installed on the base station or in the package casing.The portion of external surface of base station or shell can comprise that the color with the light of launching from the LED encapsulation forms the color of contrast.

The material that directly can comprise in certain embodiments, the light of or reflection led chip basic identical with the light color of led chip around the zone of the base station of led chip or shell.This reflector space can comprise reflector at least in part.The zone of the base station outside this reflector space can comprise the material that forms contrast with led chip light.In having the embodiment of white luminous led chip, directly can comprise the material of reflected white-light, and can form contrast with white light around the zone of white light reflection material around the zone of led chip.In some of these embodiment, the white light reflection material can be white, and contrast areas can be a black.It is understandable that contrast areas also can be many other colors, includes but not limited to blueness, brown, grey, redness, green etc.

This combination of reflecting material and contrast material provides from the contrast of improving between the light of led chip and the emission of encapsulation on every side.This contrast helps to be provided at the contrast between the LED encapsulation of using in the light-emitting diode display, and the contrast between different pixels in the display is provided thus.The contrast of this improvement can produce higher-quality image for the beholder.Simultaneously, adopt the LED of white luminous led chip to encapsulate the beyond thought result that the light quantity that does not absorb irrational LED encapsulation is provided.Before thought, and adopted this layout can cause encapsulating the excessive loss of light with white or other light wavelength conversion.Although some light from led chip possibly absorbed by contrast material, when they used in display, than having the unmatchful display that encapsulates than the LED of material, contrast can cause the beholder unexpectedly to perceive essentially identical light quantity.The light of any absorption of contrast compensation makes the beholder from the essentially identical image brightness of display perception.

Encapsulated by the LED of at least some LED light of wavelength Conversion with reference to emission hereinafter and describe embodiment.This is usually directed to the led chip arranged with transition material (for example phosphor), thus wherein at least some LED light absorbed by transition material through in transition material LED light some and with different optical wavelength by emission again.In some of these embodiment, the LED encapsulation can be launched as the light from the combination of the light of LED and transition material.Can be comprised the light of different colours by the light of wavelength Conversion, it comprises white light and blue shift yellow (blue shifted yellow, the BSY) light of different-colour.Usually, BSY light relates to by the blue-light-emitting LED of yellow/green transition material covering, and wherein at least some in the blue LED light are changed by transition material.The emission of resulting led chip is from the blue light of LED and combination from the Huang/green glow of transition material.

Encapsulation according to the utility model also can comprise a plurality of led chips, and each led chip produces white light wavelength conversion.In other embodiments, the LED encapsulation can utilize a plurality of chips, the light of these chip emission different colours, and these light are arranged with combination and produce white light.Developed from the light source of a plurality of separations and produced the technology of white light with CRI that the improvement under the required colour temperature is provided, these techniques make use are from the different tone of different discrete light sources.In the patent No. is No.7, has described such technology in 213,940 the United States Patent (USP) that is entitled as " Lighting Device and Lighting Method ".In such layout; Use yellow conversion material; YAG:Ce phosphor for example, applying peak value is the blue InGaN LED of 452nm, is yellow clearly and has the color of the color dot (color point) on the black body locus that stays in fully on the CIE chart to provide.The blue-light-emitting LED that applies with yellow conversion material often is known as blue shift Huang (BSY) LED or led chip.BSY emission and light combination from pale red AlInGaP LED, its yellow color with yellow led " is drawn " to blackbody curve to produce gentle white light.

In the embodiment of many led chips, led chip can be coupled in the encapsulation and make their conductings or shutoff so that the signal of telecommunication can be applied in each led chip, or makes the light of their emission desirable strengths.In other embodiments, led chip can be coupling in together so that control led chip conducting of the single signal of telecommunication or shutoff.These embodiment can comprise series coupled led chip together.

Can in LED billboard and display, use LED encapsulation, but it is understandable that they can use in many different application according to the utility model.LED encapsulation can be abideed by different industrial standards, makes it be suitable in LED-based billboard, channel letter luminous (channelletter lighting) or common backlight and illumination application, using.Some embodiment can comprise that also the flat-top emitting surface matees they and light pipe compatibility.For the LED encapsulation according to the utility model, these only are in many different application a little.

Some LED encapsulation embodiment according to the utility model can comprise single led chip or a plurality of led chip that is installed to base station or shell.These encapsulation also can comprise the reflector around led chip or a plurality of led chips.Can comprise with light around the upper surface of the reflector of led chip and to form the material that contrasts by the led chip emission.The part and/or the reflecting surface in cup that are exposed to the base station in the cup also can comprise the material that reflects from the light of led chip.In some of these embodiment, can be white light or other light wavelength conversion from the light of led chip emission, the reflecting surface of the surface of the base station in reflector and cup can be white or reflected white-light or light wavelength conversion.The contrast upper surface of reflector can be many different colours, but is black in certain embodiments.

Here described the utility model with reference to some embodiment, but it is understandable that, the utility model can be specifically embodied as many different forms and should not be construed as the embodiment that is confined to illustrate here.Especially, can provide to surpass above-described those many different led chips, reflector and lead frame setting, and sealant can provide and improves reliability and from the emission characteristics and other a plurality of characteristics of using LED encapsulated LED display of LED encapsulation.Although what the different embodiment of the LED of following discussion encapsulation were directed against is the use in light-emitting diode display, the LED encapsulation also can be used in many different illumination application.

Also will be understood that, when element for example layer, zone or substrate be called as another element " on " time, it can be directly on another element or also, can have intervenient element.In addition, can use relative term here, for example " top " described one deck or another regional relation with " following " and similar term.Will be understood that these terms are intended to comprise the different orientation of device the orientation of in figure, describing.

Although first, second grade of term can be used to describe various elements, parts, zone and/or part here, these terms will not limit these elements, parts, zone and/or part.These terms only are used to distinguish an element, parts, zone or part and another element, parts, zone or part.Therefore, first element that is discussed below, parts, zone or part can be called second element, parts, zone or partly not depart from the instruction of the utility model.

Here describe the embodiment of the utility model with reference to sectional view, wherein sectional view shows the illustrative diagram of the embodiment of the utility model.According to this, the actual (real) thickness of parts can be different, and owing to for example manufacturing technology and/or tolerance limit, can expect to change illustrated shape.The embodiment of the utility model will be not interpreted as the given shape in the zone that is confined to illustrate here, but owing to the reason of for example making comprises departing from shape.Typically, because the manufacturing tolerance limit of standard, diagram or square or the rectangular area described will have circle or arc characteristic.Therefore the zone shown in the figure is actually schematically, and their shape is not intended to explain the accurate shape in the zone of device, and also is not intended to limit the scope of the utility model.

Fig. 3-5 illustrates an embodiment according to the reflector encapsulation 50 that comprises surface mounted device (SMD) of the utility model.That is, arrange this device so that it can be mounted to the structure such as printed circuit board (PCB) (PCB) through adopting surface mounting technology.It is understandable that the utility model also is applicable to other reflector encapsulated type except that SMD, for example pin is installed the reflector encapsulation.Encapsulation 50 comprises the shell (or base station) 52 that carries integrated-lead frame 53.Lead frame 53 comprises and is used for a plurality of conductive connecting elements of optical transmitting set of conducting electrical signals to encapsulation, these a plurality of conductive connecting elements heat that reflector produces that also is used to help to dissipate.

Lead frame 53 can be arranged with many different modes, and in different encapsulation embodiment, can adopt the parts of varying number.Below describe encapsulation 50 for utilizing a reflector, in the illustrated embodiment, lead frame 53 is arranged to and applies the signal of telecommunication to this reflector.Lead frame 54 comprises conductive component 54a-d, and two in the conductive component are used to apply the signal of telecommunication to reflector.In an illustrated embodiment, the anode that is used to apply the signal of telecommunication to reflector can be the second conductive component 54b and negative electrode can be the 4th conductive component 54d, but it is understandable that other embodiment can utilize remaining conductive component of conductive component 54a-d.Can comprise that remaining conductive component 54a and 54c are to provide stable installation property and the extra hot path that the heat of dissipation from reflector is provided.In an illustrated embodiment, the second conductive component 54b has die attach pad 56, and it is used to install the for example reflector of light-emitting diode (LED).

Shell 52 can have many different shape and size, and in an illustrated embodiment, it is square or rectangle normally, has upper and lower surfaces 58 and 60, first and second side surfaces 62 and 64 and first and second end surfaces 66 and 68.The top of shell further comprises recessed or cavity 70, and its main body that extends into shell 52 from upper surface 58 is until lead frame 53.The encapsulation reflector is disposed on the lead frame 53 so that launch from encapsulating 50 process cavitys 70 from the light of reflector.Cavity 70 constitutes reflector around reflector to help that the light of reflector is reflected encapsulation 50.In certain embodiments, can place and fixation reflex insert or ring (not shown) along the side of cavity 70 or the part of wall 74 at least.Can be tapered and will encircle towards the inside of shell and inwardly be carried on the effect of the reflectivity that wherein comes enhanced electronic and the angle of departure of encapsulation through making cavity 70.As an example, the angle of reflection of about 50 degree provides suitable reflectivity and visual angle.

In certain embodiments, cavity 70 can be filled packing material (or sealant) 78 at least in part, thereby the reflector of lead frame 53 and carrying can be protected and on the position, stablized to packing material (or sealant) 78.In some cases, packing material 78 can cover reflector and lead frame 53 through cavity 70 exposed portions.Can select packing material 78 to have predetermined optical characteristics so that strengthen projection from the light of LED, in certain embodiments, for the light by the reflector emission of encapsulation, packing material 78 is transparent basically.Packing material 78 also can be smooth, so as its approx with upper surface 58 in same level, or it can be shaped to lens, for example hemisphere or bullet shaped.Replacedly, packing material can completely or partially be recessed in the cavity 760.Packing material 78 can be formed by resin, epoxy resin, thermoplastic condensed polymer, glass and/or other material or combination of materials that is fit to.In certain embodiments, can add the light that is used to be enhanced to LED and/or from the material of emission, absorption and/or the scattering of the light of LED to packing material 78.

Shell 52 can be by the preferably not only material preparation of electric insulation but also heat conduction.This material is well known in the art, can include, without being limited to some pottery, resin, epoxy resin, thermoplastic condensed polymer (for example polyphthalamide (polyphthalamide, PPA)) and glass.Can be through any the formation and/or assembled package 50 and shell 52 thereof in the well-known various known method in the art.For example, can for example form or molded plastic shell 52 around conductive component 54a-d through injection moulding.Replacedly, shell can be formed in a plurality of, and for example top and bottom are formed with conductive component on the bottom.Then, top and bottom can use known method and material to be bonded together, as passing through epoxy resin, adhesive or other suitable bond material.

Can use many distinct transmit devices according to the encapsulation of the utility model, and encapsulate 50 and utilize led chip 80.Various embodiment can have the different led chip of emission different colours light, in an illustrated embodiment, and led chip emission white light or other light wavelength conversion that encapsulation 50 comprises.

LED structure, characteristic and manufacturing thereof and operation are normally known in the art, and brief discussion only here.LED can have a lot of different semiconductor layers of arranging by different way and can launch different colours.Can use processes well known to make the layer of LED, and a kind of suitable manufacturing process is to use Organometallic Chemistry gas deposition (MOCVD).The layer of led chip generally includes the active layer/district that is clipped between the first and second opposite doped epitaxial layers, and its all these be to be formed on continuously on growth substrates or the wafer.The led chip that is formed on the wafer can and be used for different application by singulation, as is installed in the encapsulation.Be appreciated that growth substrates/wafer can be used as final singulation LED a part and keep or growth substrates can be removed whole or in part.

Be further appreciated that in LED, to comprise other layer and element, include but not limited to resilient coating, nucleating layer, contact layer and current extending, and light-extraction layer and element.Active area can comprise single quantum well (SQW), MQW (MQW), double heterojunction or superlattice structure.

Active area and doped layer can be made by the different materials system, and a this system is an III nitride material system.The III group-III nitride refers to the semiconducting compound that forms between those elements (normally aluminium (Al), gallium (Ga) and indium (In)) in the III of nitrogen and periodic table family.This term also relates to ternary and quaternary compound, like aluminum gallium nitride (AlGaN) and aluminium indium gallium nitrogen (AlInGaN).In a possible embodiment, doped layer is that gallium nitride (GaN) and active layer are InGaN.In alternative embodiment, doped layer can be AlGaN, gallium aluminium arsenic (AlGaAs) or Al-Ga-In-As phosphorus (AlGaInAsP) or aluminium indium gallium phosphorus (AlInGaP) or zinc oxide (ZnO).

Growth substrates/wafer can be processed by a lot of materials; Like silicon, glass, sapphire, carborundum, aluminium nitride (AlN), gallium nitride (GaN); Suitable substrate is a 4H polytype carborundum, yet also can use other carborundum polytype that comprises 3C, 6H and 15R polytype.Carborundum has some advantage, as comparing lattice match with sapphire more near the III group-III nitride, therefore causes producing to have higher-quality III nitride films.Carborundum also has very high thermal conductivity so that the gross output of the III nitride devices on the carborundum can not limited (situation that is formed on some devices on the sapphire possibly be like this) by the heat radiation of substrate.The SiC substrate can be from the North Carolina Cree Research, Inc of Du Lun obtain, and about the method for making them in scientific literature with United States Patent (USP) No.Re.34, stated in 861, No.4,946,547 and No.5,200,022.LED can also comprise supplementary features, and like the current-dispersing structure and the current extending of conduction, all these can be made by the well known materials of using the known method deposition.

Led chip 80 can be electrically coupled to the attachment pad 56 on the second conductive component 54b through the grafting material of conduction and heat conduction, and the grafting material of said conduction and heat conduction for example is scolder, adhesive, coating, film, sealant, paste, grease and/or other suitable material.In a preferred embodiment, can use on the LED bottom solder pads with the LED electric coupling and be fixed on their pads separately so as from the top invisible scolder.Closing line 82 can be comprised and between led chip 80 and the 4th conductive component 54d, extended.The signal of telecommunication that leap the second and the 4th conductive component applies makes led chip 80 launch light.

The preparation of conductive component 54a-d can be accomplished through punching press, injection moulding, cutting, etching, bending or through the combination of other known method and/or method, to realize desirable structure.For example, conductive component 54a-d can be by metal stamping partly (for example by the single sheet of associated materials by the while punching press), and is suitably crooked, and separated fully or form some or all after the shell by separation fully.

Conductive component 54a-d can be made by conducting metal or metal alloy, like the corrosion-resistant material of copper, copper alloy and/or other suitable low-resistivity or the combination of material.As indicated, the thermal conductivity of lead-in wire can be assisted the heat conduction away from led chip 80 to a certain extent.

Some or all led chip described herein can use transition material (for example or more polyphosphor) to apply, these phosphors absorb at least some led chip light also launch different wave length light in case the led chip emission from the combination (being light wavelength conversion) of the light of led chip and phosphor.In other embodiments, transition material can be arranged in other zone of encapsulation, includes but not limited to the surface (like reflector) of sealant or encapsulation.

In an embodiment according to the utility model, white luminous led chip can comprise led chip, the light of its emission blue wavelength spectrum, and the phosphor absorption portion blue light new emission gold-tinted of laying equal stress on.The white light that led chip emission blue light combines with gold-tinted.In other embodiments, United States Patent(USP) No. 7,213 as mentioned above, that kind described in 940, the non-white light that led chip emission blue light combines with gold-tinted.In certain embodiments, phosphor comprise can commercial acquisition YAG:Ce, yet adopt by based on (Gd, Y) ₃(Al, Ga) ₅O ₁₂: the Ce system is (like Y ₃Al ₅O ₁₂: the conversion particles that phosphor Ce (YAG)) is processed, FR wide yellow spectrum emission is possible.Other yellow phosphor that can be used for white luminous led chip comprises: Tb _3-xRE _xO ₁₂: Ce (TAG); RE=Y, Gd, La, Lu; Or Sr _2-x-yBa _xCa _ySiO ₄: Eu.

Replacedly, in other embodiments, apply the light of other color of led chip emission through transition material (like phosphor) with the expectation that required emission is provided.For example, the emitting red light led chip can comprise the led chip of the phosphor covering that is absorbed led chip light and red-emitting.Led chip can be launched blue light or UV light, and some phosphors that are suitable for these structures can comprise: Lu ₂O ₃: Eu ³⁺(Sr _2-xLa _x) (Ce _1-xEu _x) O ₄Sr _2-xEu _xCeO ₄SrTiO ₃: Pr ³⁺, Ga ³⁺CaAlSiN ₃: Eu ²⁺And Sr ₂Si ₅N ₈: Eu ²⁺

Can adopt many distinct methods to apply LED with phosphor; In sequence number is No.11/656; 759 and No.11/899; Described a kind of suitable method in 790 the U.S. Patent application, the utility model title of these two patent applications all is " Wafer Level Phosphor CoatingMethod and Devices Fabricated Utilizing Method ", and the two is merged in here by reference.Replacedly; Can use other method to apply LED; Like electrophoretic deposition (EPD); The U.S. Patent application No.11/473 that is called " Close Loop Electrophoretic Deposition of SemiconductorDevices " in the utility model name has described a kind of suitable EPD method in 089, and it is also incorporated into here by reference.In addition, as as known in the art, LED can have vertical or horizontal geometry.Those that comprise vertical geometry can have first contact and on P type layer, have second and contact on the substrate.The propagation of electrical signals that is applied to first contact gets into n type layer, and the signal that is applied to second contact is propagated entering p type layer.Under the situation of III nitride devices, be well known that thin translucent typically cover part or whole p type layer.Be appreciated that second contact can comprise such layer, it typically is metal, like platinum (Pt), or transparent conductive oxide, like indium tin oxide (ITO).

LED can also comprise lateral geometry, and wherein two contacts are all at the top of LED.As remove the part of p type layer and active area through etching, to expose the contact table top on the n type layer.The second horizontal n type contact is provided on the table top of n type layer.These contacts can comprise the well known materials of using known techniques of deposition.

In an illustrated embodiment, arrange encapsulation 50 so that upper surface 58 has and the color that forms contrast through recessed/cavity 70 from the light that encapsulates 50 emissions.In most of embodiment, the light of launching from cavity 70 can comprise the light by led chip 80 emissions, but in other embodiments, the light of launching through cavity 70 also can comprise the light by the transition material conversion that is arranged in the encapsulation diverse location.This can be included in the transition material on the led chip 80, the lip-deep transition material that is mixed in the transition material in the packing material 78 or in recessed 70, exposes.

In an illustrated embodiment, LED encapsulation 50 is from recessed 70 emission white lights, and upper surface can comprise the color that forms contrast with white light.Can use many various colors, for example blueness, brown, grey, redness, green, purple etc. among the shown embodiment, are black on its upper surface 58.Can adopt many different known methods to apply black pigment.Can adopt diverse ways, for example silk screen printing, ink jet printing, smear etc., the step after a while in the moulding process of shell 52 or in package fabrication process is carried out above-mentioned applying.

For the contrast color from upper surface 58 further contrasts recessed or cavity, the surface in recessed also can have color or apply with material, and said material fully reflects from the light of LED and/or the emission of transition material on every side.In certain embodiments, can comprise the material that fully reflects from the light of led chip 80 through recessed visible surperficial sidewall 74 and other surface of shell.Surface through the recessed 70 conductive component 54a-d that expose and the space between the conductive component 54a-d can be further apply improving the reflection of light by led chip 80 emissions through the light that reflects from led chip 80 with the reflector (not shown), otherwise can be by these package parts absorptions from the light of led chip 80.Preferably, the reflector comprises silver, but it is understandable that, other reflecting material, and for example aluminium also may be provided in all thickness.The reflector can completely or partially cover the part that is not occupied by led chip 80 or closing line 82 of conductive component; But it is understandable that as general fact, the reflector region covered is many more; The reflective surface area that obtains is big more, and this can improve total encapsulation reflectivity.

Cavity 70 can have many different shapes, circle or ellipse, square, rectangle or other polygonal shape shown in for example.The contrast areas of upper surface 58 can have many different shapes and can cover all or be less than whole upper surfaces.In one embodiment, upper surface 58 can be covered by contrast material, and its shape is limited the shape of upper surface 58.

As discussed above, the darker contrastive colours of upper surface 58 can cause absorbing this light when certain light when penetrating from led chip 80 emission and from encapsulating recessed 70.In order to help to minimize the amount of absorbed LED light, can arrange that upper surface 58 makes it on led chip, thereby seldom or do not have LED light directly to launch on upper surface.That is, led chip 80 is disposed in the substrate of cavity 70, and upper surface 58 is at the top of reflector, and it is on led chip 80.As a result, launch cavity 70 from the light of led chip 80 and directly do not launch on upper surface 58.This combination of contrast material provides contrast advantage above-mentioned, and unexpected effect is because the light of reflector is absorbed the reduction that therefore seldom or not can perceive LED encapsulation (or light-emitting diode display brightness) by darker surface.

As above mention, embodiment can be used for many different application according to the LED of the utility model encapsulation, but is specially adapted in light-emitting diode display, use so that the peak emission pattern of inclination to be provided.Fig. 6 illustrates the embodiment according to the light-emitting diode display 100 of the utility model, and its a plurality of LED according to the utility model capable of using encapsulate 102 to improve pixel contrast, and different light-emitting diode display embodiment can have the LED encapsulation that whole or some contrasts are improved.Different light-emitting diode display according to the utility model can have the pixel more than 300,000, and other embodiment can have 200,000 to 300,000 pixel.Other embodiment can have the pixel between 100,000 and 200,000.

It is understandable that, can arrange and can have many various parts with many different modes according to the different embodiment of the LED of the utility model encapsulation.Various embodiment can have a plurality of reflectors or led chip, and Fig. 7 and 8 illustrates another embodiment according to the LED encapsulation 200 of the utility model, and it also is arranged as SMD, but has 3 led chips.Embodiment above similar, encapsulation 200 comprises the shell 202 that carries integrated lead frame 204.Lead frame 204 comprises a plurality of conductive connecting elements, and it is used for the optical transmitting set of conducting electrical signals to encapsulation, and the also auxiliary heat that dissipates and produced by reflector.

Arrange lead frame so that each reflector is driven by separately the signal of telecommunication.Therefore, 6 conductive components are arranged among the shown embodiment, it comprises that the conductive component that is used for each reflector is right, applies the signal of telecommunication through its each reflector of conductive component subtend.For encapsulation 200, conductive component comprises first, second and third anode parts 206,208,210, and first, second and the 3rd cathode assembly 212,214,216 that all have the reflector attachment pad.Conductive component and attachment pad can be by preparing with above-mentioned those identical materials.

Be similar to above-mentionedly, shell 202 is generally square or rectangle, has upper and lower surfaces 218 and 220, first and second side surfaces 222 and 224 and first and second end surfaces 226 and 228.The top of shell further comprises recessed or cavity 230, and its main body that extends into shell 202 from upper surface 218 is until lead frame 204.Reflector is disposed on the lead frame 204 so that launch from encapsulating 200 process cavitys 230 from the light of reflector.In certain embodiments, can place and fixation reflex insert or ring (not shown) along the side of cavity 230 or the part of wall 234 at least.

The same with encapsulation 50, in certain embodiments, cavity 230 can be filled material (or sealant) 238 at least in part and fill, thereby the reflector of lead frame 204 and carrying can be protected and on the position, stablized to packing material (or sealant) 238.Packing material 238 and shell 202 can be processed by encapsulating 50 same procedure and material with preamble being used to of mentioning.

In the illustrative example of describing, encapsulation 200 utilizes first, second and the 3rd led chip 240,242,244, its each can launch and other light or the light of different colours of same color.In an illustrated embodiment, led chip 240,242,244 can send blueness, green and red respectively, and therefore these LED combination results are FR color basically when suitably being powered up.Further, when suitably being powered up, the white light combination of LED 240,242,244 emission different-colours.

Cathode assembly 212,214,216 comprises the central surface that is used to carry the led chip 240,242,244 that is linear array or pad is installed; This array extends on perpendicular to the direction 246 of side surface 222 and 224; Usually, LED 240,242,244 central axial alignment along shell 202.Than the encapsulation of the LED that has otherwise (as in a cluster) layout, this aligning can provide the color uniformity of the improvement under the different visual angles.

In an illustrated embodiment, encapsulation 200 also be arranged such that upper surface 218 have with from encapsulating the color that 200 colors through the light of cavitys 230 emission form contrast.Discuss like preamble, this can comprise from the light of led chip 240,242,244 and/or from the light that is arranged in a kind of or more transition materials in recessed.In an illustrated embodiment, LED encapsulation 200 can comprise that launching led chip 240,242,244 maybe can launch the white light combination from the light of its led chip 240,242,244.Upper surface 218 can comprise the color that forms contrast with white light.Can use many various colors, for example blueness, brown, grey, redness, green, purple etc., shown in execute in the instance, be black on its upper surface 218.Can use a kind of black pigment that applies in the method that preamble describes.

For the contrast color from upper surface 218 further contrasts recessed or cavity, the surface in recessed 230 also can have color or apply with material, and its reflection is discussed like preamble from the light of LED and/or the emission of transition material on every side.In addition, also can all apply through recessed 230 other surfaces of exposing, and also can discuss like preamble all with the coating of reflector (not shown) in the space between the conductive component with the reflector (not shown).The darker contrastive colours of upper surface 218 can cause absorbing this light when certain light when penetrating from led chip 240,242,244 emission and from encapsulating recessed 230.Be similar to preceding text,, can arrange that upper surface 218 makes it on led chip in order to help to minimize the amount of absorbed LED light, thus seldom or do not have LED light directly to impinge upon on the upper surface.The advantage that this layout provides preamble to discuss comprises that the pixel contrast of improvement does not reduce the luminous flux or the brightness of the perception that utilizes these encapsulated LED displays simultaneously basically.

With reference to first, second and third anode and cathode assembly top embodiment has been described; First, second is that the corresponding signal of telecommunication is applied to each led chip and makes allowances with third anode and cathode assembly; It is understandable that a plurality of led chips can be coupling in together with many alternate manners.Led chip can be coupling in together with many different series connection and parallel connection interconnection compound mode.In certain embodiments, led chip can be coupling at the single loop of single anode between single negative electrode that is used for applying the signal of telecommunication to led chip.

Interconnection circuit 300 shown in Figure 9 shows an embodiment who arranges according to the single loop of the utility model.A plurality of led chips 302,304,306 can in series be interconnected between single anode 308 and the single negative electrode 310, make that all led chips 302,304,306 are luminous so that be applied to the single signal of telecommunication of first chip of led chip 302.This allows single signal of telecommunication control all led chips to conducting or off state.It is understandable that in other embodiments, led chip can be connected between single anode and the single negative electrode parallelly connectedly, maybe can be other series connection/parallel connection combination.

It is understandable that, can arrange the different embodiment of reflector encapsulation with the many different modes the embodiment that mentions except that preamble.Encapsulation can have the mounting arrangements of many different surface installations or other type and can comprise the reflector with difformity and size.Other embodiment can be arranged as does not have reflector, an a kind of led chip or a plurality of led chip that is mounted to base station that comprise of these embodiment.Light reflection and contrast material can be around LED on base station, and in certain embodiments, the sealant of form of lens can be molded on the led chip.

Although describe the utility model in detail with reference to its some preferred structure, other pattern also is possible.Therefore, spirit of the utility model and scope should not be limited to above-described pattern.

Claims (6)

1. a light-emitting diode display is characterized in that, comprising:

A plurality of LED encapsulation; The light-converting material that some LED encapsulation in the said LED encapsulation comprise plastic casing, are arranged in the led chip of said shell and are arranged in reflector; Said light-converting material conversion is from least some light of said led chip emission; More said LED encapsulation emission is from the encapsulation light of said light-converting material or the emission combination from the light of the encapsulation light of said light-converting material and said led chip; Said encapsulation further comprises contrast areas, and said contrast areas is outside reflector space and have a color that forms contrast with said encapsulation light.

2. the light-emitting diode display of claim 1 is characterized in that, the said reflector space of each in more said LED encapsulation comprises the reflector around said led chip.

3. the light-emitting diode display of claim 1 is characterized in that, each in more said LED encapsulation comprises surface mounted device.

4. the light-emitting diode display of claim 1 is characterized in that, the said contrast areas in each in more said LED encapsulation is a black region.

5. the light-emitting diode display of claim 1 is characterized in that, the said contrast areas in each in more said LED encapsulation is around said reflector space.

6. the light-emitting diode display of claim 1 is characterized in that, the said contrast areas in each in more said LED encapsulation is in the level on the said led chip.

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