CN202977516U - Led display - Google Patents

Abstract

The utility model relates to and provides an LED display, comprising a plurality of LED packages, the plurality of LED packages are installed relative to each other so as to generate messages or images, wherein at least one of the plurality of LED packages includes: a housing, at least a part of the housing Including a part of the outer surface facing the viewer; an LED chip, the LED chip is installed in the cavity of the housing; a filling material, the filling material is arranged in the cavity and above the LED chip, wherein at least the filling material A portion includes a portion of the outer viewer-facing surface; and at least a portion of the outer viewer-facing surface of the package includes a matte surface. The LED display of the present invention provides LED billboards and good contrast between different pixels in the display without reducing the perceived luminous flux or brightness of the display and reducing reflections from ambient or background light.

Description

LED display

technical field

The utility model relates to a light emitting diode (LED) display. the

Background technique

Light-emitting diodes (LEDs) are solid-state devices that convert electrical energy into light, typically comprising one or more active layers of semiconductor material sandwiched between oppositely doped layers. When a bias voltage is applied across the aforementioned doped layers, holes and electrons are injected into the active layer where they recombine to generate light. Light is emitted from the active layer as well as all surfaces of the LED. the

In the last decade or more, technological advances have resulted in LEDs with smaller footprints, increased emission efficiencies, and reduced costs. LEDs also have an extended operating life compared to other emitters. For example, the operating life of LEDs can exceed 50,000 hours, while the operating life of incandescent light bulbs is about 2,000 hours. LEDs can also be more robust and consume less energy than other light sources. For these and other reasons, LEDs are more popular and are now used in more and more traditional field applications of incandescent, fluorescent, halogen and other emitters. the

In order to use LED chips in traditional applications, it is known to enclose the LED chips in packages to provide environmental and/or mechanical protection, color selection, light concentration, and the like. The LED package also includes electrical leads, contacts or traces for electrically connecting the LED package to an external circuit. In a typical two-lead LED package/component 10 shown in FIG. 1, a single LED chip 12 is mounted on a reflective cup 13 by solder bonding or conductive epoxy. One or more wire bonds 11 connect the ohmic contacts of the LED chip 12 to leads 15A and/or 15B, which may be attached to or integrated with the reflective cup 13 . The reflective cup 13 may be filled with an encapsulant 16 and a wavelength converting material such as a phosphor may be included over the LED chip or in the encapsulant. The phosphor can absorb light emitted by the LED at a first wavelength and spontaneously emit light at a second wavelength. The entire assembly can then be encased in a transparent protective resin 14 which can be molded in the shape of a lens to guide or shape the light emitted from the LED chip 12 . the

The conventional LED package 20 shown in FIG. 2 may be better suited for high power operation which can generate more heat. In the LED package 20 , one or more LED chips 22 are mounted on a carrier, such as a printed circuit board (PCB) carrier, substrate or submount 23 . A metal reflector 24 mounted on submount 23 surrounds LED chip 22 and reflects light emitted by LED chip 22 away from package 20 . Reflector 24 also provides mechanical protection for LED chip 22 . One or more wire bond connections 21 are made between the ohmic contacts on the LED chip 22 and the electrical traces 25A, 25B on the submount 23 . The mounted LED chip 22 is then covered with an encapsulant 26, which provides environmental and mechanical protection for the chip while also acting as a lens. Typically, the metal reflector 24 is attached to the carrier by solder or epoxy bonding. the

Different LED packages, such as those shown in Figures 1 and 2, regardless of size, can be used as light sources for billboards and displays. Large-screen LED-based displays, often referred to as giant screens, are becoming more common in many indoor and outdoor settings, such as stadiums, racetracks, concerts, and in large public areas such as Times Square in New York City. Some of these displays or screens may be as large as 60 feet high and 60 feet wide. As technology advances, expect to develop larger screens. the

These screens can include thousands of "pixels" or "pixel modules," each of which can contain multiple LEDs. The pixel modules can use high-efficiency, high-brightness LEDs that allow the display to be visible from a relatively long distance, even during daylight conditions. In some billboards, each pixel can have a single LED chip, and a pixel module can have as few as 3 or 4 LEDs (one red, one green, and one blue), which allows the pixel to switch from red to green. Many different colors of light are emitted in combination with blue light and/or blue light. In the largest giant screens, each pixel module can have dozens of LEDs. These pixel modules are arranged as a rectangular grid. In one type of display, the grid can be 640 modules wide and 480 modules high, and the size of the screen depends on the actual size of the pixel modules. the

An important aspect of conventional LED-based displays is the contrast between pixels in the display, which should be maximized for good image quality. Often times, increasing the contrast between pixels can lead to a decrease in the overall emission intensity of the emitters in the pixels and, as a result, the overall emission intensity of the LED display. the

To improve the contrast ratio of LED displays, LED packages have been developed that have a surface area surrounding the LED chip that contains a color that contrasts with the light emitted from the LED chip. However, these packages only use red, green and blue LEDs as their light sources. It is generally believed that the light emitted by an LED package employing such an arrangement may contain both the light of the LED chip and the light of the conversion material (eg, white light), and that employing such an arrangement would result in an unacceptable loss of brightness of the emitted light. The concern is that the contrasting surface area surrounding the LED chip absorbs package light, thus reducing the overall brightness of the package and of the billboards or displays utilizing these packages. the

Conventional LED packages such as those shown in FIGS. 1 and 2 have a transparent sealing material and a transparent reflective cup covering an LED chip so that light emitted from the LED package can be effectively utilized. Those skilled in the art routinely design package components to be light transmissive and not absorb any light generated by the LED or illuminating the package from an external source. However, the transparent encapsulant, transparent reflective cup, and surrounding contrast material in conventional LED packages may reflect too much background light when used in an LED display. These materials can be smooth and specular when cured, causing ambient light or reflections of ambient light. When viewing a display that includes conventional LED packages, consumers have problems viewing the displayed content if the display reflects too much background light. For example, consumers may find it difficult to read displayed text in the sun if the display reflects most of the sunlight. Therefore, there is a need for displays and LED packages that reflect less background light. the

Display consumers prefer high-contrast displays with low reflections. Additionally, consumers prefer displays with minimized reflections when the displays are exposed to bright background lighting. Thus, new LED devices with improved screen contrast and reduced reflection of background light are provided. the

Utility model content

The present invention is directed to emitter packages, more particularly to LED packages and LED displays utilizing LED packages. The LED package according to the invention employs at least one LED chip mounted in the cavity of the housing such that the surface of the package facing the viewer is matte. The invention has particular application to LED packages that can be installed in signs or displays to display information or images. The invention is particularly suitable for LED packages that can be installed in signs or displays to generate messages or images. The LED package provides LED billboards and good contrast between different pixels in the display without reducing the perceived luminous flux or brightness of the display, and reduces reflections from ambient or background light. the

One configuration of an LED package according to the present disclosure includes: a housing, at least a portion of which includes a portion of an outer surface facing a viewer; and an LED chip mounted in a cavity of the housing. The package also includes a fill material disposed in the cavity and over the LED chip, wherein at least a portion of the fill material includes a portion of the viewer-facing exterior surface. Additionally, at least a portion of the viewer-facing exterior surface of the enclosure has a matte surface. the

Another configuration according to the present disclosure provides a light emitting diode (LED) display including a plurality of LED packages mounted opposite to each other to generate a message or an image. At least one of the plurality of LED packages includes a housing, at least a portion of which includes a portion of an exterior surface facing a viewer. The package also includes an LED chip mounted in a cavity of the housing and a fill material disposed in the cavity and over the LED chip, wherein at least a portion of the fill material includes an outer surface facing a viewer a part of. Additionally, at least a portion of the viewer-facing exterior surface of the enclosure includes a matte surface. the

Another configuration of the present disclosure provides a method for manufacturing a light emitting diode (LED) package with reduced external reflection. The method includes providing a housing having a cavity capable of receiving an LED chip, wherein a portion of the surface of the housing includes a portion of an outer surface facing a viewer. The method also includes providing a fill material in the cavity, wherein at least a portion of the surface of the fill material includes a portion of the viewer-facing surface. Additionally, at least a portion of the viewer-facing surface is matte. the

According to the present invention there is provided a method for manufacturing a light emitting diode (LED) package with reduced external reflection, characterized in that the method comprises the steps of: providing a housing with a cavity capable of accommodating an LED chip, wherein a portion of the surface of the housing includes a portion of the viewer-facing surface; providing a fill material in the cavity, wherein at least a portion of the surface of the fill material includes a portion of the viewer-facing surface; and Wherein at least a portion of the viewer-facing surface is matte, and the portion of the viewer-facing surface formed by the enclosure outside the cavity has a contrasting color to the emitted light. the

According to a first aspect of the present invention there is provided a light emitting diode (LED) package comprising: a housing, at least a portion of which includes a portion of an outer surface facing a viewer; an LED chip mounted in a cavity of the housing a filling material disposed in the cavity and above the LED chip, wherein at least a portion of the filling material includes a portion of the viewer-facing exterior surface; and the package At least a portion of the exterior surface facing the viewer includes a matte surface. the

Specifically, according to the LED package of the first aspect of the present invention, further comprising a conversion material configured to convert at least some of the light emitted from the LED chip, the package emits light from the conversion material or from the The combination of conversion material and the light of the LED chip. the

Specifically, the LED package according to the first aspect of the present invention further includes a reflective area surrounding the LED chip within the cavity, the reflective area substantially reflecting light emitted from the LED chip. the

Specifically, in the LED package according to the first aspect of the present invention, the reflective area includes a reflective cup. the

Specifically, according to the LED package of the first aspect of the present invention, wherein, the portion of the outer surface facing the viewer constituted by the shell outside the cavity is configured as a contrasting area, and the contrasting area has a Encapsulated light creates contrasting colours. the

Specifically, in the LED package according to the first aspect of the present invention, the contrasting area is black. the

Specifically, the LED package according to the first aspect of the present invention, wherein the contrast area is around the reflective area. the

Specifically, the LED package according to the first aspect of the present invention, wherein the contrast region is located at a level above the LED chip. the

Specifically, the LED package according to the first aspect of the present invention further includes a lead frame at least partially located in the housing, and the LED chip is electrically coupled to the lead frame. the

Specifically, the LED package according to the first aspect of the present invention, wherein the cavity forms a reflective cup surrounding the LED chip. the

Specifically, the LED package according to the first aspect of the present invention includes a surface mount device (SMD). the

Specifically, the LED package according to the first aspect of the present invention, wherein the contrasting area and the LED chip are arranged such that the LED light is emitted from the package without being directly emitted on the contrasting area. the

Specifically, the LED package according to the first aspect of the present invention, wherein at least a part of the housing portion of the outer surface facing the viewer is matted by transfer from a forming die during the forming process of the housing change. the

Specifically, the LED package according to the first aspect of the present invention, wherein at least a part of the filling material portion of the viewer-facing outer surface is matted by etching. the

Specifically, the LED package according to the first aspect of the present invention, wherein at least a part of the filling material portion of the outer surface facing the viewer is matted by stamping. the

Specifically, the LED package according to the first aspect of the present invention, wherein at least a part of the filling material portion of the viewer-facing outer surface is matted by grinding. the

Specifically, according to the LED package of the first aspect of the present invention, at least a part of the filling material includes a matting agent, so that a part of the outer surface facing the viewer is matted. the

According to a second aspect of the present invention there is provided a light emitting diode (LED) display comprising: a plurality of LED packages mounted relative to each other so as to generate a message or an image, wherein in the plurality of LED packages At least one of the embodiments includes: a housing, at least a portion of which includes a portion of an outer surface facing a viewer; an LED chip mounted in a cavity of the housing; a filler material disposed in the cavity and located at the above the LED chip, wherein at least a portion of the filler material includes a portion of the viewer-facing exterior surface; and at least a portion of the viewer-facing exterior surface of the package includes a matte surface. the

Specifically, the LED display according to the second aspect of the present invention, wherein said LED package further comprises a conversion material arranged to convert at least some of the light emitted from said LED chip, said package emitting light from said conversion material or a combination of light from the conversion material and the LED chip. the

Specifically, the LED display according to the second aspect of the present invention, wherein the LED package further includes a reflective area surrounding the LED chip located in the cavity, the reflective area substantially reflects the light emitted from the LED chip Light. the

Specifically, in the LED display according to the second aspect of the present invention, the reflective area includes a reflective cup. the

Specifically, the LED display according to the second aspect of the present invention, wherein the portion of the outer surface facing the viewer constituted by the shell outside the cavity has a color that contrasts with the encapsulated light. the

Specifically, in the LED display according to the second aspect of the present invention, the contrasting area is black. the

Specifically, in the LED display according to the second aspect of the present invention, the contrast area is around the reflective area. the

Specifically, the LED display according to the second aspect of the present invention, wherein the contrast region is located at a level above the LED chip. the

Specifically, the LED display according to the second aspect of the present invention, wherein the LED package further includes a housing with a lead frame, and the LED chip is electrically coupled to the lead frame. the

Specifically, the LED display according to the second aspect of the present utility model, wherein the cavity forms a reflective cup surrounding the LED chip. the

Specifically, the LED display according to the second aspect of the present invention, wherein at least one LED package comprises a surface mount device (SMD). the

Specifically, the LED display according to the second aspect of the present invention, wherein the contrasting area and the LED chip are arranged such that the LED light is emitted from the package without being directly emitted on the contrasting area. the

Specifically, the LED display according to the second aspect of the present invention, wherein at least a part of the housing portion of the outer surface facing the viewer is matted by transfer from a forming mold during the forming process of the housing change. the

Specifically, in the LED display according to the second aspect of the present invention, at least a part of the filling material part of the outer surface facing the viewer is matted by etching. the

Specifically, in the LED display according to the second aspect of the present invention, at least a part of the filling material portion of the outer surface facing the viewer is matted by punching. the

Specifically, in the LED display according to the second aspect of the present invention, at least a part of the filling material portion of the outer surface facing the viewer is matted by grinding. the

Specifically, in the LED display according to the second aspect of the present invention, at least a part of the filling material includes a matting agent, and the matting agent causes a part of the outer surface facing the viewer to be matted. the

Specifically, the LED display according to the second aspect of the present invention, wherein said LED display comprises a higher pixel contrast ratio than the same LED display having an LED package with no contrast area. the

Specifically, the LED display according to the second aspect of the present invention, wherein the at least one LED package emits white light. the

According to a third aspect of the present invention there is provided a method for manufacturing a light emitting diode (LED) package with reduced external reflection, the method comprising the steps of: providing a housing having a cavity capable of receiving an LED chip, wherein a portion of the surface of the housing includes a portion of the viewer-facing surface; providing a fill material in the cavity, wherein at least a portion of the surface of the fill material includes a portion of the viewer-facing surface; and Wherein at least a portion of the viewer-facing surface is matte. the

Specifically, the method according to the third aspect of the present invention further comprises forming the shell on a mold having a textured surface, such that the texture is transferred to at least a part of the surface of the shell. the

Specifically, the method according to the third aspect of the present invention further includes the step of: etching at least a part of the surface of the filling material including a part of the surface facing the viewer to form a matte surface. the

Specifically, the method according to the third aspect of the present invention further includes the step of stamping at least a part of the surface of the filling material including a part of the viewer-facing surface to form a matte surface. the

Specifically, the method according to the third aspect of the present invention further comprises the step of: grinding at least a part of the surface of the filling material, including a part of the surface facing the viewer, to form a matte surface. the

Specifically, the method according to the third aspect of the present invention further includes the step of grinding at least a part of the surface of the housing including a part of the viewer-facing surface to form a matte surface. the

Specifically, according to the method of the third aspect of the present invention, wherein the filling material includes a matting agent and a polymer material. the

Specifically, the method according to the third aspect of the present invention, wherein a part of the matting agent remains on the surface of the filling material after curing, thereby forming a matting surface. the

Specifically, the method according to the third aspect of the present invention further includes: arranging a conversion material such that the conversion material can convert at least some light emitted from the LED chip; and emitting light from the conversion material or from The combination of the conversion material and the light of the LED chip. the

Specifically, the method according to the third aspect of the present invention further includes providing a reflective area within the cavity surrounding the LED chip, the reflective area substantially reflecting light emitted from the LED chip. the

Specifically, in the method according to the third aspect of the present invention, wherein the reflective area includes a reflective cup. the

In particular, the method according to the third aspect of the invention, wherein the portion of the viewer-facing surface constituted by the enclosure external to the cavity has a contrasting color to the emitted light. the

Specifically, in the method according to the third aspect of the present invention, the contrasting area is black. the

Specifically, in the method according to the third aspect of the present invention, wherein the contrast area is around the reflective area. the

Specifically, the method according to the third aspect of the present invention further includes: providing a lead frame inside the housing, and electrically coupling the LED chip to the lead frame. the

Specifically, according to the method of the third aspect of the present invention, wherein the LED package comprises a surface mount device (SMD). the

Specifically, the method according to the third aspect of the present invention, wherein the contrasting area and the LED chip are arranged such that the light of the LED is emitted from the package without being directly emitted on the contrasting area. the

These and other aspects and advantages of the invention will become apparent from the ensuing detailed description and accompanying drawings illustrating features of the invention, illustrating by way of example. the

Description of drawings

Figure 1 is a side view of a conventional light emitting diode package;

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

Figure 3 is a perspective view of one embodiment of an LED package according to the present disclosure;

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

Fig. 5 is a sectional view of the LED package shown in Fig. 4 along section line 5-5;

Figure 6 is a side view of an embodiment of an LED display according to the present disclosure;

7 is a perspective view of another LED package according to the present disclosure;

Figure 8 is a top view of the LED package shown in Figure 7;

Figure 9a is a side view of a shell forming die with an improved surface according to the present disclosure;

Figure 9b is a side view of the housing formed above the mold of Figure 9a;

Figure 9c is a side view of a housing formed with the mold of Figure 9a according to the present disclosure;

Figure 10a is a side view of the package before surface matting;

Figure 10b is a side view of the package after surface matting according to the present disclosure;

Figures 11a-11c are side views of packages according to the present disclosure showing the stamping process used to create surface matting;

Figure 12 is a side process diagram of the stage of the filling material in the curing process;

Figure 13a is a side view of a package with a matting agent in the fill material prior to curing;

Figure 13b is a side view of a package with a matting agent in the fill material after curing and forming a matte surface according to the present disclosure;

14 is a graph illustrating the effect of exemplary optical properties of using a matting agent in a fill material according to the present disclosure; and

15a-15c are side views of a package according to the present disclosure showing a grinding process to produce a surface matte. the

Detailed ways

The present invention is directed to LED packages and LED displays using LED packages, wherein the LED packages include different arrangements to improve the emission contrast between adjacent LED packages in the display and reduce reflections caused by light outside the packages. These packages may include one or more LED chips mounted on a submount or in a package housing and conversion material. A portion of the exterior surface of the submount or housing may comprise a color that contrasts with the color of light emitted from the LED package. Part of the exterior surface of the submount may also include a matte surface to reduce reflections. the

In some embodiments, the area of the submount or housing immediately surrounding the LED chip may comprise a material that is substantially the same color as or reflects light from the LED chip. Such a reflective area may at least partially comprise a reflective cup. Areas of the submount outside such reflective areas may comprise a material that contrasts with the LED chip light. In embodiments having a white emitting LED chip, the area immediately surrounding the LED chip can include a material that reflects white light, while the area surrounding the white light reflective material can contrast white light. In some of these embodiments, the white light reflective material can be white and the contrasting areas can be black. It will be appreciated that the contrasting regions may be many other colors including, but not limited to, blue, brown, gray, red, green, and the like. the

This combination of reflective material and contrasting material provides improved contrast between the light emitted from the LED chip and the surrounding packaging. This contrast helps to provide contrast between LED packages used in LED displays, thereby providing contrast between different pixels in the display. This improved contrast can produce a higher quality image for the viewer. At the same time, LED packages employing white-emitting LED chips provide the unexpected result of not absorbing unreasonable amounts of light from the LED package. It was previously believed that employing such an arrangement with white or other wavelength converted light would result in excessive loss of packaged light. Although some of the light from the LED chips may be absorbed by the contrast material, when they are used in a display, the contrast can cause the viewer to unexpectedly perceive substantially the same amount of light as compared to a display with an LED package without the contrast material. The contrast compensates for any absorbed light so that the viewer perceives substantially the same image brightness from the display. the

Embodiments are described below with reference to LED packages that emit LED light. In some configurations the LED light has been wavelength converted. This typically involves an LED chip arranged with a conversion material, such as a phosphor, through which at least some of the LED light passes so that some of the LED light is absorbed by the conversion material and re-emitted at a different wavelength of light. In some of these embodiments, the LED package can emit light that is a combination of light from the LED and the conversion material. The wavelength-converted light may include light of different colors, including white light and blue shifted yellow (BSY) light of different color temperatures. Typically, BSY light involves a blue emitting LED covered by a yellow/green conversion material, wherein at least some of the blue LED light is converted by the conversion material. The resulting LED chip emits a combination of blue light from the LED and yellow/green light from the conversion material. the

The package according to the present invention may also include a plurality of LED chips, each LED chip producing white wavelength-converted light. In other embodiments, an LED package may utilize multiple chips that emit different colors of light that are arranged to combine to produce white light. Techniques have been developed to generate white light from multiple discrete light sources to provide improved CRI at the desired color temperature, using different hues from different discrete light sources. Such a technique is described in U.S. Patent No. 7,213,940, entitled "Lighting Device and Lighting Method." In one such arrangement, a blue InGaN LED with a peak at 452nm is coated with a yellow conversion material, such as a YAG:Ce phosphor, to provide a yellow that is clear and has a blackbody locus that stays well on the CIE chart. The color of the color point (color point). Blue-emitting LEDs coated with yellow-converting materials are often referred to as blue-shifted yellow (BSY) LEDs or LED chips. The BSY emission is combined with light from the reddish AlInGaP LED, which "pulls" the yellow color of the yellow LED towards the blackbody curve to produce mild white light. the

In multiple LED chip embodiments, the LED chips can be coupled in the package so that an electrical signal can be applied to each LED chip to turn them on or off, or to cause them to emit a desired intensity of light. In other embodiments, the LED chips may be coupled together so that a single electrical signal controls the LED chips to turn on or off. These embodiments may include LED chips coupled together in series. the

LED packages according to the invention can be used in LED billboards and displays, but it will be appreciated that they can be used in many different applications. LED packages can comply with various industry standards, making them suitable for use in LED-based signage, channel letter lighting, or general backlighting and lighting applications. Some embodiments may also include flat top emitting surfaces to make them compatible with light pipes. These are but a few of the many different applications for LED packages according to the invention. the

Some LED package embodiments according to the present invention may include a single LED chip or multiple LED chips mounted to a submount or housing. These packages may also include a reflective cup surrounding the LED chip or LED chips. The upper surface of the reflective cup surrounding the LED chip may include a material that contrasts with the light emitted by the LED chip. Portions of the submount exposed within the cup, and/or reflective surfaces within the cup may also include a material that reflects light from the LED chip. In some of these embodiments, the light emitted from the LED chip can be white or other wavelength converted light, and the surface of the submount within the reflective cup and the reflective surface of the cup can be white or reflect white or wavelength converted light. The contrasting upper surface of the reflective cup can be many different colors, but in some embodiments is black. the

The invention has been described herein with reference to some embodiments, but it will be understood that the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In particular, many different LED chip, package, reflective cup, and lead frame arrangements are available beyond those described above, and the encapsulant can provide additional benefits of improved reliability and emission characteristics from the LED package and LED displays using the LED package. multiple features. Although the different embodiments of LED packages discussed below are directed to use in LED displays, LED packages can also be used in many different lighting applications. the

It will also be understood that when an element such as a layer, region or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Also, relative terms such as "above" and "below" and similar terms may be used herein to describe the relationship of one layer or another region. It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. the

Although the terms first, second, etc. may be used herein to describe various elements, components, regions and/or sections, these terms shall not limit these elements, components, regions and/or sections. These terms are only used to distinguish one element, component, region or section from another element, component, region or section. Thus, a first element, component, region or section discussed below could be termed a second element, component, region or section without departing from the teachings of the present invention. the

Embodiments of the invention are described herein with reference to cross section illustrations that are schematic illustrations of embodiments of the invention. Accordingly, the actual thickness of the components may vary and variations from the illustrated shapes are contemplated for reasons such as manufacturing techniques and/or tolerances. Embodiments of the invention are not to be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes for, for example, manufacturing reasons. Typically, square or rectangular regions illustrated or described will have rounded or arcuate features due to standard manufacturing tolerances. The regions shown in the figures are thus schematic in nature and their shapes are not intended to illustrate the precise shape of a region of a device and are not intended to limit the scope of the invention. the

3-5 illustrate one embodiment of an emitter package 50 including a surface mount device (SMD) according to the present invention. That is, the device is arranged so that it can be mounted to a structure such as a printed circuit board (PCB) by employing surface mount technology. It is understood that the present invention is also applicable to other emitter package types than SMD, such as pin mount emitter packages. Package 50 includes a housing (or submount) 52 carrying an integrated leadframe 53 . Leadframe 53 includes a plurality of conductive connections for conducting electrical signals to the packaged light emitters and also for helping to dissipate heat generated by the emitters. the

The lead frame 53 can be arranged in many different ways, and different numbers of components can be employed in different package embodiments. Package 50 is described below as utilizing an emitter to which, in the illustrated embodiment, leadframe 53 is arranged to apply electrical signals. Lead frame 54 includes conductive members 54a-d, two of which are used to apply electrical signals to the emitters. In the illustrated embodiment, the anode for applying an electrical signal to the transmitter may be the second conductive member 54b and the cathode may be the fourth conductive member 54d, but it will be appreciated that other embodiments may utilize conductive members 54a- d the rest of the conductive parts. The remaining conductive components 54a and 54c may be included to provide mounting stability and to provide an additional thermal path to dissipate heat from the emitter. In the illustrated embodiment, the second conductive member 54b has a die attach pad 56 for mounting an emitter such as a light emitting diode (LED). the

Housing 52 can have many different shapes and sizes, and in the illustrated embodiment, it is generally square or rectangular, with 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 upper portion of the housing further includes a recess or cavity 70 extending from the upper surface 58 into the body of the housing 52 up to the lead frame 53 . The package emitter is arranged on the leadframe 53 so that light from the emitter is emitted from the package 50 through the cavity 70 . Cavity 70 constitutes a reflective cup surrounding the emitter to help reflect the emitter light out of package 50 . In some embodiments, a reflective insert or ring (not shown) may be placed and secured along at least a portion of the side or wall 74 of the cavity 70 . The effect of the reflectivity of the ring and the emission angle of the package can be enhanced by tapering the cavity 70 and carrying the ring inwardly towards the interior of the housing. As an example, a reflection angle of about 50 degrees provides suitable reflectivity and viewing angle. The upper surface 58 of the housing 52 forms part of the viewer-facing surface of the package and may be smooth (as shown in FIG. 4 ) or the upper surface may be a rough or matte surface 90 (as in FIG. 3 ). and shown in Figure 5). In other configurations, a combination of smooth polished surfaces and rough or matte surfaces may be used. Surface roughness or matting may facilitate reflection of light from outside the package, such as sunlight, ambient or background light, from the viewer-facing surface towards the viewer. the

In some embodiments, the cavity 70 may be at least partially filled with a filler material (or encapsulant) 78 capable of protecting and positionally stabilizing the lead frame 53 and the carried emitter. In some cases, filler material 78 may cover the emitters and portions of leadframe 53 exposed through cavity 70 . Fill material 78 may be selected to have predetermined optical properties to enhance projection of light from the LED, and in some embodiments, fill material 78 is substantially transparent to light emitted by the encapsulated emitter. Fill material 78 may also be flat so that it is approximately level with upper surface 58, or it may be shaped as a lens, such as a hemisphere or a bullet. Alternatively, the filling material may be fully or partially recessed into cavity 760 . Fill material 78 may be formed from resin, epoxy, thermoplastic polycondensate, glass, any polymeric material, and/or other suitable material or combination of materials. In some embodiments, materials for enhancing the emission, absorption, and/or scattering of light to and/or from the LEDs may be added to the fill material 78 . Filler or sealant 78 forms part of the viewer-facing surface of the package and may be smooth (as shown in FIG. 4 ), or it may be a rough or matte surface 92 (as shown in Figures 3 and 5). In other configurations, a combination of smooth polished surfaces and rough or matte surfaces may be used. Surface roughness or matting can help reduce the reflection of light from outside the package, such as sunlight, ambient light, or background light, from the viewer-facing surface toward the viewer. the

Housing 52 may be fabricated from a material that is preferably both electrically insulating and thermally conductive. Such materials are well known in the art and may include, without limitation, certain ceramics, resins, epoxies, silicones, and thermoplastics, polycondensates (such as polyphthalamide (PPA)), and glass . Package 50 and its housing 52 may be formed and/or assembled by any of a variety of known methods well known in the art. For example, housing 52 may be formed or molded around conductive components 54a-d, such as by injection molding. Alternatively, the housing may be formed in multiple parts, such as a top and a bottom, on which the conductive member is formed. The top and bottom may then be bonded together using known methods and materials, such as by epoxy, adhesive, or other suitable bonding material. the

Many different emitters can be used with packages according to the invention, and package 50 utilizes LED chips 80 . Different embodiments may have different LED chips that emit different colors of light, and in the embodiment shown, package 50 includes LED chips that emit white or other wavelength-converted light. the

LED structures, features, and their manufacture and operation are generally known in the art and are only briefly discussed here. LEDs can have many different semiconductor layers arranged in different ways and can emit different colors. The layers of the LED can be fabricated using known processes, and one suitable fabrication process is the use of Metal Organic Chemical Vapor Deposition (MOCVD). The layers of an LED chip typically include an active layer/region sandwiched between first and second oppositely doped epitaxial layers, all of which are formed continuously on a growth substrate or wafer. The LED chips formed on the wafer can be singulated and used in various applications, such as being mounted in a package. It is understood that the growth substrate/wafer may remain as part of the final singulated LED or the growth substrate may be removed in whole or in part. the

It is also understood that additional layers and elements may also be included in the LED, including but not limited to buffer layers, nucleation layers, contact layers, and current spreading layers, as well as light extraction layers and elements. The active region may comprise single quantum well (SQW), multiple quantum well (MQW), double heterojunction or superlattice structures. the

The active region and doped layers can be fabricated from different material systems, one such system is a Ill-nitride based material system. Group III nitrides refer to those semiconductor compounds formed between nitrogen and an element in group III of the periodic table, usually aluminum (Al), gallium (Ga), and indium (In). The term also refers to ternary and quaternary compounds such as aluminum gallium nitride (AlGaN) and aluminum indium gallium nitride (AlInGaN). In a possible embodiment, the doped layer is gallium nitride (GaN) and the active layer is InGaN. In alternative embodiments, the doped layer may be AlGaN, aluminum gallium arsenide (AlGaAs) or aluminum gallium indium arsenide phosphide (AlGaInAsP) or aluminum indium gallium phosphide (AlInGaP) or zinc oxide (ZnO). the

The growth substrate/wafer can be made of many materials such as silicon, glass, sapphire, silicon carbide, aluminum nitride (AlN), gallium nitride (GaN), a suitable substrate is 4H polytype silicon carbide, however also Other silicon carbide polytypes including 3C, 6H and 15R polytypes may be used. Silicon carbide has certain advantages such as a closer lattice match to Ill-nitride than sapphire, thus resulting in Ill-nitride films of higher quality. SiC also has very high thermal conductivity so that the total output power of a III-nitride device on SiC is not limited by heat dissipation from the substrate (as may be the case for some devices formed on sapphire). SiC substrates are available from Kerry Research, Durham, NC, USA, and methods for making them are set forth in the scientific literature and in US Patent Nos. Re. 34,861, 4,946,547, and 5,200,022. LEDs can also include additional features, such as conductive current spreading structures and current spreading layers, all of which can be made from known materials deposited using known methods. the

The LED chip 80 may be electrically coupled to the attachment pad 56 on the second conductive member 54b by an electrically and thermally conductive bonding material such as solder, adhesive, coating, film, encapsulant, Paste, grease and/or other suitable materials. In a preferred embodiment, the LEDs can be electrically coupled and secured to their respective pads using solder pads on the bottom of the LEDs so that the solder is not visible from the top. A bonding wire 82 may be included and extend between the LED chip 80 and the fourth conductive member 54d. An electrical signal applied across the second and fourth conductive members causes LED chip 80 to emit light. the

Fabrication of the conductive features 54a-d may be accomplished by stamping, injection molding, cutting, etching, bending, or by other known methods and/or combinations of methods to achieve the desired configuration. For example, the conductive components 54a-d may be partially metal stamped (eg, simultaneously stamped from a single sheet of the relevant material), suitably bent, and completely separated or completely separated after some or all of the housings are formed. the

Conductive members 54a-d may be fabricated from conductive metals or metal alloys, such as copper, copper alloys, and/or other suitable low resistivity corrosion resistant materials or combinations of materials. As noted, the thermal conductivity of the leads can somewhat assist in conducting heat away from the LED chip 80 . the

Some or all of the LED chips described herein may be coated with a conversion material such as one or more phosphors that absorb at least some of the LED chip light and emit light at a different wavelength so that the LED chip emits light from the LED chip and the phosphor Combination of light from the body (ie, wavelength-converted light). In other embodiments, the conversion material may be located in other areas of the package, including but not limited to encapsulant materials or surfaces of the package such as reflective cups. the

In one embodiment according to the present invention, the white emitting LED chip may comprise an LED chip that emits light in the blue wavelength spectrum, while the phosphor absorbs part of the blue light and re-emits yellow light. The LED chip emits white light which is a combination of blue light and yellow light. In other embodiments, the LED chips emit a combination of blue and yellow non-white light, as described in the above-mentioned US Patent No. 7,213,940. In some embodiments, the phosphor comprises YAG:Ce which is commercially available, however using a (Gd,Y) ₃ (Al,Ga) ₅ O ₁₂ :Ce based system such as Y ₃ Al ₅ O ₁₂ :Ce( YAG)), the full range of broad yellow spectral emission is possible. Other yellow phosphors that can be used in white-emitting LED chips include: Tb _3-x RE _x O ₁₂ :Ce(TAG); RE=Y, Gd, La, Lu; or Sr _2-xy Ba _x Ca _y SiO ₄ : Eu.

Alternatively, in other embodiments, the LED chip emits light of other colors by coating it with a desired conversion material, such as a phosphor, that provides the desired emission. For example, a red emitting LED chip may include an LED chip covered with a phosphor that absorbs light from the LED chip and emits red light. LED chips can emit blue or UV light, and some phosphors suitable for these structures can include: Lu ₂ O ₃ :Eu ³⁺ ; (Sr _2-x La _x )(Ce _1-x Eu _x )O ₄ ; Sr _{2 -x} Eu _x CeO ₄ ; SrTiO ₃ :Pr ³⁺ ,Ga ³⁺ ; CaAlSiN ₃ :Eu ²⁺ ; and Sr ₂ Si ₅ N ₈ :Eu ²⁺ .

LEDs can be coated with phosphors in a number of different ways, one suitable method is described in U.S. Patent Application Serial Nos. 11/656,759 and 11/899,790, both of which have utility model titles is "Wafer Level Phosphor Coating Method and Devices Fabricated Utilizing Method", and both are incorporated herein by reference. Alternatively, other methods can be used to coat the LEDs, such as electrophoretic deposition (EPD), a suitable EPD is described in U.S. Patent Application No. 11/473,089 with the utility model title "Close Loop Electrophoretic Deposition of Semiconductor Devices" method, which is also incorporated herein by reference. Additionally, LEDs can have vertical or lateral geometries, as is known in the art. Those comprising vertical geometries may have a first contact on the substrate and a second contact on the p-type layer. An electrical signal applied to the first contact propagates into the n-type layer, and a signal applied to the second contact propagates into the p-type layer. In the case of Ill-nitride devices, it is known that a thin translucent layer typically covers part or all of the p-type layer. It will be appreciated that the second contact may comprise a layer, typically a metal, such as platinum (Pt), or a transparent conducting oxide, such as indium tin oxide (ITO). the

LEDs can also include lateral geometries where both contacts are on top of the LED. The p-type layer and a part of the active region are removed by etching to expose the contact mesa on the n-type layer. A second lateral n-type contact is provided on the mesa of the n-type layer. These contacts may comprise known materials deposited using known deposition techniques. the

In some configurations, package 50 may be arranged such that upper surface 58 has a color that contrasts with light emitted from package 50 through recess/cavity 70 . In most embodiments, the light emitted from cavity 70 may include light emitted by LED chip 80, but in other embodiments, the light emitted through cavity 70 may also include light emitted by a conversion material located at a different location in the package. Converted light. This may include the conversion material over the LED chip 80 , the conversion material mixed in the fill material 78 , or the conversion material on the surface exposed in the recess 70 . the

In some configurations, LED package 50 emits white light from recess 70, and the upper surface may include a color that contrasts with the white light. Many different colors can be used, such as blue, brown, gray, red, green, purple, etc., and in the embodiment shown, its upper surface 58 is black. Black pigments can be applied by many different known methods. The application can be done during the molding of the housing 52 or at a later step in the package manufacturing process using different methods such as screen printing, inkjet printing, painting, etc. the

To further contrast the recess or cavity from the contrasting color of the upper surface 58, the surface in the recess may also be colored or coated with a material that sufficiently reflects light emitted from the LED and/or surrounding conversion material . In some embodiments, the surfaces visible through the recess sidewalls 74 and other surfaces of the housing may include a material that substantially reflects light from the LED chips 80 . Both the surfaces of the conductive features 54a-d exposed by the recesses 70 and the spaces between the conductive features 54a-d can be further coated with a reflective layer (not shown) to improve the performance of the LED display by reflecting light from the LED chip 80. Reflection of light emitted by the LED chip 80 that would otherwise be absorbed by these packaging components. Preferably, the reflective layer comprises silver, but it will be appreciated that other reflective materials, such as aluminum, may also be provided in various thicknesses. The reflective layer may completely or partially cover the portion of the conductive member not occupied by the LED chip 80 or the bond wire 82, but it will be appreciated that, as a general fact, the more area covered by the reflective layer, the greater the reflective area obtained, which The overall package reflectivity can be improved. the

Cavity 70 may have many different shapes, such as circular as shown, or oval, square, rectangular, or other polygonal shapes. The contrasting area of upper surface 58 can have many different shapes and can cover all or less than all of the upper surface. In an embodiment, upper surface 58 may be covered by a contrasting material, the shape of which is defined by the shape of upper surface 58 . the

As discussed above, the darker contrasting color of upper surface 58 may result in absorption of certain light as it is emitted from LED chip 80 and exits package recess 70 . To help minimize the amount of LED light that is absorbed, upper surface 58 may be arranged so that it is above the LED chips so that little or no LED light is emitted directly onto the upper surface. That is, the LED chip 80 is disposed at the base of the cavity 70 , while the upper surface 58 is on top of the reflective cup, which is above the LED chip 80 . As a result, light from LED chip 80 is emitted out of cavity 70 and not directly onto upper surface 58 . This combination of contrasting materials provides the contrasting benefits mentioned above, with the unexpected effect that little or no perception of the LED package (or LED display brightness) is due to the emitter's light being absorbed by the darker surface. reduce. the

As mentioned above, LED package embodiments according to the present invention can be used in many different applications, but are particularly suitable for use in LED displays to provide a sloped peak emission pattern. FIG. 6 shows an embodiment of an LED display 100 according to the present invention, which can utilize multiple LED packages 102 according to the present invention to improve pixel contrast. Different LED display embodiments can have all or several contrast-improved LED packages. . Different LED displays according to the invention may have more than 300,000 pixels, while other embodiments may have 200,000 to 300,000 pixels. Other embodiments may have between 100,000 and 200,000 pixels. the

It will be appreciated that different embodiments of LED packages according to the present invention can be arranged in many different ways and have many different components. Different embodiments can have multiple emitters or LED chips, Figures 7 and 8 show another embodiment of an LED package 200 according to the invention, also arranged as SMD, but with 3 LED chips. Like the above embodiments, package 200 includes a housing 202 carrying an integrated leadframe 204 . The leadframe 204 includes a plurality of conductive connections for conducting electrical signals to the packaged light emitters and also assisting in dissipating heat generated by the emitters. the

The leadframes are arranged so that each emitter is driven by a respective electrical signal. Thus, in the illustrated embodiment there are 6 conductive members comprising a pair of conductive members for each emitter through which the electrical signal is applied to each emitter. For package 200, the conductive components include first, second and third anode components 206, 208, 210, and first, second and third cathode components 212, 214, 216 each having an emitter attachment pad. The conductive member and the attachment pad can be made of the same materials as those described above. the

Similar to the above, housing 202 is generally square or rectangular having 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 upper portion of the housing further includes a recess or cavity 230 that extends from the upper surface 218 into the body of the housing 202 to the lead frame 204. The emitters are arranged on the lead frame 204 such that light from the emitters is emitted from the package 200 through the cavity 230 . In some embodiments, reflective inserts or rings (not shown) may be placed and secured along at least a portion of the sides or walls 234 of the cavity 230 . As noted above, in some configurations, some or all of the viewer-facing surface of the package (consisting of the upper surface 218 of the housing 202 and the filler material, sealing material, or optic) may be smooth , rough, or a combination of both. In FIG. 7 , upper surface 218 of housing 202 is shown as roughened surface 290 . the

As with package 50, in some embodiments, cavity 230 may be at least partially filled with a filler material (or encapsulant) 238 capable of protecting and positionally stabilizing lead frame 204 and the carrier. launcher. Fill material 238 and housing 202 may be made from the same methods and materials as previously mentioned for package 50 . the

In the illustrative embodiment described, package 200 utilizes first, second and third LED chips 240, 242, 244, each of which may emit the same color of light or a different color of light than the others. In the illustrated embodiment, the LED chips 240, 242, 244 can emit blue, green and red respectively, so that the combination of these LEDs produces substantially the full range of colors when properly powered. Further, when properly powered, the LEDs 240, 242, 244 emit white light combinations of different color temperatures. the

Cathode assemblies 212, 214, 216 include a central surface or mounting pad for carrying LED chips 240, 242, 244 in a linear array extending in a direction 246 perpendicular to side surfaces 222 and 224, typically LEDs 240, 242 , 244 are aligned along the central axis of the housing 202 . Such alignment can provide improved color uniformity across viewing angles compared to packages with LEDs arranged in other ways, such as in groups. the

In the illustrated embodiment, package 200 is also arranged such that upper surface 218 has a color that contrasts with the color of light emitted from package 200 through cavity 230 . As previously discussed, this may include light from the LED chips 240, 242, 244 and/or light from one or more conversion materials disposed within the recess. In the illustrated embodiment, the LED package 200 may include an emitting LED chip 240, 242, 244 or a white light combination that may emit light from its LED chip 240, 242, 244. Upper surface 218 may include a color that contrasts with white light. Many different colors can be used, such as blue, brown, gray, red, green, purple, etc., and in the embodiment shown, its upper surface 218 is black. The black pigment can be applied using one of the methods described previously. the

To further contrast the recess or cavity from the contrasting color of upper surface 218, the surfaces within recess 230 may also be colored or coated with a material that reflects light emitted from the LED and/or surrounding conversion material, such as discussed earlier. Additionally, other surfaces exposed through recesses 230 may also be fully coated with a reflective layer (not shown), as well as spaces between conductive components may be fully coated with a reflective layer (not shown), as previously discussed. . The darker contrasting color of the upper surface 218 may result in absorption of certain light as it is emitted from the LED chips 240 , 242 , 244 and exits the package recess 230 . Similar to the above, to help minimize the amount of LED light that is absorbed, the upper surface 218 can be arranged so that it is above the LED chips so that little or no LED light directly shines on the upper surface. This arrangement provides the advantages discussed above, including improved pixel contrast without substantially reducing the perceived luminous flux or brightness of LED displays utilizing these packages. the

The above embodiments have been described with reference to first, second and third anode and cathode components which allow for corresponding electrical signals to be applied to each LED chip, it being understood Fortunately, multiple LED chips can be coupled together in many other ways. LED chips can be coupled together in many different combinations of series and parallel interconnections. In some embodiments, the LED chips may be coupled together in a single loop between a single anode and a single cathode for applying electrical signals to the LED chips. the

As mentioned above, it is advantageous to reduce the reflection of light from outside the package. This can be accomplished by roughening, matting, or otherwise modifying the package top surface or viewer-facing surfaces such as the housing and fill material. In one configuration, the viewer-facing or upper surface of the housing is roughened. As shown in Figures 9a-9c, injection molding may be used to form the housing. In these configurations, the housing surface has the same shape or finish as the mold surface. Therefore, in one embodiment, a mold with a trimmed mold surface is used. The finished mold surface is matte or roughened such that the roughness pattern on the mold surface is transferred to the shell surface during the forming process. FIG. 9 a shows a trim die 92 with a roughened surface 94 . Rough surface 94 of mold 92 may be formed by any suitable process, such as micro-pitting by electrical discharge, grinding, lapping, cutting, stamping, or any other available process . the

After forming the mold 92 with the roughened surface, the shell 96 is formed by injection into the mold as in conventional shell forming. As shown in Figure 9b, during forming, the roughened surface 94 of the mold 92 contacts the shell as the shell material flows into the mold during injection. This area of housing 96 serves as the upper surface of the fabricated package. The pattern on the roughened surface 94 of the mold 92 is transferred to the shell 96 during the shell forming process. This process forms a shell 96 with a roughened surface 94 as shown in FIG. 9c. In other configurations, the mold itself may not include a trimmed surface, and a mask may be placed between the mold and the shell material to provide a rough pattern for transfer to the shell material during forming. In yet other configurations, the housing material may be trimmed after forming using etching, grinding, cutting, stamping, or any other available process. the

There is a difference between a shell surface formed using a conventional smooth mold and a shell surface formed using a modified rough surface. The surface of the shell formed using the trimmed rough mold has a rough texture. the

In another configuration, the outer surface of the filler material may be roughened. In one embodiment, as shown in Figures 10a and 10b, surface matting of the fill material or encapsulant may be achieved by a chemical process, such as the use of an etchant. Although both isotropic and anisotropic etching can be used, it is preferred to use an anisotropic etching process so that the surface reaction is different on various regions of the surface, resulting in a matte surface 116 . An etchant may be used after the fill material 114 has cured. Any etchant (such as wet etching) that can provide a different etch rate across the surface of fill material 114 may be used. Figure 10a shows a conventional package with a housing 112 that includes a cavity 118 filled with a filler material, encapsulant, or optic 114 such that the outer surface of the filler material 114 is smooth. Figure 10b shows a package with a housing 112 comprising a cavity 118 filled with a filler material, encapsulant or optical mirror 114 such that the outer surface of the filler material 114 is matted or roughened 116 by an etching process . the

In one embodiment, as shown in Figures 11a-11c, surface matting of the fill material or sealant 124 can be achieved by a physical process such as a stamping process, wherein a textured or microtextured mask 129 is placed and pressed against the filler material 124 . A mask may be used during the curing process. The package has a housing 122 as shown in FIG. 11 a . The housing 122 includes a cavity 128 filled with a filler or sealing material 124 . Next, in FIG. 11 b , a textured or micro-textured mask 129 is placed over the filling material 124 . In some embodiments, the mask 129 is first treated with a release agent so that the mask 129 can be easily removed from the filling material 124 when the stamping process is complete. Mask 129 may be made of a textured film, metal, glass, plastic, or any other suitable material that can be used to imprint texture onto fill material 24 . After the mask 129 is placed over the fill material 124 , the grind is pressed in place and the fill material is cured such that the texture 126 is transferred to the upper surface of the fill material 124 . Next, as shown in FIG. 11 c , the mask 129 is removed by means of a release agent, and the upper surface of the filling material 124 remains with the texture 126 transferred thereto from the mask 129 . the

In yet another embodiment, as shown in Figures 12-13b, a matting agent may be used with the filler material 144, 132 to achieve surface matting of the filler material or sealant 144. In configurations where a matting agent is used to create a rough or matte surface, the matting agent 134, 149 is provided in or with the filler material 132, 144. Figure 12 shows the three stages of setting and curing the fill material. In a first stage 131 , the fill material 132 is shown in a wet or uncured form with the matting agent 134 disposed substantially uniformly or randomly within the fill material. Preferably, the matting agent 134 is uniformly disposed in the fill material 132, however, in other configurations, the matting agent 134 may be distributed at other concentrations. In the next stage 133, the fill material 132 is shown to have a small amount of shrinkage due to evaporation of the solvent in the fill material during curing. As shown, during this stage, the particles of matting agent 134 are brought closer to the surface due to film shrinkage. In a final stage 135, the fill material 132 is shown in a dried or cured form. As can be seen from the figure, at this stage, due to further shrinkage during drying, some particles of the matting agent 134 force the surface of the filling material 132 to be arranged in a non-uniform manner, thereby providing a rough, textured, or matte surface 136 . the

The matting agent used should have an appropriate mass density to prevent the matting agent particles from settling or settling in the filling material. Any material that has an appropriate mass density relationship to the filler material can be used as a matting agent. Matting agents must also have an appropriate surface treatment (such as an inorganic treatment) and an appropriate specified surface area to match the fill material system. Silica (silicon dioxide) particles are used as a matting agent in some configurations, with a particle size of 4-10 μm and a surface area of 2-200 (m ² /g). However, in other configurations, other matting agents, such as other polycrystalline particles and organic materials, with appropriate mass and density specifications may also be used. The matting agent can be of any shape, however, irregularly shaped particles are preferred for the matting effect. Exemplary matting agents are materials that may be applied to paint coats, resins, or other polymers to help roughen the surface after the chemical has dried or cured. Some matting agents may include silica (surface treated or untreated); wax products such as those based on polytetrafluoroethylene (PTFE), polyethylene, polypropylene, Carnauba, and amides; And other inorganic or organic particles that can be dispersed in the filling material and show good anti-sedimentation properties in the filling material. Preferred matting agents do not affect light output and produce a micro-textured surface, and do not sink or settle in the fill material, and in some cases float on top of the fill material.

Additionally, in some configurations, the use of matting agents, such as silica, does not result in significant light output degradation. Figure 14 shows the effect or degradation of light output for a reference fill material and two different fill materials incorporating two matting agents. As shown, the maximum degradation is 4%, and in some examples the output is even improved by 3%. Preferably, the matting agent should not absorb light. Thus, these matting agents in the fill material can reflect light, and this should help make the light output appear more uniform even after these "random" reflections. the

13a and 13b show side views of the package including housing 142 . The housing 142 has a molded cavity 148 that holds a fill material 144 . As described with reference to FIG. 12 , the filler material 144 includes a matting agent 149 disposed substantially uniformly throughout the filler material 144 . Figure 13a shows the filler material 144 with a smooth surface before curing. Figure 13b shows the result of curing a filler material 144 with matting agent particles 149 disposed therein. As shown and described above, curing of filler material 144 with matting agent 149 causes shrinkage of filler material 144 and exposes portions of the particles of matting agent 149 , resulting in a matted, rough, or textured surface 146 . In some embodiments, a similar curing process can be used for the fill material and remain with or without matting agent particles. the

In another embodiment where surface matting of the filler material or sealant 174 and/or housing 172 can be achieved by a physical process, as shown in FIGS. , micro-textured, micro-pitting grinding plate 179 grinds or dresses the housing 172 and/or fill material while pressure is applied to the potting or grinding plate 179 to force these components together. A package has a housing 172 as shown in FIG. 15a. The housing 172 includes a cavity 178 filled with a filler or sealing material 174 . Next, in Figure 15b, a textured or micro-textured grinding plate 179 is placed over at least a portion of the package so that the grinding plate can be used to grind or dress the housing 172 or filler material 174, or to grind Or regrind both shell and fill material. Abrasive plate 179 may be made of metal, sandpaper, any other substrate to which an abrasive is attached, or any other suitable material exhibiting a higher hardness compared to shell 172 and filler material 174 . The abrasive pad substrate may include paper, cloth, rubber, and the like. The lapping plate abrasives attached to the substrate may include silicon carbide, aluminum oxide, silicon oxide, diamond, and the like. Next, as shown in FIG. 15c , after grinding, the filler material 174 and shell 172 are shown having a textured upper surface 176 . In still other embodiments, other processes may also be used to form grooves, pitting, or other textures on the surface of the housing or fill material. In other configurations, anti-reflective coatings can be added to these surfaces. the

It will be appreciated that the different embodiments of the emitter package may be arranged in many different ways than the previously mentioned embodiments. Packages can have many different surface mount or other types of mounting arrangements and can include reflective cups of different shapes and sizes. Other embodiments may be arranged without a reflective cup, one of these embodiments comprising an LED chip or LED chips mounted to a submount. A light reflective and contrasting material can surround the LED on the submount, and in some embodiments, an encapsulant in the form of a lens can be molded over the LED chip. It is also understood that any of the roughening, texturing or surface matting techniques may be used on only a portion of the upper surface or on the entire upper surface. Additionally, these techniques may be used for other purposes or on surfaces other than the upper or viewer-facing surfaces, such as side, rear or interior surfaces. Furthermore, any combination of these techniques can be used together or alone. the

Although the invention has been described in detail with reference to certain preferred configurations thereof, other versions are possible. Therefore, the spirit and scope of the present invention should not be limited to the versions described above. the

Claims (19)

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

A plurality of LED encapsulation, described a plurality of LED encapsulation relative to each other are mounted in order to produce message or image, and at least one in wherein said a plurality of LED encapsulation comprises:

Shell, at least a portion of described shell comprise the part in the face of beholder's outer surface;

LED chip, described LED chip are arranged in the cavity of described shell;

Packing material, described packing material are arranged in described cavity and are positioned at the top of described LED chip, and at least a portion of wherein said packing material comprises the part of the described beholder's of facing outer surface; And

Described at least a portion of facing beholder's outer surface of described encapsulation comprises frosting.

2. light-emitting diode display according to claim 1, it is characterized in that, described LED encapsulation further comprises and is arranged to conversion from the transition material of at least some light of described LED chip emission, and described encapsulation emission is from the light of described transition material or from the combination of the light of described transition material and described LED chip.

3. light-emitting diode display according to claim 1, is characterized in that, described LED encapsulation further comprises the reflector space around described LED chip that is positioned at described cavity, and described reflector space reflection is from the light of described LED chip emission.

4. light-emitting diode display according to claim 3, is characterized in that, described reflector space comprises reflector.

5. light-emitting diode display according to claim 1, is characterized in that, the section construction that the shell by described cavity outside of described outer surface in the face of the beholder consists of is in pairs than the zone, and described contrast district has the color that forms contrast with the light of described encapsulation.

6. light-emitting diode display according to claim 5, is characterized in that, described contrast district is black.

7. light-emitting diode display according to claim 5, is characterized in that, described contrast district is around described reflector space.

8. light-emitting diode display according to claim 5, is characterized in that, described contrast district is positioned at the level height place of described LED chip top.

9. light-emitting diode display according to claim 1, is characterized in that, described LED encapsulation further comprises the shell with lead frame, and described LED chip is electrically coupled to described lead frame.

10. light-emitting diode display according to claim 1, is characterized in that, described cavity forms the reflector around described LED chip.

11. light-emitting diode display according to claim 1 is characterized in that, at least one LED encapsulation comprises surface mounted device (SMD).

12. light-emitting diode display according to claim 5 is characterized in that, described contrast district and described LED chip are arranged so that the light of described LED launches from described encapsulation, and directly launch on described contrast district.

13. light-emitting diode display according to claim 1 is characterized in that, at least a portion of the housing parts of the described beholder's of facing outer surface is passed through in the forming process of described shell from the transfer printing of a shaping dies and by delustring.

14. light-emitting diode display according to claim 1 is characterized in that, at least a portion of the packing material part of described outer surface in the face of the beholder by etching by delustring.

15. light-emitting diode display according to claim 1 is characterized in that, at least a portion of the packing material part of described outer surface in the face of the beholder by punching press by delustring.

16. light-emitting diode display according to claim 1 is characterized in that, at least a portion of the packing material part of described outer surface in the face of the beholder by grinding by delustring.

17. light-emitting diode display according to claim 1 is characterized in that, at least a portion of described packing material comprises the delustering agent with a part of delustring of the described beholder's of facing outer surface.

18. light-emitting diode display according to claim 1 is characterized in that, described light-emitting diode display comprises higher pixel contrast than having the unmatchful same light-emitting diode display that encapsulates than the LED in zone.

19. light-emitting diode display according to claim 1 is characterized in that, at least one LED encapsulation transmitting white.

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