CN104218135A - Solid-state transmitter packaging, multi-pixel transmission packaging and LED display - Google Patents

Abstract

The invention discloses a solid-state emitter package, a multi-pixel emitter package and an LED display. A solid state emitter package comprising: a plurality of pixels each having at least one solid state emitter; a common submount for controlling light emission of a first one of the pixels and controlling a second one of the pixels glowing electrical signal. The package of the present invention provides advantages such as reducing the cost and interconnection complexity of the package and display.

Description

Solid State Emitter Packages, Multi-Pixel Emitter Packages and LED Displays

technical field

The present invention relates to a light emitting diode package and a display using the light emitting diode package as its light source.

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 doped layer, holes and electrons are injected into the active layer, where the holes and electrons recombine to generate light. Light is emitted from the active layer and from all surfaces of the LED.

Technological developments over the last decade or more have produced LEDs with smaller footprints, increased emission efficiencies, and reduced costs. LEDs also have an increased operating life compared to other emitters. For example, LEDs can have a working life of over 50,000 hours, while an incandescent light bulb has a working life of about 2,000 hours. LEDs can also be more robust and consume less power than other light sources. For these reasons and others, LEDs have become more popular and are now being used in a growing number of applications that have traditionally been the domain of incandescent, fluorescent, halogen and other emitters.

In order to use LED chips in conventional 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 with external circuitry. In a typical two-pin 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 with leads 15A and/or 15B, which may be attached to or integral with the reflective cup 13 . The reflective cup 13 may be filled with encapsulation material 16 and, either on the LED chip or in the encapsulation, a wavelength converting material, such as a phosphor, may be included. Light emitted by the LED at the first wavelength may be absorbed by the phosphor, which may responsively emit light at the second wavelength. The entire assembly may then be encapsulated in a transparent protective resin 14 , possibly molded into the shape of a lens to direct or shape the light emanating from the LED chip 12 .

The conventional LED package 20 shown in FIG. 2 may be more suitable for high power operation, which may 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 the submount 23 surrounds the LED chip 22 and reflects light emitted by the LED chip 22 away from the package 20 . The reflector 24 also provides mechanical protection for the LED chip 22 . One or more wire bond connections 21 are formed 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 to the chip while also acting as a lens. Typically, the metal reflector 24 is attached to the carrier by soldering or epoxy bonding.

FIG. 3 shows another LED package 30 comprising a housing 32 and a lead frame 34 at least partially embedded in the housing 32 . The lead frame 34 is arranged for surface mounting of the package 30 . Portions of lead frame 34 on which three LEDs 36 a - c are mounted and connected by wire bonds 38 to other portions of the lead frame are exposed through cavities in housing 32 . Different types of LEDs 36a-c can be used, with some packages having red, green and blue emitting LEDs. Package 30 includes a pinout structure having six pins 40 , and the leadframe is arranged such that the illumination of each LED 36a - c can be independently controlled by a corresponding pair of pins 40 . This allows the package to emit various combinations of colors from LEDs 36a-c.

Different LED packages such as those shown in Figures 1 to 3 are available as light sources for signs and displays (both large and small). Displays containing large LED screens (often called giant screens) are becoming more common in a variety of indoor and outdoor venues, for example, at stadiums, running tracks, concerts, and in large shared areas, for example, in New York City. square. With current technology, some of these displays or screens can be as large as 60 feet high and 60 feet wide. Larger screens are expected to be developed as the technology develops.

These screens can include millions or hundreds of thousands of "pixels" or "pixel modules," each of which can contain one or more LED chips or packages. The pixel modules can use high-efficiency and high-brightness LED chips, which allow the display to be seen from relatively far away, even during the day when exposed to sunlight. In some signs, each pixel may have one LED chip, and a pixel module may have as few as three or four LEDs (e.g., one red, one green, one blue), which allow the pixel to switch from red, green, and Many different colors of light are emitted in a combination of blue light and/or blue light. The pixel modules can be arranged in a rectangular grid, which can include hundreds of thousands of LEDs or LED packages. In one type of display, the grid can be 640 modules wide by 480 modules high, with the size of the screen depending on the actual size of the pixel modules. As the number of pixels increases, so does the interconnection complexity of the display. This interconnect complexity can be one of the major expenses of these displays, and can be one of the major sources of failure both during the manufacturing process and during the operating life of the display.

Contents of the invention

The present invention relates to an emitter package and an LED display using the package arranged to reduce the cost and interconnection complexity of the display. Arranging some package embodiments to provide multiple display pixels in one package reduces the cost per pixel and simplifies the design and manufacture of displays using the package.

One embodiment of a solid state emitter package according to the present invention includes a plurality of pixels, each pixel having at least one solid state emitter. A common base station for transmitting electrical signals is included to control the light emission of the first pixel and control the light emission of the second pixel.

One embodiment of a multi-pixel light emitting package according to the present invention includes a housing having a plurality of cavities, each cavity having at least one LED. A leadframe structure is included integrally with the housing, the at least one LED of each cavity being mounted to the leadframe structure. The package is capable of receiving electrical signals for controlling light emission from the first and second cavities.

One embodiment of the LED display according to the invention comprises a plurality of LED packages mounted relative to each other to generate a message or image. At least some of the LED packages include a plurality of pixels, each pixel having at least one LED. Each package is capable of receiving electrical signals for controlling light emission of at least first and second ones of said pixels.

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

Description of drawings

FIG. 1 is a side view of a conventional LED package;

2 is a side view of another conventional LED package;

3 is a plan view of another conventional light emitting diode package;

Figure 4 is a plan view of one embodiment of an LED package according to the present invention;

Fig. 5 is a side view of the LED package shown in Fig. 4;

Fig. 6 is another side view of the LED package shown in Fig. 4;

Figure 7 is a plan view of an embodiment of an LED display according to the present invention;

FIG. 8 is a schematic diagram showing the interconnection between LEDs in an LED package according to the present invention;

9 is a plan view of another embodiment of an LED package according to the present invention;

10 is a schematic diagram showing the interconnection between LEDs in another LED package according to the present invention;

11 is a plan view of another embodiment of an LED package according to the present invention;

12 is a plan view of another embodiment of an LED package according to the present invention;

13 is a plan view of another embodiment of an LED package according to the present invention;

14 is a plan view of yet another embodiment of an LED package according to the present invention;

15 is a plan view of an embodiment of an LED display according to the present invention;

16 is a plan view of another embodiment of the LED display according to the present invention;

Figure 17 is a perspective view of another embodiment of an LED package according to the present invention;

18 is a plan view of the LED package shown in FIG. 17 without the LED shown in the pixel;

Figure 19 is a plan view of a pixel in the LED package of Figures 17 and 18;

20 is a side view of the LED package shown in FIGS. 17 and 18 taken along section line 20-20;

Figure 21 is a bottom view of the LED package shown in Figures 17 and 18;

Figure 22 is a bottom perspective view of the LED package shown in Figures 17 and 18;

23 is another bottom view of the LED package shown in FIGS. 17 and 18 having a pin numbering arrangement;

Figure 24 is a schematic diagram of an embodiment of pin marking in an embodiment of an LED package according to the present invention;

FIG. 25 is a schematic diagram showing the interconnection between LEDs in an LED package according to the present invention, the LED package utilizing the pin labels shown in FIG. 24;

26 is a plan view of another embodiment of an LED display according to the present invention;

Fig. 27 is a plan view of another embodiment of the LED display according to the present invention.

Detailed ways

The present invention relates to improved LED packages and LED displays using the LED packages, LED packages according to the invention including "multi-pixel" packages. That is, the package includes more than one pixel, and each pixel includes one or more light emitting diodes. Different implementations include different features for applying electrical signals to the LEDs in the pixels. In some embodiments, a corresponding electrical signal can be applied to each pixel to control the color and/or intensity of its light emission, while in other embodiments, two or more pixels can be controlled with the same electrical signal. In embodiments where pixels have multiple LEDs, one or more LEDs in each pixel can be controlled with corresponding signals, while in other embodiments LEDs in different pixels can be controlled with the same signal. In some of these embodiments, the same signal can be used to control the lighting of two or more pixels, while in other embodiments, a corresponding signal can be used to control each pixel.

In some embodiments, the term pixel is understood in its ordinary meaning as an element of an image that can be individually processed or controlled in a display system. In some of these embodiments, some or all of the pixels may include red, green, and blue emitting LEDs, at least some of the pixels being arranged to allow the intensity of each LED in the pixel to be controllable. of. This allows each pixel to emit light of one color, which is a combination of red, green, or blue light, and allows flexibility in driving each pixel so that it emits a different color, which is derived from Combination of LED light.

In other embodiments, the package may include pixels capable of emitting light of a single color, and these packages are used in different applications, such as lighting or backlighting. In some of these embodiments, the pixel can emit white light and can include at least one blue LED with one or more phosphors that emits a combination of blue and phosphorescent white light. Different ones of these embodiments may allow control of the individual LEDs in each pixel, while in other embodiments the LEDs may be driven with the same drive signal. In some embodiments, a pixel may include one or more white-emitting LEDs combined with red-emitting LEDs to achieve desired pixel lighting, eg, a desired color temperature. In other embodiments, the lighting of the LEDs in the pixels can be controlled such that the pixels emit different color temperatures ranging from cool to hot.

Packages according to the present invention can have a variety of different shapes and sizes, and can be arranged with a variety of different numbers of pixels. In some embodiments, the package may be square and may have pixels in the form of 2x2, 4x4, 8x8, etc. FIG. In other embodiments, the package may be rectangular in shape, and the pixels may have a form with fewer pixels in one direction than the other. For example, the package can have 2×3, 2×4, 2×5, 2×6, etc., 3×4, 3×5, 3×6, 3×7, etc., or 4×5, 4×6, 4 ×7, 4×8, etc. in pixel form. In yet other embodiments, the pixels may be formed as a linear array of pixels having a length of 2, 3, 4, 5, etc. These are just some of the package shapes, others are triangular, circular or irregular.

The LED package according to the invention offers particular advantages over prior art single pixel packages. The LED package can enable lower cost per pixel by reducing material cost (eg, lead frame material). The spacing between adjacent pixels can also be reduced while maintaining the Lambertian beam profile. By reducing the pitch between pixels, higher resolution displays can be manufactured. Display manufacturing costs can also be reduced by reducing handling costs and the cost of picking and placing components. The complexity of pixel interconnection can also be reduced, thereby reducing material costs and display manufacturing levels. This also reduces possible interconnections that could fail over the lifetime of the display.

The present invention can relate to many different package types, some of the embodiments below are surface mount devices. It should be understood that the present invention is also applicable to other package types, for example, packages with pins for through-hole mounting processes.

In LED signs and displays, LED packages according to the present invention may be used, but it will be understood that they may be used in a variety of different applications. The LED package can comply with various industry standards, making it suitable for use in LED-based signage, channel letter lighting, or general backlighting and lighting applications. Some embodiments may also include a flat top emitting surface making it compatible to match the light pipe. These are just a few of the many different applications for LED packages according to the present invention.

Some LED package embodiments according to the present invention may include a single LED chip or multiple LED chips, and may include a reflective cup surrounding the single LED chip or multiple LED chips. The upper surface of the housing around each reflective cup may comprise a material opposite to that of light emitted by the LED chip. Portions of the housing exposed within the cup, and/or reflective surfaces within the cup may also include a material that reflects light from the LED chips. In some of these embodiments, the light emitted from the LED chip can be white light, or other wavelength-converted light, and the surface of the submount inside the reflective cup and the reflective surface of the cup can be white, or in the form of Others reflect white light or wavelength converted light. The contrasting (opposite) upper surface of the reflective cup can be a variety of different colors, however, in some embodiments it can be black.

The invention is described herein with reference to certain embodiments, but it should be understood that the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In particular, a variety of different LED chip, reflective cup and lead frame arrangements can be provided in addition to those embodiments described above, and the encapsulant can provide further features to improve the reliability of the LED package and the LED display using the LED package. and luminous properties. Although various embodiments of LED packages are discussed herein for use in LED displays, LED packages can be used in a variety of different lighting applications.

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, relational terms such as "above" and "beneath," 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.

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

Embodiments of the invention are described herein with reference to cross-sectional illustrations, which are schematic illustrations of embodiments of the invention. Likewise, the actual thicknesses of these layers may vary and are expected to vary from the illustrated shapes, for example, as a result of manufacturing techniques and/or tolerances. Embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. A region illustrated or described as square or rectangular will typically have rounded or curved features due to normal manufacturing tolerances. Thus, the regions illustrated in the figures are 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.

Figures 4-7 illustrate one embodiment of a multi-pixel emitter package 50 according to the invention, with Figure 7 illustrating in more detail a pixel emitter that may be used in some embodiments according to the invention. The package includes four pixels 52a-d arranged in a 2x2 formation or layout, and the package 50 has a generally square footprint. Package 50 may include features for different mounting methods, with the illustrated embodiment having features that allow surface mounting. That is, the package 50 comprises a surface mount device (SMD) having a pin and lead frame structure in which the pin outputs are arranged so that the package can be mounted to a structure (eg, a printed circuit board (PCB) using surface mount technology. ))of. As mentioned above, it should be understood that the present invention is also applicable to other emitter package types besides SMD, eg pin mount emitter packages. Package 50 includes a housing or submount 54 that carries an integral lead frame 56 . Lead frame 56 includes a plurality of conductive connections for conducting electrical signals to the packaged light emitters and for helping to dissipate heat generated by the emitters.

The housing or submount (housing) 54 may be formed from a variety of different materials or combinations of materials, and may have different materials in different portions. One acceptable housing material is an electrically insulating, eg, dielectric material. Housing 54 may at least partially comprise ceramics, such as alumina, aluminum nitride, silicon carbide, or polymeric materials such as polyimide and polyester. In some embodiments, housing 54 may comprise a dielectric material having a relatively high thermal conductivity, such as aluminum nitride and aluminum oxide. In other embodiments, submount 54 may comprise a printed circuit board (PCB), sapphire or silicon or any other suitable material, eg, T-plated thermally insulating substrate material available from Bergquist Corporation of Chanhassen, MN. For PCB implementation, different PCB types can be used, for example, standard FR-4 PCB, metal core PCB, or any other type of printed circuit board.

The lead frame 56 can be arranged in many different ways, and in different package implementations, different numbers of parts can be used. Pixels may have the same emitter or emitters, such as LEDs, and, in some embodiments, different pixels may have different numbers of LEDs. As best shown in FIG. 7, each pixel in package 50 may include three LEDs 58a-c, and in the embodiment shown, lead frame 56 is arranged to apply electrical signals to LEDs 58a-c. Leadframe 56 includes conductive features for conducting electrical signals from the package mounting surface (eg, PCB) to LEDs 58a-c. The lead frame may also include features that may be included to provide mounting stability to the LED, as well as provide an additional thermal path for dissipating heat from the emitter. The leadframe may also include physical features, such as holes, cutouts, etc., to increase the stability and reliability of the package and, in some embodiments, help maintain a watertight seal between components. These various features are described in U.S. Patent Application Serial No. 13/192,293 to Chan et al., entitled "Water Resistant Surface Mount Device Package," which is incorporated by reference in its entirety here.

Fabrication of the leadframe 56 may be accomplished by stamping, injection molding, cutting, etching, bending, or by other known methods and/or combinations of these methods to achieve the desired structure. For example, the conductive parts may be partially metal stamped (eg, simultaneously stamped from a single piece of related material), bent appropriately, and completely separated, or completely separated after forming part or all of the housing.

Leadframe 56 may be fabricated from a conductive metal or metal alloy (eg, copper, copper alloy), and/or other suitable low-resistance, corrosion-resistant material, or combinations of these materials. As noted above, the thermal conductivity of the leads may help conduct heat away from the LEDs 58a-c to some extent.

Housing 54 can have a variety of different shapes and sizes, and in the illustrated embodiment is generally square or rectangular, with an upper surface 60 and a lower surface 62 (best shown in FIGS. 5 and 6 ). ), and first and second side surfaces 64 and 66 . The upper portion of the housing further includes a recess or cavity 72 that extends from the upper surface 60 into the body of the housing 54 to the lead frame 56 . The LEDs 58a - c of each pixel are arranged on the leadframe 56 in a respective one of the cavities 72 such that light from the LEDs exits the package 50 through the cavities 72 . Each cavity 72 may have angled side surfaces that form reflective cups around the LEDs 58a - c to help reflect the light from the emitters out of the package 50 . In some embodiments, a reflective insert or ring (not shown) may be positioned and secured along at least a portion of the side surface 74 of the cavity 72 . The reflective efficiency of the ring and the emission angle of the package can be increased by tapering the cavity 72 and carrying the ring inwardly towards the interior of the housing in the cavity. By way of example, a reflection angle of about 50 degrees provides suitable reflectivity and viewing angle.

In some embodiments, cavity 72 may be at least partially filled with a filler material (or encapsulant) that protects lead frame 56 and LEDs 58a-c and stabilizes the lead frame and LEDs in position. In some embodiments, a filler material may cover the emitters and portions of the leadframe 56 exposed by the cavity 72 . The fill material can be selected to have predetermined optical properties to enhance light projected from the LED, and, in some embodiments, the fill material is substantially transparent to light emitted by the encapsulated emitter. The fill material can also be flat so that it is about the same plane as the upper surface 60, or it can be shaped in the form of a lens, eg, hemispherical or bullet-shaped. Alternatively, the fill material may be fully or partially recessed in one or more cavities 72 . The filler material may be formed from resins, epoxies, thermoplastic polycondensates, glass, and/or other suitable materials or combinations of these materials. In some embodiments, material may be added to the fill material to enhance emission, absorption, and/or diffusion of light to and/or from the LED.

Housing 54 may be made of a material that is preferably electrically insulating and thermally conductive. Such materials are well known in the art and may include, but are not limited to, certain ceramics, resins, epoxies, thermoplastics, condensation polymers (eg, polyphthalamide (PPA)), and glass. Package 50 and its housing 54 may be formed and/or assembled by any of a variety of methods known in the art. For example, housing 54 may be formed or molded around the lead frame, eg, by injection molding. Alternatively, the housing may be formed in parts such as top and bottom, with conductive parts formed on the bottom. The top and bottom can then be bonded together using known methods and materials (eg, by epoxy, adhesive, or other suitable bonding material).

A variety of different emitters can be used with packages according to the invention, with package 50 using LEDs 58a-c. Different embodiments may have different LED chips emitting different colors of light, and, in the embodiment shown, each pixel in package 50 includes red, green, and blue emitting LED chips that Luminescence (including white light) can be produced in a combination of colors at many different wavelengths.

LED chip structures, features, and their fabrication and operation are generally known in the art and are only briefly discussed here. LED chips can have many different semiconductor layers arranged in different ways and can emit different colors. These layers of the LED chip can be manufactured by known methods, a suitable method being by metal organic chemical vapor deposition (MOCVD). These layers of the LED chip typically include active layers/regions 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 (separated) and used in different applications, for example, mounted in a package. It should be understood that the grown substrate/wafer may remain as part of the final singulated LED chips, or the grown substrate may be completely or partially removed.

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

The active region and doped layers may be made of 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 elements of 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 preferred embodiment, the doped layer is gallium nitride (GaN) and the active region 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 grown substrate/wafer can be made of a variety of materials such as silicon, glass, sapphire, silicon carbide, aluminum nitride (AlN), gallium nitride (GaN), where a suitable substrate is 4H polycrystalline silicon carbide type, although other silicon carbide polytypes can also be used, including the 3C, 6H, and 15R polytypes. Silicon carbide has some advantages, such as a better lattice match with III-nitrides than sapphire, and produces III-nitride films with higher quality. Silicon carbide also has very high thermal conductivity so that the total output power of III-nitride devices on silicon carbide is not limited by heat dissipation from the substrate (as is the case with some devices formed on sapphire). SiC substrates are available from Cree Research Inc., Durham, NC, and methods for their fabrication are described in the scientific literature and in US Patent Nos. Re34,861; 4,946,547 and 5,200,022. LEDs can also include additional features, such as conductive current distribution structures and current distribution layers, all of which can be made from known materials deposited by known methods.

LEDs 58a-c may be mounted to lead frame 56 and electrically coupled to the LED by an electrically and thermally conductive bonding material (e.g., solder, adhesive, coating, film, sealant, paste, lubricant, and/or other suitable material). Connected to lead frame 56 . In a preferred embodiment, the LEDs can be electrically coupled and secured to their corresponding pads with solder pads on the bottom of the LEDs so that the solder is not visible from the top. Wire bonds 74 (shown in FIG. 7 ) extending between LEDs 58a - c and lead frame 56 may be included.

Different embodiments of the invention may have different pinout arrangements, which may depend on various factors, such as the number of LEDs, the interconnection of the LEDs, and the number of LEDs on each pixel and/or on each LED in a pixel. levels of separation and independent control. Figure 7 shows a package 50 having 8 pins 76 in its pinout structure, and Figure 8 shows an embodiment of an interconnect structure 80 according to the pin output section. Interconnect structure 80 shows four pixels 52a-d, each pixel including three LEDs 58a-c, and electrical connections between LEDs 58a-c may be through lead frame 56 and/or wire bonds as shown in FIG. Section 74 to provide. Electrical signals V1 and V2 on pins provide power to drive the LEDs, with V1 driving the first and third pixels 52a, 52c and V2 driving the other two pixels 52b, 52d. Electrical signals R1, G1 and B1 on pins control the lighting of LEDs 58a-c in the first two pixels 52a, 52b, and signals R2, G2 and B2 control the lighting of LEDs 58a-c in the last two pixels 52c, 52d. This arrangement allows dynamic control of the pixels 52a-d, each controlled by a corresponding combination of drive and control signals. In the illustrated embodiment, V1, R1, G1 and B1 control the light emission of the first pixel 52a, and V1, R2, G2 and B2 control the light emission of the third pixel 52c. Similarly, V2, R1, G1 and B1 control the light emission of the second pixel 52b, and V2, R2, G2 and B2 control the light emission of the fourth pixel 52d.

It should be understood that different packages may have different numbers of pins in their pinout configurations, and that pixels and LEDs may be interconnected in a number of different ways, with different lead frame configurations and wires combination. Fig. 9 shows another embodiment of an LED package 100 according to the present invention, also having four pixels 102a-d in a 2x2 layout. The package further includes a housing 104 and a lead frame 106, each of which can be fabricated using the same methods and materials as described above. Each pixel 102a-d may also include one or more LEDs, the embodiment including three LEDs 108a-c similar to those described above. Package 100 may also include wire bonds 110 to provide electrical connections between lead frame 106 and LEDs 108a-c in pixels 102a-d.

Package 100 also includes a pin output structure with 16 pins 112, and FIG. The structure of the pixel is the same as in the embodiment of FIG. 9 . Interconnect structure 120 is provided by lead frame 106 and wire bonds 110 and allows individual control of pixels 102a-d. That is, each pixel 102a-d has its own pin to provide a corresponding power signal and a set of pins to provide control over the lighting of the LEDs 108a-c in its pixel. For pixel 102a, a power signal may be provided on pin V11 that controls the lighting of LEDs 108a-c disposed on pins R11, G11 and B11. For pixel 102b, power is provided on V12 and LED control is provided on pins R12, G12 and B12. Similarly, pixel 102c is powered and controlled by V22, R22, G22, and B22, and pixel 102d is powered and controlled by V21, R21, G21, and B21. This arrangement requires more pins 112 than the package 50 described above, but allows the lighting of each pixel 102a-d to be controlled accordingly. These are just two of the many different pinouts and interconnect structures that may be provided by packages in accordance with the present invention.

As discussed above, in addition to the 2x2 layout shown in packages 50 and 100, packages according to the present invention may be provided with a variety of different matrix layouts. Figure 11 shows another embodiment of a package 130 having six pixels 132a-f arranged in a 2x3 matrix layout. Figure 12 shows another embodiment of a package 140 having eight pixels 142a-h arranged in a 2x4 matrix layout. Each package 130, 140 includes a housing with leadframes, pins and wire bonds similar to those described above, but arranged to accommodate a greater number of pixels. Each pixel may also include a different number of LEDs, as noted above, the pixel shown has three LEDs.

LED packages according to the invention may also be provided in an array or in a linear layout. Fig. 13 shows an LED package 150 according to another embodiment of the present invention having two pixels 152a-b arranged in a 2x1 linear formation. Figure 14 shows an LED package 160 according to yet another embodiment of the present invention having four pixels 162a-d arranged in a 4x1 linear formation. Each package also includes a housing, lead frame, pins, and wire bonds as described above, and each pixel may include an LED as described above.

Multiples of the above LED packages can be mounted together to form a display, with different sized displays having different numbers of packages. FIG. 15 shows a portion of a display 170 having sixteen of the aforementioned 2×2 LED packages 50 surface mounted to a display panel 172 . Packages 50 have eight pins 76, and panel 172 may include interconnects to allow dynamic driving of pixels 52a-d in each package 50, as described above. The panel may comprise a number of different structures arranged in a number of different ways, with one embodiment at least partially comprising a printed circuit board (PCB) with conductive traces, and the package being surface mounted in electrical contact with the traces. It should be understood that a typical display will have many more packages to form the display, with some displays having enough packaging to provide hundreds of thousands of pixels.

Similarly, other above-mentioned packages may be provided in displays. FIG. 16 shows another portion of a display 180 with sixteen of the aforementioned 2×2 LED packages 100 surface mounted to a display panel 182 . These packages have 16 pins, and panel 182 may include interconnects to allow pixels 102a-d to be driven individually, as described above. Panel 182 may at least partially comprise a PCB with conductive traces, and a full display may also have more packages 100 .

By arranging multiple pixels on a single package, the pixels can be arranged closer to each other (ie, closer pitch), which can result in higher resolution LED displays. At the same time, multi-pixel packaging allows for a reduction in the complexity of LED displays compared to using single-pixel LED packages. In some embodiments, the LED packages may have a pitch ranging from 0.5 to 3.0 mm, while in other embodiments the pitch may range from 1.0 to 2.0 mm. In yet other embodiments, the pitch between pixels is about 1.5 mm.

The package can also have different sized footprints depending on the number of pixels in the package. For the 2x2 LED packages 50, 100 described above, the footprint can be square or rectangular, with some embodiments having sides in the range of 2 to 6 mm. In other embodiments, the sides may be in the range of 3 to 5 mm. In some generally square embodiments, the sides may be in the range of 3 to 4 mm, while in some generally rectangular embodiments, one side may be in the range of 3 to 4 mm and the other side may be in the range of 4 mm. to within the range of 5mm. It should be understood that these are only some examples of dimensions for LED packages according to the present invention, and that these dimensions may increase in proportion to the number of pixels in the package.

Different embodiments of LED packages according to the present invention may also include square matrix layouts larger than the 2×2 matrix layout described above, including 4×4, 5×5, 6×6, and the like. 17 to 22 illustrate an LED package 200 according to another embodiment of the present invention, which includes 16 pixels 202 arranged in a 4×4 matrix layout. Package 200 may include housing 204, lead frame 206, and wire bonds 208 (shown in FIG. 19), the housing, lead frame, and wire bonds being fabricated from the same materials as described above by the same method as described above. Each pixel may also include one or more LEDs, similar to those described above, the embodiment shown has a pixel including three LEDs 208a-c.

Different implementations of package 200 may have leadframes with different numbers of pins, with the leadframes and wire bonds interconnecting the LEDs in different ways. In the illustrated embodiment, the leadframe 206 includes a pinout structure having 20 pins 210 as best shown in FIGS. 21 and 22 . The pins 210 extend from the side surface of the package and bend under the housing 204 to provide convenient surface mounting, for example, to a display board. The bottom surface of package 200 may also include a polarity indicator that may be used by a pick and place machine to install the package in the proper orientation. Referring now to FIG. 21 , a "+" shaped polarity indicator 212 is provided in a corner of package 200, however, it should be understood that the polarity indicator could take many different shapes and be in many different positions. For example, FIG. 22 provides triangular polarity indicators 214 in different corners of package 200 .

Referring now to FIG. 23, twenty pins 210 are labeled with numbers 1-20 around the perimeter of the package. FIG. 24 shows the functions performed by the electrical signals provided on the different pins 210 . Denoting pins 1-4 by R1P, R2P, R3P, and R4P, each pin supplies power to the red LEDs in the four pixels. Denoted by GB1P, GB2P, GB3P and GB4P, pins 12-15 each provide power to the green and blue LEDs in the four pixels. With R1, R2, R3 and R4 representing pins 5-8, each pin controls the lighting of the red LEDs in the four pixels. Similarly, pins 9-11 and 16 are denoted G1, G2, G3 and G4, each controlling the lighting of green LEDs in four pixels. Finally, with B1, B2, B3 and B4 representing pins 17-20, each pin controls the lighting of the blue LEDs in the four pixels.

FIG. 25 shows one embodiment of an interconnection 240 between LEDs in different pixels when using the pinout labeling shown in FIG. 24 . Each electrical signal applied to pins 1-4 (R1P-R4P) applies power to the red LEDs 208a in a corresponding row of pixels 202, while signals applied to pins 5-8 control the red LEDs 208a in a column of pixels 202. glow. This arrangement of rows and columns allows control of the lighting of individual red LEDs. For example, the lighting of the red LED R8 in the second row and column can be controlled by electrical signals applied to pin 2 (R2P) and pin 6 (R2).

A similar approach can be used to control the illumination of the green and blue LEDs 208b, 208c. Each electrical signal applied to pins 12 - 15 ( GB1P - GB4P ) applies power to the green and blue LEDs 208 b , 208 c in a corresponding row of pixels 202 . Signals applied to pins 9-11 and 16 (G1-G4) control the lighting of green LED 208b in the corresponding column of pixels 202, and signals applied to pins 17-20 (B1-B4) control the corresponding column of pixels Lighting of blue LED 208c in 202 . This arrangement of rows and columns allows control of the respective green and blue luminescence. For example, the lighting of the green LED G8 in the pixels in the second row and second column can be controlled by electrical signals applied to pin 14 (GB2P) and pin 10 (G2). The lighting of the blue LED B8 in the pixels in the second row and second column can be controlled by an electrical signal also applied to pin 14 (GB2P) and pin 18 (B2). This interconnection arrangement is only one of many arrangements that may be used in embodiments according to the invention.

As with the packages described above, multiple 4×4 LED packages can be mounted together to form a display, with different sizes of displays having different numbers of packages. Figure 26 shows one embodiment of a display or a portion of a display 300 having sixty 4x4 packages 200 mounted to a display panel 302 in a 6x10 layout. Panel 302 may include interconnects to the 20-pin pinout structure of package 200 to allow driving of pixels 202 . Panel 302 may include a variety of different structures arranged in a variety of different ways, with one embodiment at least partially comprising a printed circuit board (PCB) with conductive traces, and the package is surface mounted in electrical contact with the traces.

FIG. 27 shows another embodiment of a display 350 with seventy 4×4 LED packages mounted on a display board 352 in a 6×12 layout. Panel 352 may include interconnects to the 20-pin pinout structure of package 200 to allow pixel 202 to be driven. It should be understood that a typical display will have many more packages to form a display, with some displays having enough packaging to provide hundreds of thousands of pixels.

Referring again to FIG. 17 , package 200 may be arranged such that the color of the upper surface of housing 204 contrasts with the color of light emitted from package 200 through recess/cavity 211 . In most embodiments, the light emitted from cavity 211 may include a combination of light emitted by LEDs 208a-c. In some embodiments, the LED can emit white light, and the upper surface of the housing can include a color that contrasts with the white light. A variety of different colors can be used, eg, blue, brown, gray, red, green, purple, etc., and the embodiment shown has black on its upper surface. The black coloration can be applied by a number of different known methods. It can be applied during the molding of the housing 204, or it can be applied in a later step during the manufacture of the package by a different method, eg screen printing, inkjet printing, painting, etc. LED packages with contrasting faces are described in U.S. Patent Application Serial No. 12/875,873 to Chan et al., entitled "LED Packagae With Contrasting Face," which is adopted in its entirety by Incorporated by reference.

While the invention has been described in detail with reference to certain preferred structures of the invention, other modifications are possible. The package can have many different shapes and sizes, can be arranged in many different ways, and can be made of many different materials. The pixel cavities can be arranged in many different ways and in many different patterns. The pixels can be interconnected using a variety of different features, and by a variety of interconnect structures. Therefore, the spirit and scope of the present invention should not be limited to the above-mentioned modifications.

Claims (41)

1. a soild state transmitter encapsulation, comprising:

Multiple pixel, each pixel all has at least one soild state transmitter;

Share base station, transmit the luminescence for controlling the first pixel in described pixel and control the signal of telecommunication of luminescence of the second pixel in described pixel.

2. encapsulation according to claim 1, wherein, described base station is arranged as the luminescence for controlling described first pixel and described second pixel independently.

3. encapsulation according to claim 1, wherein, described first pixel or described second pixel transmitting white.

4. encapsulation according to claim 1, wherein, described soild state transmitter comprises LED.

5. encapsulation according to claim 4, wherein, at least one in described pixel comprises the LED of the blue light-emitting with phosphor.

6. encapsulation according to claim 4, wherein, at least one in described pixel comprises the LED emitted white light and the LED glowed.

7. encapsulation according to claim 2, wherein, described pixel can control, to send the white light of different temperatures.

8. encapsulation according to claim 2, wherein, described pixel can control, to send different colors.

9. encapsulation according to claim 2, wherein, described pixel can control, to send the light of different wave length.

10. encapsulation according to claim 2, wherein, each in described first pixel and described second pixel includes redness, green and blue led.

11. encapsulation according to claim 1, wherein, described base station comprises housing, and pin and lead frame structure and described housing form entirety.

12. encapsulation according to claim 11, comprise the multiple cavitys being arranged in described housing further, each cavity limits a pixel.

13. encapsulation according to claim 12, wherein, each cavity has at least one solid-state light emitters.

14. encapsulation according to claim 11, comprise the contrast district on the end face being positioned at described housing further.

15. encapsulation according to claim 1, wherein, described base station comprises pottery, printed circuit board (PCB), metal-core printed circuit board or FR-4 plate at least in part.

16. encapsulation according to claim 1, wherein, described base station comprises pin and lead frame structure.

17. encapsulation according to claim 1, wherein, described pixel is in matrix layout.

18. encapsulation according to claim 1, wherein, described pixel is in square matrices layout.

19. encapsulation according to claim 1, wherein, described pixel is in linear array layout.

20. encapsulation according to claim 1, wherein, described pin arrangement is allow the surface of described encapsulation to install.

21. encapsulation according to claim 1, wherein, at least two pixels share a transmitter power signal, and at least two pixels share a reflector control signal.

22. encapsulation according to claim 1, wherein, described pixel is arranged with matrix layout, and wherein one-row pixels shares a transmitter power signal, and the described pixel of row shares a reflector control signal.

Pixel more than 23. 1 kinds launches encapsulation, comprising:

Housing, has multiple cavity, and each cavity has at least one LED; And

Lead frame structure, forms entirety with described housing, and at least one LED described of each described cavity is mounted to described lead frame structure, and described encapsulation can receive the signal of telecommunication of the luminescence for controlling to come from the first cavity in described cavity and the second cavity.

24. encapsulation according to claim 23, described encapsulation is arranged to the signal of telecommunication that reception controls to come from the luminescence of described first cavity in described cavity and described second cavity independently.

25. encapsulation according to claim 23, wherein, each described cavity and corresponding at least one LED described thereof comprise pixel.

26. encapsulation according to claim 23, wherein, the luminescence of described first cavity and described second cavity can control, to send different colors.

27. encapsulation according to claim 23, wherein, each in described cavity includes redness, green and blue led.

28. encapsulation according to claim 23, comprise the contrast district on the end face being positioned at described housing further.

29. encapsulation according to claim 23, wherein, described pixel is in matrix layout or linear placement.

30. encapsulation according to claim 23, wherein, described pixel is in square matrices layout.

31. encapsulation according to claim 23, wherein, described pixel is in linear array layout.

32. encapsulation according to claim 23, comprise the pin efferent being arranged to and allowing the surface of described encapsulation to install further.

33. encapsulation according to claim 23, wherein, at least two LED in two cavitys share a LED power signal, and at least two LED in two cavitys share a reflector control signal.

34. encapsulation according to claim 23, wherein, described cavity is arranged with matrix layout, and wherein, the LED in one-row pixels shares a transmitter power signal, and the LED in the described cavity of row shares a LED control signal.

35. 1 kinds of light-emitting diode displays, comprising:

Multiple LED, install related to each other to produce message or image, at least some LED in described LED comprises multiple pixel, each pixel all has at least one LED, and each wherein, in described encapsulation all can receive the signal of telecommunication of the luminescence for controlling at least the first pixel in described pixel and the second pixel.

36. light-emitting diode displays according to claim 35, wherein, the described at least some encapsulation of described encapsulation is arranged to the signal of telecommunication of the luminescence received for controlling at least the first pixel in described pixel and the second pixel independently.

37. light-emitting diode displays according to claim 35, wherein, at least some encapsulation in described encapsulation comprises surface mounted device.

38. light-emitting diode displays according to claim 35, wherein, described first pixel and described second pixel comprise lead frame structure and the pin of the signal of telecommunication of the luminescence for pixel described in transfer control.

39. light-emitting diode displays according to claim 35, wherein, described first pixel and described second pixel can control, to send different colors.

40. light-emitting diode displays according to claim 35, wherein, at least one LED described comprises redness, green and blue led.

41. light-emitting diode displays according to claim 35, wherein, described pixel is in matrix layout or linear placement.