Multi-chip LED package with common electrode

Abstract

Disclosed are light-emitting diode (LED) packages, more specifically, multi-chip LED packages having a common electrode. The LED package includes a lead frame structure having a common electrode for a plurality of LED chips and other corresponding electrodes individually coupled to the individual LED chips. The common electrode forms an anode or cathode connection for each of the LED chips. The common electrode includes a plurality of extensions or pins that individually emerge from the package to provide individual external electrical connections to the common electrode. The common electrode may result in an increased metal surface area within the LED package and form an improved heat body for heat dissipation. The plurality of pin extensions from the common electrode allow the LED package to maintain the same form factor, enable drop-in replacement of existing packages, and improve adhesion to the housing surrounding the lead frame structure.

Description

[Technical Field]

[0001]

[0001] The present invention relates to a light-emitting diode (LED) package, and more specifically to a multiple chip LED package having a common electrode. [Background technology]

[0002]

[0002] Solid-state lighting devices, such as light-emitting diodes (LEDs), are increasingly used in both consumer and commercial applications. Advances in LED technology have resulted in highly efficient, mechanically robust, and long-lasting light sources. Consequently, modern LEDs enable a variety of new display applications and are increasingly being used in general lighting applications, often as a replacement for incandescent and fluorescent light sources.

[0003]

[0003] An LED is a solid-state device that converts electrical energy into light and generally includes an active layer (or active region) of one or more semiconductor materials positioned between an inversely doped n-type layer and a p-type layer. When a bias is applied to the entire doped layer, holes and electrons are injected into one or more active layers, where they recombine to produce emission, such as visible light or ultraviolet emission. An LED chip typically includes an active region which may be manufactured from, for example, gallium nitride, gallium phosphide, aluminum nitride, indium nitride, gallium indium-based materials, gallium arsenide-based materials, and / or organic semiconductor materials. Photons generated by the active region are emitted in all directions.

[0004]

[0004] LED packages have been developed that can provide mechanical support, electrical connections, and encapsulation for LED emitters. Lumiphoric materials, such as phosphors, can also be placed near the LED emitters to convert some of the light emission to different wavelengths. Multi-chip LED packages, such as LED packages with LED chips of different colors, are commonly used in LED display applications. LED technology continues to be developed for ever-evolving modern applications, and there are challenges in addressing the operational requirements for LED packages and their associated components.

[0005]

[0005] The technical field continues to seek improved LED and solid-state lighting devices that have desirable lighting characteristics and can overcome the challenges associated with conventional lighting devices. [Overview of the project] [Means for solving the problem]

[0006]

[0006] The present invention relates to a light-emitting diode (LED) package, and more specifically to a multi-chip LED package having a common electrode. The LED package may include a lead frame structure having a common electrode for a plurality of LED chips and other corresponding electrodes individually coupled to each individual LED chip. The common electrode may form an anode connection or a cathode connection for each of the LED chips. The common electrode may include a plurality of extensions or pins that individually exit the package to provide individual external electrical connections to the common electrode. The common electrode results in an increased metal surface area within the LED package and forms an improved thermal body for heat dissipation. Multiple pin extensions from the common electrode allow the LED package to maintain the same form factor, enable drop-in replacement for existing packages, and improve adhesion to the body or housing surrounding the lead frame structure.

[0007]

[0007] In one embodiment, the LED package comprises a first LED chip, a second LED chip, a third LED chip, a housing, and a lead frame structure at least partially located within the housing and electrically coupled to the first LED chip, the second LED chip, and the third LED chip, the lead frame structure comprising a first lead electrically connected to the first LED chip, the second LED chip, and the third LED chip, having a plurality of pins extending outward from the housing, a second lead electrically connected to the first LED chip, and a third lead electrically connected to the second LED chip. In a particular embodiment, the first lead forms a common anode connection for the first LED chip, the second LED chip, and the third LED chip. In a particular embodiment, the first lead forms a common cathode connection for the first LED chip, the second LED chip, and the third LED chip. In certain embodiments, the first lead extends from the first edge of the housing beyond the center line of the housing. In certain embodiments, the surfaces of multiple pins define a package mounting surface in a first plane, the surfaces of the first and second leads define an LED chip mounting surface in a second plane, and the intermediate portion of the lead frame structure extends between the first and second planes.

[0008]

[0008] In certain embodiments, the housing forms a recess in which a first LED chip, a second LED chip, and a third LED chip reside. The LED package may further include a light collector in the recess and above the first LED chip, the second LED chip, and the third LED chip, the light collector forming an aperture configured to allow light from the first LED chip, the second LED chip, and the third LED chip to pass through. The LED package may further include a fill material in the recess that covers part of the light collector. In certain embodiments, the housing forms a first recess in which a first LED chip resides, a second recess in which a second LED chip resides, and a third recess in which a third LED chip resides.

[0009]

[0009] In certain embodiments, a first LED chip, a second LED chip, and a third LED chip are mounted on a first lead and thermally coupled to the first lead. In certain embodiments, the first LED chip is further mounted on a second lead and thermally coupled to the second lead, the second LED chip is further mounted on a third lead and thermally coupled to the third lead, and the third LED chip is further mounted on a fourth lead of the lead frame structure and thermally coupled to the fourth lead. In certain embodiments, the LED package further comprises a fourth LED chip, and the first lead is a common electrode for the first LED chip, the second LED chip, the third LED chip, and the fourth LED chip.

[0010]

[0010] In another embodiment, the LED package comprises a housing, a first LED chip, a second LED chip, and a lead frame structure having a first lead, the first lead forming a common electrode for the first and second LED chips, the first lead comprising a plurality of pins extending from the same side of the housing, the plurality of pins configured to accept an external electrical connection to the common electrode. In a particular embodiment, the common electrode is a common anode connection for the first and second LED chips. In a particular embodiment, the common electrode is a common cathode connection for the first and second LED chips. In a particular embodiment, the surfaces of the plurality of pins define a package mounting surface in a first plane, the surface of the first lead defines an LED chip mounting surface in a second plane, and the intermediate portion of the lead frame structure extends between the first and second planes. In a particular embodiment, the housing forms a recess in which the first and second LED chips reside. The LED package may further include a light-gathering device within the recess and above the first and second LED chips, the light-gathering device forming an opening configured to allow light from the first and second LED chips to pass through. The LED package may further include a filler within the recess covering a portion of the light-gathering device. In certain embodiments, the housing forms a first recess where the first LED chip resides and a second recess where the second LED chip resides. The LED package may further include a third LED chip, and the first lead is a common electrode for the first, second, and third LED chips. In certain embodiments, the lead frame structure further includes a second lead and a third lead, the first LED chip being flip-tip mounted between the first and second leads, and the second LED chip being flip-tip mounted between the first and third leads. In certain embodiments, the first LED chip and the second LED chip are mounted on the first lead and thermally coupled to the first lead.

[0011]

[0011] In another aspect, further advantages can be obtained by individually or collectively taking any of the foregoing aspects and / or by combining various individual aspects and features described herein. Any of the various features and elements disclosed herein can be combined with one or more other disclosed features and elements, unless the contrary is indicated herein.

[0012]

[0012] Those skilled in the art will recognize the scope of the present disclosure and understand its additional aspects after reading the following detailed description of the preferred embodiments in connection with the accompanying drawings.

[0013] The accompanying drawings, which are incorporated herein and form part of this specification, illustrate some aspects of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

Brief Description of the Drawings

[0013] [Figure 1]

[0014] FIG. 1 is a top view of a light-emitting diode (LED) package having a plurality of LED chips according to the principles of the present disclosure. [Figure 2]

[0015] FIG. 2 is a top view of an LED package similar to the LED package of FIG. 1, except that the LED chip is connected to one or more wire bonds. [Figure 3]

[0016] FIG. 3 is a perspective view of an LED package similar to the LED package of FIG. 1, illustrating an exemplary surface mount device (SMD) structure. [Figure 4]

[0017] FIG. 4 is a cross-sectional view of an LED package having an indentation provided in the lead along the vertical length within the housing. [Figure 5]

[0018] FIG. 5 is a cross-sectional view of an LED package similar to the LED package of FIG. 4, but without the indentation of FIG. 4. [Figure 6]

[0019] Figure 6 is a cross-sectional view of an LED package, similar to the LED package in Figure 4, with a single recess for each lead. [Figure 7A]

[0020] Figure 7A is a top view of an LED package similar to the LED package in Figure 1, but with an increased surface area of ​​leads. [Figure 7B]

[0021] Figure 7B is a top view of an LED package similar to the LED package in Figure 7A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 7C]

[0022] Figure 7C is a top view of an LED package similar to the LED package in Figure 7A for an embodiment in which the leads include one or more through-holes. [Figure 7D]

[0023] Figure 7D is a top view of an LED package similar to the LED package in Figure 7B for an embodiment in which the leads include one or more through holes. [Figure 8A]

[0024] Figure 8A is a top view of an LED package similar to the LED package in Figure 1, but with leads provided in a different shape. [Figure 8B]

[0025] Figure 8B is a top view of an LED package similar to the LED package in Figure 8A, for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 9A]

[0026] Figure 9A is a top view of an LED package similar to the LED package in Figure 1, with increased surface area along the central portion of the leads. [Figure 9B]

[0027] Figure 9B is a top view of an LED package similar to the LED package in Figure 9A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 9C]

[0028] Figure 9C is a top view of an LED package similar to the LED package in Figure 9B, except that the LED chips are inverted and arranged in a straight line. [Figure 10A]

[0029] Figure 10A is a top view of an LED package similar to the LED package in Figure 9A, in which the leads are provided with a different shape from that of Figure 9A, and have an increasing surface area along the central portion. [Figure 10B]

[0030] Figure 10B is a top view of an LED package similar to the LED package in Figure 10A for embodiments in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 10C]

[0031] Figure 10C is a top view of an LED package similar to the LED package in Figure 10A for an embodiment in which the leads include at least one through-hole. [Figure 10D]

[0032] Figure 10D is a top view of an LED package similar to the LED package in Figure 10B for an embodiment in which the leads include at least one through hole. [Figure 11A]

[0033] Figure 11A is a top view of an LED package similar to the LED package in Figure 1, where the lead pins are located on the opposite side of the housing. [Figure 11B]

[0034] Figure 11B is a top view of an LED package similar to the LED package in Figure 11A, for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 12A]

[0035] Figure 12A is a top view of an LED package similar to the LED package in Figure 11A, in which the lead shape has been modified to position the LED chips closer to each other. [Figure 12B]

[0036] Figure 12B is a top view of an LED package similar to the LED package in Figure 12A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 13A]

[0037] Figure 13A is a top view of an LED package similar to the LED package in Figure 11A, but with a different arrangement of leads.

[0014] [Figure 13C]

[0038] Figure 13C is a top view of an LED package similar to the LED package in Figure 13A for an embodiment in which the leads include at least one through-hole. [Figure 13D]

[0039] Figure 13D is a top view of an LED package similar to the LED package in Figure 13B for an embodiment in which the leads include at least one through hole. [Figure 14A]

[0040] Figure 14A is a top view of an LED package similar to the LED package in Figure 11A, but with a different arrangement of leads. [Figure 14B]

[0041] Figure 14B is a top view of an LED package similar to the LED package in Figure 14A for embodiments in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 14C]

[0042] Figure 14C is a top view of an LED package similar to the LED package in Figure 14A for an embodiment in which the leads include at least one through-hole. [Figure 14D]

[0043] Figure 14D is a top view of an LED package similar to the LED package in Figure 14B for an embodiment in which the leads include at least one through hole. [Figure 15A]

[0044] Figure 15A is a top view of an LED package similar to the LED package in Figure 14A, but with a different arrangement of leads. [Figure 15B]

[0045] Figure 15B is a top view of an LED package similar to the LED package in Figure 15A, for embodiments in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 15C]

[0046] Figure 15C is a top view of an LED package similar to the LED package in Figure 15A for an embodiment in which the leads include at least one through-hole. [Figure 15D]

[0047] Figure 15D is a top view of an LED package similar to the LED package in Figure 15B for an embodiment in which the leads include at least one through hole. [Figure 16A]

[0048] Figure 16A is a top view of an LED package similar to the LED package in Figure 14A, but with a different arrangement of leads. [Figure 16B]

[0049] Figure 16B is a top view of an LED package similar to the LED package in Figure 16A for embodiments in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 17A]

[0050] Figure 17A is a top view of an LED package similar to the LED package in Figure 1 for an embodiment in which the leads are common electrodes for at least four LED chips. [Figure 17B]

[0051] Figure 17B is a top view of an LED package similar to the LED package in Figure 17A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 18A]

[0052] Figure 18A is a top view of an LED package similar to the LED package in Figure 17A for an embodiment in which the leads are common electrodes for at least four LED chips and extend between opposite corners of the housing. [Figure 18B]

[0053] Figure 18B is a top view of an LED package similar to the LED package in Figure 18A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 19A]

[0054] Figure 19A is a top view of an LED package similar to the LED package in Figure 17A for an embodiment in which the leads are common electrodes for at least four LED chips and extend from one corner of the housing to another corner on the same side of the housing. [Figure 19B]

[0055] Figure 19B is a top view of an LED package similar to the LED package in Figure 19A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 20A]

[0056] Figure 20A is a top view of an LED package similar to the LED package in Figure 19A for an embodiment in which the leads are common electrodes for at least four LED chips and the pins are adjacent to each other on the same side of the housing. [Figure 20B]

[0057] Figure 20B is a top view of an LED package similar to the LED package in Figure 20A for an embodiment in which the LED chip embodies a vertical and / or lateral structure having wire bonds. [Figure 20C]

[0058] Figure 20C is a top view of an LED package similar to the LED package in Figure 20A for an embodiment in which the leads include at least one through-hole. [Figure 20D]

[0059] Figure 20D is a top view of an LED package similar to the LED package in Figure 20B for an embodiment in which the leads include at least one through hole. [Figure 21A]

[0060] Figure 21A is a top view of an LED package similar to the LED package in Figure 13A, with a light-gathering element added. [Figure 21B]

[0061] Figure 21B is a cross-sectional view of the LED package in Figure 21A, cut along the cross-sectional line 21B-21B in Figure 21A. [Figure 22A]

[0062] Figure 22A is a top view of an LED package having multiple cavities or recesses for multiple LED chips and a common electrode, according to the principle of this disclosure. [Figure 22B]

[0063] Figure 22B is a top view of an LED package similar to the LED package in Figure 22A, except that it does not have a bump-out portion on the leads, as illustrated in Figure 21A. [Figure 22C]

[0064] Figure 22C is a top view of the lead frame structure that can be implemented in the LED package shown in Figure 22A. [Modes for carrying out the invention]

[0015]

[0065] The embodiments described below provide the information necessary to enable those skilled in the art to carry out the embodiments and illustrate the best way to carry out the embodiments. By reading the following description with reference to the accompanying drawings, those skilled in the art will understand the concepts of this disclosure and recognize applications of these concepts not specifically addressed herein. It should be understood that these concepts and applications are included within the scope of this disclosure and the accompanying claims.

[0016]

[0066] In this specification, terms such as "first," "second," etc., may be used to describe various elements, but it will be understood that these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the terms "and / or" include any one or more and all combinations of the relevant enumerated items.

[0017]

[0067] When an element such as a layer, region, or substrate is described as being "on top of" or "extending above" another element, it will be understood that the element may be directly above or able to extend directly above the other element, or there may be an intervening element. In contrast, when an element is described as being "directly above" or extending directly above another element, there is no intervening element. Similarly, when an element such as a layer, region, or substrate is described as being "above" or "extending above" another element, it will be understood that the element may be directly above or able to extend directly above the other element, or there may be an intervening element. In contrast, when an element is described as being "directly above" or extending directly above another element, there is no intervening element. Also, when an element is described as being "connected" or "bonded" to another element, it will be understood that the element may be directly connected to or able to bond to the other element, or there may be an intervening element. In contrast, when an element is said to be "directly connected" or "directly coupled" to another element, there is no intervening element.

[0018]

[0068] In this specification, relative terms such as “down,” “up,” “above,” “downward,” “horizontal,” or “vertical” may be used to describe the relationship between one element, layer, or region and another, as illustrated in the figures. It will be understood that these terms and the terms discussed above are intended to encompass different orientations of the device, in addition to the orientation shown in the figures.

[0019]

[0069] The terms used herein are for the sole purpose of describing specific embodiments and are not intended to limit the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural form unless the context clearly indicates otherwise. Furthermore, the terms “equipped,” “equipped,” “contains,” and / or “contains” as used herein identify the presence of a described feature, complete, step, action, element, and / or component, but it will be understood that they do not exclude the presence or addition of one or more other features, complete, step, action, element, component, and / or group thereof.

[0020]

[0070] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those generally understood by those skilled in the art to the extent of this disclosure. Furthermore, terms used herein should be interpreted as having meanings consistent with their meanings in the context of this specification and related art, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0021]

[0071] Embodiments are described herein with reference to schematic drawings of embodiments of the present disclosure. Therefore, the actual dimensions of layers and elements may differ, and variations from the shapes shown in the drawings are expected, for example, as a result of manufacturing techniques and / or tolerances. For example, areas illustrated or described as squares or rectangles may have rounded, i.e., curved features, and areas illustrated as straight lines may have some irregularities. Thus, the areas illustrated in the drawings are schematic, and the shapes of those areas are not intended to illustrate the exact shapes of areas in the device, nor are they intended to limit the scope of the disclosure. In addition, the size of structures or areas may be exaggerated in comparison to other structures or areas for illustrative purposes, and are therefore provided to illustrate a general structure of the subject matter of the present invention, and may or may not be drawn to scale. Elements common to both drawings may be indicated herein by common element numbers and may not be described again later.

[0022]

[0072] The present invention relates to a light-emitting diode (LED) package, and more specifically to a multi-chip LED package having a common electrode. The LED package may include a lead frame structure having a common electrode for a plurality of LED chips and other corresponding electrodes individually coupled to each individual LED chip. The common electrode may form an anode or cathode connection for each of the LED chips. The common electrode may include a plurality of extensions or pins that individually emerge from the package to provide individual external electrical connections to the common electrode. The common electrode increases the surface area of ​​the metal within the LED package and forms an improved heat body for heat dissipation. The plurality of pin extensions from the common electrode allow the LED package to maintain the same form factor, enable drop-in replacement for existing packages, and improve adhesion to the body or housing surrounding the lead frame structure.

[0023]

[0073] Before delving into the specific details of various aspects of this disclosure, an overview of the various elements that may be included in an exemplary LED package of this disclosure is provided for context. An LED chip typically comprises an active LED structure or region which may have many different semiconductor layers arranged in different ways. The manufacturing and operation of LEDs and their active structures are generally known in the art and will be briefly discussed herein. The layers of an active LED structure can be manufactured using known processes which have a suitable process, such as manufacturing using metal-organic chemical vapor deposition. The layers of an active LED structure may comprise many different layers, and generally may comprise an active layer sandwiched between n-type and p-type oppositely doped epitaxial layers, all of which are formed in a continuous manner on a growth substrate. The active LED structure is understood to include, but is not limited to, additional layers and elements such as a buffer layer, nucleation layer, superlattice structure, undoped layer, cladding layer, contact layer, current-spreading layer, light extraction layer, and elements. The active layer may comprise a single quantum well, multiple quantum well, double heterostructure, or superlattice structure.

[0024]

[0074] Active LED structures can be manufactured from different material systems, some of which are Group III nitride-based material systems. Group III nitrides refer to semiconductor compounds formed between nitrogen (N) and elements of Group III of the periodic table, typically aluminum (Al), gallium (Ga), and indium (In). Gallium nitride (GaN) is a common binary compound. Group III nitrides also refer to ternary and quaternary compounds such as aluminum gallium nitride (AlGaN), indium gallium nitride (InGaN), and aluminum indium gallium nitride (AlInGaN). In the case of Group III nitrides, silicon (Si) is a common n-type dopant, and magnesium (Mg) is a common p-type dopant. Therefore, the active layer, n-type layer, and p-type layer may include one or more layers of Si or Mg-doped or undoped GaN, AlGaN, InGaN, and AlInGaN in the case of a material system based on a group III nitride. Other material systems include organic semiconductor materials and other group III-V systems such as gallium phosphide (GaP), gallium arsenide (GaAs), and related compounds.

[0025]

[0075] Active LED structures may be grown on growth substrates that can contain many materials, including sapphire, SiC, silicon, aluminum nitride (AlN), and GaN. Sapphire is a common substrate for Group III nitrides and has certain advantages, including low cost, established manufacturing processes, and excellent light-transmitting optical properties.

[0026]

[0076] Different embodiments of the active LED structure can emit light of different wavelengths depending on the composition of the active layer. In some embodiments, the active LED structure emits blue light with a peak wavelength range of approximately 430 nanometers (nm) to 480 nm. In other embodiments, the active LED structure emits green light with a peak wavelength range of 500 nm to 570 nm. In yet another embodiment, the active LED structure emits red light with a peak wavelength range of 600 nm to 700 nm. In certain embodiments, the active LED structure may be configured to emit light outside the visible spectrum, including one or more portions of the ultraviolet (UV) spectrum, or one or more portions of the near-infrared spectrum, and / or the infrared spectrum (e.g., 700 nm to 1000 nm). The UV spectrum is typically divided into three wavelength range categories, indicated by the letters A, B, and C. Thus, UV-A light is typically defined as having a peak wavelength range of 315 nm to 400 nm, UV-B as typically defined as having a peak wavelength range of 280 nm to 315 nm, and UV-C as typically defined as having a peak wavelength range of 100 nm to 280 nm. UV LEDs are of particular interest for use in applications related to the disinfection of microorganisms in air, water, and surfaces. For other applications, UV LEDs may also be equipped with one or more luminescent materials to provide LED packages with aggregate emission having a broad spectrum and improved color quality for visible light applications.

[0027]

[0077] The LED chip may also be covered with one or more light-emitting materials (hereinafter also referred to as phosphors), such that at least a portion of the light from the LED chip is absorbed by one or more lumiphors and converted into one or more different wavelength spectra according to the characteristic emission from one or more lumiphors. In this regard, at least one lumiphor that receives at least a portion of the light produced by the LED light source may re-emit light having a different peak wavelength than the LED light source. The LED light source and one or more light-emitting materials may be selected so that the combined output of them is light having one or more desired properties such as color, color point, and intensity. In certain embodiments, the collective emission of the LED chip may optionally be combined with one or more light-emitting materials to provide cool white, neutral white, or warm white light, such as in the color temperature range of 2,500 Kelvin (K) to 10,000 K. In certain embodiments, light-emitting materials having cyan, green, amber, yellow, orange, and / or red peak emission wavelengths may be used. In some embodiments, a combination of an LED chip and one or more light-emitting elements (e.g., phosphors) emits a combination of nearly white light. The one or more phosphors may be yellow (e.g., YAG:Ce), green (e.g., LuAg:Ce), and red (e.g., Ca i-x-y Sr x EU y The material may include luminescent phosphors of AlSiN3, and combinations thereof.

[0028]

[0078] The light-emitting materials described herein may be one or more of the following, or may include, phosphors, scintillators, light-emitting inks, quantum dot materials, day glow tapes, etc. The light-emitting materials may be provided by any suitable means, such as direct coating on one or more surfaces of an LED, dispersion in an encapsulant material configured to cover one or more LEDs, and / or coating on one or more optical elements or support elements (e.g., by powder coating, inkjet printing, etc.). In certain embodiments, the light-emitting materials may be down-converted or up-converted, and combinations of both down-converted and up-converted materials may be provided. In certain embodiments, several different (e.g., different compositions) light-emitting materials arranged to produce different peak wavelengths may be arranged to receive light from one or more LED chips. One or more light-emitting materials may be provided in various configurations on one or more parts of an LED chip. In certain embodiments, the light-emitting material may be provided on one or more surfaces of the LED chip, but the other surfaces of such an LED chip may not have any light-emitting material.

[0029]

[0079] As used herein, a layer or region of an emitting device may be considered “transparent” if at least 80% of the light that strikes the layer or region passes through the layer or region and exits. Furthermore, as used herein, a layer or region of an LED is considered “reflective,” or embodies a “mirror” or “reflector,” if at least 80% of the light that strikes the layer or region is reflected. In some embodiments, the light emission comprises visible light, such as blue and / or green LEDs, with or without the emitting material. In other embodiments, the light emission may comprise invisible light. For example, in the case of GaN-based blue and / or green LEDs, silver (Ag) may be considered a reflective material (e.g., at least 80% reflectivity). In the case of UV LEDs, appropriate materials may be selected to achieve, in some embodiments, high reflectivity and / or, in some embodiments, low absorptivity, as desired. In certain embodiments, a “light-transmitting” material may be configured to transmit at least 50% of the light emission at a desired wavelength.

[0030]

[0080] This disclosure can be useful for LED chips having various shapes, such as vertical geometry or lateral geometry. Vertical geometry LED chips typically include an anode and a cathode on opposite sides or faces of the LED chip. Lateral geometry LED chips typically include both an anode and a cathode on the same side of the LED chip opposite to a substrate, such as a growth substrate. In certain embodiments, a lateral geometry LED chip may be mounted on a submount or lead frame such that the anode and cathode connections are on the side of the LED chip opposite the submount or lead frame of the LED package. In this configuration, wire bonds may be used to provide the electrical connection between the anode and cathode connections. In other embodiments, a lateral geometry LED chip may be flip-chip mounted on the surface of a submount or lead frame such that the anode and cathode connections are on the surface of the active LED structure adjacent to the submount or lead frame of the LED package. In the context of a lead frame, the leads of the lead frame structure are provided as electrical connections to the anode and cathode connections of one or more LED chips. In a flip-chip configuration, the active LED structure is configured between the substrate of the LED chip and the lead frame structure of the LED package. Therefore, light emitted from the active LED structure may pass through the substrate in the desired emission direction. In other embodiments, the active LED structure may be coupled to a carrier submount, and the growth substrate may be removed so that light can be emitted from the active LED structure without passing through the growth substrate.

[0031]

[0081] In aspects of this disclosure, an LED package may include one or more elements, such as a light-emitting material, a encapsulant, a light-altering material, a lens, and an electrical contact, that provide one or more LED chips. The light-altering material may be placed within the LED package to reflect or redirect light from one or more LED chips to a desired radiation direction or pattern. In certain embodiments, the LED package may include a support member, such as a submount or lead frame.

[0032]

[0082] In certain embodiments, aspects of the present disclosure relate to LED packages having a lead frame structure at least partially housed by a body or housing. The lead frame structure may typically be formed of a metal such as copper, a copper alloy, or other conductive metal. The lead frame structure may initially be part of a larger metal structure that is individualized during the manufacture of individual LED packages. Within an individual LED package, isolated portions of the lead frame structure may form the anode and cathode connections of the LED chips. The body or housing may be formed of an insulating material that is arranged to surround or enclose a portion of the lead frame structure. For example, the body or housing may comprise one or more of the following: PPA, PCT, EMC, FR4, BT, impregnated fiber, and / or plastic. The body may be formed on the lead frame structure before individualization, so that individual lead frame portions are electrically isolated from each other and mechanically supported by the body within an individual LED package. The body may form cups or recesses, and one or more LED chips may be mounted on the lead frame at the bottom of the recesses. A portion of the lead frame structure may extend from the recess through the body and protrude to the outside of the body, or be accessible to the outside of the body to provide external electrical connections. One or more LED chips may be sealed by filling the recess with a sealing material such as silicone or epoxy.

[0033]

[0083] The light-modifying materials used herein may include many different materials, including light-reflective materials that reflect or redirect light, light-absorbing materials that absorb light, and materials that act as thixotropic agents. The term “light-reflective” as used herein refers to a material or particle that reflects, refracts, or redirects light. In the case of light-reflective materials, the light-modifying material may include at least one of fused silica, fumed silica, titanium dioxide (TiO2), or metal particles suspended in a binder such as silicone or epoxy. In the case of light-absorbing materials, the light-modifying material may include at least one of carbon, silicon, or metal particles suspended in a binder such as silicone or epoxy. Light-reflective and light-absorbing materials may comprise nanoparticles. In certain embodiments, the light-modifying material may have a substantially white color in order to reflect and redirect light. In other embodiments, the light-modifying material may be substantially opaque, i.e., black, in order to absorb light and improve contrast.

[0034]

[0084] A multi-chip LED package typically contains two or more LED chips housed and electrically connected within a common package. An exemplary multi-chip package includes one having red, blue, and green light-emitting LED chips. An additional exemplary package may further include a white LED chip, which is a blue or green LED chip having a corresponding light-emitting material such as a phosphor. In yet other applications, the disclosed principle is equally applicable to multiple LED chips of the same light-emitting color within a common package. In a lead frame structure, it is common to have a separate pair of leads for each LED chip. For example, a 3-chip LED package may have a total of six leads that couple with the LED chips and extend from the LED package to accept external electrical connections. In this regard, a 3-LED chip package with a lead frame structure may be referred to as a 6-pin LED package. Similarly, a 2-chip LED package may be referred to as a 4-pin LED package, and a 4-chip LED package may be referred to as an 8-pin LED package. Such lead frame-based LED packages are sometimes called surface mount devices (SMDs) because when the package is mounted on another surface, such as a printed circuit board, the leads (e.g., pins) extending from the package are electrically coupled to external connections.

[0035]

[0085] According to aspects of this disclosure, a multi-chip LED package is described that reduces multiple cathode leads or multiple anode leads to a single common electrode. The single common electrode may be formed by a single lead or pad of a lead frame structure. For example, in a 3-chip LED package, instead of a total of six leads in the lead frame, one anode or cathode connection is coupled to all chips. Thus, the 3-chip LED package may include a total of four leads while maintaining the individual addressing capability of each LED chip. A single common electrode lead is provided for the anode or cathode connection, but the single common electrode lead may still include multiple extensions emanating from the package, and as a result, the 3-chip LED package may still have a total of six pins for electrical connection. In such embodiments, three of the total six pins are electrically coupled within the package to form a common electrode for the anode or cathode connection.

[0036]

[0086] Aspects of the present disclosure can offer many advantages over conventional packages. For example, such a structure may be advantageous when using flip-chip LED chips in SMD packages where the LED chip is thermally and electrically coupled to the package without the need for bonding wires. In addition, the common electrode increases the metal surface area within the LED package, forming an improved heat body for heat dissipation. In certain embodiments, by maintaining multiple pin extensions from the common electrode, the LED package can maintain the same form factor and be drop-in interchangeable with existing packages. In yet another embodiment, the multiple pin extensions can improve adhesion to the body or housing that accommodates the lead frame structure.

[0037]

[0087] In certain embodiments, a common electrode with multiple pins can facilitate the use of flip-chip LED chips. In flip-chip bonding, having a horizontal or planar surface for mounting is advantageous. The common electrode can enhance alignment by providing a common mounting surface for the anodes or cathodes of multiple flip chips. In such embodiments, improved reliability can be achieved by reducing or eliminating the presence of wire bonding, thereby avoiding known failure mechanisms associated with wire bonding, and extending the lifespan of the LED package by enhanced heat dissipation. In certain embodiments, improved light output performance may be achieved by a flip-chip arrangement that reduces and / or eliminates absorbing material (e.g., excess gold bonding wire) that would otherwise be present in the light dissipation path. Furthermore, such a lead frame structure can more easily facilitate non-linear alternative LED chip layouts for better, or more desirable, pairing with an integrated optical collector in the package for higher light mixing and uniformity of package emission. For example, to distribute light more evenly to the optical collector, the layout of the LED chips, such as in a triangular or off-center direction for multiple LED chips, can make it easier to avoid placing the LED chip at the center point of the package. While aspects of this disclosure are applicable to flip-chip LED chips, the disclosed principles are also applicable to LED chips employing bond wire connections.

[0038]

[0088] Figure 1 is a top view of an LED package 10 having a plurality of LED chips 12-1 to 12-3 according to the principle of this disclosure. The LED chips 12-1 to 12-3 may all be configured to emit the same light color, or they may be configured to emit different light colors, such as red, green, and blue wavelengths. The LED package 10 is a lead frame package including a lead frame structure collectively formed by leads 18, 20, 22, and 24 within a housing 16. The LED chips 12-1 to 12-3 are located in recesses 16 of the housing 16. R Located inside, recess 16 R Parts of the leads 18, 20, 22, 24 exposed at the bottom are attached to and / or electrically connected. In Figure 1, each LED chip 12-1 to 12-3 is a flip-chip LED structure electrically connected to the common lead 18. The other leads 20, 22, 24 provide individual electrical connections to the corresponding chips among the LED chips 12-1 to 12-3. Thus, lead 18 may form a common electrode (e.g., a common anode or common cathode) for each of the LED chips 12-1 to 12-3, while leads 20, 22, 24 provide the other of anode or cathode connections separately. As illustrated, parts of lead 18 extend from the housing 16 to form a plurality of pins 18-1 to 18-3. Similarly, each of leads 20, 22, 24 also extends from the housing 16 to form corresponding pins 20-1, 22-1, 24-1. Thus, the LED package 10 contains multiple LED chips 12-1 to 12-3, each having a number of leads 18, 20, 22, and 24 that is less than twice the number of LED chips 12-1 to 12-3, as well as a number of pins 18-1 to 18-3, 20-1, 22-1, and 24-1 that is twice the number of LED chips 12-1 to 12-3. For illustrative purposes, the portions of leads 18, 20, 22, and 24 located within the housing 16 are illustrated with dashed lines.

[0039]

[0089] Figure 2 is a top view of an LED package 26 similar to the LED package 10 in Figure 1, except that the LED chips 12-1 to 12-3 are connected to one or more wire bonds. In this regard, the lead frame structure formed by leads 18, 20, 22, and 24 may also be applicable when none of the LED chips 12-1 to 12-3 have a flip-chip structure. For example, LED chip 12-1 is illustrated with a single wire bond 26, thereby embodying a vertical chip structure. LED chips 12-2 and 12-3 are illustrated with two wire bonds 28, thereby embodying a lateral chip structure. In a particular embodiment, each of the LED chips 12-1 to 12-3 is mounted on the same lead 18, and the wire bond 28 provides connection to the corresponding lead among leads 20, 22, and 24.

[0040]

[0090] Figures 1 and 2 are provided to illustrate that both the principles of this disclosure and the embodiments shown in the subsequent figures may include multiple LED chips having a flip-chip structure, a vertical structure, a lateral structure, and any combination thereof, within the same package.

[0041]

[0091] Figure 3 is a perspective view of an LED package 30, similar to the LED package 10 in Figure 1, illustrating an exemplary SMD structure. For illustrative purposes, the housing 16 is shown transparently, and the LED chips 12-1 to 12-3 in Figure 1 are omitted. As illustrated, the lead 18 includes several pins 18-1 to 18-3 that extend from the housing 16 and wrap around the bottom of the housing 16. Similarly, the pins 20-1, 22-1, and 24-1 of the leads 20, 22, and 24 also extend from the housing 16 and wrap around the bottom of the housing 16 from the opposite side. In certain embodiments, the leads 18, 20, 22, and 24 have multiple bends within the housing 16, such as a so-called S-shape, to improve adhesion with the housing 16. The lead frame structure may also include various other possible features to enhance the adhesion between the casing and the lead frame, such as stepped sections (e.g., S-shaped or S-shaped leg sections), spot punches 32, through holes 34, metal gaps 36, recesses 38, and tabs 40. Such features improve the structural integrity of the LED package 30 and enhance its resistance to water (and other contaminants or environmental intrusion). In addition, they also improve the adhesive reliability between the housing 16 and the lead frame structure. Thus, these shapes can improve structural integrity by altering the surface area of ​​the lead frame structure and allowing the housing 16 material to surround it.

[0042]

[0092] Figures 4 to 6 show possible embodiments of lead frame structures similar in shape to that of the LED package 30 in Figure 3. Figures 4 to 6 provide cross-sectional views including leads 18, 20 and corresponding pins 18-1, 20-1 as illustrated in Figure 3.

[0043]

[0093] Figure 4 is a cross-sectional view of an LED package 42 in which recesses 38 are provided in the leads 18, 20 along the vertical length within the housing 16. The package mounting surface may be defined along a first plane P1 at the bottom surface of pins 18-1, 20-1, and the LED chip mounting surface is the recess 16 RThe recess 38 may be defined along the second plane P2 on the upper surface of the internal leads 18,20. Other parts of the leads 18,20 (and the rest of the lead frame structure) may form an intermediate portion extending between the first plane P1 and the second plane P2. Thus, the recess 38 is provided in the portion of the leads 18,20 that lies between the first plane P1 and the second plane P2. The recess 38 increases the available surface area and improves the coupling and adhesion with the housing 16.

[0044]

[0094] Figure 5 is a cross-sectional view of an LED package 44, similar to the LED package 42 in Figure 4, but without the recess 38 in Figure 4. As illustrated, this configuration allows for a shorter lead frame length between the first plane P1 and the second plane P2, and compared to Figure 4, the recess 16 R The depth can be increased.

[0045]

[0095] Figure 6 is a cross-sectional view of an LED package 46, similar to the LED package 42 of Figure 4, having a single recess 38 for each of the leads 18, 20. According to the principles of this disclosure, the lead frame structure may have any number of features, such as recesses 38, to improve adhesion and reduce environmental intrusion. As described above, the leads 18 may form a common electrode for multiple LED chips. By forming multiple pins 18-1 to 18-3 extending from the same lead 18, additional surface area is provided for recesses 38 and / or stepped portions, punches 32, through holes 34, metal gaps 36, and / or tabs 40, as illustrated in Figure 3.

[0046]

[0096] Figures 7A to 20D illustrate various configurations of LED packages similar to the LED package 10 in Figure 1 or the LED package 26 in Figure 2. Figures 7A to 20D illustrate the advantages of lead frame structure layouts when implementing common electrodes (e.g., common anode or common cathode) for the leads 18 according to the principles of this disclosure.

[0047]

[0097] FIG. 7A is a top view of an LED package 48 similar to the LED package 10 of FIG. 1, with an increased surface area of the lead 18. In FIG. 7A, the LED chips 12-1 to 12-3 have a flip-chip structure. As illustrated, the lead 18 extends beyond the center line C of the housing 16 and / or the recess 16 R and the center line C L is defined between the opposite side surfaces of the housing 16 from which the pins 18-1 and the leads 20, 22, 24 respectively emerge. The increased surface area may increase the thermal spreading of the LED chips 12-1 to 12-3. In addition, for certain light-emitting applications, the LED chips 12-1 to 12-3 may be arranged offset from the center. As illustrated, the lead 18 may have a tab or a lateral protrusion near the LED chip 12-2 for attachment and for increasing the surface area along the center of the housing 16. FIG. 7B is a top view of an LED package 50 similar to the LED package 48 of FIG. 7A for an embodiment in which the LED chips 12-1 to 12-3 embody a vertical and / or a lateral structure having wire bonds 28. FIG. 7C is a top view of an LED package 52 similar to the LED package 48 of FIG. 7A for an embodiment in which the lead 18 includes one or more through holes 34. When the surface area of the lead 18 is increased, it becomes possible to arrange the through holes 34, and for improving adhesion, a part of the housing 16 can at least partially fill the through holes 34. FIG. 7D is a top view of an LED package 54 similar to the LED package 50 of FIG. 7B for an embodiment in which the lead 18 includes one or more through holes 34.

[0048]

[0098] FIG. 8A is a top view of an LED package 56 similar to the LED package 10 of FIG. 1, in which the lead 18 is provided in another shape. For example, a part of the lead 18 is along the center line C of the LED chips 12-1, 12-3 L ​​It extends beyond the center line C. Similarly, lead 22 also extends from the opposite side of the housing 16 for the LED chip 12-2 to the center line C. L They extend beyond the recess 16. In this way, leads 18, 20, and 24 may form an interdigitated arrangement. As illustrated, this provides a layout (e.g., triangular) for LED chips 12-1 to 12-3, where any of the LED chips 12-1 to 12-3 are located in the recess 16. R This avoids positioning at the center point. This layout may be advantageous for applications employing a concentrator, as will be described in detail later. Figure 8B is a top view of an LED package 58 similar to the LED package 56 in Figure 8A for embodiments in which LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having wire bonds 28. In Figure 8B, the positions of the LED chips 12-1 to 12-3 are not necessarily the same as in Figure 8A, illustrating the design flexibility for different embodiments. In particular, the LED leads 12-1 to 12-3 in Figure 8B are provided in a linear arrangement.

[0049]

[0099] Figure 9A is a top view of an LED package 60 similar to the LED package 10 in Figure 1, where the surface area is increased along the central portion of the lead 18. For example, lead 18 is along the center line C of LED leads 12-2. L It extends beyond the center line C. Similarly, leads 20 and 24 also extend from the side of housing 16 opposite to lead 18 to the center line C. L They extend beyond the recess 16. In this way, leads 18, 20, and 24 may form an interlocking arrangement with respect to each other. As illustrated, this provides a layout (e.g., triangular) for LED chips 12-1 to 12-3, where any of the LED chips 12-1 to 12-3 are located in the recess 16. RTo avoid being positioned at the center point. Figure 9B is a top view of an LED package 62 similar to the LED package 60 in Figure 9A for an embodiment in which LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having a wire bond 28. Figure 9C is a top view of an LED package 64 similar to the LED package 62 in Figure 9B, except that the positions of LED chips 12-1 and 12-2 are reversed to form a linear arrangement. As illustrated, LED chip 12-1 may embody a vertical structure having a single wire bond 38.

[0050]

[0100] Figure 10A is a top view of an LED package 66 similar to the LED package 60 in Figure 9A, in which the lead 18 is provided with a surface area that increases along the central portion, in a different shape than in Figure 9A. In Figure 10A, a portion of the lead 18 is aligned with the center line C of the LED chip 12-2. L Extending beyond the lead 18, this portion provides an increased surface area compared to Figure 9A by forming an angled edge. Figure 10B is a top view of an LED package 68 similar to the LED package 66 of Figure 10A for an embodiment in which the LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having a wire bond 28. Figure 10C is a top view of an LED package 70 similar to the LED package 66 of Figure 10A for an embodiment in which the lead 18 includes at least one through hole 34. The increased surface area of ​​the lead 18 makes it possible to accommodate the through hole 34, and for improved adhesion, a portion of the housing 16 can at least partially fill the through hole 34. In addition, in certain embodiments, the material of the housing 16 may be more reflective to light from the LED chips 12-1 to 12-3 than the surface of the lead 18, so a portion of the housing 16 within the through hole 34 can form a recess 16 R A highly reflective surface may be formed inside. Figure 10D is a top view of an LED package 72 similar to the LED package 68 in Figure 10B for an embodiment in which the lead 18 includes at least one through hole 34.

[0051]

[0101] Figure 11A is a top view of an LED package 74 similar to the LED package 10 in Figure 1, where the pins 18-1 to 18-3 of lead 18 are located on opposite sides of the housing 16. As illustrated, lead 18 may extend continuously from one side of the housing 16 to the other. Thus, pins 18-1 and 18-3 exit from one side of the housing 16, and pin 18-2 exits from the opposite side. Such an arrangement may also provide a layout (e.g., triangular) for LED leads 12-1 to 12-3, where any of the LED leads 12-1 to 12-3 are located in the recess 16 R To avoid being positioned at the center point. Figure 11B is a top view of an LED package 76 similar to the LED package 74 of Figure 11A for an embodiment in which the LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having a wire bond 28. As illustrated, the LED leads 12-1 to 12-3 are arranged linearly along the lead 18.

[0052]

[0102] Figure 12A is a top view of an LED package 78 similar to the LED package 74 of Figure 11A, in which the shapes of leads 18, 22, 24 are modified to place the LED chips 12-1 to 12-3 closer to each other. As illustrated, the LED leads 12-1 to 12-3 may still have a triangular layout. Figure 12B is a top view of an LED package 80 similar to the LED package 78 of Figure 12A, for an embodiment in which the LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having wire bonds 28.

[0053]

[0103] Figure 13A is a top view of an LED package 82 similar to the LED package 74 in Figure 11A, but with a different arrangement of leads 18 and leads 22, 24. In Figure 13A, leads 18 still extend from one side of the housing 16 to the other, and pins 18-1 and 18-3 are located on the side of the housing 16 opposite to pin 18-2. As illustrated, pins 18-1 and 18-3 are located adjacent to each other on one side of the housing 16, with pin 18-3 being between pins 22-1 and 18-1. Such an arrangement allows the flip-chip LED chips 12-1 to 12-3 to be placed in the recess 16 R It is suitable for arranging in a layout that avoids the center (for example, triangular). Furthermore, by placing a gap between lead 18 and leads 20, 22, 24, LED chips 12-1 to 12-3 are positioned in the recess 16 R The placement can be adjusted by moving it closer to or further away from the center. Figure 13B is a top view of an LED package 84 similar to the LED package 82 of Figure 13A for an embodiment in which the LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having wire bonds 28.

[0054]

[0104] Figure 13C is a top view of an LED package 86 similar to the LED package 82 in Figure 13A for an embodiment in which the lead 18 includes at least one through-hole 34. As previously described, increasing the surface area of ​​the lead 18 allows for the placement of the through-hole 34, and for improved adhesion, a portion of the housing 16 at least partially fills the through-hole 34. Figure 13D is a top view of an LED package 88 similar to the LED package 84 in Figure 13B for an embodiment in which the lead 18 includes at least one through-hole 34.

[0055]

[0105] Figure 14A is a top view of an LED package 90 similar to the LED package 74 in Figure 11A, but with a different arrangement of leads 18 and leads 22, 24. In Figure 14A, leads 18 still extend from one side of the housing 16 to the other, and pins 18-1 and 18-3 are located on the side of the housing 16 opposite to pin 18-2. As illustrated, pins 18-1 and 18-3 are located adjacent to each other on one side of the housing 16, with pin 18-1 between pins 20-1 and 24-1. Compared to Figure 11A, the positions of pins 22-1 and 18-1 are swapped. Figure 14B is a top view of an LED package 92 similar to the LED package 90 in Figure 14A, for embodiments in which LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having a wire bond 28. Figure 14C is a top view of an LED package 94 similar to the LED package 90 in Figure 14A, for an embodiment in which the lead 18 includes at least one through hole 34. Figure 14D is a top view of an LED package 96 similar to the LED package 92 in Figure 14B, for an embodiment in which the lead 18 includes at least one through hole 34.

[0056]

[0106] Figure 15A is a top view of an LED package 98 similar to the LED package 90 in Figure 14A, but with a different arrangement of leads 18 and leads 22, 24. In Figure 15A, leads 18 still extend from one side of the housing 16 to the other, and pins 18-1 and 18-3 are located on the housing 16 opposite to pin 18-2. As illustrated, pins 18-1 and 18-3 are located adjacent to each other on one side of the housing 16, with pin 18-3 being between pins 22-1 and 18-1. Figure 15B is a top view of an LED package 100 similar to the LED package 98 in Figure 15A, for embodiments in which LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having wire bonds 28. Figure 15C is a top view of an LED package 102 similar to the LED package 98 in Figure 15A, for an embodiment in which the lead 18 includes at least one through-hole 34. Figure 15D is a top view of an LED package 104 similar to the LED package 100 in Figure 15B, for an embodiment in which the lead 18 includes at least one through-hole 34.

[0057]

[0107] Figure 16A is a top view of an LED package 106 similar to the LED package 90 in Figure 14A, but with a different arrangement of leads 18 and leads 22, 24. In Figure 16A, leads 18 still extend from one side of the housing 16 to the other, and pins 18-2 and 18-3 are located on the side of the housing 16 opposite to pin 18-1. On one side of the housing 16, pin 24-1 is located between pins 22-1 and 18-1, and on the other side of the housing 16, pin 20-1 is located between pins 18-2 and 18-3. Such an arrangement also provides a layout (e.g., a triangle) in which LED chips 12-1 to 12-3 are offset from the center. Figure 16B is a top view of an LED package 108 similar to the LED package 106 in Figure 16A, for an embodiment in which LED chips 12-1 to 12-3 embody a vertical and / or lateral structure having wire bonds 28.

[0058]

[0108] Figure 17A is a top view of an LED package 110 similar to the LED package 10 in Figure 1 for an embodiment in which lead 18 is a common electrode for at least four LED chips 12-1 to 12-4. For example, the LED leads 12-1 to 12-4 may be configured to provide red, green, blue, and white light emission, respectively, with the white light emission provided by a blue chip having a corresponding light-emitting material. In certain embodiments, lead 18 may extend continuously between opposite sides of the housing 16, and pins 18-1, 18-2 may be formed on the opposite sides of the housing 16. An additional lead 112 and corresponding pin 112-1 are provided for a fourth LED lead 12-4 to provide a corresponding electrical connection. As illustrated, each of the other leads 20, 22, 24, 112 forms a separate electrode for the corresponding chip among the LED chips 12-1 to 12-4. In Figure 17A, leads 20, 22, 24, and 112 are located at the four corners of the housing 16, and a common lead 18 extends between them along the central portion of the housing 16. Figure 17B is a top view of an LED package 114 similar to the LED package 110 in Figure 17A, for an embodiment in which LED chips 12-1 to 12-4 embody a vertical and / or lateral structure having wire bonds 28.

[0059]

[0109] Figure 18A is a top view of an LED package 116 similar to the LED package 110 in Figure 17A, for an embodiment in which lead 18 is a common electrode for at least four LED chips 12-1 to 12-4 and extends between opposite corners of the housing 16. For example, pin 18-1 is located closest to the lower left corner of the housing 16, while pin 18-2 on the opposite side of lead 18 is located in the upper right corner of the housing 16. In this way, lead 18 extends between the two furthest corners of the housing 16. As illustrated, such an arrangement is suitable for positioning the LED leads 12-1 to 12-4 away from the center point of the housing 16. Figure 18B is a top view of an LED package 118 similar to the LED package 116 in Figure 18A, for an embodiment in which the LED chips 12-1 to 12-4 embody a vertical and / or lateral structure having a wire bond 28.

[0060]

[0110] Figure 19A is a top view of an LED package 120 similar to the LED package 110 in Figure 17A, for an embodiment in which lead 18 is a common electrode for at least four LED chips 12-1 to 12-4 and extends from one corner of the housing 16 to another corner on the same side of the housing 16. As illustrated, pin 18-1 is located closest to the upper left corner of the housing 16, and pin 18-2 is located closest to the lower left corner of the housing 16. The remaining portion of lead 18 extends along the central portion of the housing 16, thereby forming a U-shape with pins 18-1 and 18-2 extending from the same side. As further illustrated, lead 22 and pin 22-1 may be located between the portions of lead 18 that form the U-shape. Figure 19B is a top view of an LED package 122 similar to the LED package 120 in Figure 19A, for an embodiment in which LED chips 12-1 to 12-4 embody a vertical and / or lateral structure having wire bonds 28.

[0061]

[0111] Figure 20A is a top view of an LED package 124 similar to the LED package 124 in Figure 19A for an embodiment in which lead 18 is a common electrode for at least four LED chips 12-1 to 12-4 and pins 18-1, 18-2 are adjacent to each other on the same side of the housing 16. In this regard, lead 18 may form a large pad extending from the corner of the housing 16 toward the center, with the remaining leads 20, 22, 24, 112 positioned in close proximity around lead 18. The large pad may help to enhance heat dissipation. In this arrangement, pin 22-1 is provided on the same side of the housing 16 as pins 18-1, 18-2, but not between pins 18-1, 18-2. Figure 20B is a top view of an LED package 126 similar to the LED package 124 in Figure 20A for an embodiment in which the LED chips 12-1 to 12-4 embody a vertical and / or lateral structure having a wire bond 28.

[0062]

[0112] Figure 20C is a top view of an LED package 128 similar to the LED package 124 in Figure 20A, for an embodiment in which the lead 18 includes at least one through-hole 34. Figure 20D is a top view of an LED package 130 similar to the LED package 126 in Figure 20B, for an embodiment in which the lead 18 includes at least one through-hole 34. As illustrated, a larger pad formed by the lead 18 may also accommodate the through-hole 34 to enhance adhesion with the housing 16.

[0063]

[0113] Figure 21A is a top view of an LED package 132 similar to the LED package 82 in Figure 13A, with a light concentrator 134 added. Figure 21B is a cross-sectional view of the LED package 132 in Figure 21A, cut along the cross-sectional line 21B-21B in Figure 21A. The light concentrator 134 is located in the recess 16 R Within the package, it is positioned above the LED chips 12-1 to 12-3 and collects the light emitted from there. In certain embodiments, the light collector 134 includes an opening 136 and a stem portion 138. The opening 136 is a recess 16 that defines an area from which the light emitted escapes the package.R It forms a small aperture that is substantially smaller than the size of the aperture. In certain embodiments, the light concentrator 134 may be formed from epoxy, silicone, or some other light-transmitting material. The light concentrator 134 may have a reflective coating on its top surface, except for the apex, center, or top or near the aperture 136 of the light concentrator 134. The light concentrator 134 may have a reflective material that passes through the light concentrator 134. For example, the light concentrator 134 may contain a white material. The light emitted from the LED chips 12-1 to 12-3 may enter the light concentrator 134, be reflected once or multiple times, thereby being mixed within the light concentrator 134, and finally exit through the aperture 136. By mixing the light within the light concentrator 134 before exiting through the aperture 136, the light from each of the LED chips 12-1 to 12-3 appears to be emitted from a single light-emitting point or region (i.e., the aperture 136) rather than from three separate and distinct locations on the LED chips 12-1 to 12-3. Therefore, the emission pattern and color can be improved with respect to the angle shift of light. When this disclosure refers to a single light-emitting point, it should be recognized that this refers to a single light source (e.g., an LED chip, or the output of multiple LED chips from aperture 136), not a point in a mathematical sense. In this view, point can be a term that represents a light source smaller than the LED package 132 or system described, and the size may depend on the entire system.

[0064]

[0114] In certain embodiments, the light condenser 134 is configured to receive light from LED chips 12-1 to 12-3, and the stem portion 138 may have a cylindrical shape protruding from the top, center, or apex of the light condenser 134. In other embodiments, the stem portion 138 may have a shape other than cylindrical. The height of the stem portion 138 can be used to reduce or avoid the line of sight from the LED chips 12-1 to 12-3. In other embodiments, the light condenser 134 may be formed without the stem portion 138.

[0065]

[0115] In a particular embodiment, the filling material 140 is placed in the recesses 16 above and around the concentrator 134. R The opening 136 may be filled with filler 140. The opening 136 may not be covered by the filler 140, allowing light to exit the package without interacting with the filler 140. In various embodiments, the filler 140 may include light-modifying materials such as light-reflective or light-absorbing materials that completely or partially reflect, block, or reduce light that may pass through or around the light concentrator 134. In this way, most of the light emitted by the LED package 132 may pass through the opening 136. The filler 140 may be epoxy or silicone having a composition configured to reflect or block light. In certain embodiments, the filler 140 is white to increase reflectivity. In other embodiments, the filler 140 is black to increase the contrast of the light emitting from the LED package 132. In further embodiments, the filler 140 may be white on the inside and black on the top.

[0066]

[0116] As previously explained, the specific arrangement of leads 18, 20, 22, 24 is such that the layout of LED chips 12-1 to 12-3 is such that the housing 16 and / or recess 16 R It is provided to be offset from the center. For example, LED chips 12-1 to 12-3 are located in the recess 16 R The arrangement is shown in a triangular shape. Such an arrangement can be advantageous in avoiding direct line of sight through the aperture 136 of light from any of the LED leads 12-1 to 12-3. In yet another embodiment, the stem portion 138 may be implemented to further avoid direct line of sight. In this way, the light from each of the LED leads 12-1 to 12-3 may be arranged radially with respect to the aperture 136 to enhance the mixing of the light. The light concentrator 134 may be useful for such an arrangement that avoids the centrally positioned LED leads 12-1 to 12-3, while the light concentrator 134 can also be implemented in any of the previously described embodiments, including Figures 1 to 20D.

[0067]

[0117] Figure 22A shows multiple cavities or recesses 16 for multiple LED chips 12-1 to 12-3 according to the principle of this disclosure. R -1~16 R -3 is a top view of an LED package 142 having a common electrode. As illustrated, the housing 16 has a plurality of recesses 16 R -1~16 R -3 is formed, and each recess contains one of the LED chips 12-1 to 12-3. Lead 18 forms a common electrode as previously described and extends continuously within the housing 16 to the recess 16. R -1~16 R Each of the three leads has an exposed portion. The other leads 20, 22, and 24 form other electrodes for each of the LED chips 12-1 to 12-3. In Figure 22A, leads 20, 22, and 24 have protrusions, on which each of the LED leads 12-1 to 12-3 is located. As an alternative configuration, Figure 22B is a top view of an LED package 144 similar to the LED package 142, except that leads 20, 22, and 24 do not have protrusions as illustrated in Figure 21A.

[0068]

[0118] Figure 22C is a top view of a lead frame structure 146 that can be mounted in the LED package 142 of Figure 22A. As illustrated, the lead 18 is located in the recess 16 of Figure 22A. R -1~16 R-3 forms a continuous metal structure configured to extend between each of the three leads. The leads 20, 22, 24 are discontinuous from each other and from lead 18, so as to form electrodes (e.g., anode or cathode) corresponding to the common anode or common cathode formed by lead 18. As illustrated, multiple pins 18-1 to 18-3 of lead 18 are formed and extend from the same side of the housing 16 in Figure 22A. Similarly, the pins 20-1, 22-1, 24-1 of the other leads 20-1, 22-1, 24-1 may extend from the opposite side of the housing 16 in Figure 22A. In certain embodiments, each of the leads 18, 20, 22, 24 may have one or more through holes 34 to improve adhesion with the housing 16 in Figure 22A. In certain embodiments, the lead frame structure 146 may also include one or more recesses and / or stepped portions, punches, metal gaps, and / or tabs.

[0069]

[0119] Any of the embodiments described herein, and / or any of the various individual embodiments and features described herein, may be combined for further advantages. Any of the various embodiments disclosed herein may be combined with one or more other disclosed embodiments unless otherwise indicated herein.

[0070]

[0120] Those skilled in the art will recognize improvements and modifications to preferred embodiments of this disclosure. All such improvements and modifications are considered to be within the scope of the concepts disclosed herein and the appended claims.

Claims

1. Light-emitting diode (LED) package, The first LED chip, The second LED chip, The third LED chip, Housing and A lead frame structure that is at least partially located within the housing and electrically coupled to the first LED chip, the second LED chip, and the third LED chip, The lead frame structure is provided with, A first lead electrically connected to the first LED chip, the second LED chip, and the third LED chip, the first lead having a plurality of pins extending outward from the housing, A second lead electrically connected to the first LED chip, A third lead electrically connected to the second LED chip and An LED package equipped with [specific features / features].

2. The LED package according to claim 1, wherein the plurality of pins of the first lead extend from the same side of the housing.

3. The LED package according to claim 1, wherein the first lead forms a common anode connection for the first LED chip, the second LED chip, and the third LED chip.

4. The LED package according to claim 1, wherein the first lead forms a common cathode connection for the first LED chip, the second LED chip, and the third LED chip.

5. The LED package according to claim 1, wherein the first lead extends from the first edge of the housing beyond the centerline of the housing.

6. The surfaces of the plurality of pins define a package mounting surface in the first plane, The surfaces of the first lead and the second lead define an LED chip mounting surface in the second plane, The LED package according to claim 1, wherein the intermediate portion of the lead frame structure extends between the first plane and the second plane.

7. The LED package according to claim 1, wherein the housing forms recesses in which the first LED chip, the second LED chip, and the third LED chip are located.

8. The recess and above the first LED chip, the second LED chip, and the third LED chip are further provided with a light concentrator. The LED package according to claim 7, wherein the light concentrator forms an opening configured to allow light from the first LED chip, the second LED chip, and the third LED chip to pass through.

9. The LED package according to claim 8, further comprising a filler material covering a portion of the light concentrator within the recess.

10. The LED package according to claim 1, wherein the housing forms a first recess in which the first LED chip is located, a second recess in which the second LED chip is located, and a third recess in which the third LED chip is located.

11. The LED package according to claim 1, wherein the first LED chip, the second LED chip, and the third LED chip are mounted on the first lead and thermally coupled to the first lead.

12. The first LED chip is further mounted on the second lead and thermally coupled to the second lead. The second LED chip is further mounted on the third lead and thermally coupled to the third lead. The LED package according to claim 1, wherein the third LED chip is further mounted on the fourth lead of the lead frame structure and thermally coupled to the fourth lead.

13. The LED package according to claim 1, further comprising a fourth LED chip, wherein the first lead is a common electrode for the first LED chip, the second LED chip, the third LED chip, and the fourth LED chip.

14. Light-emitting diode (LED) package, Housing and The first LED chip, The second LED chip, A lead frame structure having a first lead and An LED package comprising, wherein the first lead forms a common electrode for the first LED chip and the second LED chip, and the first lead comprises a plurality of pins extending from the same side of the housing, the plurality of pins configured to accept an external electrical connection to the common electrode.

15. The LED package according to claim 14, wherein the common electrode is a common anode connection for the first LED chip and the second LED chip.

16. The LED package according to claim 14, wherein the common electrode is a common cathode connection for the first LED chip and the second LED chip.

17. The surfaces of the plurality of pins define a package mounting surface within the first plane, The surface of the first lead defines an LED chip mounting surface within the second plane, The LED package according to claim 14, wherein the intermediate portion of the lead frame structure extends between the first plane and the second plane.

18. The LED package according to claim 14, wherein the housing forms a recess in which the first LED chip and the second LED chip are located.

19. The LED package according to claim 18, further comprising a light concentrator within the recess and above the first LED chip and the second LED chip, wherein the light concentrator forms an opening configured to allow light from the first LED chip and the second LED chip to pass through.

20. The LED package according to claim 19, further comprising a filler material covering a portion of the light concentrator within the recess.

21. The LED package according to claim 14, wherein the housing forms a first recess in which the first LED chip is located and a second recess in which the second LED chip is located.

22. The LED package according to claim 14, further comprising a third LED chip, wherein the first lead is the common electrode for the first LED chip, the second LED chip, and the third LED chip.

23. The lead frame structure further comprises a second lead and a third lead, The first LED chip is flip-chip mounted between the first lead and the second lead. The LED package according to claim 14, wherein the second LED chip is flip-chip mounted between the first lead and the third lead.

24. The LED package according to claim 14, wherein the first LED chip and the second LED chip are mounted on the first lead and thermally coupled to the first lead.

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