Light emitting devices and methods

Light emitting device and method

The subject matter disclosed herein generally relates to light-emitting devices and methods. More specifically, the subject matter disclosed herein relates to light-emitting devices and methods used in higher voltage applications.

This application claims the rights of the U.S. Provisional Patent Application Serial No. 61/404,985 filed on October 13, 2010 and the U.S. Partial Succession Patent Application Serial No. 13/227,961 filed on September 8, 2011. This The disclosures of other applications are incorporated herein by reference in their entirety.

Light-emitting devices (such as light-emitting diodes (LED)) can be used in products that provide white light (for example, perceived as white or close to white), and these light-emitting devices are developed into incandescent lamps, fluorescent lamps, and metal halide Substitute for object lighting products. A representative example of an LED lamp includes a package having at least one LED chip, and a portion of the LED chip can be coated with a phosphor such as, for example, yttrium aluminum garnet (YAG). The LED chip can generate an emission of a desired wavelength in the LED lamp, and the phosphor can emit yellow fluorescent light having a peak wavelength of about 550 nm when the emission is received. At least a portion of the emission from the LED chip can be transmitted through the phosphor, and at least a portion can be absorbed by the phosphor. The portion of the light transmitted through the phosphor is mixed with the yellow light emitted by the phosphor, and the observer perceives the light emitted mixture as white light. As an alternative to phosphor-converted white light, red, blue, and green (RGB) light-emitting devices can be operated in a combined manner to generate light that is perceived as white. Conventional LEDs, packages, and methods for producing white light can be designed for lower voltage applications.

Regardless of the practicability of the various LEDs and LED packages on the market, improved packages suitable for applications such as them that use higher voltages still need to enhance light output performance, enhance thermal performance, improve device reliability, and facilitate manufacturing sex.

According to the present invention, a novel light-emitting device and method that can be adapted to various applications and power requirements are provided. Therefore, one purpose of the subject matter disclosed herein is to provide a light emitting device and method that includes improved reliability in higher voltage applications.

These and other objects of the present invention that have become apparent from the present invention are achieved at least in whole or in part by the subject matter set forth herein.

In the remainder of this specification (including referring to the accompanying drawings), a full and authorized disclosure of one of the subject matter disclosed herein is more specifically stated, including the best mode known to those who are familiar with the technology.

Reference will now be made in detail to the feasibility aspects or embodiments of the subject matter herein. One or more examples of the feasibility aspects or embodiments are shown in the figures. Each example is provided to illustrate the subject matter and does not serve as a limitation. In fact, features illustrated or described as part of one aspect or embodiment can be used in another embodiment to yield yet another embodiment. The subject matter disclosed and anticipated in this article is intended to cover these modified forms and changes.

As illustrated in the various figures, certain sized structures or parts are exaggerated relative to other structures or parts for illustration purposes, and therefore these certain sized structures or parts are provided to illustrate what is disclosed herein The general structure of the subject matter. In addition, various aspects of the subject matter disclosed herein are described with reference to a structure or a part being formed on other structures, parts, or both. Those familiar with the art will understand that the reference being formed "on" or "above" another structure or part is expected to intervene in additional structures, parts, or both. In the absence of an intervening structure or part, reference to a structure or part being formed "on" another structure or part is described herein as being formed "directly" on the structure or part. Similarly, it will be understood that when an element is referred to as being "connected," "attached," or "coupled" to another element, it can be directly connected, attached or coupled to the other element, or intervening elements may be present. In contrast, when one element is referred to as being "directly connected," "directly attached," or "directly coupled" to another element, there are no intervening elements.

In addition, relative terms such as "upper", "above", "upper", "top", "lower" or "bottom" are used in this text to illustrate one structure or part versus another as illustrated in these figures. A structure or part of the relationship. It will be understood that in addition to the orientations depicted in these figures, relative terms such as "upper", "above", "upper", "top", "lower" or "bottom" are also intended to cover different device orientations. For example, if the devices in these figures are inverted, the structure or part described as being "above" other structures or parts will now be oriented "below" these other structures or parts. Similarly, if the devices in these figures rotate along an axis, the structure or part described as being "above" other structures or parts will now be oriented "closer" or "left" to those other structures or parts. The same numbers refer to the same elements throughout the text.

The light-emitting device according to the embodiments described herein may include a III-V nitride (eg, gallium nitride)-based light-emitting diode (LED) or a laser, such as Durham, fabricated on a silicon carbide substrate. These devices are manufactured and sold by the Cree Company of North Carolina. For example, the silicon carbide (SiC) substrate/layer discussed herein may be a 4H polytype silicon carbide substrate/layer. However, other silicon carbide candidate polytypes, such as 3C, 6H, and 15R polytypes, can also be used. Appropriate SiC substrates are available from NC, Cree, Durham, the assignee of the subject matter of this article, and the methods used to produce these substrates are described in the scientific literature and in a number of joint U.S. patents. Patents include (but are not limited to) U.S. Patent No. 34,861, U.S. Patent No. 4,946,547, and U.S. Patent No. 5,200,022, and the disclosures of these patents are incorporated herein by reference in their entirety.

As used herein, the term "group III nitride" refers to the combination of nitrogen and one or more elements of group III in the periodic table (usually aluminum (Al), gallium (Ga), and indium (In)). Between their semiconductor compounds. The term also refers to divalent, trivalent, and tetravalent compounds, such as GaN, AlGaN, and AlInGaN. These group III elements can be combined with nitrogen to form divalent (e.g., GaN), trivalent (e.g., AlGaN), and tetravalent (e.g., AlInGaN) compounds. These compounds may have an empirical formula in which one mole of nitrogen is combined with a total of one mole of group III elements. Therefore, molecular formulas (such as Al_xGa_1-xN, where 1>x>0) to illustrate these compounds. The epitaxial growth technology for III nitrides has become reasonably well developed, and is reported in appropriate scientific literature and joint US patents. These US patents include US Patent No. 5,210,051 and US Patent No. 5,393,993 No. and U.S. Patent No. 5,523,589, the disclosures of these U.S. patents are hereby incorporated by reference in their entirety.

Although the various embodiments of the LED disclosed herein may include a substrate, those skilled in the art will understand that the crystal epitaxial growth substrate on which the epitaxial layer including an LED is grown can be removed, and the independent epitaxial growth substrates The crystal layer can be mounted on an alternative carrier substrate or base, which can have better thermal, electrical, structural and/or optical properties than the original substrate. The subject matter disclosed herein is not limited to a structure having a crystal epitaxial growth substrate and can be used in combination with a structure in which the epitaxial layer has been removed from its original growth substrate and bonded to a replacement carrier substrate.

For example, according to certain embodiments of the subject matter, a III-nitride-based LED can be fabricated on a growth substrate (such as a silicon carbide substrate) to provide a horizontal device (in which two electrical contacts are located on the LED One on the same side) or a vertical device (where the electrical contacts are on the opposite side of the LED). In addition, the growth substrate can be maintained on the LED after fabrication or removed (for example, by etching, grinding, polishing, etc.). For example, the growth substrate can be removed to reduce the thickness of one of the resulting LEDs and/or reduce the forward voltage across a vertical LED. For example, a horizontal device (with or without a growth substrate) can be flip chip bonded (for example, using solder) to a carrier substrate or printed circuit board or wire bonded to the carrier substrate or printed circuit board. A vertical device (with or without a growth substrate) may have a first terminal solder bonded to a carrier substrate or printed circuit board and a second terminal wire bonded to the carrier substrate or printed circuit board. Examples of the vertical LED chip structure and the horizontal LED chip structure are discussed by way of examples in U.S. Publication No. 2008/0258130 issued to Bergmann et al. and U.S. Patent No. 7,791,061 issued to Edmond et al. The disclosure is hereby incorporated by reference in its entirety.

Referring now to FIGS. 1-12B, FIG. 1 illustrates a top perspective view of an aspect or embodiment of a light-emitting device and package (for example, an LED package, usually designated as 10). The LED package 10 may include a body 12 that defines a reflector cavity 18 and contains one or more LED chips 14 mounted on an upper surface of one or more thermal elements. The LED chip 14 can be directly mounted to a thermal element, or mounted on one or more intervening substrates (not shown) between the one or more LED chips 14 and the thermal element. The LED chip 14 may be thermally connected to the one or more thermal elements. The LED chip 14 may be electrically connected to one or more electrical components. The LED package 10 may further include an electrostatic discharge (ESD) protection device 16 mounted on a top surface of an electrical component. For example, the ESD protection device 16 may include a Zener diode, a ceramic capacitor, a transient voltage suppression (TVS) diode, a chip varistor, a Schottky diode, and/or the technology Any other well-known ESD device. The ESD protection device 16 can be electrically connected to the first and second electrical components through, for example, a conductive wire 20 using wire bonding technology.

Still referring to FIG. 1, the main body 12 may include an upper surface 11, a lower surface 13 and at least one external side wall. The upper face 11 may include a corner notch 23 that can transmit the electrical properties of the package (for example, the side of the body 12 containing the cathode and/or the anode). The lower face may include one or more recesses defined therein, and the one or more recesses are generally designated 80. In one aspect, the main body 12 may include four outer side walls that are 15, 17, 19, and 21, respectively. In other aspects, the main body 12 may only include an outer wall to form a substantially circular main body. The outer walls 15, 17, 19, and 21 may include a substantially similar and/or substantially equal length dimension so that the LED package 10 includes a substantially square occupied area. In other aspects, the length of the one or more outer walls may not be equal so that the main body 12 includes a rectangular footprint and/or any other shape desired by the manufacturer and/or an end user. For example, the main body 12 may include an occupied area of a substantially circular shape, or an occupied area of a regular and/or irregular polygonal shape.

The main body 12 may comprise any suitable material, such as, for example, a material selected from the group consisting of the following components: molded plastic, thermoset plastic, thermoplastic plastic, polymer, ceramic, nylon, liquid crystal polymer (LCP), Reinforced polymers (polymers containing fibers, ceramics or composite materials) and polyphthalamide (PPA), in which the main body 12 can be placed around the thermal and electrical components to retain these components. For example, the main body 12 may be formed around a thermal element including a heat transfer material 32. The main body 12 may be simultaneously formed by winding one or more electrical components including, for example, the first and second electrical lead components 22 and 24, respectively. In one aspect, a molding process may be used to form the main body 12, such as injection molding of a thermoplastic material and/or a thermosetting material that can be electrically insulated. However, any other forming method known in the art can be used, including sintering and/or a combination of molding and sintering. The main body 12 can be white or other colored light to minimize the light absorbed by the LED package 10. In addition, the main body 12 may include an upper main body portion 12A and a lower main body portion 12B, which may be formed in, for example, an upper molded die portion and a lower molded die portion (not shown), respectively. The reflector cavity 18 can be formed, for example, as an inversion of a central protrusion of an upper molded die. One or more isolation parts of the main body can be formed between respective thermal components and electrical components. For example, the first and second isolation portions 26 and 28 may be formed, and the first and second isolation portions 26 and 28 may electrically and/or thermally isolate one or more thermal elements from one or more electrical components. During or after the main body is formed, one or more LED chips 14 may be mounted on the heat transfer material 32 and electrically connected to one or both of the first and second lead components 22 and 24 using wires 20, respectively.

Referring now to FIGS. 2 and 3, a lead frame component is shown, which is generally designated 30. The lead frame element 30 may include at least one thermal element and one or more electrical components. The thermal element may include a heat transfer material 32 or a substrate (such as, for example, a heat sink). The thermal element may be electrically and/or thermally isolated from one or more electrical components. The electrical components may include first and second lead components 22 and 24, respectively. The first and second lead components 22 and 24 can also be collectively referred to as "leads". The thermal element 32 can be optionally arranged between the respective middle ends 38 and 58 of the first and second lead components 22 and 24, respectively. The main body 12 may be molded, disposed or otherwise formed around the lead frame element 30 so that the heat transfer material 32 may be disposed on a bottom surface of one of the reflector cavity 18. The main body 12 may surround at least a portion of the lead frame element 30 so as to retain a portion of the heat transfer material 32 and portions of the first and second lead components 22 and 24, respectively. One or more protrusions 34 of the heat transfer material may be exposed along the outer walls 15 and 19 of the main body 12 to help retain the heat transfer material 32.

One or more lead frame components 30 may initially include a component sheet (not shown). The lead frame element 30 can be formed from and/or from the sheet using any suitable method (e.g., stamping, cutting, and/or bending one or more parts of the sheet and/or the lead frame element 30 in the sheet) Single grain. The main body 12 of the LED package 10 can be formed around at least a part of the lead frame element 30 and a plurality of LED package sub-assemblies can be formed around the thin plate of the lead frame element 30. The plurality of LED package sub-assemblies can be separated from the element sheet by cutting, shearing or otherwise separating the termination ends 40 and 60 of the outer walls 15 and 19 and the first and second lead components 22 and 24, respectively Into individual LED packages10. This separation can expose the protrusion 34 of the heat transfer material 32 along the outer walls 15 and 19 of each LED package 10.

Still referring to FIGS. 2 to 3, electrical components are disclosed. The electrical components include first and second lead components 22 and 24 formed by a lead frame element 30. The first and second lead assemblies 22 and 24 can be used to supply the LED chip 14 with a current sufficient to cause light emission to be connected to the anode and the cathode respectively. The first and second lead components 22 and 24 may comprise a metal or any other suitable conductive material known in the art. The first lead assembly 22 may include a respective substrate portion 36, an intermediate end 38, an opposite termination end 40, a tap portion 42, at least one aperture 44, and one or more bends (e.g., 46 and 48, respectively). The first and second bends). The first aperture 44 may form one or more lead sections within the first lead assembly 22. For example, in one aspect, the first lead assembly 22 includes an aperture 44 and two lead sections 50 and 52. The second lead assembly 24 may be adjacent and symmetrical with respect to the first lead assembly 22. In addition, the second lead assembly 24 may include features similar to those of the first electrical lead assembly 22 in both form and function. For example, the second lead assembly 24 may include a respective substrate portion 56, an intermediate end 58, an opposite termination end 60, a tap portion 62, at least one aperture 64, and one or more bends (e.g., respectively The first and second bends of 66 and 68). Each individual lead component 22 and/or 24 may include one or more notches N, and the one or more notches N can be changed to remain in the main body 12 at the outer walls 15 and 19. The one or more notches N can assist in handling and placing the LED package 10. For example, the notch N may be provided in an area where a lead frame having an array of package housings retains the housings in a proper position until the appropriate time when the LED package 10 is singulated. The one or more bends (for example, the respective first and second bends 46, 48, 66, and/or 68) may be defined in the lead assembly 22 and the lead assembly before, during, or preferably after the main body 12 of the LED package 10 is formed. 24 in. With reference to the second lead assembly 24, the second aperture 64 may form one or more lead sections within the second lead assembly 24. For example, in one aspect, the second lead assembly 24 includes an aperture 64 and two lead sections 61 and 63. There may be any number of apertures and/or lead sections in a given electrical lead assembly.

The tap portions 42 and 62 may be opposite to the first and second intermediate ends 38 and 58. After the main body 12 is formed, the first and second tap portions 42 and 62 may respectively extend away from a center of the LED package 10 outward and terminate at respective ends 40 and 60. The apertures 44 and 64 of the respective lead components 22 and 24 can separate the substrate portions 36 and 45 into a plurality of electrical lead sections, such as 50, 52, 61, and 63. In one embodiment, each of the lead components 22 and 24 may include multiple apertures to separate the components into two or more (e.g., three or more) electrical lead sections. The first part of each of the openings 44 and 64 can be filled with the same material that forms the main body 12. A second part of each opening 44 and 64 can be placed outside the outer walls 17 and 21 of the main body 12 so that the individual electrical lead sections 50, 52, 61, and 63 can pass through the holes along the outer walls 17 and 21 of the main body 12 The ports 44 and 64 are separated from the remaining lead sections 50, 52, 61, and 63. Each lead assembly 22 and 24 may include respective first and second bends 46, 48, 66, and 68. The bends 46, 48, 66, and 68 may include first and second bends 47 and 67, respectively. The bent portions 47 and 67 may be perpendicular to each of the respective substrate portions 36 and 56 and the tap portions 42 and 62 of the first and second lead assemblies 22 and 24, respectively. The bent portions 47 and 67 may be disposed between the corresponding base portions 36 and 56 and the tap portions 42 and 62. In addition, the bent portions 47 and 67 may include vertical elements facing downward along the outer walls 17 and 21 of the main body 12. The bent portions 47 and 67 may include transition regions that allow the linear substrate portions 36 and 56 of the first and second lead components 22 and 24 to vertically transition to the respective linear tap portions 42 and 62, respectively. The tap portions 42 and 62 may be parallel to the corresponding base portions 36 and 56 and positioned along a plane different from the corresponding base portions 36 and 56. The bent portions 47 and 67 allow the respective base portions 36 and 56 to transition to the respective tap portions 10 and 62.

One or more apertures (such as apertures 44 and 64) may extend at least partially to the first bends 48 and 68 of the respective lead components. The apertures 44 and 64 can provide a number of benefits, including facilitating the safe retention of the lead assemblies 22 and 24 within the body. In addition, the apertures 44 and 64 can reduce the amount of lead material (e.g., metal) that undergoes bending to form the first bends 46 and 66. This can reduce the cost of the overall package and reduce one of the bending forces required to form the first bends 46 and 66. The bending allows at least a portion of each electrical lead assembly 22 and 24 to be positioned in the first and second tapered portions 25 and 27 of the main body 12 (FIG. 9).

As illustrated in FIG. 3, the heat transfer material 32 may include an upper surface 70, a lower surface 72, and one or more lateral protrusions (for example, the first and second lateral protrusions of 74 and 76, respectively). The heat transfer material 32 may optionally include a lower protrusion 78, and the lower protrusion 78 includes a lower surface 72 extending from a recess 80 disposed in the lower surface 13 of the LED package 10. The lateral protrusions 74 and 76 can promote the main body 12 to safely retain the heat transfer material 32 and can also reduce the possibility of leakage (for example, solder and/or encapsulant) along the interface between the main body 12 and the heat transfer material 32. These lateral protrusions 74, 76 may vary in number, size, shape, and/or orientation (Figures 12A and 12B). The heat transfer material 32 can conduct heat away from the LED chip 14 and the LED package 10 to improve its heat dissipation properties.

Figure 4 illustrates a perspective bottom view of an LED package (usually designated as 10). The bottom view can also show a higher voltage LED package 90 (FIGS. 6-8). The LED package 10 may include a body 12 formed around the lead frame element 30 and the heat transfer material 32. The heat transfer material 32 may extend from a recess 80 formed in the lower surface 13 of the LED package 10. In one aspect, the heat transfer material 32 may include a bottom surface 72 that is flush with the recess 80 of the LED package 10. In other aspects, the heat transfer material 32 may include a lower protrusion 78 extending from the recess 80 of the LED package 10. The lower protrusion 78 can include any height and width dimensions known in the art. The recess 80 may provide a space to allow any of the attachment materials (not shown) such as solder and/or flux to overflow to move into the recess 80. This feature can eliminate or reduce the need to clean residues left behind, for example, after an attachment process using a "no-clean" solder. The recessed portion 80 may also allow more access to the solvent to remove the flux after the reflow process when using, for example, the "cleaning" solder which has to undergo a cleaning process. Due to program variability, the amount of solder and/or flux that can be dispersed for connecting components such as the heat transfer material 32 and an external circuit (not shown) (eg, a printed circuit board (PCB)) can vary significantly. Since it is extremely difficult to remove the solder and/or flux from the substrate (such as PCB), the recess 80 provides a space for any excess solder and/or flux to flow into and produce (one or more) A) area. One or more exposed portions of the heat transfer material 32 (FIG. 10) may also be located or otherwise located in the recess 80.

4, the first and second tap portions 42 and 62 of the respective first and second lead components 22 and 24 may extend outward from approximately a central portion of the LED package 10 and bend outside to include substantially Horizontal components. In an alternative, the tap portions 42 and 62 may extend from the LED package 10 and bend inwardly toward each other. Therefore, the tap portions 42 and 62 may include a "J-bend" and/or "gull wing" type orientation, which is well known in the art. The tap portions 42 and 62 may be substantially flush with the lower surface 13 of the LED package. The tap portions 42 and 62 can be electrically connected to an external circuit and a heat sink (not shown) (for example, a PCB) using any desired attachment method and material, and mounted on the external circuit and the heat sink. For example, standard soldering techniques can connect the tap portions 42 and 62 and the heat transfer element 32 to an external circuit or substrate, where solder can wet the bottom surface of each component. The heat transfer material 32 may be thermally connected to a heat sink and/or an external circuit and installed above the heat sink and/or the external circuit. These attachment methods may further include, for example, soldering the LED package 10 and the PCB in a reflow oven or placing the LED package 10 and the PCB on a hot plate. Any suitable solder material that is desired and capable of fastening the thermal and electrical components (ie, the heat transfer material 32 and the taps 42 and 62 of the respective lead components 22 and 24) to the PCB can be used. For example, the attachment material may include solder paste of gold, tin, silver, lead, and/or copper (Au, Sn, Ag, Pb, and/or Cu), reflow solder flux, and/or any combination thereof. For example, Sn 96.5/Ag 3.0/Cu 0.5 is a common Pb-free solder like Sn 95.5/Ag 3.8/Cu 0.7.

The heat transfer material 32 as illustrated in FIG. 4 may comprise a single component as a whole or it may comprise several components assembled together using any assembly procedure as desired and/or well known in the art. For example, the lower protrusion 78 may be formed as a whole as a piece of heat transfer material 32 or may be assembled to the heat transfer material 32 such that it extends from a base portion of the heat transfer material 32. In one aspect, the heat transfer material 32 may include an intermediate heat structure for transferring heat to another structure (such as a heat transfer layer or a heat sink) for further heat dissipation. In this aspect, the heat transfer material 32 may include a thermal structure that has limited thermal capacity and can heat up fairly quickly without being thermally connected to another heat transfer device (such as an actual heat sink).

FIGS. 5 to 8 illustrate top views of LED packages (usually designated 10 and 90) that include variable configurations of LED chips 14. As shown in FIG. One or more LED chips 14 may be arranged above the thermal element (for example, the heat transfer material 32), and the arrangement may vary depending on the application. Figure 5 illustrates one or more LED chips 14 positioned to be in electrical communication with each of the first and second lead assemblies 22 and 24, respectively. The LED chip 14 can be electrically connected to the first and second lead components 22 and 24 using the wires 20 so that a first portion 82A of the LED chip 14 is electrically connected to the first electrical lead component 22 and a second portion 82B of the LED chip is electrically connected To the second electrical lead assembly 24. The first part 82A and the second part 82B of the LED chip 14 may include different electrical polarities, that is, one of the first and second parts 82A and 82B respectively serves as an anode and the remaining part serves as a cathode so that it can be driven Electric current passes through each LED chip 14 to generate light. As illustrated in FIG. 5, connecting one of the plurality of chips or each of the plurality of LED chips 14 to each of the first and second lead assemblies 22 and 24 includes a first configuration or electrical assembly state. In this electrical configuration, each LED chip 14 can be configured in parallel with the remaining LED chips 14 of the plurality. That is, each LED chip 14 can receive less than or about the same voltage from a power source, so that a lower voltage power source can be used. When configured in parallel, the LED chip 14 can also be mounted on the heat transfer material 32. In one aspect, the LED chip can be directly mounted to the heat transfer material 32. In an alternative solution, the LED chip 14 may be mounted to one or more intervening substrates (not shown) disposed between the LED chip 14 and the heat transfer material 32.

The LED configuration illustrated and illustrated in Figure 5 allows a package to be operated with a power supply including, for example, approximately 3.2 volts (V). In some applications, it may be desirable for the LED package to operate at a lower voltage of less than about 3.2 V (for example, about 1.5 V to 2 V or about 2 V to 3.2 V). In other applications, the LED package may be expected to operate at a higher voltage. Figures 6 to 8 illustrate examples (not limiting) of LED packages (usually designated as 90) operable for applications with voltages greater than approximately 3.2 V. For example, in one aspect, the LED package 90 can operate in a range of approximately 3.2 V to 5 V. In other aspects, the LED package 90 can operate in a range of 5 V to 10 V. In other aspects, the LED package 90 can operate in a range of approximately 10 V to 20 V. In a further aspect, the LED package 90 can be operated at a voltage greater than 20V. The LED package 90 can include a variable configuration of the LED chip 14 in the package, and has the remaining features of the LED package 90 having similar forms and functions as described with respect to the LED package 10. For example, the LED package 90 may include a molded body 12 around the lead frame element 30 (FIGS. 1 to 4). The lead frame includes a heat transfer material 32 and the first and second lead components 22, which are 22 and 24, respectively. And 24.

6 to 8 illustrate higher voltage packages, such as LED package 90. According to the subject matter herein, a higher voltage package can be partially realized by changing the configuration or electrical configuration of the LED chip 14 in the package. For example, FIGS. 6 to 8 illustrate an LED package 90 that includes one or more LED chips 14 electrically connected in series with at least one other LED chip 14. The LED package 90 may include a first lead component 22 and a second lead component 24. One of the first and second lead components 22 and 24 respectively can be operated as a cathode and the remainder can be used as an anode for supplying current to one or more LED chips 14. The first and second lead components 22 and 24, respectively, may protrude and/or extend outward from the main body (for example, from a lateral side of the LED package 90 and/or a bottom surface). The lead components 22 and 24 can be bent externally to form bent portions 47 and 67 that can extend downward and parallel to the outer sides 17 and 21. The LED package 90 may include first and second lead components 22 and 24. The first and second lead components 22 and 24 extend from a central portion of the main body and are bent externally to form linear, outwardly extending first and The second tap portion 42 and 62. The one or more LED chips 14 can be electrically connected to the first and/or second lead components 22 and 24 by using one or more conductive wires 20. The first and second lead components 22 and 24 can also be electrically isolated and/or thermally isolated from a heat transfer material 32, and one or more LED chips 14 can be directly or indirectly mounted on the heat transfer material 32. One or more isolation portions 26 and 28 of the LED package 90 can thermally and/or electrically isolate the heat transfer material 32 from the first and second lead components 22 and 24, respectively.

FIGS. 6 to 8 illustrate an LED chip 14 including a variable configuration and an electrical configuration in the LED package 90. That is, one or more LED chips 14 may be connected to the first and second lead components 22 and 24 in series, in parallel, and/or in a combination thereof. This can be achieved using a wire bonding process in which one or more LED chips 14 can be electrically connected to another LED chip 14 in series using one or more wires 20. The first and last LED chips 14 in a given series can then be connected to the first and second lead assemblies 22 and 24 using wires 20 for driving current through the LED chips 14. When the LED chips 14 are connected in series, the voltage from a power source can be divided among the LED chips 14 or spread in other ways. That is, a higher power source can be used with LEDs, LED packages and methods because the voltage can be divided across the series sequence of one or more LED chips 14. The higher voltage generated by the power source may include a series of respective lower voltages across each individual LED chip 14. As previously disclosed, the power supply voltage can operate in a range of 5 V to 20 V for certain applications, and it can be expected to operate at greater than 20 V in other applications.

FIG. 6 illustrates one configuration of the LED chip 14, which is generally designated 92. Configuration 92 includes three LED chips 14 configured in an electrical configuration. Here, the LED chip 14 is illustrated as being electrically connected in a series configuration. The first LED chip 14 in the series sequence can be connected to the first lead assembly 22 and the last LED chip in the series sequence can be connected to the second lead assembly 24. This is similar to an alternative configuration (usually designated 94) illustrated in FIG. 7 of the LED chip 14 in the LED package 90. Configuration 94 includes six LED chips in LED package 90 that are electrically connected in a series configuration. The first LED chip 14 in the series sequence can be electrically connected to the first lead assembly 22, and the last LED chip 14 in the series sequence including the configuration 94 can be electrically connected to the second lead assembly 24. The respective first and last LED chips 14 in a series sequence are connected to the lead assembly so that current can be supplied to the entire series sequence of LED chips 14. The configurations 92 and 94 illustrated herein may include any number or type of LED chips 14. In general, the series configuration can be more efficient when using the same type of LED chips 14 so that the voltage is distributed or otherwise spread across each chip in the series sequence consistently and evenly.

FIG. 8 illustrates a configuration that includes LED chips 14 installed in a combination of both a series electrical configuration and a parallel electrical configuration. For example, FIG. 8 illustrates a configuration generally designated as one of 96. The configuration 96 may include, for example, two groups of three LED chips 14, wherein at least one LED chip 14 constituting each group can be electrically connected in series to at least one other LED chip 14 in the respective group. The first group of LED chips, usually designated as 98A, can then be electrically connected in parallel with the second group of LED chips, usually designated as 98B. Each of the first and second groups 98A and 98B may respectively include one or more LED chips 14 electrically connected in series, and the first and last LED chips 14 of each of the respective series sequence may be Connected to the first and second lead components 22 and 24, respectively. Therefore, configuration 96 utilizes an electrical configuration including each of a series configuration and a parallel configuration, where each of the first and second groups 98A and 98B includes one or more LEDs connected in series The chip 14 and the first group 98A can be connected in parallel to the second group 98B. Note that the configurations 92, 94, and 96 shown in FIGS. 6 to 8 may include any number of chips mounted in a series, and are not limited to the configurations shown. Configuration 96 can also include any number of groups connected in parallel. When wire-connected in series, attention should be paid to ensure that the appropriate LED terminals of the respective LED chips 14 are wire-bonded to electrically connect the chips. As shown earlier, the LED chip 14 may include a first portion 82A and a second portion 82B, and these portions include different electrical polarities. That is, the first portion 82A may include a negative terminal and the second portion 82B may include a positive terminal or vice versa. When connecting LED chips in series, the first part 82A of a previous LED chip 14 should preferably become wire bonded and electrically connected to the second part 82B of a subsequent LED chip 14. Otherwise, the LED chip 14 may not illuminate because the current may be insufficiently supplied to the series sequence. As previously disclosed, the configuration 96 may include any number of groups and is not limited to the first and second groups 98A and 98B as shown. The combination of LED chips mounted in series and in parallel can be adjusted for a given application and/or desired voltage source. Therefore, the LED chips 14 can be advantageously connected in parallel, in series, or a combination thereof to adapt to various voltage applications.

Still referring to FIGS. 6 to 8, for illustration purposes and without limitation, the LED chip 14 is illustrated as a series configuration in series alignment or a zigzag configuration, but any of the LED chips can be used. A suitable alignment or configuration. For example and without limitation, the LED chips 14 can be arranged in parallel and/or vertically in series into a grid or an array or even a combination thereof. Moreover, with regard to different applications using LED packages, and generally speaking, objects connected in parallel can drain a power supply faster than objects connected in series, because the objects connected in parallel can draw more current from the power supply as a result. It can also be helpful when all the LED chips in use have the same power specifications.

Figure 9 illustrates a side view of an LED package generally designated 90. FIG. 9 can also illustrate the LED package 10 because each of the LED packages 10 and 90 can include similar features of similar form and function except for one of the configurations of the LED chips 14 in the packages. FIG. 9 illustrates a main body 12 that includes an upper body portion 12A and a lower body portion 12B that can be formed in, for example, an upper molded die portion and a lower molded die portion (not shown), respectively. One or more tapered portions (such as the first and second tapered portions 25 and 27) may be defined by the outer side walls 17 and 21 of the main body 12 and may be adjacent (for example, below) the first and second lead components 22 And 24 extend through the positions of the outer side walls 17 and 21. These first and second tapered portions 25, 27 may be configured to receive at least a portion of the thickness of the curved portions 47, 67 or the curved portions 47, 67 of the first and second lead components 22 and 24. Each of the first and second tapered portions 25 and 27 may include a depth with respect to the corresponding outer side walls 17 and 21. The depth of each of the first and second tapered portions 25 and 27 may preferably include a depth substantially equal to or greater than the average thickness of the first and second electrical lead components 22 and 24, respectively. The first and second tapered portions 25 and 27 can provide multiple benefits. For example, the first and second tapered portions 25 and 27 can substantially eliminate the presence of one of the materials placed directly under the first bends 46 and 66, thereby reducing the application of the first bend 46 and 66 to the main body 12 One amount of the stress can form the first bends 46 and 66 after the lead frame element 30 is retained in the main body 12. Another benefit of the first and second tapered portions 25 and 27 is that each of the first bends 46 and 66 has a tighter bend radius. This can reduce or eliminate the outward extension of the bent portions 47 and 67. The bent portions 47 and 67 can be substantially parallel to the outer walls 17 and 21 and at least substantially perpendicular to the lower surface 13 and the first and second lead components 22 and 24 Thus, the effective area occupied by the LED package 10 is reduced. The reduction in the effective footprint of the LED packages can enable these packages 10 to be mounted on an outer substrate (not shown) at a higher density, and/or depending on the situation with a Lambertian reflector or diffuser with a reduced hole pitch. The device (e.g., within a backlit display device (such as an LCD display)) overlaps. Therefore, the tapered portions 25 and 27 can enable LED packages (such as 10 and 90) to exhibit enhanced light efficiency by achieving higher flux density and/or greater light emission uniformity.

FIG. 10 illustrates a cross-sectional view of the LED package 90. The reflector cavity 18 can be filled, coated or otherwise covered with an encapsulant E. The encapsulant E may include any suitable material well known in the art and optionally includes a phosphor or a phosphor to interact with the light emitted by one or more LED chips 14 and in response to emit a desired wavelength The light of the spectrum. For illustration purposes, the encapsulant E is shown as being positioned and filling the reflector cavity 18 to be substantially flush with one of the upper faces 11 of the main body 12. However, the encapsulant E can be filled to any suitable level in the reflector cavity 18 or even extend beyond and extend above the reflector cavity 18.

FIG. 10 illustrates one or more exposed portions of the heat transfer material 14. For example, the heat transfer material 32 may include exposed portions 73, 75, 77, 72, 81, 83, and 85 that protrude from the recessed portion generally designated 80 of the LED package 90 and are disposed therein. Each of the exposed portions 73, 75, 77, 72, 81, 83, and 85 may include an outer surface of the heat transfer material 32. The heat transfer material 32 may be formed as a whole or consist of more than one part (such as FIGS. 3 and The protruding part 78) illustrated in 4 is formed. FIG. 10 also illustrates the heat transfer material 32 that extends the full thickness of the lower portion 12B of the main body 12. The first and second lead components 22 and 24 respectively lean on the lower part 12B of the main body 12 and can be disposed between the respective upper part 12A and the lower part 12B of the main body 12. As illustrated in FIGS. 3 and 4, the first and second lead components 22 and 24 may include substrates 36 , 56. The substrates 36 , 56 may be located on a horizontal plane above the respective tap portions 42 and 62 and are opposite to The bent portions 47 and 77 are arranged vertically.

11A and 11B illustrate simplified schematic cross-sectional views of the main body 12 that can form the LED package 10 and/or 90. The LED package may include a reflector cavity 18 bounded by a bottom surface F. The bottom surface F may include portions of the first and second lead components 22 and 24, the isolation portions 26 and 28, and the top surface 70 of the heat transfer material 32. The reflector cavity 18 may be bounded by the outer side walls 15, 17, 19, and 21 along the edges. The reflector cavity 18 may include any shape. For example, the reflector cavity 18 may include a circular wall defining a circular reflector cavity 18 or the reflector cavity 18 may include defining a substantially square reflector cavity 18 wall. The reflector cavity 18 may include any size and/or shape well known in the art. The reflector cavity 18 may include one or more portions that may transition from the inclined portion and/or its wall perpendicular to the substantially vertical portion of the outer walls 15, 17, 19, and 21. For example, the reflector cavity 18 may include a first portion having an angle θ with respect to a plane perpendicular to the bottom surface F. Similarly, and possibly in the same package, the reflector cavity 18 may include an angle φ with respect to a plane perpendicular to the bottom surface F. In one aspect, the reflector cavity 18 includes an inclination angle θ of at least about 20 degrees. In another aspect, the angle θ may include at least about 30 degrees. In a further aspect, the angle θ may include at least about 40 degrees. The inclination angle θ may also include at least about 45 degrees, or at least about 50 degrees.

Referring to FIG. 11B, the reflector cavity may include a tilt at an angle φ of at least about 30 degrees, at least about 40 degrees, or at least about 50 degrees. In a further embodiment, the angle φ may comprise about 55 degrees, or at least about 60 degrees. These equal angles θ and φ can be larger than those generally used in conventional LED packages. Although the reflector cavity 18 described herein may include vertical walls angled from the bottom surface of the cavity to the upper edge of the package, alternative embodiments may include partitioned and/or curved cross-sections, that is, extending from the bottom surface F The wall to the upper edge of the package may include a non-linear profile along at least a portion thereof. If these walls are curved or partitioned, the above-mentioned inclination angle may correspond to an average angle of a curved or partitioned wall, or an angle between the end points of this wall. The reflector cavity 18 containing alternating angles allows a front area of the reflector cavity 18 to be maximized relative to the upper surface 11 of the square shape, while desirably providing diffuse reflection output beam characteristics, especially when multiple LEDs are arranged in the reflector cavity Within 18.

12A and 12B, an alternative embodiment of the heat transfer material 32 is illustrated. The heat transfer material 32 may include an upper surface 70, a lower surface 72, a lower protrusion 78, and lateral protrusions 74 and 76 that protrude outward from the lateral sidewalls of the material. Figure 12A reveals the lateral protrusions 74 and 76 that can be nonlinear and curved upwards. Figure 12B illustrates an alternative embodiment in which the heat transfer material 32 includes upwardly angled or otherwise tapered lateral protrusions 74 and 76, the lateral protrusions 74 and 76 facing outward from the side walls of the heat transfer material 32 and Extend upward. The lateral protrusions 74 and 76 may include any desired size, shape, and/or configuration. For example, downwardly curved and/or angled lateral protrusions can be used. Likewise, any combination of the aforementioned lateral protrusions can be used. Any suitable manufacturing method known in the art can be used to form the lateral protrusions. For example, stamping, forging, extrusion, milling, and/or machining may be used to form the lateral protrusions 74 and 76. In some cases, recesses (not shown) in the outer side wall of the heat transfer material 32 can be used to replace or supplement the lateral protrusions 74 and 76 to provide a similar sealing effect, which can be formed using similar methods as outlined above. And other recesses. The heat transfer material 72 can include a surface, one or more LED chips 14 can be mounted on the surface and one of the reflector cavities 18 can be placed around the LED chip 14.

The embodiments of the present invention shown in the drawings and described above are examples of many embodiments that may fall within the scope of the appended patent application. The configurations of LED devices, methods, and packages capable of achieving higher voltage applications can be expected to include many configurations other than those specifically disclosed.

<p>10. . . LED package</p><p>11. . . Upper face</p><p>12. . . main body</p><p>12A. . . Upper body part</p><p>12B. . . Lower body part</p><p>13. . . Lower face</p><p>14. . . LED chip</p><p>15. . . Outer wall</p><p>16. . . Electrostatic discharge (ESD) protection device</p><p>17. . . Outer wall</p><p>18. . . Reflector cavity</p><p>19. . . Outer wall</p><p>20. . . Conductive thread</p><p>twenty one. . . Outer wall</p><p>twenty two. . . First electrical lead assembly</p><p>twenty three. . . Corner notch</p><p>twenty four. . . Second electrical lead assembly</p><p>25. . . First tapered part</p><p>26. . . The first isolation part</p><p>27. . . Second tapered part</p><p>28. . . The second isolation part</p><p>30. . . Lead frame components</p><p>32. . . Heat transfer material</p><p>34. . . Projection</p><p>36. . . Substrate part</p><p>38. . . Middle end</p><p>40. . . Relative termination</p><p>42. . . Tap section</p><p>44. . . Orifice</p><p>46. . . First bend</p><p>47. . . First bend</p><p>48. . . Second bend</p><p>50. . . Electric lead section</p><p>52. . . Electric lead section</p><p>56. . . Substrate part</p><p>58. . . Middle end</p><p>60. . . Terminating end</p><p>61. . . Electric lead section</p><p>62. . . Tap section</p><p>63. . . Electric lead section</p><p>64. . . Orifice</p><p>66. . . First bend</p><p>67. . . Second bend</p><p>68. . . Second bend</p><p>70. . . Upper surface</p><p>72. . . Lower surface</p><p>73. . . Exposed part</p><p>74. . . First lateral protrusion</p><p>75. . . Exposed part</p><p>76. . . Second lateral protrusion</p><p>77. . . Exposed part</p><p>78. . . Projection</p><p>80. . . Recess</p><p>81. . . Exposed part</p><p>82A. . . first part</p><p>82B. . . the second part</p><p>83. . . Exposed part</p><p>85. . . Exposed part</p><p>90. . . LED package</p><p>92. . . Configuration</p><p>94. . . Configuration</p><p>96. . . Configuration</p><p>98A. . . First LED chip group</p><p>98B. . . Second LED chip group</p><p>E. . . Encapsulant</p><p>F. . . Underside</p><p>N. . . Notch</p>

Figure 1 illustrates a perspective top view of a light emitting diode (LED) package and an LED according to one aspect of the subject matter of this article;

Figure 2 illustrates a perspective view of the components of the LED package according to one aspect of the subject matter of this article;

Figure 3 illustrates an end view of the LED assembly shown in Figure 2;

Figure 4 illustrates a perspective bottom view of an LED package according to one aspect of the subject matter of this article;

Figure 5 illustrates a top plan view of the LED package shown in Figure 1;

Figure 6 illustrates a top plan view of an LED according to one aspect of the subject matter of this article;

Figure 7 illustrates a top plan view of an LED according to one aspect of the subject matter of this article;

Figure 8 illustrates a top plan view of an LED according to one aspect of the subject matter of this article;

Figure 9 illustrates a side view of an LED package according to one aspect of the subject matter of this article;

Figure 10 illustrates a cross-sectional view of an LED package according to one aspect of the subject matter of this article;

11A and 11B illustrate an LED package according to one aspect of the subject matter herein; and

Figures 12A and 12B illustrate an LED package according to one aspect of the subject matter herein.