The subject matter herein relates generally to solid state lighting, and more particularly, to connectors for lighting assemblies.
Solid-state light lighting systems use solid state light sources, such as light emitting diodes (LEDs), and are being used to replace other lighting systems that use other types of light sources, such as incandescent or fluorescent lamps. The solid-state light sources offer advantages over the lamps, such as rapid turn-on, rapid cycling (on-off-on) times, long useful life span, low power consumption, narrow emitted light bandwidths that eliminate the need for color filters to provide desired colors, and so on. LED lighting systems typically include LED packages that have a substrate with power leads on the substrate connected to an LED chip. A lens surrounds the LED chip, and light is emitted by the LED through the lens.
The LED packages typically have power leads that are soldered to pads on a printed circuit board (PCB) to make an electrical and mechanical connection to the PCB. The power leads are arranged on the bottom of the substrate of the LED packages for such connections. Some known lighting systems use sockets to hold the LED packages, where the sockets have power contacts that contact corresponding power leads on the LED package. The power leads are typically on the sides of the substrate of the LED package for such connections. Because of the heat generated by LED packages, it is desirable to use a heat sink to dissipate heat from the LED packages. Heretofore, LED manufacturers have had problems designing a thermal interface that efficiently dissipates heat from the LED package because the power leads are arranged along the bottom and/or the sides of the substrate. Some LED manufacturers are creating LED packages that have power leads on the top of the substrate, to allow the thermal interface to be positioned along the bottom and/or sides of the substrate. However, as the size of LED packages decreases, problems arise with being able to connect the power leads to power conductors. Known LED packages of such configurations have had wires soldered to the power leads. Such connections are difficult, time consuming, and are not well adapted for automation.
Additionally, some known LED packages are integrating multiple LED chips, such as for multiple color effects. Each LED chip needs separate power leads. As such, the power leads are made smaller, so as to fit many power leads on the top of the substrate. Terminating power conductors to such leads by way of soldering is very difficult and uneconomical.
A need remains for lighting systems that can be powered efficiently. A need remains for lighting systems with LED packages that have adequate thermal dissipation. A need remains for lighting systems with LED packages that are assembled in an efficient and cost-effective manner.
In one embodiment, a lighting assembly is provided for a light emitting diode (LED) package having an LED chip on the top of a mounting substrate with power leads on the top of the mounting substrate arranged proximate to a first edge of the mounting substrate. The mounting substrate is mounted to a base. The lighting assembly includes power contacts defining separable interfaces for contacting the power leads on the mating substrate of the LED package and supplying power to the LED chip. The power contacts have compliant beams extending to the separable interfaces that are deflected when contacting the power leads such that the power contacts are biased against the power leads. The power contacts are terminated to corresponding power conductors opposite the separable interfaces. The lighting assembly also includes a dielectric housing holding the power contacts, with the housing having mounting features for securing the housing to the base independent of the LED package.
In another embodiment, a lighting assembly is provided for a LED package having an LED chip on the top of a mounting substrate with power leads on the top of the mounting substrate arranged proximate to a first edge of the mounting substrate, which is mounted to a base. The lighting assembly includes power contacts each having a first mating portion and a second mating portion. The first mating portion defining a separable interface for contacting a corresponding power lead on the mating substrate of the LED package and supplying power to the LED chip. The second mating portion is terminated to a corresponding power conductor opposite the separable interface. A dielectric housing holds the power contacts and includes an upper portion holding the first mating portions of the power contacts and a lower portion holding the second mating portions of the power contacts. The upper portion is secured to the base adjacent the LED package, and the lower portion extends from the upper portion through an opening in the base. The lower portion has a port being configured to receive the power conductors for mating with the second mating portions of the power contacts.
In a further embodiment, a lighting assembly is provided for a light emitting diode (LED) package having an LED chip on the top of a mounting substrate with power leads on the top of the mounting substrate arranged proximate to a first edge of the mounting substrate, which is mounted to a base. The lighting assembly includes power contacts each having a first mating portion and a second mating portion. The first mating portions define separable interfaces for contacting corresponding power leads on the mating substrate of the LED package and supplying power to the LED chip. The first mating portions have compliant beams extending to the separable interfaces that are deflected when contacting the power leads such that the power contacts are biased against the power leads. The second mating portions have insulation displacement contacts (IDCs) for terminating to corresponding power conductors of power supply wires. A dielectric housing holds the power contacts and has mounting features for securing the housing to the base independent of the LED package.
The lighting ballast 102 includes power conductors 106 at an end thereof that is configured to receive power from a power supply. The lighting ballast includes a frame 108 configured to hold the power conductors 106 and the lighting assembly 104. The power conductors 106 are electrically coupled to the lighting assembly 104 to supply power to the lighting assembly 104. The lighting ballast 102 includes a recess 110 that receives the lighting assembly 104. Optionally, the lighting ballast 102 may include a lens (not shown) attached to the top of the frame 108 that covers the lighting assembly 104. The light is directed through the lens.
The lighting assembly 104 includes a base 112, a light emitting diode (LED) package 114 mounted to the base 112, and a power connector 116 mounted to the base 112, and a power supply connector 118 coupled to the power connector 116. The power supply connector 118 receives power from a power supply, such as from the power conductors 106. The power supply connector 118 supplies power to the power connector 116. The power connector 116 supplies power to the LED package 114.
The base 112 includes a top surface 120 and a bottom surface 122. The LED package 114 and the power connector 116 are mounted to the top surface 120. In an exemplary embodiment, the LED package 114 is secured to the base 112 separate from the power connector 116. For example, the LED package 114 may be soldered to the base 112. The power connector 116 is coupled to the LED package 114 after the LED package 114 is mounted to the base 112 in a separate assembly step. The power connector 116 makes contact with the LED package 114 at a separable interface.
Optionally, the base 112 may represent a heat sink. The LED package 114 and/or the power connector 116 may be in thermal contact with the base 112 such that the base 112 may dissipate heat from the LED package 114 and/or the power connector 116. Optionally, the base 112 may be a printed circuit board (PCB). The PCB may include a heat sink therein, such as one or more layers defining a heat sink to dissipate heat from the LED package 114 and/or the power connector 116.
Power leads 132 are also provided on the top 126 of the mounting substrate 124 and electrically connected to corresponding LED chips 130. The power leads 132 may be pads and/or conductive traces extending on one or more layers of the mounting substrate 124. In the illustrated embodiment, three LED chips 130 are provided, with each LED chip 130 corresponding to a different color (e.g. red, green, blue, and the like). Two power leads 132 are provided for each LED chip 130, representing an anode power contact 134 and a cathode power contact 135, resulting in a total of six power leads 132 on the top 126. It is realized that any number of LED chips 130 and corresponding power leads 132 may be provided in alternative embodiments. When the power leads 132 are powered, the LED chips 130 are activated, causing the LED package 114 to emit light. Different combinations of LED chips 130 may be powered to have different lighting effects.
In the illustrated embodiment, the power leads 132 are arranged only on the top 126, and are not provided on the bottom 128 or any of the edges 136. The power leads 132 are arranged proximate to one edge 136 of the mounting substrate 124 in a row, however other arrangements are possible in alternative embodiments. Because no power leads 132 are arranged on the edges 136, the mounting substrate 124 may be relatively thin, reducing the profile and/or allowing the LED chips 130 to be relatively close to the bottom 128. Because no power leads 132 are arranged on the bottom 128, the entire, or substantially the entire, bottom 128 may include a thermal component 138 therein.
The thermal component 138 may be a thermal layer, a thermal grease, a thermal epoxy, a thermal pad, solder paste, or another type of thermal component. When the LED package 114 is mounted to the base 112 (shown in
The housing 142 includes mounting features 148 for securing the housing 142 to the base 112 independent of the LED package 114. In the illustrated embodiment, the mounting features 148 are represented by ears that have openings that receive fasteners 150. Other types of mounting features 148 may be used in alternative embodiments, such as pegs, latches, solder pads, and the like.
The housing 142 includes an upper portion 152 holding a first mating portion 154 (portions shown in phantom in
In an exemplary embodiment, the housing 142 includes punch-out windows 164. The punch-out windows 164 are configured to receive a tool (not shown) that removes portions of the power contacts 140. For example, in an exemplary embodiment, the power contacts 140 are stamped and formed as part of a lead frame, wherein each of the power contacts 140 are integrally formed from a common sheet of metal material. The power contacts 140 remain attached to one another during manufacture of the housing 142. For example, the housing 142 may be overmolded over the power contacts 140. By having the power contacts 140 connected to one another during the overmolding process, the relative positions of the power contacts 140 with respect to one another and with respect to the housing 142 may be accurately maintained. After the housing 142 is formed, the power contacts 140 need to be separated from one another to define discrete power contacts 140. The tool is inserted into the punch-out windows 164 and the connecting pieces that connect the power contacts 140 is removed, thus isolating the power contacts 140 from one another.
The lower portion 156 of the housing 142 includes a port 172 open at a bottom 174 of the housing 142. The second mating portions 158 are exposed within the port 172 and include mating interfaces 176 that are configured to mate with corresponding power conductors 178 of the power supply connector 118 (both shown in
The power contacts 140 have first mating ends 182 and second mating ends 184. Optionally, the first mating ends 182 may be clustered together in more than one group. The first mating ends 182 within each group are separated by a first pitch 186 for contacting the power leads 132. The second mating ends 184 may be arranged in a different pattern than the first mating ends 182. For example, the second mating portions 158 may be parallel to one another and equally spaced apart by a second pitch 188 different from the first pitch 186. The second mating portions 158 may be sized differently than the first mating portions 152. The first mating ends 182 may include a protrusion or button that is curved to define a point of contact with the corresponding power lead 132.
The housing 242 is sized and shaped differently than the housing 142 (shown in
The housing 342 includes a mating tongue 352 along an outer surface thereof. The power contacts 340 are exposed on a surface 354 of the mating tongue 352. The power contacts 340 extend between a first mating portion 356 and a second mating portion 358. The first mating portion 356 has a first mating end 360 defining the separable interface 344, and is configured to engage the power leads 132. The second mating portion 358 has a second mating end 362 at the opposite end of the power contact 340. The second mating portions 358 are exposed on the surface 354 of the mating tongue 352. The mating tongue 352 is configured to be coupled to a power supply connector 364, represented by a card edge connector. The power supply connector 364 has mating contacts 366 defining the power conductors. The power contacts 340 are configured to engage corresponding mating contacts 366 when the card edge connector is mated to the mating tongue 352.
The power connector 416 represents a jumper connector having power contacts 440 held within a dielectric housing 442. In an exemplary embodiment, the housing 442 includes channels 444 formed therein that receive the power contacts 440 therein. Each power contact 440 has a first separable interface 446 at a first mating end 448 thereof and a second separable interface 450 at a second mating end 452 thereof. The first separable interface 446 is positioned for contacting the power leads 132 on the mating substrate 124 of the LED package 114. The second separable interface 446 is positioned for contacting a power conductor 454 on the base 456. The base 456 differs from the base 112 (shown in
The housing 442 includes a bottom 462 that rests upon the base 456. Locating posts 464 extend from the bottom 462 and are received in corresponding openings 466 in the base 456 for locating the power connector 416 relative to the LED package 114. Optionally, the locating posts 464 may be of different sizes to orient the housing 442 with respect to the base 456 and LED package 114. The openings 466 in the base 456 may also be of different sizes to receive the corresponding locating posts 464. The separable interfaces 446, 450 are exposed at the bottom 462 for engaging the power leads 132 and power conductors 454, respectively.
Each power contact 540 has a first separable interface 548 and an insulation displacement contact (IDC) 550 at the opposite end thereof. The first separable interface 548 is positioned for contacting the power leads 132 on the mating substrate 124 of the LED package 114. The IDC 550 is positioned for contacting the power conductor 546. For example, the power supply wires are loaded into the wire slots 544 and terminated to the IDCs 550. The wire slots 544 include clips 552 that hold the power supply wires in the wire slots 544. The housing 542 includes mounting features 558 for securing the housing 542 to the base 112 independent of the LED package 114.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.