TW201311053A - Solid state light emitting device and method of forming same - Google Patents

Abstract

A solid state light emitting device is disclosed that can include a substrate having one of first and second opposing surfaces, wherein at least one of the opposing surfaces is configured to mount a device thereon. A series of on-board wafer light emitting diode (LED) groups can be located on the first surface of the substrate and coupled in series with one another. An ac voltage source input from outside the solid state lighting device can be coupled to the first surface or the second surface of the substrate.

Description

Solid state light emitting device and method of forming same

The subject matter of the present invention relates to light-emitting devices and methods, and more particularly to solid state light-emitting devices and methods of formation.

The present application claims priority to U.S. Provisional Patent Application Serial No. 61/581,923, filed on Dec. Priority is also relevant to these US applications: The title of the application filed on July 28, 2011 is "Solid State Lighting Apparatus and Methods Using Integrated Driver Circuitry" (Agency File: 5308-1364). US Application No. 192,755, filed on September 16, 2011, titled "State Lighting Apparatus And Methods Using Energy Storage" (Attorney's Profile: 5308-1459), US Application No. 13/235,103 and 2011 The US application filed on September 16, the title of "Solid State Lighting Apparatus And Methods Using Current Diversion Controlled By Lighting Device Bias States" (Attorney's Profile: 5308-1461), serial number 13/235,127, hereby The disclosures of these U.S. applications are incorporated herein by reference in their entirety.

Solid state light emitting arrays are used in several lighting applications. For example, solid state light emitting panels comprising arrays of solid state light emitting devices have been used, for example, as direct light sources in architectural and/or reinforced illumination. A solid state light emitting device can comprise, for example, one of a packaged one or more light emitting diodes (LEDs) Optical devices, such light emitting diodes may comprise inorganic LEDs (which may comprise a semiconductor layer forming a p-n junction) and/or organic LEDs (OLEDs (which may comprise an organic light emitting layer).

Solid state light emitting arrays are used in several lighting applications. For example, solid state light emitting panels comprising arrays of solid state light emitting devices have been used as direct light sources in, for example, architectural and/or reinforced lighting. A solid state light emitting device can comprise, for example, a packaged light emitting device comprising one or more light emitting diodes (LEDs). Inorganic LEDs typically comprise a semiconductor layer that forms a p-n junction. An organic LED (OLED), which includes an organic light emitting layer, is another type of solid state light emitting device. Typically, a solid state light emitting device produces light through recombination of electron carriers (i.e., electrons and holes) in a light emitting layer or region.

Solid state lighting panels are commonly used as backlights for small liquid crystal display (LCD) screens, such as the LCD display screens used in portable electronic devices. Additionally, there has been an increased interest in using solid state lighting panels as backlights for larger displays, such as LCD television displays.

Although solid-state light sources with high color rendering index (CRI) and/or high efficiency have been demonstrated, one of the problems with the large-scale adoption of such light sources in architectural applications is that commercial lighting systems utilize designs designed to communicate with alternating current (ac) The lamps of the standardized connectors used together can be phased by using a phase-cut dimmer device. Typically, a solid state light source is provided with or coupled to a power converter that converts ac power to dc power, and the dc power is used to enable the light source. However, the use of such power converters can increase the cost of the illumination source and/or the total installation and can reduce efficiency.

Some attempts to provide solid state light sources have involved the use of a rectified ac waveform To drive an LED or LED string or group. However, since the LEDs require a minimum forward voltage to turn on, the LEDs can be partially turned on for only one of the rectified ac waveforms, which can result in visible flicker, undesirably reducing the power factor of the system, and / or can increase the resistance loss in the system.

Other attempts to provide an ac-driven solid state illumination source have involved placing the LEDs in an anti-parallel configuration such that one half of the LEDs are driven during each half cycle of an ac waveform. However, this method requires more than twice the number of LEDs used to generate the same luminous flux for a rectified ac signal.

A solid state lighting device can include a substrate having one of a first and a second opposing surface, wherein at least one of the opposing surfaces is configured to mount a device thereon. A string of on-wafer (COB) light emitting diode (LED) groups can be located on the first surface of the substrate and coupled in series with one another. An ac voltage source input from outside the solid state lighting device can be coupled to the first surface or the second surface of the substrate.

In some embodiments of the present invention, a solid state light emitting device can include a rectifier circuit mounted on a surface of one of the substrates mounted in the solid state light emitting device, coupled to an ac voltage source, It is configured to provide a rectified ac voltage to the substrate. A current source circuit can be mounted on the surface of the substrate and coupled to the rectifier circuit. A string of light emitting diodes (LEDs) can be mounted on the surface of the substrate and coupled in series with one another and coupled to the current source circuit. A plurality of shunt circuits can be mounted on the surface of the substrate, wherein each of the plurality of shunt circuits is coupled to a respective node of the string and can be configured to respond to respective ones of the groups of LEDs The bias state transitions to operate.

In some embodiments in accordance with the invention, at least the plurality of shunt circuits comprise discrete electronic component packages mountable on the substrate. In some embodiments in accordance with the invention, the LEDs in the string can be mounted on an on-board wafer LED on the surface of the substrate. In some embodiments according to the present invention, the substrate can be a flexible circuit substrate, wherein the device can further comprise a heat sink mountable on an opposite surface of the substrate and thermally coupled to the string of LED strings. In some embodiments in accordance with the invention, the substrate can be a metal core printed circuit board (MCPCB).

In some embodiments in accordance with the invention, a solid state lighting device can include a rectifier circuit configurable to couple to an ac voltage source to provide a rectified ac voltage. A current source circuit can be coupled to the rectifier circuit and a string of series connected LED groups can be coupled to one of the current source circuits. At least one capacitor can be coupled to the output of the current source circuit. A current limiter circuit can include a current mirror circuit configured to limit current flow through at least one of the groups of LEDs to be less than a current generated by the current source circuit and responsive The rectified ac voltage applied to one of the input of the current source circuit causes the at least one capacitor to be selectively charged via the current source circuit and discharged via the at least one of the groups of LEDs. A plurality of shunt circuits can be coupled to respective nodes between the LEDs in the string and configured to respond to a bias state transition of the LED groups as a function of a magnitude of the rectified ac voltage Selectively enable and disable.

In some embodiments according to the present invention, the plurality of shunt circuits can each Self-contained: a transistor that provides a controllable current path between a first node of the string and a terminal of the rectifier circuit; and a shutdown circuit coupled to one of the second nodes of the string and A control terminal coupled to one of the transistors and configurable to control the current path in response to a control input.

In some embodiments of the present invention, the apparatus may further include a substrate having first and second opposing surfaces, wherein at least the string is connected to the LED group in series, the plurality of shunt circuits, the rectifier circuit, and the current The source circuit is mounted on the substrate. In some embodiments in accordance with the invention, the LEDs in the string can be mounted on an on-board wafer LED on the substrate.

In some embodiments according to the present invention, the substrate can be a flexible circuit board, wherein the device can further include a heat sink mounted on the substrate opposite the string of LED groups and adjacent to the string of LEDs. In some embodiments in accordance with the invention, the substrate can be a metal core printed circuit board (MCPCB).

In some embodiments in accordance with the present invention, a method of forming a solid state lighting circuit can be provided by placing a plurality of on-board wafer light emitting diodes (LEDs) in a string configuration on one surface of a substrate. An encapsulant material can be applied over the plurality of on-board wafer LEDs and the encapsulant material can be formed to cover one of the plurality of on-board wafer LEDs to provide a lens for the plurality of on-board wafer LEDs.

In some embodiments of the invention, the method can also include placing a plurality of shunt circuits including discrete electronic component packages on the surface of the substrate. In certain embodiments according to the present invention, an encapsulant material is applied Provided by applying the encapsulant material to cover portions of the surface between the plurality of on-board wafer LEDs and the plurality of on-board wafer LEDs.

In some embodiments according to the present invention, the encapsulant material is formed as a layer by simultaneously contacting a mold with the encapsulant material to simultaneously form a layer covering the plurality of on-board wafer LEDs for the plurality of The on-board wafer LEDs are provided with the lenses provided, wherein the mold includes on-board wafer LED recesses positioned in a surface of one of the molds opposite the plurality of on-board wafer LEDs.

In some embodiments according to the present invention, the method may further comprise: placing a plurality of shunt circuits including discrete electronic component packages on the surface of the substrate prior to applying the encapsulant material, wherein the mold further comprises A discrete electronic component package recess in the surface of the mold opposite the plurality of shunt circuits on the surface. In certain embodiments according to the present invention, application of an encapsulant material can be provided by individually dispensing the encapsulant material onto the plurality of on-board wafer LEDs.

In some embodiments according to the present invention, application of an encapsulant material can be provided by simultaneously dispensing the encapsulant material onto the plurality of on-board wafer LEDs. In some embodiments according to the present invention, the encapsulant material is formed to cover one of the plurality of on-board wafer LEDs to provide a lens for the plurality of on-board wafer LEDs by providing respective encapsulant barriers Reducing flow of the encapsulant material away from each of the plurality of on-board wafer LEDs during application of the encapsulant material to provide a separate lens for each of the plurality of on-board wafer LEDs .

In some embodiments according to the present invention, the encapsulant barrier at least partially surrounds the LEDs and is configured to reduce flow of the encapsulant material away from one of the LEDs during application of the encapsulant material Promote the formation of such lenses. In certain embodiments according to the present invention, the method can further comprise removing the encapsulant barriers from the lenses.

In some embodiments according to the present invention, a printed circuit board (PCB) can include a substrate configured to be included in a solid state light emitting device, wherein the substrate can have first and second opposing surfaces, Wherein at least one of the opposing surfaces is configured to mount a plurality of on-board wafer light emitting diodes (LEDs) thereon, and the substrate is configured to couple to an ac voltage from an exterior of the solid state lighting device a source input, and configured to mount a plurality of discrete shunt circuit devices thereon, the plurality of discrete shunt circuit devices being coupled to respective nodes between the plurality of LEDs and configured to respond in response The activation and deactivation are selectively enabled and disabled by a bias state transition of the LED groups that are provided to one of the LEDs as a function of a change in the magnitude of the rectified ac voltage.

In some embodiments in accordance with the invention, the substrate can be a metal core PCB. In some embodiments of the present invention, the first surface may be a conductive circuit pattern layer and the second surface may have a base metal layer greater than one of the thicknesses of the conductive circuit pattern layer, wherein the PCB may further A dielectric layer is disposed between the conductive circuit pattern layer and the base metal layer. In some embodiments in accordance with the invention, the substrate can be a flexible PCB.

In some embodiments according to the present invention, the PCB can further include a location in the substrate opposite the chip LED set on the string to be mounted thereon One of the heat shields at one of the specific locations. In some embodiments according to the present invention, the PCB may further comprise an encapsulant barrier, the encapsulant barrier protruding from the surface, at least partially surrounding the surface in which at least one of the LEDs is to be mounted The upper position is configured to reduce flow of the encapsulant material away from one of the LEDs during application of an encapsulant material to promote formation of the at least one of the LEDs.

Embodiments of the inventive subject matter will now be described more fully hereinafter with reference to the accompanying drawings in which, However, the inventive subject matter can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and the scope of the inventive subject matter will be fully conveyed by those skilled in the art. The same reference numerals are used throughout the drawings to refer to the same elements.

As used herein, the phrase "lighting device" is not limiting except that the pointing device is capable of emitting light. That is, a light-emitting device can be: one device that illuminates one area or volume (for example, a structure), a swimming pool or a spa, a room, a warehouse, an indicator, a road, a parking lot, a vehicle, signboard (eg, road sign), a billboard, a boat, a toy, a mirror, a ship, an electronic device, a boat, an airplane, a stadium, a computer, a remote audio device, a a remote video device, a cellular telephone, a tree, a window, an LCD display, a cave, a tunnel, a courtyard, a street light pole; or an array of devices or devices that illuminate a housing; or for the following items One device: edge or Backlight illumination (eg, backlit posters, signage, LCD displays), lamp replacement (eg, for replacing ac incandescent lamps, low voltage lamps, fluorescent lamps), lamps for outdoor lighting, lamps for safety lighting, For exterior residential lighting (wall mounted, pole/column mounted), ceiling downlights/wall lights, cabinet lighting, lights (floor lamps and / or table lamps and / or table lamps), landscape lighting, track lighting, work lighting, Professional lighting, ceiling fan lighting, archival/artistic display lighting, high vibration/impact lighting, work lights, mirror/dresser lighting; or any other lighting device.

The subject matter of the present invention is further directed to a light-emitting housing (the volume of which may be uniformly or unevenly illuminated), the housing comprising an enclosed space and at least one illumination device according to the inventive subject matter, wherein the illumination device illuminates the illumination device At least a portion of the enclosed space (evenly or unevenly).

1 is a schematic block diagram illustrating one of the solid state lighting devices 101 in accordance with some embodiments of the present invention. According to FIG. 1, solid state lighting device 101 includes a light emitting diode (LED) driver circuit 105 coupled to an LED string circuit 110, both of which are mounted on a surface of a substrate 100. The LED driver circuit 105 is coupled to an ac voltage that provides current and voltage to the LED string circuit 110 and other circuitry included in the device 101 to illuminate from the solid state lighting device 101.

It will be appreciated that the embodiments illustrated herein may utilize the ac voltage applied directly to device 101 (from an external power source) without including an "on-board" switching mode. Based on the ac voltage signal provided directly to the solid state lighting device 101, the LED driver circuit 105 can alternatively provide a rectified ac voltage to the LED string circuit 110 for operation from a device in accordance with certain embodiments of the present invention. For acceptable light. It will be further appreciated that solid state lighting device 101 in accordance with the present invention can be used in any format lighting fixture, such as the lighting fixture illustrated in FIG.

The LED driver circuit 105 can include: a component for rectifying the ac voltage, a component for providing a current source to the LED string circuit 110, a component for the shunt circuit, and a current limiting circuit for limiting the pass through the LED string circuit 110. A component of the current amount of at least one of the LEDs and at least one energy storage device (such as a capacitor). It will be further appreciated that in some embodiments in accordance with the invention, at least some of the components can be mounted on the substrate 100 as a discrete electronic component package. Still further, in some embodiments in accordance with the present invention, some of the remaining circuits set forth herein may be integrated into a single integrated circuit package mounted on substrate 100.

The LED string circuit 110 can include a plurality of "on-board wafer" (COB) LED groups that are coupled in series with each other and mounted on the substrate 100. Thus, the on-board wafer LEDs can be mounted in other applications where the LEDs are intended to be used, for example, where the LEDs are provided on a submount, an interposer substrate, or other wafer carrier to which the LEDs are mounted, etc. An additional package of substrate 100 can be included. Such other methods are described, for example, in U.S. Application Serial No. 13/192,755 (Attorney Docket: 5308-1364), which is incorporated herein by reference. Positioned on the lower substrate to provide a stacked configuration.

It should also be understood that the LED string circuit 110 can replace the COB LED with a packaged LED device in certain embodiments in accordance with the present invention. For example, at the root In accordance with some embodiments of the present invention, LED string circuit 110 may comprise an XML-HV LED commercially available from Cree, Inc. of Durham, N.C., USA.

Thus, device 101 can take the form of a relatively small form factor plate that is directly coupled to the ac voltage signal and provides a rectified ac voltage signal to string circuit 110 without the use of an on-board switching mode power supply. Additionally, string circuit 110 may be comprised of a COB LED or an LED device on a board.

The substrate 100 can be provided in any relatively small apparent size (symmetric or asymmetrical), such as those set forth herein with reference to Figures 4D, 4E, and 5A-5C. Moreover, in some embodiments in accordance with the invention, the resulting small plate of COB LED or LED device having thereon is operated by directly applying an ac voltage signal (but without the need for an on-board switching mode power supply) A small packaged high efficiency output illumination device 101 that can operate as detailed in the tables shown in Figures 14 and 15 can be provided.

It will be understood that the term "mounted on" as used herein includes components (such as an on-board wafer LED) without the use of an intervening abutment, substrate, carrier or other surface (such as the co-transfer cited above). The configuration of the physical connection to the substrate 100 in the case of the surface described in the U.S. Application Serial No. 13/192,755 (Attorney Docket No. 5308-1364). Thus, components illustrated as being "mounted" on a substrate can be located on the same surface of a substrate or on opposite surfaces of the same substrate. For example, components that are placed and soldered to the same substrate during assembly can be described as being "mounted" on the substrate.

It should be understood that in some embodiments according to the present invention, the ac voltage signal may There is any magnitude sufficient to operate the device 101. For example, in some embodiments in accordance with the invention, the ac voltage signal can be 90 volts ac, 110 volts ac, 220 volts ac, 230 volts ac, 277 volts ac, or any intermediate voltage. In some embodiments in accordance with the invention, an ac voltage signal is provided from a single phase ac voltage signal. However, in some embodiments in accordance with the invention, the ac voltage signal can be provided via a voltage signal from two leads of a three phase ac voltage signal. Thus, the ac voltage signal can be provided from a higher voltage ac voltage signal, regardless of phase. For example, in some embodiments in accordance with the invention, an ac voltage signal can be provided from a three phase 600 volt ac signal. In still other embodiments in accordance with the invention, the ac voltage signal can be a relatively low voltage signal, such as 12 volts ac.

2 is a schematic block diagram illustrating one of the solid state lighting devices 101 shown in FIG. 1 in accordance with some embodiments of the present invention. According to FIG. 2, LED driver circuit 105 includes a rectifier circuit 205 coupled to a shunt circuit 210 and coupled to a plurality of LED string circuits 110 comprising a plurality of LED strings coupled in series with one another. As further shown in FIG. 2, shunt circuit 210 is coupled to selected nodes between several of the LED groups in string 110.

The shunt circuit 210 can be configured to operate in response to a bias state transition across its respective set of LEDs coupled by its shunt circuit 210. Thus, in some embodiments in accordance with the invention, the groups of LEDs within the string can be incrementally activated and deactivated in response to the bias states of the devices in the groups. For example, when a rectified ac voltage is applied to the LED string circuit 110, some of the shunt circuits can be activated and deactivated in response to the forward bias of the LED group. The shunt circuit can include a shunt circuit configured to surround the LED group 210 is coupled to a transistor between its selected nodes that provides a respective controllable shunt path. These transistors can be turned on/off by a bias transition of the LED group that can be used to affect the bias of the transistor. A shunt circuit incorporating a LED string operation is further described in, for example, the commonly assigned U.S. Application Serial No. 13/235,127 (Attorney Docket: 5308-1461).

As further shown in FIG. 2, rectifier circuit 205, shunt circuit 210, and LED string circuit 110 can be mounted on substrate 100 such that each of these components is provided on a single surface of substrate 100. In other embodiments in accordance with the invention, some of the circuits illustrated herein are mounted on a first side of the substrate 100 and the remaining circuitry is mounted on opposite sides of the substrate 100. However, in some embodiments according to the present invention, the circuits set forth herein are used without the use of intervening substrates, abutments, carriers, or other types of surfaces that are sometimes used to provide stacked type assemblies in conventional configurations. In this case, it is mounted on the substrate 100.

In some embodiments in accordance with the present invention, at least some of the components set forth with reference to FIG. 2 can be mounted on substrate 100 as a discrete electronic component package. Still further, in some embodiments in accordance with the present invention, some of the remaining circuits described with reference to FIG. 2 may be integrated into a single integrated circuit package mounted on substrate 100.

Still referring to FIG. 2, an exemplary solid state lighting device 101 is constructed and operated in accordance with the parameters illustrated in the table of FIG. In particular, device 101 utilizes a shunt circuit coupled to string circuit 110 as shown in FIG. 13 without the use of the current limiter circuit and capacitors shown in FIG. The device contains 12 high-voltage 16-junction COB LEDs, each measuring approximately 1.4 mm × 1.4 Mm × 0.170 mm. The data in the table of Figure 14 shows an exemplary panel providing lumens ranging from about 704 Lm to about 816 Lm in a range of efficiency (lumens per watt) from about 71 Lm/W to about 79 Lm/W. (Lm) to provide an acceptable color point and a relatively high power factor. However, it will be appreciated in certain embodiments in accordance with the present invention that a larger output can be achieved, for example, by increasing the number of COB LEDs on the board or by increasing the current level used to drive the COB LEDs.

3 is a schematic block diagram of a solid state lighting device 101 including an LED driver circuit 105 (including a rectifier circuit 205 and a shunt circuit 210) coupled to a current limiter circuit 305 connected in parallel to a capacitor 310. Both the streamer circuit 305 and the capacitor 310 are coupled in series with the LED string circuit 110, all of which can be mounted on the surface of the substrate 100.

It should be understood that the current limiter circuit 305 and capacitor 310 can be used to reduce flicker that would otherwise be caused by the ac voltage provided to the solid state lighting device 101. For example, capacitor 310 can be used to store energy near the peak voltage and use the stored energy to drive LED string 110 when the ac voltage magnitude is less than the amount of voltage that can be required to apply forward bias to the LEDs in string 110. Still further, the current limiter circuit 305 can be configured to direct current to the capacitor 310 such that energy is stored therein or configured to discharge the charge in the capacitor 310 through the LED string 110.

Although FIG. 3 shows capacitor 310 for storing and delivering energy, it should be understood that any type of electronic energy storage device can be used as an alternative to or in combination with capacitor 310, such as an inductor. It should be understood that the use of current limiter circuits in conjunction with LED string circuits is further illustrated by, for example, common Let it be in the US application with serial number 13/235,103 (Attorney's Profile: 5308-1459).

In accordance with some embodiments of the present invention, the components shown in FIG. 3 can be mounted on the same surface of substrate 100. In other embodiments in accordance with the present invention, some of the circuits shown in FIG. 3 may be mounted on one of the first surfaces of the substrate 100, and the remaining circuitry is mounted on a second opposing surface of the substrate 100. In some embodiments according to the present invention, the LEDs included in the LED string circuit 110 can be mounted on any surface of the substrate 100 or can be mounted on a substrate or a board coupled to other substrates of the substrate 100. The upper wafer LEDs are described, for example, in the U.S. Application Serial No. 13/192,755, the entire disclosure of which is incorporated herein by reference.

Still referring to FIG. 3, exemplary solid state light emitting device 101 is configured to provide the materials illustrated in the table of FIG. In particular, device 101 utilizes a shunt circuit coupled to string circuit 110 as shown in FIG. 13 in conjunction with the use of the current limiter circuit and capacitor shown in FIG. The device contains 12 high voltage 16 junction COB LEDs, each measuring approximately 1.4 mm x 1.4 mm x 0.170 mm. The data in the table of Figure 15 shows that the exemplary panel provides an acceptable range of from about 674 Lm to about 785 Lm in an efficiency range from about 69 Lm/W to about 74 Lm/W, thereby providing acceptable Color point and relatively high power factor. However, it will be appreciated in certain embodiments in accordance with the present invention that a larger output can be achieved, for example, by increasing the number of COB LEDs on the board or by increasing the current level used to drive the COB LEDs.

4A illustrates the inclusion of a substrate in accordance with some embodiments of the present invention. A plan view of a solid state light emitting device 101 of 100, the substrate 100 including an LED driver circuit 105 and an LED string circuit 110 mounted on a surface thereof. 4B is a cross-sectional view of one portion of the solid state light emitting device 101 shown in FIG. 4A in accordance with some embodiments of the present invention. 4C is a cross-sectional replacement view of one portion of a solid state light emitting device 101 in accordance with some embodiments of the present invention, wherein the substrate 100 includes a thermally conductive block 417 embedded therein opposite the LED string circuit 110.

According to FIG. 4A, in some embodiments in accordance with the invention, substrate 100 can be a printed circuit board (PCB). The PCB can be formed from a number of different materials that can be configured to provide the desired electrical isolation and high thermal conductivity. In some embodiments, the PCB can include, at least in part, a dielectric to provide the desired electrical isolation. In other embodiments in accordance with the invention, the PCB may comprise a ceramic such as alumina, aluminum nitride, tantalum carbide or a polymeric material such as polyimide and polyester.

For panels made of materials such as polyimine and polyester, the panels may be flexible (sometimes referred to as a flexible printed circuit board). The above may allow the board to take a non-planar or curved shape in which the LED chips are also arranged in a non-planar manner. In certain embodiments according to the present invention, the panel can be a flexible printed substrate such as one of Kapton® polyimine available from Dupont. In some embodiments in accordance with the invention, the board can be a standard FR-4 PCB.

This can assist in providing a plate that emits different light patterns, wherein the non-planar shape allows for a less directional emission pattern. In certain embodiments according to the present invention, this configuration may allow for more omnidirectional transmissions, such as transmissions from 0° to 180°. angle. In certain embodiments in accordance with the invention, the PCB may include a highly reflective material such as a reflective ceramic or metal (like silver) layer to enhance light extraction from the component.

In some embodiments, the board can include a dielectric layer 50 to provide electrical isolation, while also including an electrically neutral material that provides good thermal conductivity. Different dielectric materials can be used for dielectric layers comprising epoxy-based dielectrics in which different electrically neutral thermally conductive materials are dispersed. Many different materials can be used including, but not limited to, alumina, aluminum nitride (AlN), boron nitride, diamond, and the like. Different dielectric layers in accordance with the present invention can provide electrical isolation at different levels, some of which provide for electrical isolation of the crash in the range of 100 volts to 5000 volts. In some embodiments, the dielectric layer can provide electrical isolation in the range of 1000 volts to 3000 volts. In still other embodiments, the dielectric layer can provide electrical isolation of a collapse of approximately 2000 volts. In certain embodiments according to the present invention, the dielectric layer can provide different levels of thermal conductivity, with some of the dielectric layers having a thermal conductivity in the range of 1 w/m/k to 40 w/m/k. Sex. In some embodiments, the dielectric layer can have a thermal conductivity greater than 10 w/m/k. In still other embodiments, the dielectric layer can have a thermal conductivity of about 3.5 W/m-k.

The dielectric layer can have a number of different thicknesses to provide the desired electrical isolation and thermal conductivity characteristics, such as in the range of 10 microns to 100 microns (μm). In other embodiments, the dielectric layer can have a thickness in the range of 20 to 50 (μm). In still other embodiments, the dielectric layer can have a thickness of about 35 (μm).

In some embodiments in accordance with the invention, the substrate 100 can be from The Bergquist, Chanhassen, Minn, USA. One of the metal core PCBs available from Company, such as a "hot-clad" (T-Clad) insulating substrate material. "Hot-coated" substrates reduce thermal impedance and provide more efficient thermal conduction than standard boards. The MCPCB may also include a substrate plate on the dielectric layer opposite the LED string circuit 110 and may include a thermally conductive material to assist in dissipating heat. The base plate may comprise different materials such as copper, aluminum or aluminum nitride. The substrate sheets can have different thicknesses, such as in the range of 100 μιη to 2000 μιη, while other embodiments can have one thickness in the range of 200 μιη to 1000 μιη. Some embodiments may have a thickness of about 500 μm.

These substrates are mechanically robust and durable compared to thick film ceramics and direct bonded copper configurations. Therefore, the metal core printed circuit board can effectively transfer heat generated by the LEDs included in the LED string circuit 110 away from the solid state light emitting device 101. However, it should be understood that the substrate 100 can be adapted to mount any of the materials of the LED driver circuit 105 and the LED string circuit 110 that provide sufficient thermal conduction away from the LED string circuit 110.

In some embodiments, the MCPCB includes a solder mounting layer on the bottom surface of the substrate board made of a material that is compatible to mount directly to a heat sink, such as by solder reflow. Such materials may include one or more layers of different metals such as nickel, silver, gold, palladium. In some embodiments, the mounting layer can comprise a layer of nickel and silver, the nickel having a thickness in the range of 2 μm to 3 μm and the silver being in the range of 0.1 μm to 1.0 μm. In certain embodiments, the mounting layer can comprise other layer stacks, such as approximately 5 μm of electroless nickel, approximately 0.25 μm of electroless palladium, and approximately 0.15 μm of immersion gold. Soldering the MCPCB directly to a heat sink enhances heat dispersion from the plate to the heat sink by providing an increased thermal contact area between the plate and the heat sink. this Both vertical heat transfer and horizontal heat transfer can be enhanced. In some embodiments in accordance with the present invention, the MCPCB can provide different levels of thermal characteristics, with a junction to backside performance of approximately 0.4 °C/W.

The size of the substrate 100 can vary depending on various factors, such as the size and number of on-chip wafer LEDs mounted on the substrate. For example, in some embodiments, the substrate can be attached to each side by approximately 33 mm. In some embodiments in accordance with the invention, the components on the substrate can exhibit a height of about 2.5 mm. Other sizes can also be used for the substrate 100.

It should be understood that the substrate 100 can incorporate a heat sink structure that is mounted to or incorporated within the respective substrate to provide sufficient heat transfer away from the solid state light emitting device 101, such as, for example, in Figure 4C. Show. In some embodiments according to the present invention, a flexible heat transfer tape (such as available from Ohio Graphtech Lake dock (Lakewood, OH) of, the International's available GRAFIHX ^TM) may be used to attach a heat sink To the substrate 100. The heat sink can be any thermally efficient material sufficient to conduct heat away from the substrate 100. For example, the heat sink can be a metal such as aluminum. In some embodiments in accordance with the invention, the heat sink can be graphite. In some embodiments in accordance with the invention, the heat sink includes a reflective surface to improve light extraction.

As further shown in FIG. 4A, solid state lighting device 101 includes LED driver circuit 105 mounted on its surface, along with a plurality of LED groups configured to be coupled in series with each other to provide a plurality of on-board wafer LEDs of LED string circuit 110 (having It is called a COB LED array). In some embodiments in accordance with the invention, the COB LEDs of string 110 can be disposed in approximately the center of substrate 100 in accordance with a particular pattern. However, it should be understood that the COB LED can be adapted to The solid state lighting device 101 provides any configuration of the desired light output. For example, the COB LEDs can be configured as an approximately circular array, a random array, or a half random array. In some embodiments in accordance with the present invention, the COB LEDs can be mounted to a single circuitized substrate 100 in which the "invalid space" between the COB LEDs is reduced, which can reduce the size of the solid state lighting device 101 or the distribution within the device 101. The size of the substrate 100.

In a COB embodiment, a microchip or die (such as an LED) is mounted on its final circuit substrate and electrically interconnected to its final circuit substrate instead of being conventionally assembled or packaged into a separate LED package or integrated circuit. . Eliminating the use of the package during use of the COB assembly simplifies the overall process of design and fabrication, reduces space requirements, reduces cost, and improves performance due to shorter interconnect paths. A COB process can include three main steps: 1) LED die attach or die mounting; 2) wire bonding; and 3) grain and wire encapsulation. These COB configurations may also provide additional advantages that allow direct mounting and interface with the main device heat sink.

In certain embodiments (LED array embodiments), each of the wafers in the array can have its own unique lens formed thereon to facilitate light extraction and emission by the first channel. The first channel light extraction/emission refers to the first channel of light emitted from a particular LED chip through the respective lens and from the LED wafer to the surface of the primary lens. That is, light is reflected back, for example, by total internal reflection (TIR), in which some of the light can be absorbed. This first channel emission enhances the emission efficiency of the LED assembly by reducing the amount of LED light that can be absorbed. Some embodiments may include a high density light emitting assembly while maximizing light extraction, which may increase the efficiency of the respective solid state light emitting devices. According to the invention Certain embodiments may be configured as a subset of LED wafers within the array, with each subgroup having its own primary lens for improved light extraction. In some embodiments, the lens can be hemispherical, which can further increase light extraction by providing a lens surface that promotes first channel light emission.

In some embodiments according to the present invention, an LED array can include LED wafers that emit light of the same color or different colors (eg, red, green, and blue LED wafers or subgroups, white LEDs, and red LED wafers or sub- Group, etc.). Techniques have been developed for generating white light from a plurality of discrete light sources to provide a desired CRI at a desired color temperature that utilizes different chromaticities from different discrete sources. Such a technique is described in U.S. Patent No. 7,213,940, the disclosure of which is incorporated herein in

In some embodiments, in addition to the primary lens or optics, a secondary lens or optic may be used, for example, one of the larger secondary optics above the plurality of emitter groups having primary optics. In the case where each emitter or group of emitters has its own unique primary lens or optics, embodiments in accordance with the present invention may exhibit greater extensibility of providing larger LED arrays. In some embodiments in accordance with the invention, LED string circuit 110 can include hundreds of COB LEDs.

In some embodiments, the LED array can be mounted to a COB having a substrate 100 that provides improved operational characteristics. The substrate 100 can provide electrical isolation characteristics that allow for plate level electrical isolation of the COB LEDs. At the same time, the board can have the property of providing a highly efficient heat path to dissipate heat from the COB LED. Efficient heat dispersion from the heat of COB LEDs leads to improved LED chip reliability and color consistency. The substrate 100 can also be configured to allow for efficient installation of a primary heat sink. In certain embodiments in accordance with the present invention, substrate 100 includes features that allow it to be easily and efficiently mounted to a heat sink using mechanical components. In other embodiments, the circuit board can include a material that allows it to be efficiently and easily soldered to a heat sink, such as through a reflow process.

The present invention can provide a scalable LED array configuration such that certain embodiments can have as few as three emitters and other embodiments can have as many as 10 or 100 emitters.

It will be further appreciated that some of the components in the LED driver circuit 105 can be mounted to discrete electronic component packages on the substrate 100 to provide, for example, a plurality of shunt circuits mounted on the surface of the substrate 100. It will be further appreciated that other electronic component packages can be provided on the substrate 100 to provide the remainder of the circuitry contained in the solid state lighting device 101.

According to FIG. 4B, the substrate 100 can comprise a metal core multilayer PCB for providing an interaction between one of the electronic component packages on the surface of the substrate 100. A lower metal (or substrate) layer 415 can be used to facilitate thermal transfer away from the LED string circuit 110 and can be relatively thicker than the upper metal layer 405. The upper metal layer 405 and the lower metal layer 415 are separated by a thermally conductive dielectric layer 410 that electrically insulates the upper metal layer 405 from the lower metal layer 415 while still providing from the LED string array 110 to the lower metal layer 415. One of the hot aisles.

Thus, the lower metal layer 415 can provide a heat sink for transferring heat away from the LED string circuit 110. In still other embodiments in accordance with the present invention, a secondary heat sink may be attached to a lower surface of one of the lower metal layers 415 to provide Additional heat transfer for leaving the LED string circuit 110.

In some embodiments in accordance with the invention, the lower metal layer 415 can be a metal such as aluminum, copper or yttria. In some embodiments according to the present invention, the thermally conductive dielectric layer 410 can serve as a bonding medium and a thermal path for thermal conduction and provide an insulating layer between the upper metal layer 405 and the lower metal layer 415. Things. In some embodiments in accordance with the present invention, the thermal conductivity of the thermally conductive dielectric layer 410 can be from about 4 to about 16 times greater than conventional FR4 dielectrics.

Although a single (i.e., upper) metal layer 405 is shown in Figure 4B, other embodiments in accordance with the present invention may be provided in which an additional signal layer is provided as part of a metal core PCB. For example, in some embodiments in accordance with the invention, an additional upper metal layer 405 can be provided within a thicker thermally conductive dielectric layer 410 to provide a two or two layer in accordance with certain embodiments of the present invention. The above multi-core printed circuit board. In still other embodiments in accordance with the present invention, an additional thermally conductive dielectric layer can be provided beneath the lower metal layer 415 such that the lower metal layer 415 is within the metal core printed circuit board, rather than on an exposed surface thereof.

According to FIG. 4C, a flexible printed circuit board is provided as a substrate 100 having an LED string circuit 110 mounted thereon. A thermally conductive block 417 can be embedded within the substrate 100 proximate to the LED string circuit 110 to provide thermal transfer away from the LED string circuit 110. In some embodiments in accordance with the invention, the thermally conductive block 417 can be a metal such as copper, aluminum or yttria. Other thermally conductive materials can also be used.

4D is a plan view of one exemplary circuit substrate having an approximately symmetrical appearance dimension in accordance with some embodiments of the present invention. According to Figure 4D, six An LED (as part of the string circuit 110) is mounted on a central portion 460 of the substrate 100, and an ac voltage source input J1 is mounted on the substrate 100 proximate to the outer edge. As shown in FIG. 4D, the LEDs are located in the central portion 460 in a first configuration based on the desired light output from the device 101. In some embodiments according to the present invention, the plurality of LEDs are separated from the remaining portion of one of the electronic components mounted to the substrate 100 by one of the remaining portions 465 of the substrate 100, wherein the other electronic components are mounted on the substrate 100 only in the reserved portion 465 is between the outer perimeter 470 of the substrate 100. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion 465.

Still referring to FIG. 4D, an exemplary embodiment in accordance with the present invention is constructed in which the center of the LED in the central portion 460 is positioned at a center of the substrate 100. The device shown produces about 2000 lumens at about 85 degrees Celsius using six XML-HV LEDs available from Cree, Inc. of Durham, N.C., USA. The central portion 460 has a diameter of about 21 mm and a total plate size of about 54 mm x 60 mm. The remaining portion 465 is measured over the central portion 460 by an additional 9.5 mm. At a total power consumption of 25.2 W of the device 101, the total power supplied to the device is approximately 31.4 W, of which approximately 20.6 W is consumed by the LED.

4E is a plan view of one exemplary circuit substrate having another approximately symmetrical appearance dimension in accordance with some embodiments of the present invention. According to FIG. 4E, five LEDs (as part of the string circuit 110) are mounted on the central portion 460 of the substrate 100, and an ac voltage source input J1 is mounted on the substrate 100 proximate to the outer edge. As shown in FIG. 4E, the LEDs are located in the central portion 460 in a second configuration based on the desired light output from the device 101. In some embodiments according to the present invention, a plurality of LEDs are retained by the substrate 100 Portion 465 is separate from the remainder of the electronic components mounted to substrate 100, with other electronic components mounted on substrate 100 only between retention portion 465 and outer perimeter 470 of substrate 100. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion 465.

Still referring to FIG. 4E, an exemplary embodiment in accordance with the present invention is constructed in which the center of the LED in the central portion 460 is positioned at a center of the substrate 100. The device shown produces approximately 800 lumens at approximately 85 degrees Celsius using five XML-HV LEDs available from Cree, Inc. of Durham, N.C., USA. The central portion 460 has a diameter of about 16.1 mm and a total plate size of about 54 mm x 54 mm. The remaining portion 465 is measured over the central portion 460 by an additional 9.5 mm. At a total power consumption of 11.5 W of device 101, the total power supplied to the device is approximately 13.9 W, of which approximately 9.5 W is consumed by the COB LED.

5A is a plan view of one of solid state lighting devices 101 including LED string circuit 110 and LED driver circuit 105 mounted on substrate 100 and including capacitor 310, in accordance with some embodiments of the present invention. It should be understood that the LED driver circuit 105 shown in FIG. 5 can also include a plurality of shunt circuits as set forth herein, and a current limiter circuit that operates in conjunction with the capacitor 310 to provide operation of the LED string circuit 110 as set forth herein. 305. It will be further appreciated that capacitor 310 can be mounted on a substrate to reduce the likelihood that the profile of capacitor 310 can introduce a shadow to the light emitted by solid state lighting device 101. Thus, capacitor 310 can be positioned adjacent one of the outer perimeters of substrate 100.

The size of the substrate 100 may depend on different factors such as being mounted on the substrate The size and number of wafer LEDs on the board vary. For example, in some embodiments, the substrate can be rectangular with a size of approximately 33 mm by 46 mm. In some embodiments in accordance with the invention, the components on the substrate can exhibit a height that is approximately equal to one of the heights of the capacitors 310. In some embodiments in accordance with the invention, the components on the substrate can exhibit a height that is approximately equal to 13.5 mm. Other sizes can also be used for the substrate 100.

Figure 5B is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention. According to FIG. 5B, six LEDs (as part of the string circuit 110) are mounted on one side portion 560 of the substrate 100. As shown in FIG. 5B, LEDs are located in side portion 560 in a first configuration, and an ac voltage source input J1 is mounted on substrate 100 proximate to the outer edge, depending on the desired light output from device 101. In some embodiments according to the present invention, a plurality of LEDs are separated from the remaining portion of the electronic component mounted to the substrate 100 by the remaining portion 565 of the substrate 100, wherein the other electronic components are mounted on the substrate 100 only in the remaining portion 565 Between the outer perimeters 570 of the substrate 100. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion 565.

Still referring to FIG. 5B, an exemplary embodiment in accordance with the present invention is constructed in which the center of the LED in the central portion 460 is positioned about 17.5 mm from the top and bottom edges of the substrate 100 and about 15.2 mm from the right edge. The device shown produces about 2000 lumens at about 85 degrees Celsius using six XML-HV LEDs available from Cree, Inc. of Durham, N.C., USA. The central portion 560 has a diameter of about 21 mm and a total plate size of about 71.3 mm x 35 mm. The reserved portion 565 is measured over the center portion 560 by an additional 9.5 mm. At a total power consumption of 252 W of device 101, the total power of the device provided is approximately 31.4 W, of which approximately 20.6 W is consumed by the LED.

Figure 5C is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention. According to FIG. 5C, five LEDs (as part of the string circuit 110) are mounted on one side portion 560 of the substrate 100. As shown in FIG. 5C, LEDs are located in side portion 560 in a first configuration, and an ac voltage source input J1 is mounted on substrate 100 proximate to the outer edge, depending on the desired light output from device 101. In some embodiments according to the present invention, the LED is separated from the remaining portion of the electronic component mounted to the substrate 100 by the remaining portion 565 of the substrate 100, wherein the other electronic components are mounted on the substrate 100 only at the remaining portion 565 and the substrate 100. Between the outer perimeters 570. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion 565.

Still referring to FIG. 5C, an exemplary embodiment in accordance with the present invention is constructed in which the center of the LED in the central portion 560 is positioned approximately 16.2 mm from the top and bottom edges of the substrate 100 and approximately 12.827 mm from the right edge. The device shown produces approximately 800 lumens at approximately 85 degrees Celsius using five XML-HV LEDs available from Cree, Inc. of Durham, N.C., USA. The central portion 560 has a diameter of about 16.1 mm and a total plate size of about 66.875 mm x 32.4 mm. The reserved portion 565 is measured over the center portion 560 by an additional 9.5 mm. At a total power consumption of 11.5 W of the device 101, the total power of the device provided is approximately 13.9 W, of which approximately 9.5 W is consumed by the LED.

Figure 5D is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention. According to Figure 5D, A single LED (as part of the string circuit 110) is mounted on one side portion 560 of the substrate 100. Depending on the desired light output from device 101, the single LED is disposed in side portion 560 and an ac voltage source input J1 is mounted on substrate 100 proximate to the outer edge. In some embodiments according to the present invention, the LED is separated from the remaining portion of the electronic component mounted to the substrate 100 by the remaining portion 565 of the substrate 100, wherein the other electronic components are mounted on the substrate 100 only at the remaining portion 565 and the substrate 100. Between the outer perimeters 570. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion 565.

In accordance with the above description with reference to Figures 4 through 5, it should be understood that a wide range of variations can be provided by varying the number, type, and configuration of LEDs (or COB LEDs in accordance with certain embodiments) in accordance with certain embodiments of the present invention. Light output. For example, other embodiments may provide for generating 600 lumens using four XTE-HV LEDs (and current to drive the LEDs). In some embodiments in accordance with the invention, 1000 lumens can be generated using 3 XML-HV LEDs. Other combinations of the number and type of lumens and COB LEDs can also be used to provide embodiments in accordance with the present invention.

Thus, a relatively small substrate that does not include an on-board switching mode power supply but emits relatively high levels of light can be provided in accordance with embodiments of the present invention. For example, in some embodiments in accordance with the invention, a substrate can occupy one area of about 3240 mm ² or less while emitting at least 2000 lumens. Moreover, in some embodiments in accordance with the invention, a portion of the substrate utilized by the LED (or COB LED) can be about 1384 mm ² or less. In some embodiments in accordance with the invention, the LED (or COB LED) can utilize about 40% or less of the entire area of the substrate. In some embodiments according to the present invention, the remaining portion of the portion adjacent to the substrate utilized by the LED (or COB LED) may be about 16% or more of the length of the largest dimension (i.e., length or width) of the substrate. .

In a further embodiment in accordance with the invention, a substrate can occupy at least one of an area of about 2900 mm ² or less while emitting at least 800 lumens. Moreover, in some embodiments in accordance with the invention, a portion of the substrate utilized by the LED (or COB LED) can be about 814 mm ² or less. In some embodiments in accordance with the invention, the LED (or COB LED) can utilize about 30% or less of the entire area of the substrate. In some embodiments according to the present invention, the remaining portion of the portion adjacent to the substrate utilized by the LED (or COB LED) may be about 18% of the length of the largest dimension (ie, length or width) of the substrate or the above.

In a further embodiment in accordance with the invention, a substrate can occupy at least one of about 3240 mm ² or less while emitting at least 2000 lumens. Moreover, in some embodiments in accordance with the invention, a portion of the substrate utilized by the LED (or COB LED) can be about 1384 mm ² or less. In some embodiments in accordance with the invention, the LED (or COB LED) can utilize about 40% or less of the entire area of the substrate. In some embodiments according to the present invention, the remaining portion of the portion adjacent to the substrate utilized by the LED (or COB LED) may be about 13% or more of the length of the largest dimension (i.e., length or width) of the substrate. .

In accordance with a further embodiment of the present invention, a substrate can occupy at least one of about 2144 mm ² or less while emitting at least 800 lumens. Moreover, in some embodiments in accordance with the invention, a portion of the substrate utilized by the LED (or COB LED) can be about 814 mm ² or less. In some embodiments in accordance with the invention, the LED (or COB LED) can utilize about 38% or less of the entire area of the substrate. In some embodiments according to the present invention, the remaining portion of the portion adjacent to the substrate utilized by the LED (or COB LED) may be about 14% of the length of the largest dimension (ie, length or width) of the substrate or the above.

Figure 5E is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention. According to FIG. 5E, six LED devices (as part of the string circuit 110) are mounted on one side portion 580 of the substrate 100. Such LED devices are commercially available from Cree, Inc. of Durham, NC, USA, as described, for example, in the following U.S. Patent Application: February 14, 2011 Japanese Patent Application No. 13/027,006, filed on Jul. 8, 2011, and Serial No. 13/112, 791, filed on May 20, 2011, the disclosure of which is hereby incorporated by reference. This is incorporated herein by reference. As shown in FIG. 5E, the LED devices each include a respective submount 581 and a respective lens 582 in a first configuration in side portion 580, depending on the desired light output from the device. The LED device is electrically coupled to the remainder of the electronic component on substrate 100 by conductive traces 583. In some embodiments in accordance with the invention, a plurality of LED devices are separated from the remainder of the electronic component by a remaining portion of the substrate 100, wherein the other electronic components are mounted on the substrate 100 outside of the remaining portion of the substrate 100. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion.

Figure 5F is an approximately non-pair in accordance with some embodiments of the present invention A plan view of one of the exemplary circuit substrates. According to FIG. 5F, five LED devices (as part of the string circuit 110) are mounted on one side portion 590 of the substrate 100. Such LED devices are commercially available from Cree, Inc. of Durham, NC, USA, and are described, for example, in the following U.S. Patent Application: February 2011 No. 13/027,006, which was filed on the 14th, and No. 13/178,791, which was filed on July 8, 2011, and No. 13/112,502, which was filed on May 20, 2011. As shown in FIG. 5F, the LED devices each include a respective base 591 and a respective lens 592 located in side portion 590, depending on the desired light output from the device. The LED device is electrically coupled to the remainder of the electronic component on substrate 100 by conductive traces 593. In some embodiments in accordance with the present invention, the LED device is separated from the remainder of the electronic component mounted to the substrate 100 by a remaining portion of the substrate 100 mounted on the substrate 100 external to the remaining portion of the substrate 100. In some embodiments in accordance with the invention, other electronic components are mounted in the retention portion. It will be further appreciated that the features specifically illustrated in Figures 5E and 5F, such as the base of the respective LEDs, the conductive traces, and the remainder of the electronic components, may also be included in the embodiments of Figures 4 through 5D.

6 through 8 are cross-sectional views illustrating a method of forming a solid state light emitting device in accordance with some embodiments of the present invention. According to FIG. 6, the on-chip wafer LEDs included in the LED string circuit 110 are mounted on the substrate 100. An encapsulation material 605 is applied over the on-board wafer LEDs. In some embodiments in accordance with the invention, encapsulation material 605 provides a continuous layer covering a portion of the LED and a portion of substrate 100 between adjacent ones of the LEDs. Therefore, the encapsulating material 605 can be applied to the on-board wafer LEDs substantially simultaneously with each other.

It should be understood that the encapsulation material 605 can be used to form a lens over the on-board wafer LED. In certain embodiments according to the present invention, the encapsulating material 605 may comprise liquid polyoxyn and/or liquid epoxy, and/or a volatile solvent material (such as alcohol, water, acetone, methanol, ethanol, ketone). , isopropanol, hydrocarbon solvent, hexane, ethylene glycol, methyl ethyl ketone and combinations thereof).

In still other embodiments in accordance with the present invention, portions of the encapsulating material 605 extending between adjacent ones of the on-board wafer LEDs may be retained on the substrate 100 after the assembly process is completed, while in accordance with certain aspects of the present invention In an embodiment, the intervening encapsulation material 605 is removed from the substrate 100. In still other embodiments in accordance with the invention, the encapsulating material 605 can comprise other materials such as optical conversion materials, diffusing materials, and the like.

According to Figure 7, a mold 710 is brought into contact with the encapsulating material 605 on the on-chip wafer LED. The mold 710 includes a recess 711 in a lower surface thereof that is positioned relative to where the on-board wafer LED is to be positioned on the substrate 100. The recess 711 has a shape that is given to one of the lenses on the on-chip wafer LED.

Mold 710 may be adapted to mold a selected encapsulating material 605 (i.e., such as polyfluorene oxide) into a conformal or other contoured layer of any material. In some embodiments in accordance with the invention, the mold 710 can be a metal such as aluminum. In certain embodiments in accordance with the invention, the mold 710 can be either ruthenium or tantalum carbide. Other materials can be used as the mold 710.

Mold 710 can have a release material applied to it. In particular, a release material may be sprayed or otherwise applied to the surface of one of the substrate and the die 710 on which the wafer LED is separated. on. The release material can be any material that will facilitate the removal of the on-wafer wafer LEDs and substrate 100 from the mold 710. In certain embodiments according to the present invention, the release material can be a release agent based on polyoxymethylene.

It should be understood that although the encapsulating material 605 extending over the substrate 100 between adjacent ones of the on-board wafer LEDs may be compressed to a relatively thin layer, the encapsulating material 605 may remain on the substrate 100, although not provided As part of a lens for a particular on-board wafer LED.

According to FIG. 8, each of the on-board wafer LEDs on substrate 100 is provided with a lens 815 made of molded encapsulation material 605. In some embodiments in accordance with the invention, the encapsulation material 605 between adjacent ones of the on-board wafer LEDs shown in FIG. 8 can be removed. It will be further appreciated that additional layers of encapsulation material 605 can be provided on lens 815 to provide additional optical features to LED string circuit 110. After the molded lens 815, an additional discrete electronic component package can be mounted on the substrate 100. For example, in some embodiments in accordance with the present invention, the discrete electronic component packages that make up the LED driver circuit 105 can be mounted to the substrate 100 after the lens 815 formed by the encapsulation material 605.

9 is a cross-sectional view illustrating one method of forming a solid state light emitting device 101 using a mold to form a lens 815 in accordance with some embodiments of the present invention. In particular, the mold 910 further includes a discrete electronic component package recess 911 that is configured to receive discrete electronic components mounted on the substrate 100 that are external to the LED string circuit 110 having the encapsulation material 605 thereon. The outline of the package 905. Thus, the discrete electronic component package 905 can be mounted to the substrate along with the on-board wafer LEDs in the string circuit 110. 100 on. Encapsulation material 605 can then be applied to the on-board wafer LEDs, which can then contact mold 910 with encapsulation material 605 to form lens 815 while avoiding damage to discrete electronic component package 905 by including discrete electronic component package recesses 911 .

10 through 12 are cross-sectional views illustrating a method of forming a solid state light emitting device 101 in accordance with some embodiments of the present invention. According to FIG. 10A, the on-board wafer LED is mounted on the substrate 100 and is at least partially surrounded by the encapsulation barrier 1005 on the substrate 100. It should be understood that the upper surface of one of the encapsulating barriers 1005 is lower than the upper surface of the on-wafer LEDs that are surrounded by the encapsulating walls 1005.

An encapsulation material 1015 is dispensed onto the on-board wafer LED. In some embodiments in accordance with the invention, the encapsulating material 1015 is dispensed onto the on-board wafer LED using a nozzle 1110. The encapsulating material 1015 is dispensed in an amount sufficient to provide for each of the individual lenses 815 formed over the wafer LEDs on the respective boards. In some embodiments in accordance with the invention, the nozzles 1110 are moved over the on-board wafer LEDs to dispense the encapsulation material 1115 to each of the wafer LEDs on the other board in an order. For example, the nozzles 1110 can be positioned over the wafer LEDs on the leftmost plate in a first position to distribute the encapsulation material 1115 onto the individual plate wafer LEDs just below the nozzles 1110.

After dispensing the encapsulating material 1115, the nozzle 1110 is moved to a second position above the wafer LED on the right side of the wafer LED on the leftmost side plate. This procedure can be repeated to dispense the encapsulation material 1115 to each of the on-board wafer LEDs included in the string circuit 110. In still other embodiments in accordance with the present invention, the plurality of nozzles 1110 are predetermined to be positioned over at least two of the on-board wafer LEDs, thereby simultaneously encapsulating the material 1115 substantially simultaneously with each other. The ground is applied to each of the on-board wafer LEDs.

The encapsulation barrier 1005 is configured to restrict the flow of an encapsulation material 1115 onto the individual on-wafer LEDs to allow the formation of the lens 815 to have a desired shape 1105. It should be understood that, as shown in FIG. 10B, for example, the encapsulation barrier 1005 can at least partially surround each of the individual on-wafer LEDs. For example, in some embodiments in accordance with the invention, the encapsulation barrier 1005 can completely enclose the individual on-board wafer LEDs. In other embodiments in accordance with the invention, the encapsulating barrier 1005 may only partially surround the on-board wafer LEDs.

In some embodiments in accordance with the present invention, the encapsulation barrier 1005 can have a periodic or aperiodic spacing formed therein but still allow for the formation of a lens 815 having a desired shape 1105 for the on-board wafer LED. It should also be understood that although the barrier barrier 1005 is shown as having a rectangular cross-section on the substrate, other forms of encapsulation barrier 1005 can be used. For example, the encapsulation barrier 1005 can have a semi-circular shape or other geometric shape that provides sufficient surface tension to promote the shape 1105 of the encapsulation material 1115 when dispensed to the on-board wafer LED.

In certain embodiments in accordance with the invention, the barrier barrier wall 1005 can have any shape that limits the flow of the encapsulation material 1015. For example, in some embodiments in accordance with the invention, the encapsulating barrier 1005 has a square or rectangular perimeter shape to at least partially surround the on-board wafer LED. Other shapes can be used.

Figure 12 is a cross-sectional view showing the removal of the encapsulating barrier 1005 from the periphery of the on-wafer LED 1004 after forming the lens 815 having a desired profile 1105. In particular, the encapsulation barrier 1005 can be etched from the outer edge of the lens 815 at one of the base wafer LEDs to the outermost edge of one of the lenses 815 A recess 1205 is formed at the surface of the substrate 100. In some embodiments in accordance with the invention, the barrier wall 1005 is not removed from the lens 815.

Figure 13A is a circuit diagram illustrating one of the LED driver circuits coupled to a LED string circuit in accordance with some embodiments of the present invention. The device 101 includes a string 110 of LED groups 110-1, 110-2, ..., 110-N connected in series. Each of the LED groups 110-1, 110-2, ..., 110-N includes at least one LED. For example, individual of the groups can include a single LED and/or individual groups can include multiple LEDs connected in various parallel and/or series configurations. The LED groups can be configured in a number of different ways and can have various compensation paths associated therewith, such as, for example, co-assigned in the same application number 13/235,103 (Attorney Profile: 5308-1459) The US application is discussed in US Application Serial No. 13/235,127 (Attorney Docket: 5308-1461).

Power is supplied to the LED string 110 from a rectifier circuit 105 that is configured to couple to an ac power source 10 and from which a rectified voltage v _R and current i _R are generated. The rectifier circuit 105 can be included in the illumination device 101 or can be coupled to a portion of one of the individual units of the device 101.

Apparatus 101 further includes respective shunt circuits 130-1, 130-2, ..., 130-N coupled to respective nodes of string 110. The shunt circuits 130-1, 130-2, ..., 130-N are configured to provide current paths for each of the bypass LED groups 110-1, 110-2, ..., 110-N. The shunt circuits 130-1, 130-2, ..., 130-N each include a configuration to provide one of the LED groups 110-1, 110-2, ..., 110-N that can be used to selectively bypass One of the current paths is controlled by a transistor Q1. The transistor Q1 is biased using a transistor Q2, resistors R1, R2, ..., RN and a diode D. The transistor Q2 is configured to operate as a diode with its substrate and collector terminals connected to each other. A plurality of diodes D are connected in series with the transistors Q2 of the respective shunt circuits 130-1, 130-2, ..., 130-N such that the respective shunt circuits 130 are at different voltage levels. The base terminal of the current path transistor Q1 in -1, 130-2, ..., 130-N is biased. The transistors R1, R2, ..., RN are used to limit the base current of the current path transistor Q1. The current path transistors Q1 of the respective shunt circuits 130-1, 130-2, ..., 130-N will be turned off at different emitter bias voltages, and the emitter biases are passed through a resistor. One of the currents of R0 is determined. Accordingly, the shunt circuits 130-1, 130-2, ..., 130-N are configured to respond to the LED groups 110-1, 110-2, ..., which increase and decrease with the rectified voltage v _R . The bias state transition of 110-N operates to cause the LED groups 110-1, 110-2, ..., 110-N to be incrementally activated and deactivated as the rectified voltage v _R rises and falls. The current path transistor Q1 is turned on and off as the bias states of the LED groups 110-1, 110-2, ..., 110-N change.

As further shown in FIG. 13A, the string 110 connected in series via the LEDs is also coupled in series with a current limiter circuit that is implemented as a current mirror circuit 1420, although any of the embodiments can be used in accordance with embodiments of the present invention. Type of current limiter circuit. One or more storage capacitors 310 are coupled in parallel with a string 110 of series connected LED groups and a current mirror circuit 1420. The current mirror circuit 1420 can be configured to limit the current through the string 110 connected through the series connected LED groups to less than one of the nominal currents provided to the string circuit 110.

As further shown in FIG. 13A, current mirror circuit 1420 includes first transistor Q1 and second transistor Q2 coupled in a current mirror configuration and resistors R1, R2, R3. Current mirror circuit 1420 can provide a current limit of approximately (V _LED -0.7) / (R1 + R2) x (R2 / R3). A voltage limiter circuit 1460 (eg, a Zener diode) can also be provided to limit the voltage developed across one or more storage capacitors 310. In this manner, one or more storage capacitors 310 can be alternately charged via rectifier circuit 105 and discharged via string 110 connected in series via LED groups that provide more uniform illumination. Current mirror circuit 1420 is coupled to one of a plurality of LED groups 1410 included in string circuit 110. It should be understood that the LED group 1410 can include a plurality of LEDs coupled in parallel with one another.

13B-13D illustrate circuit diagrams of a shunt circuit in accordance with some embodiments of the present invention. In particular, the transistor Q2 shown as part of the shunt circuits 130-1 to 130-N in FIG. 13A is replaced by the diode D in FIGS. 13B to 13D to the respective substrates of the associated transistors Q1. Provide sufficient bias. In addition, each of the shunt circuits 130-1 through 130-N stages includes a corresponding number of diodes D to provide a bias voltage originally provided by transistor Q2. For example, the first stage 130-1 includes two diodes for biasing, and the next stage 130-2 includes three diodes D for biasing. Further, each of the stages 130-1 to 130-N may share the diode D for the bias of the previous stage.

Figure 13E is a circuit diagram illustrating one of the LED driver circuits coupled to a LED string circuit in accordance with some embodiments of the present invention. Figure 13E shows the shunt circuit of Figures 13B through 13D used by the alternate shunt circuits 130-1 through 130-N. According to Fig. 13E, in the first segment, the bias voltage of Q1 is approximately equal to the voltage drop of (D1 + D2). In the second paragraph, the bias voltage of Q2 A voltage drop equal to (D1+D2+D3). In the N segment, the bias voltage of QN is approximately equal to the voltage drop of (D1+D2+...+DN). Thus, in some embodiments in accordance with the invention, the shunt circuit can be fabricated as a diode array and a transistor block. In some embodiments in accordance with the invention, the diode array and the transistor block can be integrated together or separated from each other.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, such elements are not limited to the terms. These terms are only used to distinguish one element from another. For example, a first element may be referred to as a second element without departing from the scope of the inventive subject matter, and similarly, a second element may be referred to as a first element. The term "and/or" as used herein includes any and all combinations of one or more of the listed items.

It will be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or the intervening element can be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, the intervening element is absent.

It is understood that when an element or layer is referred to as "on" another element or layer, the element or layer can be directly on the other element or layer or the intervening element or layer. In contrast, when an element is referred to as being "directly on" another element or layer, there are no intervening elements or layers. The term "and/or" as used herein includes any and all combinations of one or more of the listed items.

Spatially relative terms (such as "below", "below", "lower", "above", "upper", and the like) may be used herein to facilitate A description of the relationship of one element or feature to another element or feature, as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation illustrated. Throughout the specification, the same component symbols in the drawings denote the same components.

The schematic and perspective illustrations of the preferred embodiments of the present invention are intended to illustrate embodiments of the inventive subject matter. As such, variations in the shapes of the illustrations as a result of, for example, manufacturing techniques and/or tolerances are contemplated. Therefore, the inventive subject matter should not be construed as limited to the particular shapes of the items illustrated herein, but should include, for example, variations in the shape of the invention. The illustrations of the present invention are not intended to limit the actual shape of one of the devices and are not intended to limit the scope of the inventive subject matter.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to The singular forms "a", "an" and "the" It will be further understood that when the terms "comprise", "comprising", "include", and/or "including" are used herein, they indicate the presence of the feature, integer, The steps, operations, elements and/or components are not intended to exclude the presence or addition of one or more other features, integers, steps, operations, components, components and/or groups thereof.

Unless otherwise defined, all terms used herein (including techniques) The terms and scientific terms have the same meaning as commonly understood by those skilled in the art to which the subject matter of the invention pertains. It is to be further understood that the terms used herein are to be interpreted as having a meaning that is consistent with the meaning in the context of the present specification and the related art, and should not be interpreted in an idealized or excessively formalized meaning unless It is explicitly defined as such. The term "plurality" is used herein to refer to two or more of the items mentioned.

It should be understood that the term light emitting diode as used herein may include a light emitting diode, a laser diode, and/or one or more semiconductor layers (which may include germanium, tantalum carbide, gallium nitride, and Other semiconductor devices of other semiconductor materials may comprise one of sapphire, germanium, tantalum carbide and/or other microelectronic substrates and may comprise one or more contact layers of metal and/or other conductive layers.

The preferred embodiments of the present invention have been disclosed in the drawings and the specification, and the specifics are used in the general and descriptive sense and not for the purpose of limitation. The scope of the inventive subject matter is set forth in the patent scope.

10‧‧‧AC power supply

100‧‧‧Substrate

101‧‧‧Solid illuminators/devices/small packaged high-efficiency output illuminators

105‧‧‧Lighting diode driver circuit/rectifier circuit

110‧‧‧Lighting diode string circuit/string circuit/string/light emitting diode string/light emitting diode array

130-1‧‧‧Split circuit / first stage / level

130-2‧‧‧Split circuit / next level

130-N‧‧‧Split circuit/level

205‧‧‧Rectifier circuit

210‧‧‧Split circuit

305‧‧‧ Current limiter circuit

310‧‧‧ capacitor/storage capacitor

405‧‧‧Upper metal/metal layer

415‧‧‧lower metal (or base) layer / lower metal layer

417‧‧‧thermal block

460‧‧‧ central part

465‧‧‧Reserved part

470‧‧‧External perimeter

560‧‧‧ side part/center part

565‧‧‧Reserved part

570‧‧‧External perimeter

580‧‧‧ side part

581‧‧‧Abutment

582‧‧‧ lens

583‧‧‧conductive traces

590‧‧‧ side part

591‧‧‧Abutment

592‧‧‧ lens

593‧‧‧ conductive traces

605‧‧‧Encapsulation material

710‧‧‧Mold

711‧‧‧ recess

815‧‧ lens

905‧‧‧Discrete electronic component package

910‧‧‧Mold

911‧‧‧Discrete electronic component package recess

1005‧‧‧encapsulated barrier

1105‧‧‧Shape/profile

1110‧‧‧Nozzles

1115‧‧‧Encapsulation material

1205‧‧‧ recess

1410‧‧‧Lighting diode group

1420‧‧‧current mirror circuit

1460‧‧‧Voltage limiter circuit

D‧‧‧ diode

J1‧‧‧AC voltage source input

Q1‧‧‧Optoelectronic/current path transistor/first transistor

Q2‧‧‧Optocrystal / second transistor

R0‧‧‧Resistors

R1‧‧‧Resistors

R2‧‧‧ resistor

RN‧‧‧Resistors

V _R ‧‧‧ rectified voltage

1 is a schematic block diagram illustrating one of a solid state lighting device including a light emitting diode (LED) driver circuit and an LED string circuit in accordance with some embodiments of the present invention.

2 is a schematic diagram of the LED driver circuit including a rectifier circuit and a shunt circuit as shown in FIG. 1 and one of the LED string circuits coupled to the LED driver circuit in accordance with some embodiments of the present invention. Sex party Block diagram.

3 is a schematic block diagram of an LED driver circuit shown in FIGS. 1 and 2 further including a current limiter circuit and a capacitor coupled to one of the LED string circuits in accordance with some embodiments of the present invention. Figure.

4A is a plan view of an exemplary circuit substrate including a rectifier circuit, an LED string circuit, and other discrete electronic component packages in a solid state lighting device in accordance with some embodiments of the present invention.

4B is a cross-sectional view of an exemplary circuit substrate shown in FIG. 4A in accordance with some embodiments of the present invention.

4C is an alternate cross-sectional view of one of the LED string circuit portions of one of the exemplary circuit substrates shown in FIGS. 4A and 4B including a flexible circuit substrate in accordance with some embodiments of the present invention.

4D is a plan view of one exemplary circuit substrate having an approximately symmetrical appearance dimension in accordance with some embodiments of the present invention.

4E is a plan view of one exemplary circuit substrate having an approximately symmetrical appearance dimension in accordance with some embodiments of the present invention.

5A is a plan view of an exemplary circuit substrate including an rectifier circuit and an LED string circuit coupled to a capacitor in accordance with some embodiments of the present invention.

Figure 5B is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention.

Figure 5C is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention.

Figure 5D is an approximately non-pair in accordance with some embodiments of the present invention A plan view of one of the exemplary circuit substrates.

Figure 5E is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention.

Figure 5F is a plan view of one exemplary circuit substrate having an approximately asymmetric appearance dimension in accordance with some embodiments of the present invention.

6 through 9 illustrate cross-sectional views of a method of forming a solid state device on a circuit substrate comprising a wafer of LEDs mounted thereon using a mold in accordance with some embodiments of the present invention.

10 (including FIGS. 10A and 10B) and FIGS. 11-12 illustrate the use of a barrier barrier to form a solid state light emitting device comprising one of the on-wafer LEDs on a circuit substrate in accordance with some embodiments of the present invention. A cross-sectional view of the method.

Figure 13A is a circuit diagram illustrating one of the LED driver circuits coupled to a LED string circuit in accordance with some embodiments of the present invention.

13B-13D illustrate circuit diagrams of a shunt circuit in accordance with some embodiments of the present invention.

Figure 13E is a circuit diagram illustrating one of the LED driver circuits coupled to a LED string circuit in accordance with some embodiments of the present invention.

14 is a table illustrating performance data for an exemplary solid state light emitting device in accordance with some embodiments of the present invention.

15 is a table illustrating performance data for an exemplary solid state light emitting device in accordance with some embodiments of the present invention.

Figure 16 illustrates an exemplary solid state light emitting device housed in a lighting fixture in accordance with some embodiments of the present invention.

100‧‧‧Substrate

101‧‧‧Solid illuminators/devices/small packaged high-efficiency output illuminators

105‧‧‧Lighting diode driver circuit/rectifier circuit

110‧‧‧Lighting diode string circuit/string circuit/string/light emitting diode string/light emitting diode array

Claims (79)

A solid state lighting device comprising: a rectifier circuit mounted on a surface of a substrate mounted in the solid state lighting device, coupled to an ac voltage source, configured to provide a rectified ac voltage to the substrate a current source circuit mounted on the surface of the substrate and coupled to the rectifier circuit; a string of light emitting diodes (LEDs) mounted on the surface of the substrate, coupled in series with each other and coupled to the a current source circuit; and a plurality of shunt circuits mounted on the surface of the substrate, each of the plurality of shunt circuits being coupled to a respective node of the string and configured to respond to the LED groups The bias states of the individual are changed to operate. The device of claim 1, wherein at least the plurality of shunt circuits comprise discrete electronic component packages mounted on the substrate. The device of claim 1, wherein the LEDs in the string comprise on-board wafer LEDs mounted on the surface of the substrate. The device of claim 1, wherein the substrate comprises a flexible circuit substrate, the device further comprising: a heat sink mounted on an opposite surface of the substrate and thermally coupled to the string of LEDs. The device of claim 1, wherein the substrate comprises a metal core printed circuit board (MCPCB). The device of claim 5, wherein the MCPCB comprises a metal layer, the gold The sublayer is separated from the surface of the substrate by a dielectric layer and is configured to conduct heat away from the string of LEDs. The device of claim 5, wherein the MCPCB comprises a dielectric material between the first metal layer and the second metal layer. The device of claim 7, wherein the first metal layer comprises a circuit layer and the second metal layer is configured to conduct heat away from the string of LEDs. The device of claim 1, further comprising: a current limiter circuit on the surface of the substrate, in series with the current source circuit and at least one of the groups of LEDs; and at least one capacitor located at The surface of the substrate is coupled across the at least one LED group and the current limiter circuit. The device of claim 9, wherein the current limiter circuit is configured to selectively supply current from the current source circuit to the at least one LED group and the at least one capacitor. The device of claim 1, further comprising: an encapsulant layer on the surface of the substrate to encapsulate the string of LEDs. The device of claim 11, wherein the encapsulant layer comprises polyfluorene oxide. The device of claim 1, further comprising: a layer of individual encapsulants that individually encapsulate the LEDs in the string of LEDs. The device of claim 1, wherein the rectifier circuit, the current source circuit, and the plurality of shunt circuits are included in a single integrated circuit device package. The device of claim 9, wherein the rectifier circuit and the current source are The circuit, the plurality of shunt circuits, and the current limiter circuit are integrated in a special application integrated circuit. The device of claim 1, wherein the substrate comprises a germanium substrate, a gallium nitride substrate, a tantalum carbide substrate or a graphite substrate. The device of claim 1, further comprising: an encapsulant barrier on the substrate at least partially surrounding the LEDs of the groups, configured to reduce the encapsulation during application of an encapsulant material The agent material flows away from one of the LEDs to promote formation of a lens on the string of LEDs. The device of claim 17, wherein the height of one of the encapsulant barriers on the substrate is less than a height of one of the upper surfaces of the LEDs. The device of claim 1, wherein the string of LEDs comprises at least three groups coupled in series with each other, each of the three groups comprising at least two high voltage LEDs coupled in parallel with each other. The device of claim 1 wherein the ac voltage source comprises at least about 110 volts ac. The device of claim 1, wherein the string of LEDs comprises at least three groups coupled in series with each other, each of the three groups comprising at least two high voltage LEDs coupled in series with each other. The device of claim 1 wherein the ac voltage source comprises at least about 220 volts ac. The device of claim 1, wherein at least one of the string of LEDs comprises at least two high voltage LEDs coupled in parallel or in series with each other and the ac voltage source comprises at least about 110 volts ac or about 220 volts ac. A solid state light emitting device comprising: a substrate having first and second opposing surfaces, at least one of the opposing surfaces configured to mount a device thereon; a string of on-board wafer light emitting diodes ( a set of LEDs on the first surface of the substrate coupled in series with each other; and an ac voltage source input from outside the solid state light emitting device coupled to the first surface or the second surface of the substrate. The device of claim 24, further comprising: a rectifier circuit on the first surface or the second surface of the substrate coupled to the ac voltage source input to provide a rectified ac voltage to the substrate; a source circuit coupled to the first surface or the second surface of the substrate and coupled to the rectifier circuit; and a plurality of shunt circuits disposed on the first surface or the second surface of the substrate, the plurality of Each of the shunt circuits is coupled to a respective node of the string and is configured to operate in response to a bias state transition of each of the groups of LEDs. The device of claim 25, wherein at least the plurality of shunt circuits comprise discrete electronic component packages mounted on the first surface of the substrate. The device of claim 25, wherein the substrate comprises a flexible circuit substrate, the device further comprising: a thermally conductive block located in the substrate opposite to where the set of wafer LEDs on the string are to be mounted Location. The device of claim 25, further comprising: a current limiter circuit on the first surface or the second surface of the substrate, in series with the current source circuit and at least one of the LED groups; and at least one capacitor located on the substrate The first surface or the second surface is coupled across the at least one LED group and the current limiter circuit. The device of claim 24, wherein the substrate comprises a flexible circuit substrate, the device further comprising: a heat sink on the second side of the substrate, thermally coupled to the array of wafer LEDs on the substrate. The device of claim 24, wherein the substrate comprises a metal core printed circuit board. The device of claim 24, wherein the LEDs in the set of chip LEDs on the array comprise unencapsulated light emitting diodes mounted on the substrate. The apparatus of claim 24, wherein the set of on-board wafer LEDs comprises at least three groups coupled in series with each other, each of the three sets comprising at least two on-wafer high voltage LEDs coupled in parallel with each other. The device of claim 24, wherein the ac voltage source input comprises at least about 110 volts ac. The apparatus of claim 24, wherein the set of on-board wafer LEDs comprises at least three groups coupled in series with each other, each of the three sets comprising at least two high voltage on-board wafer LEDs coupled in series with each other. The device of claim 24, wherein the ac voltage source input comprises at least about 220 volts ac. The apparatus of claim 24, wherein at least one of the set of on-chip wafer LEDs comprises at least two high voltage on-board wafer LEDs coupled in parallel or in series with each other and the ac voltage source comprises at least about 110 volts ac or about 220 Volt ac. A solid state lighting device comprising: a rectifier circuit configured to be coupled to an ac voltage source to provide a rectified ac voltage; a current source circuit coupled to the rectifier circuit; a string connected to the LED group in series An at least one capacitor coupled to the output of the current source circuit; a current limiter circuit including a current mirror circuit configured to pass through One of the at least one of the groups of LEDs is limited to a current that is less than a current generated by the current source circuit and causes the at least one capacitor to be selected in response to the rectified ac voltage applied to an input of the current source circuit Charging via the current source circuit and discharging via at least one of the groups of LEDs; a plurality of shunt circuits coupled to respective nodes between the LEDs in the string and configured to respond in response The bias state transitions of the LED groups that occur as a function of a change in the magnitude of the rectified ac voltage are selectively enabled and disabled. The device of claim 37, wherein the plurality of shunt circuits each comprise: a transistor that provides a controllable current path between a first node of the string and a terminal of the rectifier circuit; A shutdown circuit coupled to one of the second nodes of the string and coupled to one of the control terminals of the transistor and configured to control the current path in response to a control input. The device of claim 37, further comprising: a substrate having first and second opposing surfaces, wherein at least the string is connected to the LED group in series, the plurality of shunt circuits, the rectifier circuit, and the current source circuit are mounted On the substrate. The device of claim 39, wherein the LEDs in the string comprise on-board wafer LEDs mounted on the substrate. The device of claim 39, wherein the substrate comprises a flexible circuit board, the device further comprising: a heat sink mounted on the substrate opposite the string of LED groups and proximate to the string of LEDs. The device of claim 39, wherein the substrate comprises a metal core printed circuit board (MCPCB). The device of claim 42, wherein the MCPCB comprises a metal layer separated from the surface of the substrate by a dielectric layer and configured to conduct heat away from the string of LEDs. The device of claim 39, wherein the substrate comprises a flexible printed circuit board. The device of claim 39, wherein at least the plurality of shunt circuits comprise discrete electronic component packages mounted on the substrate. The apparatus of claim 37, wherein the string of series connected LED groups comprises at least three groups coupled in series with each other, each of the three groups including The at least two on-wafer high voltage LEDs are coupled in parallel. The device of claim 37, wherein the ac voltage source input comprises at least about 110 volts ac. The apparatus of claim 37, wherein the string of series connected LED groups comprises at least three groups coupled in series with each other, each of the three groups comprising at least two high voltage on-board wafer LEDs coupled in series with each other. The device of claim 37, wherein the ac voltage source input comprises at least about 220 volts ac. The apparatus of claim 37, wherein the string of at least one of the series connected LED groups comprises at least two high voltage on-board wafer LEDs coupled in parallel or in series with each other and the ac voltage source comprises at least about 110 volts ac or about 220 Volt ac. A method of forming a solid state light emitting circuit, comprising: placing a plurality of on-chip wafer light emitting diodes (LEDs) in a string configuration on a surface of a substrate; applying a pattern over the plurality of on-board wafer LEDs An encapsulant material; and the encapsulant material is formed to cover one of the plurality of on-board wafer LEDs to provide a lens for the plurality of on-board wafer LEDs. The method of claim 51, further comprising: placing a plurality of shunt circuits including discrete electronic component packages on the surface of the substrate. The method of claim 51, wherein applying an encapsulant material comprises applying the encapsulant material to cover a portion of the surface between the plurality of on-board wafer LEDs and the plurality of on-board wafer LEDs . The method of claim 53, wherein forming the encapsulant material as a layer comprises: contacting a mold with the encapsulant material to simultaneously form a layer covering the plurality of on-wafer wafer LEDs for the plurality of on-board wafer LEDs The lenses are provided wherein the mold includes an on-chip wafer LED recess positioned in a surface of one of the molds opposite the plurality of on-board wafer LEDs. The method of claim 54, further comprising: placing a plurality of shunt circuits including discrete electronic component packages on the surface of the substrate prior to applying the encapsulant material, wherein the mold further comprises positioning on the surface The plurality of shunt circuits are opposed to discrete electronic component package recesses in the surface of the mold. The method of claim 51, wherein applying an encapsulant material comprises individually dispensing the encapsulant material onto the plurality of on-board wafer LEDs. The method of claim 51, wherein applying an encapsulant material comprises simultaneously dispensing the encapsulant material onto the plurality of on-board wafer LEDs. The method of claim 51, wherein forming the encapsulant material to cover one of the plurality of on-board wafer LEDs to provide a lens for the plurality of on-board wafer LEDs comprises: providing a respective encapsulant barrier to apply the pouch The encapsulant material is reduced during flow of the encapsulant material away from each of the plurality of on-board wafer LEDs to provide a separate lens for each of the plurality of on-board wafer LEDs. The method of claim 57, wherein the encapsulant barrier at least partially surrounds the LEDs and configured to reduce flow of the encapsulant material away from one of the LEDs during application of the encapsulant material to facilitate such The formation of a lens. The method of claim 58, further comprising: removing the encapsulant barriers from the lenses. The method of claim 51, wherein the string configuration comprises connecting the LED groups in series and wherein the series connected LED groups comprise at least three groups coupled in series with each other, each of the three groups comprising coupling in parallel with each other At least two on-board wafer high voltage LEDs. The method of claim 51, wherein the string configuration is configured to couple to a voltage source comprising at least about 110 volts ac. The method of claim 51, wherein the string configuration comprises connecting the LED groups in series and wherein the series connected LED groups comprise at least three groups coupled in series with each other, each of the three groups comprising coupling in series with each other At least two high voltage on-board wafer LEDs. The method of claim 51, wherein the string configuration is configured to couple to a voltage source comprising at least about 220 volts ac one ac. The method of claim 51, wherein the string configuration is configured to be coupled to an ac voltage source and wherein the string configuration comprises connecting the LED groups in series and wherein the string is connected to the LED group by at least one of the series connected LED groups At least two high voltage on-board wafer LEDs coupled in parallel or in series and the ac voltage source includes at least about 110 volts ac or about 220 volts ac. A printed circuit board (PCB) comprising: a substrate configured to be included in a solid state light emitting device, the substrate having first and second opposing surfaces, at least one of the opposing surfaces being configured Having a plurality of on-board wafer light emitting diodes (LEDs) mounted thereon, and the substrate is configured to couple to the solid state light emitting device An external ac voltage source input and configured to mount a plurality of discrete shunt circuit devices thereon, the plurality of discrete shunt circuit devices being coupled to respective nodes between the plurality of LEDs and configured The activation and deactivation are selectively enabled in response to a bias state transition of the LED groups that occurs as one of the LEDs changes in magnitude of the rectified ac voltage. The printed circuit board of claim 66, wherein the substrate comprises a metal core printed circuit board. The printed circuit board of claim 67, wherein the first surface comprises a conductive circuit pattern layer and the second surface comprises a base metal layer having a thickness greater than one of the conductive circuit pattern layers, the printed circuit board further comprising a dielectric layer between the conductive circuit pattern layer and the base metal layer. The printed circuit board of claim 66, wherein the substrate comprises a flexible printed circuit board. The printed circuit board of claim 69, further comprising: a thermally conductive block located at a particular location in the substrate opposite the location on the set of on-chip wafer LEDs. The printed circuit board of claim 66, further comprising: an encapsulant barrier protruding from the surface to at least partially surround a location on the surface in which at least one of the LEDs is to be mounted, And reducing the flow of the encapsulant material away from one of the LEDs during application of an encapsulant material to promote formation of the at least one of the LEDs. A solid state light emitting device comprising: a substrate having first and second opposing surfaces, at least one of the opposing surfaces configured to mount a device thereon, the substrate comprising a substrate region; a string of illumination a diode group (LED) on the first surface of the substrate, coupled in series with each other, and disposed in one of the LED portions of the substrate, the LED portion including one of about 40% or less of the substrate region An LED region configured to emit light comprising about 2000 lumens or more; and an ac voltage source input from outside the solid state light emitting device coupled to the first surface or the second surface of the substrate . A solid state light emitting device comprising: a substrate having first and second opposing surfaces, at least one of the opposing surfaces configured to mount a device thereon, the substrate comprising a substrate region; a string of illumination a diode group (LED) on the first surface of the substrate, coupled in series with each other, and disposed in one of the LED portions of the substrate, the LED portion including one of about 30% or less of the substrate region An LED region, the string of LEDs configured to emit light comprising about 800 lumens or more; and an ac voltage source input from outside the solid state light emitting device coupled to the first surface or the second surface of the substrate . A solid state light emitting device comprising: a substrate having first and second opposing surfaces, the opposite surfaces At least one of is configured to mount a device thereon, the substrate including a substrate region; a string of light emitting diode (LED) groups on the first surface of the substrate, coupled in series with each other, and configured In one of the LED portions of the substrate, the LED portion includes an LED region that is about 38% or less of the substrate region, the string of LEDs configured to emit light comprising about 800 lumens or more; and an ac voltage A source input from the exterior of the solid state light emitting device coupled to the first surface or the second surface of the substrate. The device of claim 74, wherein the string of LEDs comprises at least three groups coupled in series with each other, each of the three groups comprising at least two high voltage LEDs coupled in parallel with each other. The device of claim 74, wherein the ac voltage source input comprises at least about 110 volts ac. The device of claim 74, wherein the string of LEDs comprises at least three groups coupled in series with each other, each of the three groups comprising at least two high voltage LEDs coupled in series with each other. The device of claim 74, wherein the ac voltage source input comprises at least about 220 volts ac. The apparatus of claim 74, wherein the at least one of the string of LEDs comprises at least two high voltage LEDs coupled in parallel or in series with each other and the ac voltage source comprises at least about 110 volts ac or about 220 volts ac.