Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP) For Lighting Solutions And Method Of Manufacturing Thereof
The present invention provides a Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP) LED package having excellent heat dissipation and protection to the LED, thus extending the lifespan of the LED. Each of the SHDMIP LED package comprises a dual lead frame assembly comprising bottom and top lead frame, protection and driver circuit electrically connected to the top or bottom lead frame and a LED electrically connected to the top lead frame. The bottom lead frame comprises heat sink pad for heat dissipation purpose. Plurality of SHDMIP LED packages of the present invention can be configured in a matrix or row, forming a SHDMIP LED array for various lighting solutions.
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This application is a division of application Ser. No. 13/288,979 and claims priority of U.S. Provisional Application No. 61/426,497, filed on Dec. 22, 2010 and U.S. Provisional Application No. 61/452,632 filed on Mar. 14, 2011.
FIELD OF INVENTIONThe present invention relates to integrated microelectronic device. In particular, the present invention provides a Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP), particularly for lighting applications, with a good heat dissipation capability, thus long lifespan, and a method of manufacturing thereof.
BACKGROUNDApplication of integrated microelectronic devices for lighting applications includes solid-state lighting (SSL) applications, light emitting diodes (LEDs), organic light emitting diodes (OLED), optical devices, and the like. Currently, the available manufacturing methods of the integrated microelectronic devices for lighting applications are costly and non-standardized. As illustration, to manufacture LED lighting solutions, LED dies manufacturers and/or integrators manufacture and configure plurality of single LED die into LED arrays. Simultaneously, semiconductor manufacturers will manufacture power conversion for the LED arrays, and also manufacture LED protection devices in separate semiconductor packages. All of LED components are then delivered to LED luminaire manufacturers, who will use all components to assemble LED lighting solutions. Consequently, because of such complicated manufacturing process, the LED lighting solutions suffer from high manufacturing costs and are highly unreliable. Early failures of LED lighting applications are indeed unavoidable, regardless of the fact that the LED dies have long life span.
Besides high-manufacturing cost and poor manufacturing process, another important issue dealt with the integrated microelectronic devices for lighting applications is pertained to heat generated from the device and dissipation system thereof. Insufficient heat dissipation affects performance and reduces life span of the integrated microelectronic devices for lighting applications. The insufficient heat dissipation leads to dimness, even early failure of most integrated microelectronic devices for lighting applications.
US 2006/0054915 discloses a LED package which includes a heat conductive base plate and a light emitting diode (LED) mounted thereon. The heat conductive base plate functions for heat dissipation. The LED package further comprises contact electrodes disposed on a lower opaque layer which surrounds the heat conductive base plate.
SUMMARYThe following presents a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention, and is not intended to identify key features of the invention. Rather, it is to present some of the inventive concepts of this invention in a generalised form as a prelude to the detailed description that is to follow.
In one embodiment, the present invention provides a Sealable Heat Dissipating Microelectronic Integration Platform (SHDMIP) package for a lighting solution. Each SHDMIP package comprises: a dual lead frame assembly and a microelectronic lighting device. Each dual lead frame assembly comprises: a bottom lead frame and a top lead frame. The bottom lead frame has a centre, raised plateau, which defines a first heat sink pad, so that the raised plateau is connected to the surrounding lead frame material along two opposed edges of the plateau. The top lead frame has a second heat sink pad, an anode and a cathode, with the anode and cathode being disposed on opposed sides of the second heat sink pad. The microelectronic lighting device is mounted on the second heat sink pad and electrically connected to the anode and cathode. Solder or glue disposed on the first and second heat sink pads thermally connects the microelectronic lighting device to the bottom lead frame for heat dissipation.
In the above embodiment, the dual lead frame assembly comprises a plurality of dual lead frame assemblies, with the bottom lead frames being connected to adjacent lead frames by tie bars and the top lead frames being similarly connected to adjacent lead frames by separate tie bars. In one aspect, a protection and driver circuit is electrically connected to the top lead frame of the dual lead frame assembly. In another aspect, the ties bars are trimmed to produce individual lighting device. In another aspect, the tie bars are selectively trimmed to produce an array of lighting devices connected in series, parallel or combination of series and parallel. In yet another aspect, the tie bars are selectively trimmed to produce an array of lighting devices and the array is panel molded.
In another embodiment, the present invention provides a SHDMIP package for another lighting solution. Each SHDMIP package comprises: a dual lead frame assembly and a microelectronic lighting device. The dual lead frame assembly comprises a bottom lead frame and a top lead frame. Each of the bottom lead frame is formed with two T-shaped electrodes arranged as mirror images and in a north-south manner, and two first heat sinks arranged in the east-west manner, with one heat sink on each side of the T-shaped electrodes. Each of the top lead frame has a middle, raised plateau, which defines a second heat sink pad, and an anode and cathode; the anode and cathode are disposed on opposed sides of the second heat sink in a north-south manner. The microelectronic lighting device is mounted on the second heat sink pad and electrically connected to the anode and cathode. Solder on the T-shaped electrodes electrically connects the T-shaped electrode to the anode or cathode and solder or glue on first heat sinks thermally connects the microelectronic lighting device to the bottom lead frame for heat dissipation.
In the second embodiment, the dual lead frame assembly comprises a plurality of dual lead frame assemblies, with the bottom lead frames being connected to adjacent lead frames by tie bars and the top lead frames being similarly connected to adjacent lead frames by separate tie bars. In one aspect, a protection and driver circuit is disposed to bridge two limbs of the T-shaped electrodes in the north-south manner in each lead frame assembly, thereby the protection and driver circuit is electrically connected to the associated microelectronic lighting device, anode and cathode. In another aspect, the ties bars are trimmed to produce individual lighting devices, In another aspect, the tie bars are selectively trimmed to produce an array of lighting devices connected in series, parallel or combination of series and parallel. In yet another aspect, the tie bars are selectively trimmed to produce an array of lighting devices and the array of lighting devices is panel molded.
In another aspect, the dual lead frame assembly is made from an electrically conductive material selected from the following: metal, metal alloy or ceramic.
This invention will be described by way of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:
The following descriptions of a number of specific and alternative embodiments are provided to understand the inventive features of the present invention. It shall be apparent to one skilled in the art, however that this invention may be practiced without such specific details. Some of the details may not be described in length so as to not obscure the invention. For ease of reference, common reference numerals will be used throughout the figures when referring to same or similar features common to the figures.
The present invention provides a scalable heat dissipating microelectronic integration platform for lighting applications. The scalable heat dissipating microelectronic integration platform comprises a dual lead frame assembly. The dual lead frame assembly comprises a bottom lead frame and a top lead frame. The dual lead frame assembly can accommodate many electronic components essential for assembly of reliable and robust microelectronic device for lighting applications.
The present invention will now be further illustrated by referring to the following examples of assembly of scalable heat dissipating microelectronic integration platform, with LED as the lighting elements. The assembly will be referred as SHDMIP LED package. It is to be understood that the following examples do not limit the present invention in any way.
In one embodiment, the top lead frame 0042 further comprises top tie bars 0042C.
In a further embodiment, the bottom lead frame 0041 may comprise bottom tie bars.
The LED die 002 is conductively attached to the top lead frame 0042, creating electrical connection for the cathode 0042A. It is preferable, but not limited to, that in this embodiment, the LED die 002 is soldered to the top lead frame 0042.
A protection and driver circuit 005 is integrated to the top lead frame 0042 creating protection for the LED die 002. The LED die 002 and the protection circuit 005 are wire bonded to the anode 0042B of the top lead frame 0042, creating electrical connection for the anode 0042B. The clear lens 003 is then compression molded to cover the LED die 002 and the protection and driver circuit 005, creating optical path for the LED die 002 and the protection and driver circuit 005.
As the top lead frame 0042 is thermally connected to the bottom lead frame 0041, the heat from the LED die 002 attached to the top lead frame 0042 is dissipated to the heat sink of the bottom lead frame 0041. As such, the dual lead frame assembly 004 provides a good heat and power dissipation for the LED die 002, expanding the lifespan of the LED die 002.
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A perspective view of a single SHDMIP LED 100 package according to another embodiment of the present invention is shown in
In another embodiment, the bottom lead frame also may comprise external connection electrodes comprising an anode and a cathode.
The LED die 103 is disposed over the top lead frame 102 of the lead frame assembly 105 and is thermally and electrically attached thereto, forming the SHDMIP LED package 100. The anode 1021 and the cathode 1022 electrically connect the dual lead frame assembly 105 to the LED 103 as well as provide external electrical connection for the lead frame assembly 105 and the LED 103.
It is preferable that a thermally and electrically conductive material, such as solder or glue, is dispensed onto the top lead frame 102 to thermally and electrically connect the LED die 103 to the top lead frame 102 of the lead frame assembly 105. In another embodiment, electrical connection between the LED die 103 and the top lead frame 102 can also be achieved via wire bonding. The thermal and electrical connection between the LED 103 and the lead frame assembly 105 promotes heat conduction therebetween.
It is also desired that the SHDMIP LED package 100 of the present invention includes a protection circuit. The protection circuit further protects the LED 103, thus improves the protection and the reliability of the SHDMIP LED package 100. In one embodiment, the protection circuit is disposed under the top lead frame 102 and electrically connected thereto. In another embodiment, the protection circuit is disposed over the bottom lead frame 101 of the lead frame assembly 105. A plan view showing the bottom lead frame 101 with protection circuit 201 mounted thereon is illustrated in
The SHDMIP LED package 100 also comprises a driver circuit integrated to the bottom lead frame of the lead frame assembly by means of thermally conductive materials, such as solder or glue, or wire bonding. The driver circuit controls all components within the SHDMIP LED package 100.
In another embodiment, the driver circuit can also be attached on the top lead frame of the lead frame assembly.
The SHDMIP LED package of the present invention provides good heat dissipation as well as protection to the LED die. The top and bottom lead frames of the lead frame assembly is equipped with heat sink pads for excellent heat dissipation. The LED die is thermally connected to the second heat sink pad of the top lead frame so that the heat generated from the LED die is conducted to the second heat sink pad. In the meantime, the top lead frame, including the second heat sink pad, is conductively connected to the bottom lead frame having the first heat sink pad. With this manner, the heat generated from the LED die can be further conducted to the bottom lead frame, providing excellent heat dissipation to the LED die, thus extending lifespan of the LED die.
The lead frame assembly further provides electrical connections between the LED die and the protection circuit mounted on the bottom lead frame of the lead frame assembly, thus providing protection to the LED die. The electrical connection between the LED die and the protection circuit is described as follows: as the LED die is electrically connected to the top lead frame, the LED die indeed is electrically connected to the bottom lead frame, and therefore to the protection device circuitry. Accordingly, the LED die is electrically protected by the protection circuit.
It is typically preferable that some single SHDMIP LED packages 100 are arranged in a row or matrix so as to realize a SHDMIP LED array for various lighting solutions.
The plurality of bottom tie bars and the plurality of top tie bars electrically interconnect the plurality of LED dies. The tie bars are trimmed accordingly to put the plurality of LED dies in a series, parallel, anti-parallel or some combinations thereof, electrical connection.
It is preferable that dimension of the matrix of the plurality of bottom lead frames and the matrix of the plurality of top lead frames are equal so that they can fit perfectly as they are attached together to form a matrix of a plurality of lead frame assemblies.
It is to be understood that the selection of copper for the top lead frames and the bottom lead frames in this embodiment is merely an example, not a limitation. The top lead frames and the bottom lead frames can be made from any metals, alloys, ceramics or any other suitable materials, such as ceramics.
In a further embodiment, the matrix of plurality of top lead frame is both thermally and electrically attached to the matrix of plurality of top lead frame.
In another further embodiment, the plurality of protection and driver circuitries can be integrated to the matrix of plurality of top lead frames.
The present invention also provides a method to manufacture SHDMIP LED array. In general, the method comprises the steps of providing a matrix of a plurality of bottom lead frames interconnected by a plurality of bottom tie bars and a matrix of a plurality of top lead frames interconnected by a plurality of top tie bars, electrically integrating a plurality of driver circuits to the matrix of the plurality of bottom lead frames or to the matrix of the plurality of top lead frames, electrically connecting a plurality of protection device circuitries to the matrix of the plurality of bottom lead frames or to the matrix of the plurality of top lead frames, electrically connecting the matrix of the plurality of bottom lead frames and the matrix of the plurality of top lead frames to form a matrix of plurality of lead frame assembly, and electrically connecting a plurality of LED dies to the matrix of plurality of lead frame assembly.
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In a further embodiment, a plurality of driver circuits is singly attached electrically onto each of the matrix of the plurality of bottom lead frames 501.
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As previously described, in another different embodiment, the plurality of protection device circuitries can be attached to the plurality of top lead frames. Similarly, the plurality of driver circuits can be attached to the plurality of top lead frames.
The present invention provides a SHDMIP LED package with an extended lifespan compared to the prior art. The SHDMIP LED package of the present invention has excellent heat dissipation. Additionally, the SHDMIP LED package of the present invention also gives a better protection to the LED, thus guarantees the lifetime and function of the LED.
In addition, method to manufacture the SHDMIP LED package of the present invention is a standardized method that provides high rate of integration of between the LED dies and other circuitry devices. A single SHDMIP LED package of the present invention can accommodate plurality of circuitry devices, such as inverter, current/voltage protection device and a LED die, yet size of the SHDMIP LED package can be as small as 5 mm by 6 mm.
Various lighting solutions can be realized by configuring plurality of SHDMIP LED package of the present invention in a row or matrix of lead frames interconnected by plurality of tie bars. The plurality of LED dies can be electrically connected in series, parallel, anti-parallel or some combinations thereof. To configure the electrical connection of the plurality of SHDMIP LED array, some of the tie bars present in lead frame of the SHDMIP LED array need to be trimmed accordingly. The lead frame assembly can accommodate and interconnect more than hundred LEDs, thereby it is cost effective to use such high density lead frame assembly. With the high-density lead frame, the SHDMIP LED package is economical to be manufactured; yet it is effective and reliable.
The above description illustrates various embodiments of the present invention along with examples of how aspects of the present invention may be implemented. While specific embodiments have been described and illustrated it is understood that many changes, modifications, variations and combinations thereof could be made to the present invention without departing from the scope of the present invention. The above examples, embodiments, instructions semantics, and drawings should not be deemed to be the only embodiments, and are presented to illustrate the flexibility and advantages of the present invention as defined by the following claims:
Claims
1. A Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP) package for a lighting solution comprising:
- a dual lead frame assembly comprising: a bottom lead frame having a centre, raised plateau, which defines a first heat sink pad, so that the raised plateau is connected to the surrounding lead frame material along two opposed edges of the plateau; and a top lead frame having a second heat sink pad, an anode and a cathode, with the anode and cathode being disposed on opposed sides of the second heat sink pad; and
- a microelectronic lighting device mounted on the second heat sink pad and electrically connected to the anode and cathode; wherein solder or glue disposed on the first and second heat sink pads thermally connect the microelectronic lighting device to the bottom lead frame for heat dissipation.
2. A SHDMIP package according to claim 1, wherein the dual lead frame assembly comprises a plurality of dual lead frame assemblies, with the bottom lead frames being connected to adjacent lead frames by tie bars and the top lead frames being similarly connected to adjacent lead frames by separate tie bars.
3. A SHDMIP package according to claim 2, further comprising a protection and driver circuit disposed on each of the second heat sink pad, with each of the protection and driver circuit being electrically connected to the associated microelectronic lighting device, anode and cathode.
4. A SHDMIP package according to claim 3, further comprising a lens formed to encapsulate each microelectronic lighting device, protection/driver circuit and associated electrical connections onto the top lead frame.
5. A SHDMIP package according to claim 4, wherein the ties bars are trimmed to produce individual lighting devices or the tie bars are selectively trimmed to produce an array of lighting devices connected in series, parallel or combination of series and parallel.
6. A SHDMIP package according to claim 2, wherein each dual lead frame assembly is disposed in a cavity mold for encapsulation but with the second heat sink pads, anodes and cathodes being exposed.
7. A SHDMIP package according to claim 6, further comprising a protection and driver circuit disposed on each of the second heat sink pad, with each of the protection and driver circuit being electrically connected to the associated microelectronic lighting device, anode and cathode; and a lens is formed to encapsulate each microelectronic lighting device, protection/driver circuit and associated electrical connections onto the top lead frame.
8. A SHDMIP package according to claim 7, wherein the ties bars are trimmed to produce individual lighting devices or the tie bars are selectively trimmed to produce an array of lighting devices connected in series, parallel or combination of series and parallel.
9. A SHDMIP package according to claim 2, wherein the tie bars are selectively trimmed to produce an array of the dual lead frame assemblies connected in series, parallel or combination of series and parallel, and the array of assemblies is encapsulated to produce a panel molding but with the second heat sink pads, anodes and cathodes being exposed.
10. A SHDMIP package according to claim 9, further comprising a protection and driver circuit disposed on each of the second heat sink pad, with each of the protection and driver circuit being electrically connected to the associated microelectronic lighting device, anode and cathode; and a lens is formed to encapsulate each microelectronic lighting device, protection/driver circuit and associated electrical connections onto the top lead frame.
11. A Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP) package for a lighting solution comprising:
- a dual lead frame assembly comprising: a bottom lead frame formed with two T-shaped electrodes arranged as mirror images and in a north-south manner, and two first heat sinks arranged in the east-west manner, with one heat sink on each side of the T-shaped electrodes; and a top lead frame having a middle, raised plateau, which defines a second heat sink pad, and an anode and cathode, with the anode and cathode being disposed on opposed sides of the second heat sink in a north-south manner; and
- a microelectronic lighting device mounted on the second heat sink pad and electrically connected to the anode and cathode; wherein solder on the T-shaped electrodes electrically connect the T-shaped electrode to the anode or cathode and solder or glue on first heat sinks thermally connect the microelectronic lighting device to the bottom lead frame for heat dissipation.
12. A SHDMIP package according to claim 11, wherein the dual lead frame assembly comprises a plurality of dual lead frame assemblies, with the bottom lead frames being connected to adjacent lead frames by tie bars and the top lead frames being similarly connected to adjacent lead frames by separate tie bars.
13. A SHDMIP package according to claim 12, further comprising a protection and driver circuit disposed to bridge two limbs of the T-shaped electrodes in the north-south manner in each lead frame assembly, thereby the protection and driver circuit is electrically connected to the associated microelectronic lighting device, anode and cathode.
14. A SHDMIP package according to claim 13, wherein each dual lead frame assembly is disposed in a cavity mold for encapsulation but with the second heat sink pads, anodes and cathodes being exposed.
15. A SHDMIP package according to claim 14, further comprising a lens formed to encapsulate each microelectronic lighting device onto the associated top lead frame.
16. A SHDMIP package according to claim 15, wherein the ties bars are trimmed to produce individual lighting devices or the tie bars are selectively trimmed to produce an array of lighting devices connected in series, parallel or combination of series and parallel.
17. A SHDMIP package according to claim 13, wherein the tie bars are selectively trimmed to produce an array of the dual lead frame assemblies connected in series, parallel or combination of series and parallel, and the array of assemblies is encapsulated to produce a panel molding but with the second heat sink pads, anodes and cathodes being exposed.
18. A SHDMIP package according to claim 17, further comprising a lens formed to encapsulate each microelectronic lighting device.
19. A SHDMIP package according to claim 1, wherein the dual lead frame assembly is made from an electrically conductive material selected from the following: metal, metal alloy or ceramic.
20. A SHDMIP package of according to claim 11, wherein the dual lead frame assembly is made from an electrically conductive material selected from the following: metal, metal alloy or ceramic.
Type: Application
Filed: Jan 16, 2014
Publication Date: May 15, 2014
Applicant: PSI Technologies, Inc. (Barangay Punta)
Inventors: Thomas Joachim Werner MOERSHEIM (Barangay Punta), Fernando Villon Capinig (Barangay Punta), Dandy Navarro Jaducana (Barangay Punta), Anthony Augusto Malon Galay (Barangay Punta)
Application Number: 14/157,455
International Classification: F21V 29/00 (20060101);