Manufacturing methods for solid state light sheet or strip with LEDs connected in series for general illumination
First Claim
1. A method of forming a light emitting structure, the method comprising:
- providing a first layer having a first conductor pattern formed thereon;
providing a plurality of non-packaged light emitting diode (LED) dies, each of the plurality of non-packaged LED dies having at least a corresponding first die electrode and a second die electrode;
bonding the first die electrode of each of the non-packaged LED dies to the first conductor pattern on the first layer without wire bonds, such that the plurality of non-packaged LED dies are spaced apart from one another;
disposing a light-transmissive sheet over the plurality of spaced-apart non-packaged LED dies, the sheet being formed of a dielectric material, such that the sheet deforms to conform to the plurality of spaced-apart non-packaged LED dies and contacts the first conductor pattern on the first layer between the plurality of spaced-apart non-packaged LED dies to separately encapsulate each of the plurality of non-packaged LED dies;
forming first openings in the sheet over the second die electrode of each of the plurality of spaced-apart non-packaged LED dies and second openings in the sheet over portions of the first conductor pattern where the first layer is in contact with the first conductor pattern;
forming a conductor layer overlying the sheet, such that the conductor layer is in electrical contact with the second die electrode of each of the plurality of spaced-apart non-packaged LED dies through the first openings and with the first conductor pattern through the second openings; and
patterning the conductor layer to connect at least a group of the plurality of spaced-apart non-packaged LED dies in series.
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Accused Products
Abstract
A solid state light sheet and method of fabricating the sheet are disclosed. In one embodiment, bare LED chips have top and bottom electrodes, where the bottom electrode is a large reflective electrode. The bottom electrodes of an array of LEDs (e.g., 500 LEDs) are bonded to an array of electrodes formed on a flexible bottom substrate. Conductive traces are formed on the bottom substrate connected to the electrodes. A transparent top substrate is then formed over the bottom substrate. Various ways to connect the LEDs in series are described along with many embodiments. In one method, the top substrate contains a conductor pattern that connects to LED electrodes and conductors on the bottom substrate. In another embodiment, a conductor layer is formed on the outer surface of the top substrate and makes contact with the LED electrodes and conductors on the bottom substrate via openings formed in the top substrate.
104 Citations
16 Claims
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1. A method of forming a light emitting structure, the method comprising:
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providing a first layer having a first conductor pattern formed thereon; providing a plurality of non-packaged light emitting diode (LED) dies, each of the plurality of non-packaged LED dies having at least a corresponding first die electrode and a second die electrode; bonding the first die electrode of each of the non-packaged LED dies to the first conductor pattern on the first layer without wire bonds, such that the plurality of non-packaged LED dies are spaced apart from one another; disposing a light-transmissive sheet over the plurality of spaced-apart non-packaged LED dies, the sheet being formed of a dielectric material, such that the sheet deforms to conform to the plurality of spaced-apart non-packaged LED dies and contacts the first conductor pattern on the first layer between the plurality of spaced-apart non-packaged LED dies to separately encapsulate each of the plurality of non-packaged LED dies; forming first openings in the sheet over the second die electrode of each of the plurality of spaced-apart non-packaged LED dies and second openings in the sheet over portions of the first conductor pattern where the first layer is in contact with the first conductor pattern; forming a conductor layer overlying the sheet, such that the conductor layer is in electrical contact with the second die electrode of each of the plurality of spaced-apart non-packaged LED dies through the first openings and with the first conductor pattern through the second openings; and patterning the conductor layer to connect at least a group of the plurality of spaced-apart non-packaged LED dies in series. - View Dependent Claims (2, 3, 4, 5, 10, 11)
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6. A method of forming a light emitting structure, the method comprising:
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providing a first layer having a first conductor pattern formed thereon; providing a plurality of non-packaged light emitting diode (LED) dies, each of the plurality of non-packaged LED dies having at least a corresponding first die electrode and a second die electrode; bonding the first die electrode of each of the non-packaged LED dies to the first conductor pattern on the first layer without wire bonds, such that the plurality of non-packaged LED dies are spaced apart from one another; forming posts from a dielectric material over the second die electrodes of the plurality of spaced-apart non-packaged LED dies and over the first conductor pattern in between the plurality of spaced-apart non-packaged LED dies; applying a flowable material over the plurality of spaced-apart non-packaged LED dies and around the posts to form a light-transmissive second layer of a dielectric material that conforms to the outer surfaces of the plurality of non-packaged LED dies and of the posts; flattening a top surface of the second layer to expose the posts; removing the posts to create first holes in the second layer over the second die electrodes of the plurality of spaced-apart non-packaged LED dies and second holes in the second layer over the first conductor pattern in between the plurality of spaced-apart non-packaged LED dies; forming a conductor layer overlying the second layer, such that the conductor layer is in electrical contact with the second die electrode of the plurality of spaced-apart non-packaged LED dies through the first holes and with the first conductor pattern through the second holes; and patterning the conductor layer to connect at least a group of the plurality of spaced-apart non-packaged LED dies in series. - View Dependent Claims (7, 8, 12, 13)
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9. A method of forming a light emitting structure, the method comprising:
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providing a first layer having a first conductor pattern formed thereon; providing a plurality of non-packaged light emitting diode (LED) dies, each of the plurality of non-packaged LED dies having at least a corresponding first die electrode and a second die electrode; bonding the first die electrode of each of the non-packaged LED dies to the first conductor pattern on the first layer without wire bonds, such that the plurality of non-packaged LED dies are spaced apart from one another; forming a light-transmissive dielectric layer to encapsulate the plurality of spaced-apart non-packaged LED dies and the first conductor pattern and to cover the first layer; forming first holes in the dielectric layer over the second die electrode of the plurality of spaced-apart non-packaged LED dies and second holes in the dielectric layer over the first conductor pattern in between the plurality of spaced-apart non-packaged LED dies; forming trenches in a top surface of the dielectric layer to connect the formed first and second holes; depositing a conductor layer over the dielectric layer; and etching away a top portion of the conductor layer while leaving the conductor layer in the trenches and holes to interconnect the plurality of spaced-apart non-packaged LED dies in series. - View Dependent Claims (14, 15, 16)
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Specification