AC/DC light emitting diodes with integrated protection mechanism
First Claim
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1. An illumination device includinga plurality of LED devices on a semiconductor chip, said semiconductor chip having:
- (i) a buffer layer above a substrate;
(ii) a doped n-type layer above said buffer layer;
(iii) an active layer above the doped n-type layer; and
(iv) a p-type layer above said active layer;
said buffer layer, doped n-type layer, active layer, and p-type layer being etched away from areas between said LED devices to define said plurality;
a first group of LEDs in a first current path;
a second group of LEDs in a second current path; and
a protection element monolithically integrated into said chip, said protection element comprised of an unetched portion of material in an area between said LEDs, said unetched portion being formed from one of or a combination of the buffer, doped n-type, or p-type layers;
said protection element in electrical connection with said first and second groups of LEDs, said element protecting against at least one of voltage and current overages.
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Abstract
A highly reliable, high voltage AC/DC LED device with integrated protection mechanism is disclosed. The protection element can be a current-limiting resistor, monolithically integrated on LED chip, or a discrete resistor assembled in the lamp package or submount. The protection elements may also include other parts integrated on a submount.
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Citations
18 Claims
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1. An illumination device including
a plurality of LED devices on a semiconductor chip, said semiconductor chip having: - (i) a buffer layer above a substrate;
(ii) a doped n-type layer above said buffer layer;
(iii) an active layer above the doped n-type layer; and
(iv) a p-type layer above said active layer;said buffer layer, doped n-type layer, active layer, and p-type layer being etched away from areas between said LED devices to define said plurality; a first group of LEDs in a first current path; a second group of LEDs in a second current path; and a protection element monolithically integrated into said chip, said protection element comprised of an unetched portion of material in an area between said LEDs, said unetched portion being formed from one of or a combination of the buffer, doped n-type, or p-type layers; said protection element in electrical connection with said first and second groups of LEDs, said element protecting against at least one of voltage and current overages. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- (i) a buffer layer above a substrate;
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11. An illumination device including:
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an AC-LED array including a plurality of electrically connected LED devices on a semiconductor chip, said plurality of LED devices including a first group and a second group, the LED devices in said first group being electrically oriented relative to current flow in a direction opposite to a direction in which said second group is biased; and an integrated protection element included on said chip, said protection element being electrically connected with at least one of said first and second groups of LED devices, said element protecting against one of voltage and current overages. - View Dependent Claims (12, 13)
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14. A method of making an illumination device, said device being adapted for an alternating source of voltage, said method comprising:
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creating a preform by; (i) depositing a buffer layer above a substrate; (ii) depositing and doping an n-layer above said buffer layer to create a doped n-type layer; (iii) depositing an active layer above said doped n-type layer; and (iv) depositing a p-type layer above said active layer; fabricating a plurality of LED devices on a chip by removing said buffer layer, doped n-type layer, active layer, and p-type layer from portions of said preform to define said plurality; establishing a first group of LEDs in a first current path and a second group of LEDs in a second current path on said chip to accommodate said alternating source of voltage; leaving a portion of one of said buffer layer, doped n-type layer, active layer, and p-type layer outside of the defined parameters of said plurality of LED devices to create a protective element; electrically incorporating said protective element into said first and second flow paths; and creating a resistance in said element such that said element is sufficient to protect against at least one of voltage and current overages. - View Dependent Claims (15, 16)
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17. An AC-LED system comprising:
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a plurality of LEDs serially mounted on a semiconductor chip substrate surface; said semiconductor chip being flip-mounted onto an upper surface of a submount; and a protection element located between said substrate surface and said upper surface of the submount, said protection element being serially electrically connected with said plurality of LEDs on said chip using conductive elements provided on the submount.
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18. A fabrication process for a light emitting diode (LED) comprising:
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creating a preform by; (i) depositing a buffer layer above a substrate; (ii) depositing and doping an n-type layer above said buffer layer to create a doped n-type layer; (iii) depositing an active layer above said n-type layer; and (iv) depositing a p-type layer above said active layer; fabricating a plurality of LED devices on a chip by removing said buffer layer, doped n-type layer, active layer, and p-type layer from portions of said preform to define said plurality; establishing a first group of LEDs in a first current path and a second group of LEDs in a second current path on said chip; reverse biasing the first group of LEDs relative the second group of LEDs relative to a current direction; leaving a portion of one of said buffer layer, doped n-type layer, active layer, and p-type layer outside of the defined parameters of at least one of said plurality of LED devices; electrically incorporating said portion into at least one of said first and second flow paths; and creating a resistance in said portion such that said portion is sufficient to protect against at least one of voltage and current overages.
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Specification