Led light source
An LED unit ( 20 ) having increased light output. The LED unit ( 20 ) includes a submount substrate ( 22 ) having a cavity ( 24 ). An LED chip ( 30 ) is electrically mounted within the cavity ( 24 ) and a phosphor layer ( 34 ) is deposited in the cavity ( 24 ) that converts blue light from the LED chip ( 30 ) into white light suitable for a vehicle headlight ( 10 ). The walls of the cavity ( 24 ) are metalized ( 40 ) to increase the light output intensity. In one embodiment, a clear protective layer ( 46 ) is deposited in the cavity ( 24 ) over the phosphor layer ( 34 ).
1 . An LED unit comprising:
a substrate including a cavity;
at least one LED chip mounted within the cavity; and
a phosphor layer deposited within the cavity and encapsulating the LED chip.
2 . The unit according to claim 1 wherein a top surface of the phosphor layer is substantially even with a top surface of the substrate.
3 . The unit according to claim 1 further comprising a clear layer deposited in the cavity on top of the phosphor layer.
4 . The unit according to claim 3 wherein a top surface of the clear layer is substantially even with a top surface of the substrate.
5 . The unit according to claim 3 wherein the clear layer is silicon.
6 . The unit according to claim 1 wherein walls of the cavity are metalized to provide an increased light reflection therefrom.
7 . The unit according to claim 1 wherein walls of the cavity are tapered.
8 . The unit according to claim 1 further comprising a base substrate that accommodates a plurality of LED units.
9 . The unit according to claim 1 wherein the at least one LED chip is a 1×1 mm square LED chip and the cavity is a 1.2×1.2 mm square cavity.
10 . The unit according to claim 1 wherein the at least one LED chip is two LED chips.
11 . The unit according to claim 10 wherein the two LED chips are square chips.
12 . The unit according to claim 11 wherein the LED chips are 1×1 mm square LED chips.
13 . The unit according to claim 1 wherein the LED unit is part of a vehicle headlight.
14 . A vehicle headlight comprising:
a base substrate a cavity; and
a plurality of LED units mounted to the base substrate in a predetermined pattern, each LED unit including a sub-mount substrate having a cavity, each LED unit including at least one LED chip mounted within the cavity and a phosphor layer deposited within the cavity and encapsulating the LED chip.
15 . The unit according to claim 14 wherein each LED unit further includes a clear layer deposited in the cavity on top of the phosphor layer.
16 . The unit according to claim 14 wherein walls of each cavity are metalized to provide an increased light reflection therefrom.
17 . The unit according to claim 14 wherein walls of each cavity are tapered.
18 . The unit according to claim 14 wherein the at least one LED chip is two LED chips.
19 . A method of making an LED unit, said method comprising:
providing a substrate;
forming a cavity in the substrate;
electrically mounting at least one LED chip within the cavity; and
depositing a phosphor layer within the cavity to encapsulate the LED chip.
20 . The method according to claim 19 further comprising depositing a clear layer in the cavity on top of the phosphor layer.
21 . The method according to claim 19 further comprising depositing metal layer on walls of the cavity to increase light reflection therefrom.
22 . The method according to claim 19 wherein forming a cavity includes forming walls of the cavity to be tapered.
23 . The method according to claim 19 wherein mounting the at least one LED chip includes mounting two LED chips within the cavity.