ANCHORED LIGHT MIXING STRUCTURES IN LED PACKAGES AND RELATED METHODS
Light-emitting diode (LED) packages and more particularly anchored light mixing structures in LED packages and related methods are disclosed. LED packages include one or more LED chips and integrated light mixing structures, such as light collectors, that are placed over the LED chips to modify far field patterns. Light mixing structures are provided within recesses of LED package housings in positions over the LED chips. Sidewalls of recesses may include alignment features with shapes configured to receive corresponding shapes of light mixing structures. Alternative configurations, alone or in combination with the sidewall alignment features, may include alignment features on top surfaces of the LED packages outside of a recess. As disclosed herein, alignment features are arranged to effectively anchor a light mixing structure in place during package assembly. Additional package structures, such as encapsulants and/or epoxies, may further hold the light mixing structures in place.
1 . A light-emitting diode (LED) package comprising:
one or more LED chips;
a light collector arranged over the one or more LED chips; and
at least one alignment feature configured to receive a portion of the light collector.
2 . The LED package of claim 1 , further comprising a housing, wherein the housing forms a recess with a recess floor and one or more recess sidewalls, and wherein the at least one alignment feature is formed in the one or more recess sidewalls.
3 . The LED package of claim 2 , wherein the at least one alignment feature comprises one or more of a notch, an indentation, a bore hole, a channel, a groove, and a dot in the one or more recess sidewalls.
4 . The LED package of claim 2 , wherein the at least one alignment feature comprises a horizontal lip parallel to the recess floor and along the one or more recess sidewalls.
5 . The LED package of claim 4 , wherein a ratio of a lateral dimension of the at least one alignment feature parallel to the recess floor to a distance from an outer wall of the housing to an edge of the at least one alignment feature closest to the one or more LED chips is less than 0.6.
6 . The LED package of claim 4 , further comprising an adhesion feature within the horizontal lip.
7 . The LED package of claim 6 , wherein:
a ratio of a lateral dimension of the at least one alignment feature parallel to the recess floor to a distance from an outer wall of the housing to an edge of the at least one alignment feature closest to the one or more LED chips is less than 0.6; and
a ratio of the lateral dimension of the at least one alignment feature to a lateral dimension of the adhesion feature in a direction parallel to the recess floor is less than 0.5.
8 . The LED package of claim 6 , wherein the at least one alignment feature and the adhesion feature continuously extend around an entire perimeter of the recess.
9 . The LED package of claim 4 , further comprising a segmented adhesion feature within the horizontal lip.
10 . The LED package of claim 2 , wherein the at least one alignment feature comprises a cutout shape in the one or more recess sidewalls, the cutout shape configured to receive a corresponding protrusion of the light collector.
11 . The LED package of claim 10 , further comprising an adhesion feature within the cutout shape.
12 . The LED package of claim 2 , wherein the at least one alignment feature comprises two alignment features on opposing sides of the one or more LED chips.
13 . The LED package of claim 2 , further comprising a lead frame structure at least partially within the housing, wherein the one or more LED chips are electrically coupled to one or more anode leads and one or more cathode leads of the lead frame structure.
14 . The LED package of claim 13 , wherein portions of the one or more anode leads and portions of the one or more cathode leads extend out of the housing and bend along a bottom surface of the housing.
15 . The LED package of claim 2 , further comprising an underfill material on the recess floor and adjacent to the one or more LED chips.
16 . The LED package of claim 15 , further comprising:
a first encapsulant layer on the underfill material, wherein the first encapsulant layer is between the light collector and the underfill material; and
a second encapsulant layer on the light collector, wherein the light collector is between the first encapsulant layer and the second encapsulant layer.
17 . The LED package of claim 1 , further comprising a lens, wherein the light collector is between the lens and the one or more LED chips.
18 . A method for making a light-emitting diode (LED) package, the method comprising:
mounting one or more LED chips within a recess of a housing, the recess comprising a recess floor and one or more recess sidewalls with one or more alignment features;
providing a first encapsulant within the recess and on the one or more LED chips;
positioning a light collector on the first encapsulant such that portions of the light collector are received by the one or more alignment features; and
providing a second encapsulant within the recess and on the light collector.
19 . The method of claim 18 , further comprising at least partially curing the first encapsulant after providing the light collector and before providing the second encapsulant.
20 . The method of claim 19 , further comprising curing the second encapsulant.
21 . The method of claim 18 , wherein the second encapsulant comprises at least one of a light-reflective material and a light-absorbing material.
22 . The method of claim 18 , wherein the first encapsulant is provided within the recess and at least up to the one or more alignment features.
23 . The method of claim 18 , wherein the one or more alignment features comprise one or more of a notch, an indentation, a bore hole, a channel, a groove, and a dot in the one or more recess sidewalls.
24 . The method of claim 18 , wherein the one or more alignment features comprise a horizontal lip parallel to the recess floor and along the one or more recess sidewalls.
25 . The method of claim 24 , further comprising an adhesion feature within the horizontal lip.
26 . The method of claim 25 , wherein the adhesion feature is segmented within the horizontal lip.
27 . The method of claim 25 , wherein the one or more alignment features and the adhesion feature continuously extend around an entire perimeter of the recess.
28 . The method of claim 18 , wherein the one or more alignment features comprise a cutout shape in the one or more recess sidewalls, the cutout shape configured to receive a corresponding protrusion of the light collector.
29 . The method of claim 18 , further comprising providing an underfill material within the recess before providing the first encapsulant.
30 . A light-emitting diode (LED) display comprising:
a display panel; and
at least one LED package comprising:
one or more LED chips;
a light collector arranged over the one or more LED chips; and
at least one alignment feature configured to receive a portion of the light collector.