US-12624819-B1 - Lens arrays in light-emitting diode packages

Abstract

Light-emitting diode (LED) devices and more particularly lens arrays in LED packages are disclosed. Lens arrays include one or more lens shapes positioned to receive light from LED chip arrays. Individual lenses of lens arrays may be separately formed in LED packages on various surfaces, such as on top surfaces of encapsulant layers that cover LED chip arrays. Shapes of individual lenses may be tailored to provide various emission patterns. Exemplary lens arrays in LED packages include all lenses of a same shape or variably shaped lenses within a same lens array. Differently shaped lenses may be arranged over LED chips of a same serially connected string so that emission patterns and/or colors may be dynamically adjusted during operation.

Inventors

• Timothy Ling
• Ryan Mohn
• David Suich

Assignees

• CREELED, INC.

Dates

Publication Date

20260512

Application Date

20250328

Claims (18)

1. 1 . A light-emitting diode (LED) package comprising: a submount; an array of LED chips on the submount; an encapsulant on the submount and covering the array of LED chips; and an array of lenses on a top surface of the encapsulant; wherein the encapsulant comprises a first silicone, and the array of lenses comprises a second silicone that is different than the first silicone, and the first silicone comprises a lower coefficient of thermal expansion than the second silicone.
2. 2 . The LED package of claim 1 , further comprising a light-altering material on the submount, the light-altering material extending about a perimeter of the array of LED chips to form a dam for retaining the encapsulant.
3. 3 . The LED package of claim 1 , wherein the array of lenses is formed on the top surface of the encapsulant above the array of LED chips.
4. 4 . The LED package of claim 1 , wherein each discrete lens of the array of lenses is provided on a different portion of the encapsulant relative to a corresponding LED chip of the array of LED chips.
5. 5 . The LED package of claim 1 , further comprising a lumiphoric material configured to convert at least a portion of light generated by at least one LED chip of the array of LED chips.
6. 6 . The LED package of claim 5 , wherein the lumiphoric material is provided within the encapsulant with an increased concentration along a top surface of the submount and along a top surface of the array of LED chips relative to the top surface of the encapsulant.
7. 7 . The LED package of claim 5 , wherein the lumiphoric material comprises a pre-formed structure that is attached to the at least one LED chip of the array of LED chips.
8. 8 . The LED package of claim 1 , wherein a first lens of the array of lenses forms a first shape with a lens width that decreases in a direction toward the encapsulant, and the first shape further comprises an inward depression in a direction toward a first LED chip of the array of LED chips.
9. 9 . A light-emitting diode (LED) package comprising: a submount; an array of LED chips on the submount, the array of LED chips comprising a first LED chip and a second LED chip; an encapsulant on the submount and covering the array of LED chips, a first portion of a top surface of the encapsulant being vertically registered with the first LED chip relative to the submount, and a second portion of the top surface of the encapsulant being vertically registered with the second LED chip relative to the submount; and a first lens on the first portion of the top surface of the encapsulant, and the second portion of the top surface of the encapsulant being devoid of any lens; wherein the encapsulant comprises a first silicone, the first lens comprises a second silicone that is different than the first silicone, and the first silicone comprises a lower coefficient of thermal expansion than the second silicone.
10. 10 . The LED package of claim 9 , wherein the first lens is centered with respect to the first LED chip.
11. 11 . The LED package of claim 9 , wherein the first LED chip is configured to be independently addressable with respect to the second LED chip.
12. 12 . A light-emitting diode (LED) package comprising: a submount; an array of LED chips on the submount, the array of LED chips comprising a first LED chip and a second LED chip; an encapsulant on the submount and covering the array of LED chips, a first portion of a top surface of the encapsulant being vertically registered with the first LED chip relative to the submount, and a second portion of the top surface of the encapsulant being vertically registered with the second LED chip relative to the submount; a first lens on the first portion of the top surface of the encapsulant, the first lens forming a first shape; and a second lens on the second portion of the top surface of the encapsulant, the second lens forming a second shape that is different than the first shape; wherein the encapsulant comprises a first silicone, the first lens and the second lens comprise a second silicone that is different than the first silicone, and the first silicone comprises a lower coefficient of thermal expansion than the second silicone.
13. 13 . The LED package of claim 12 , wherein the first shape comprises a lens width that decreases in a direction toward the first portion of the top surface of the encapsulant.
14. 14 . The LED package of claim 13 , wherein the first shape further comprises an inward depression in a direction toward the first LED chip.
15. 15 . The LED package of claim 12 , wherein the first shape comprises a lens width that decreases in a direction toward the first portion of the top surface of the encapsulant, and the second shape is hemispherical.
16. 16 . The LED package of claim 12 , further comprising: a third LED chip of the array of LED chips; and a third lens on a third portion of the top surface of the encapsulant that is vertically registered with the third LED chip, wherein the third lens forms a third shape that is different than the first shape and the second shape.
17. 17 . The LED package of claim 16 , wherein the first LED chip, the second LED chip, and the third LED chip are individually addressable with respect to one another.
18. 18 . The LED package of claim 12 , further comprising a third LED chip of the array of LED chips, wherein the second lens is further on a third portion of the top surface of the encapsulant that is vertically registered with the third LED chip.

Description

FIELD OF THE DISCLOSURE The present disclosure relates to light-emitting diode (LED) devices, and more particularly to lens arrays in LED packages. BACKGROUND Solid-state lighting devices such as light-emitting diodes (LEDs) are increasingly used in both consumer and commercial applications. Advancements in LED technology have resulted in highly efficient and mechanically robust light sources with a long service life. Accordingly, modern LEDs have enabled a variety of new applications, including LED displays and lighting devices for general illumination. LEDs are solid-state devices that convert electrical energy to light and generally include one or more active layers of semiconductor material (or an active region) arranged between oppositely doped n-type and p-type layers. When a bias is applied across the doped layers, holes and electrons are injected into the one or more active layers where they recombine to generate emissions such as visible light or ultraviolet emissions. An LED chip typically includes an active region that may be fabricated, for example, from gallium nitride, gallium phosphide, aluminum nitride, indium nitride, gallium-indium-based materials, gallium arsenide-based materials, and/or from organic semiconductor materials. LED packages have been developed that provide mechanical support, electrical connections, and encapsulation for LED emitters. LED packages with arrays of LED chips, such as chip-on-board LED packages, have been developed for applications needing high light output and high lumen density. As LED technology continues to be developed for ever-evolving modern applications, challenges exist in keeping up with operating demands for LED packages and related elements of LED packages. The art continues to seek improved LEDs and solid-state lighting devices having desirable illumination characteristics capable of overcoming challenges associated with conventional lighting devices. SUMMARY The present disclosure relates to light-emitting diode (LED) devices, and more particularly to lens arrays in LED packages. Lens arrays include one or more lens shapes positioned to receive light from LED chip arrays. Individual lenses of lens arrays may be separately formed in LED packages on various surfaces, such as on top surfaces of encapsulant layers that cover LED chip arrays. Shapes of individual lenses may be tailored to provide various emission patterns. Exemplary lens arrays in LED packages include all lenses of a same shape or variably shaped lenses within a same lens array. Differently shaped lenses may be arranged over LED chips of a same serially connected string so that emission patterns and/or colors may be dynamically adjusted during operation. In one aspect, an LED package comprises: a submount; an array of LED chips on the submount; an encapsulant on the submount and covering the array of LED chips; and an array of lenses on a top surface of the encapsulant. The LED package may further comprise a light-altering material on the submount, the light-altering material extending about a perimeter of the array of LED chips to form a dam for retaining the encapsulant. In certain embodiments, the array of lenses is formed on the top surface of the encapsulant above the array of LED chips. In certain embodiments, the encapsulant comprises a first silicone, and the array of lenses comprises a second silicone that is different than the first silicone. In certain embodiments, the first silicone comprises a lower coefficient of thermal expansion than the second silicone. In certain embodiments, each discrete lens of the array of lenses is provided on a different portion of the encapsulant relative to a corresponding LED chip of the array of LED chips. The LED package may further comprise a lumiphoric material configured to convert at least a portion of light generated by at least one LED chip of the array of LED chips. In certain embodiments, the lumiphoric material is provided within the encapsulant with an increased concentration along a top surface of the submount and along a top surface of the array of LED chips relative to the top surface of the encapsulant. In certain embodiments, the lumiphoric material comprises a pre-formed structure that is attached to the at least one LED chip of the array of LED chips. In certain embodiments, a first lens of the array of lenses forms a first shape with a lens width that decreases in a direction toward the encapsulant, and the first shape further comprises an inward depression in a direction toward a first LED chip of the array of LED chips. In another aspect, an LED package comprises: a submount; an array of LED chips on the submount, the array of LED chips comprising a first LED chip and a second LED chip; an encapsulant on the submount and covering the array of LED chips, a first portion of a top surface of the encapsulant being vertically registered with the first LED chip relative to the submount, and a second portion of the top surface o