Package for multiple light emitting diodes

• US 9,554,457 B2
• Filed: 03/31/2014
• Issued: 01/24/2017
• Est. Priority Date: 04/08/2009
• Status: Active Grant

• Current Assignee: Ledengin, Inc. (Ams-Osram AG)
• Original Assignee: Ledengin, Inc. (Ams-Osram AG)
• Inventors: Yan, Xiantao
• Primary Examiner(s): ARORA, AJAY
• Application Number:
  US14/231,406
• Publication Number:
  US 20140360766A1
• Time in Patent Office: 1,030 Days
• Field of Search: 257/88
• US Class Current: 1/1
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/0313 Organic insulating material
• CPC Class Codes: H05K 1/112 directly combined with via connections
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/2054 Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics

Abstract

Substrates and packages for LED-based light devices can significantly improve thermal performance and provide separate electrical and thermal paths through the substrate. One substrate includes multiple electrically insulating base layers. On a top one of these layers are disposed top-side electrical contacts, including light device pads to accommodate a plurality of light devices. External electrical contacts are disposed on an exterior surface of the substrate. Electrical paths connect the top-side electrical contacts to the external electrical contacts. At least portions of some of the electrical paths are disposed between the electrically insulating base layers. The electrical paths can be arranged such that different subsets of the light device pads are addressable independently of each other. A heat dissipation plate can be formed on the bottom surface of a bottom one of the base layers.

Claims

1. A lighting apparatus comprising:

a substrate having;

a plurality of electrically insulating base layers;

a plurality of top-side electrical contacts disposed on a top one of the electrically insulating base layers;

a plurality of external electrical contacts disposed on an exterior surface of the substrate; and

a plurality of electrical paths connecting the top-side electrical contacts to the external electrical contacts, wherein at least a portion of the plurality of electrical paths is disposed between the electrically insulating base layers; and

a plurality of light-emitting diodes (LEDs) arranged on the top one of the electrically insulating base layers and electrically connected to the plurality of top-side electrical contacts, wherein the electrical paths in the substrate are arranged such that different subsets of the LEDs are connected in a plurality of independently addressable groups and wherein at least one of the independently addressable groups includes at least two of the LEDs.

2. The lighting apparatus of claim 1 wherein at least some of the top-side electrical contacts are sized and shaped to accommodate electrical connections to two different ones of the LEDs.

3. The lighting apparatus of claim 1 wherein the external electrical contacts are disposed on a plurality of side surfaces of the substrate.

4. The lighting apparatus of claim 1 wherein each of the top-side electrical contacts is connected to a different one of the external electrical contacts.

5. The lighting apparatus of claim 1 wherein two or more of the top-side electrical contacts are connected to a same one of the external electrical contacts.

6. The lighting apparatus of claim 1 wherein the LEDs in a first one of the independently addressable groups produce warm white light and the LEDs in a second one of the independently addressable groups produce cool white light.

7. The lighting apparatus of claim 1, further comprising:

at least one electrically insulating upper layer overlying the top one of the electrically insulating base layers, wherein each upper layer has an opening therethrough, the opening having angled walls and being sized and shaped such that at least a portion of each of the top-side electrical contacts is disposed within the opening, wherein the LEDs are arranged within the opening.

8. The lighting apparatus of claim 7 further comprising:

a light sensor disposed within the opening,

wherein the plurality of top-side electrical contacts includes at least two contacts connected to the light sensor, the at least two contacts being connected to at least two contacts of the plurality of external contacts.

9. The lighting apparatus of claim 1 wherein each of the LEDs has an electrical contact on a bottom surface thereof that is electrically connected to a respective one of the top-side electrical contacts.

10. The lighting apparatus of claim 1 wherein each of the LEDs has:

a first electrical contact on a bottom surface thereof, the first electrical contact connected to one of the top-side electrical contacts; and

a second electrical contact on a top surface thereof, the second electrical contact connected to a different one of the top-side electrical contacts by a wire bond.

12. The lighting apparatus of claim 9 wherein the primary lens has a rounded upper surface.

13. The lighting apparatus of claim 9 wherein the primary lens has a sidewall with a tapered portion that is tapered at an angle that matches an angle of the angled sidewall of the circular opening in the at least one electrically insulating upper layer.

14. The lighting apparatus of claim 9 wherein the LEDs in different ones of the independently addressable groups produce light of different colors.

15. The lighting apparatus of claim 12 wherein the LEDs in a first one of the independently addressable groups produce warm white light and the LEDs in a second one of the independently addressable groups produce cool white light.

16. The lighting apparatus of claim 12 wherein the LEDs in a first one of the independently addressable groups produce red light, the LEDs in a second one of the independently addressable groups produce green light, the LEDs in a third one of the independently addressable groups produce blue light, and the LEDs in a fourth one of the independently addressable groups produce amber light.

17. The lighting apparatus of claim 9 wherein each of the LEDs has an electrical contact on a bottom surface thereof that is electrically connected to a respective one of the top-side electrical contacts.

18. The lighting apparatus of claim 9 wherein each of the LEDs has:

a first electrical contact on a bottom surface thereof, the first electrical contact connected to one of the top-side electrical contacts; and

a second electrical contact on a top surface thereof, the second electrical contact connected to a different one of the top-side electrical contacts by a wire bond.

19. The lighting apparatus of claim 9 wherein the external electrical contacts are disposed on a plurality of side surfaces of the substrate.

20. The lighting apparatus of claim 9 wherein each of the top-side electrical contacts is connected to a different one of the external electrical contacts.

21. The lighting apparatus of claim 9 wherein two or more of the top-side electrical contacts are connected to a same one of the external electrical contacts.

22. The lighting apparatus of claim 9 further comprising:

a metal heat dissipation plate disposed on a bottom surface of a bottom one of the electrically insulating base layers,

wherein the metal heat dissipation plate is electrically isolated from the plurality of external contact pads.

11. A lighting apparatus comprising:

a substrate having;

a plurality of electrically insulating base layers;

a plurality of top-side electrical contacts disposed on a top one of the electrically insulating base layers;

a plurality of external electrical contacts disposed on an exterior surface of the substrate; and

a plurality of electrical paths connecting the top-side electrical contacts to the external electrical contacts, wherein at least a portion of the plurality of electrical paths is disposed between the electrically insulating base layers;

a plurality of light-emitting diodes (LEDs) arranged on the top one of the electrically insulating base layers and electrically connected to the plurality of top-side electrical contacts, wherein the electrical paths in the substrate are arranged such that different subsets of the LEDs are connected in a plurality of independently addressable groups and wherein at least one of the independently addressable groups includes at least two of the LEDs;

at least one electrically insulating upper layer overlying the top one of the electrically insulating base layers, wherein each upper layer has an circular opening therethrough, the circular opening having an angled sidewall and being sized and shaped such that at least a portion of each of the top-side electrical contacts is disposed within the opening, wherein the LEDs are arranged within the opening; and

a primary lens disposed at least partially within the opening.