Light emitting device

Patent metadata

Field	Value
Publication number	US-12347736-B2
Application number	US-202117467315-A
Country	US
Kind code	B2
Filing date	Sep 6, 2021
Priority date	May 21, 2019
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

A light emitting device includes a circuit substrate, a plurality of light emitting elements, a control element, and a sealing structure. The circuit substrate has a plurality of upper electrical connecting pads at the top thereof and a plurality of testing pads and a plurality of lower electrical connecting pads at the bottom thereof. The light emitting elements are arranged on the circuit substrate. The control element is arranged on the circuit substrate and electrically connected to the light emitting elements. The sealing structure is configured to cover the light emitting elements and the control element, and the testing pads of the circuit substrate are exposed from the sealing structure for testing respective characteristic parameter values of the light emitting elements.

First claim

What is claimed is:

1. A light emitting device, comprising:
a circuit substrate having a plurality of upper electrical connecting pads at the top thereof and a plurality of testing pads and a plurality of lower electrical connecting pads at the bottom thereof;
a plurality of light emitting elements arranged on the circuit substrate;
a control element arranged on the circuit substrate and electrically connected to the light emitting elements; and
a sealing structure configured to cover the circuit substrate and the light emitting elements;
wherein the circuit substrate has a plurality of test paths and a plurality of operation paths, the test paths being in electrical connection with one of the lower electrical connecting pads, the testing pads, and the light emitting elements, and the operation paths being in electrical connection with the other lower electrical connecting pads, the light emitting elements, and the control element;
wherein the testing pads are exposed from the sealing structure for testing respective characteristic parameter values of the light emitting elements through the test paths, and the control element is configured to record the characteristic parameter values.

2. The light emitting device according to claim 1 , wherein the sealing structure includes a package body and an external wall, the package body covering the light emitting elements and the control element, and the external wall surrounding the package body, the light emitting elements, and the control element.

3. The light emitting device according to claim 2 , wherein the sealing structure further includes a light reflecting layer that is formed on an inner side surface of the external wall and contains light diffusing particles; wherein the light diffusing particles are selected from the group consisting of silicon dioxide particles, titanium dioxide particles, or the combination thereof.

4. The light emitting device according to claim 3 , wherein a thickness of the light reflecting layer reaches 50 μm and does not exceed a width of the external wall.

5. The light emitting device according to claim 1 , wherein the circuit substrate has a first area and a second area at the top thereof, the light emitting elements are arranged in the first area, and the control element is arranged in the second area.

6. The light emitting device according to claim 5 , wherein the circuit substrate includes a base layer, a first upper patterned metal layer, a second upper patterned metal layer, and a lower patterned metal layer, the first upper patterned metal layer and the second upper patterned metal layer are laminated on a surface of the base layer, the second upper patterned metal layer is located between the base layer and the first upper patterned metal layer, and the lower patterned metal layer is laminated on another opposite surface of the base layer; wherein the first upper patterned metal layer defines the upper electrical connecting pads, the second upper patterned metal layer is a circuit redistribution layer, and the lower patterned metal layer defines the testing pads and the lower electrical connecting pads.

7. The light emitting device according to claim 6 , wherein the circuit substrate further includes an insulating core layer disposed between the first upper patterned metal layer and the second upper patterned metal layer, and the insulating core layer has a plurality of conductive vias to electrically connect the first upper patterned metal layer to the second upper patterned metal layer.

8. The light emitting device according to claim 6 , wherein the second upper patterned metal layer is formed on the base layer by an adhesive layer, and a recessed area of the second upper patterned metal layer is filled with the adhesive layer.

9. The light emitting device according to claim 5 , further comprising a first light barrier structure arranged on the control element to cover at least one functional layer of the control element.

10. The light emitting device according to claim 9 , wherein the control element further has a surface layer and a middle layer, the surface layer is located above the at least one functional layer and has a plurality of exposed electrical contacts, and the middle layer is located between the surface layer and the at least one functional layer; wherein the first light barrier structure is buried in the middle layer.

11. The light emitting device according to claim 10 , wherein the first light barrier structure is a metal layer.

12. The light emitting device according to claim 9 , wherein the first light barrier structure encapsulates the control element.

13. The light emitting device according to claim 12 , wherein the first light barrier structure is an opaque encapsulant formed from a resin composition.

14. The light emitting device according to claim 9 , wherein the control element further has a surface layer and a middle layer, the surface layer is located above the at least one functional layer and has a plurality of exposed electrical contacts, and the middle layer is located between the surface layer and the at least one functional layer; wherein the first light barrier structure is covered on the surface layer while avoiding positions where the electrical contacts are formed.

15. The light emitting device according to claim 14 , wherein a coverage rate of the first light barrier structure to the at least one functional layer is greater than 60%.

16. The light emitting device according to claim 14 , wherein the first light barrier structure is a metal layer.

17. The light emitting device according to claim 9 , further comprising a second light barrier structure that is located between the first area and the second area of the circuit substrate to separate the light emitting elements from the control element.

18. The light emitting device according to claim 17 , wherein the second light barrier structure is an internal wall that contains light diffusing particles; wherein the light diffusing particles are selected from the group consisting of silicon dioxide particles, titanium dioxide particles, or the combination thereof.

19. The light emitting device according to claim 18 , wherein a height of the second light barrier structure is from 200 μm to 250 μm.

20. The light emitting device according to claim 18 , wherein a quantity of the upper electrical connecting pads extend from the first area to the second area, and each thereof includes a first connecting portion located in the first area, a second connecting portion located in the second area, and a bridge portion located between the first area and the second area; wherein the second light barrier structure extends over the bridge portions of the quantity of the upper electrical connecting pads.

Assignees

• Lite On Opto Tech Changzhou Co Ltd
• Lite On Technology Corp

Inventors

• Lin Chen-Hsiu
• Lin Wen-Hsiang
• Yu Chung-Hsien

Classifications

• H10W90/00 Primary

  Package configurations · CPC title

• H10P74/273 Primary

  Interconnections for measuring or testing, e.g. probe pads · CPC title

• H10H20/882

  Scattering means (H10H20/82 takes precedence) · CPC title

• H10H20/0364

  of interconnections · CPC title

• H10H20/0363

  of optical field-shaping means · CPC title