Encapsulation of light-emitting elements on a display module

• US 9,172,929 B2
• Filed: 12/03/2013
• Issued: 10/27/2015
• Est. Priority Date: 12/10/2012
• Status: Active Grant

• Current Assignee: Daktronics Incorporated
• Original Assignee: Daktronics Incorporated
• Inventors: Mutschelknaus, Shannon Lee, Gab, Jordan, Nearman, Nathan Lane, Nielsen, Ryan J.
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US14/095,584
• Publication Number:
  US 20140160363A1
• Time in Patent Office: 693 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: F21V 19/002 the fastening means engaging the encapsulation or the packaging of the semiconductor device
• CPC Class Codes: F21V 19/003 Fastening of light source holders, e.g. of circuit boards or substrates holding light sources
• CPC Class Codes: F21V 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G09F 27/008 Sun shades, shades, hoods or louvres on electronic displays to minimise the effect of direct sun light on the display
• CPC Class Codes: G09F 9/3026 Video wall, i.e. stackable semiconductor matrix display modules video wall control systems G06F3/1446, G09G2300/026
• CPC Class Codes: G09F 9/33 being semiconductor devices, e.g. diodes
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H04N 9/30 using solid-state colour display devices
• CPC Class Codes: H05B 33/04 Sealing arrangements , e.g. against humidity
• 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 2203/1316 Moulded encapsulation of mounted components
• CPC Class Codes: H05K 2203/1327 Moulding over PCB locally or completely
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence

Abstract

A video display module comprises a circuit board having a front face, a plurality of light-emitting elements electrically coupled to the front face of the circuit board, and a polymer encapsulating member adhered to the front face of the circuit board, the polymer encapsulating member substantially covering at least a portion of the circuit board and a portion of the plurality of light-emitting elements, the polymer encapsulating member substantially sealing the portion of the circuit board and the portion of the plurality of light-emitting elements.

Claims

1. A video display module comprising:

a circuit board having a front face;

a plurality of light-emitting elements electrically coupled to the front face of the circuit board; and

a polymer encapsulating member chemically bonded to at least the front face of the circuit board, the polymer encapsulating member substantially covering at least a portion of the circuit board and a portion of the plurality of light-emitting elements, the polymer encapsulating member substantially sealing the portion of the circuit board and the portion of the plurality of light-emitting elements.

2. The video display module of claim 1, wherein the polymer encapsulating member has a profile that substantially corresponds to a mating profile of the portion of the circuit board and the portion of the plurality of light-emitting elements.

3. The video display module of claim 1, wherein the portion of the circuit board and the portion of the plurality of light-emitting elements is treated to promote chemical bonding between the polymer encapsulating member and the portion of the circuit board and the portion of the plurality of light-emitting elements.

4. The video display module of claim 3, wherein at least the portion of the circuit board and the portion of the plurality of light-emitting elements is treated by at least one of plasma treating the portion of the circuit board and the portion of the plurality of light-emitting elements;

flame treating the portion of the circuit board and the portion of the plurality of light-emitting elements; and

applying a primer to the portion of the circuit board and the portion of the plurality of light-emitting elements.

5. The video display module of claim 1, wherein the plurality of light-emitting elements comprises surface-mounted light-emitting elements that are soldered to the circuit board with a ultraviolet light resistant solder.

6. The video display module of claim 1, wherein at least a portion of the polymer encapsulating member over each of the portion of the plurality of light-emitting elements is substantially transparent to visible light.

7. The video display module of claim 1, further comprising a louver mounted over the polymer encapsulating member, the louver comprising a plurality of openings, wherein the polymer encapsulating member comprises a plurality of light-emitting element receiving projections that extend from an exterior side of the polymer encapsulating member, each projection being configured to receive one of the plurality of light-emitting elements, wherein each light-emitting element receiving projection extends at least partially into one of the plurality of openings in the louver.

8. The video display module of claim 1, wherein the circuit board comprises a rear face opposing the front face and an edge along one or more sides extending rearward from the front face toward the rear face, wherein the polymer encapsulating member is chemically bonded to substantially all of the front face, substantially all of the edge, and substantially all of the rear face.

9. The video display module of claim 8, wherein the front face, the edge, and the rear face of the circuit board are treated to promote chemical bonding between the polymer encapsulating member and the front face and the rear face.

10. The video display module of claim 9, wherein the front face, the edge, and the rear face of the circuit board are treated by at least one of plasma treating, flame treating, and applying a primer thereto.

11. The video display module of claim 1, wherein the polymer encapsulating member comprises a silicone or polyurethane material.

12. A video display module comprising:

a circuit board having a front face;

a plurality of light-emitting elements electrically coupled to the front face of the circuit board; and

a polymer encapsulating member bonded to the front face of the circuit board, the polymer encapsulating member substantially covering at least a portion of the circuit board and a portion of the plurality of light-emitting elements, wherein the polymer encapsulating member is shaped over each of the portion of the plurality of light-emitting elements to form a lens over each of the portion of the plurality of light-emitting elements.

13. The video display module of claim 12, wherein the shape of each lens over each of the portion of the plurality of light-emitting elements is configured to provide for a predetermined viewing angle of each of the portion of the plurality of light-emitting elements.

14. The video display module of claim 12, where in the polymer encapsulating member substantially seals the portion of the circuit board and the portion of the plurality of light-emitting elements.

15. The video display module of claim 12, wherein the portion of the circuit board and the portion of the plurality of light-emitting elements are treated to promote bonding between the polymer encapsulating member and the portion of the circuit board and the portion of the plurality of light-emitting elements.

16. The video display module of claim 15, wherein at least the portion of the circuit board and the portion of the plurality of light-emitting elements is treated by at least one of plasma treating the portion of the circuit board and the portion of the plurality of light-emitting elements;

flame treating the portion of the circuit board and the portion of the plurality of light-emitting elements; and

applying a primer to the portion of the circuit board and the portion of the plurality of light-emitting elements.

17. The video display module of claim 12, wherein the circuit board comprises a rear face opposing the front face and an edge along one or more sides extending rearward from the front face toward the rear face, wherein the polymer encapsulating member is bonded to substantially all of the front face, substantially all of the edge, and substantially all of the rear face.

18. The video display module of claim 17, wherein the front face, the edge, and the rear face of the circuit board are treated to promote bonding between the polymer encapsulating member and the front face and the rear face.

19. The video display module of claim 18, wherein the front face, the edge, and the rear face of the circuit board are treated by at least one of plasma treating, flame treating, and applying a primer thereto.

20. The video display module of claim 12, wherein the polymer encapsulating member comprises a silicone or polyurethane material.

21. A method of manufacturing a video display module, the method comprising:

providing or receiving a circuit board comprising a plurality of light-emitting elements mounted to a face of the circuit board;

forming a polymer encapsulating member over at least a portion of the face of the circuit board and at least a portion of the plurality of light-emitting elements;

chemically bonding the polymer encapsulating member to the face of the circuit board; and

sealing at least the portion of the face of the circuit board and the portion of the plurality of light-emitting elements with the polymer encapsulating member.

22. The method of claim 21, further comprising forming the polymer encapsulating member with a profile that substantially corresponds to a mating profile of the portion of the face of the circuit board and the portion of the plurality of light-emitting elements.

23. The method of claim 21, wherein forming the polymer encapsulation member comprises molding or casting a polymer material comprising at least one of polyurethane or silicone over at least the portion of the face of the circuit board and the portion of the plurality of light-emitting elements.

24. The method of claim 21, further comprising treating at least one of the portion of the face of the circuit board and the portion of the plurality of light-emitting elements to promote chemical bonding between the polymer encapsulating member and the portion of the face of the circuit board or the portion of the plurality of light-emitting elements.

25. The method of claim 24, wherein the treating comprises at least one of plasma treating, flame treating, or applying a primer thereto.