SMART PIXEL SURFACE MOUNT DEVICE PACKAGE

• US 20170009971A1
• Filed: 02/08/2014
• Published: 01/12/2017
• Est. Priority Date: 02/08/2014
• Status: Active Grant

• Current Assignee: Cree Huizhou Solid State Lighting Company Limited (Smart Global Holdings Incorporated)
• Original Assignee: Cree Huizhou Solid State Lighting Company Limited (Smart Global Holdings Incorporated)
• Inventors: CHAN, Chi Keung Alex, ZHONG, Zhenyu, PANG, Chak Hau Charies, LAU, Yue Kwong Victor, LIU, Erzhuang
• Granted Patent: US 10,833,054 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21V 17/101 permanently, e.g. welding, gluing or riveting
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: G09G 2300/0452 Details of colour pixel setup, e.g. pixel composed of a red, a blue and two green components
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• 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 3/0044 : Mechanical working of the substrate, e.g. drilling or punching H05K3/0008 takes precedence
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/303 : Surface mounted components, e.g. affixing before soldering, aligning means, spacing means H05K3/32 takes precedence

Abstract

Emitter panels and displays utilizing solid state packages and methods for fabricating the same are disclosed. One emitter panel comprises a raised barrier on a submount defining a plurality of cavities, each cavity having at least one LED in a pixel area. The panel is capable of receiving electrical signals for independently controlling the emission from the emitters. Solid state displays utilize the emitter panels mounted in relation to one another to generate a message or image. The panels comprise multiple pixels each having at least one light emitter, with each panel capable of receiving electrical signals for independently controlling the emission of at the pixels.

Claims

1. A method for fabricating solid state emitter panel, comprising:

providing a barrier on a submount such that a plurality of pixel areas are defined;

affixing at least one light emitter in each of said pixel areas;

electrically connecting said emitters to said submount;

at least partially covering said light emitters in said pixel areas with an encapsulant.

2. The method of claim 1, wherein said barrier is provided on said submount using an additive process.

3. The method of claim 1, wherein said barrier is a mask.

4. The method of claim 1, further comprising molding said barrier into a grid shape and affixing it to said submount.

5. The method of claim 1, further comprising stamping said barrier into a grid shape and affixing it to said submount.

6. The method of claim 1, further comprising drilling said barrier into a grid shape and affixing it to said submount.

7. The method of claim 1, wherein said barrier comprises a polymer material.

8. The method of claim 1, wherein said barrier comprises a polyphthalamide (PPA) material.

9. The method of claim 1, wherein said barrier comprises a printed circuit board (PCB) material.

10. The method of claim 1, further comprising applying an adhesive to said submount and affixing said barrier to said submount.

11. The method of claim 10, further comprising B-staging said adhesive after said adhesive is applied to said submount and prior to affixing said barrier to said submount.

12. The method of claim 10, wherein said adhesive is a Room Temperature Vulcanizing (RTV) material.

13. The method of claim 1, wherein light emitters in said pixel areas are covered by at least partially filling said pixel areas with an encapsulant material.

14. The method of claim 1, wherein said barrier is provided on said submount using a subtractive process.

15. The method of claim 1, wherein said barrier is provided by drilling recesses into said submount to define said pixel areas.

16. The method of claim 1, wherein said barrier is provided on said submount before said emitters are electrically connected to said submount.

17. The method of claim 1, wherein said barrier is provided on said submount after said emitters are connected to said submount.

18. The method of claim 1, wherein said barrier is provided on said submount by affixing a molded encapsulant to said submount after said emitters have been electrically connected to said submount such that said emitters are within said pixel areas.

19. The method of claim 18, further comprising cutting a plurality of grooves into said submount between said pixel areas prior to affixing said encapsulant to said submount.

20. The method of claim 18, further comprising removing flash material from said submount between said pixel areas.

21. The method of claim 18, further comprising filling in areas of said submount between said pixel areas with a filler material.

22. The method of claim 21, wherein said filling comprises covering said pixel areas with a stencil and applying paint on said areas of said submount between said pixel areas and on sidewalls of said molded encapsulant.

23. The method of claim 21, wherein said filling comprises applying a conformal photo-sensitive material to said submount and said molded encapsulant and exposing said photo-sensitive material for a duration such that some of said photo-sensitive material remains in said areas of said submount between said pixel areas and on sidewalls of said molded encapsulant after development of said photo-sensitive material.

24. The method of claim 21, wherein said filling comprises applying a conformal material to said submount and said molded encapsulant and mechanically removing said material to an extent such that an emission surface of said molded encapsulant is exposed and some of said material remains in said areas of said submount between said pixel areas and on sidewalls of said molded encapsulant.

25. The method of claim 21, wherein said filler material is black.

26. The method of claim 1, wherein said at least one light emitter comprises at least one emitter that provides red light, at least one emitter that provides green light, and at least one emitter that provides blue light.

27. The method of claim 1, wherein said at least one light emitter is electrically connected to said submount using wire bonds.

28. A solid state emitter panel, comprising:

a submount comprising a mount surface; and

a barrier on and raised above said mount surface, said barrier defining an array of pixel areas;

a plurality of pixels arranged in said pixel areas on said submount, each of said pixels comprising;

at least one light emitter in said pixel area; and

an encapsulant at least partially covering said at least one emitter.

29. The solid state emitter panel of claim 28, wherein said submount comprises electrical interconnections, each of said light emitters electrically connected to said submount in said pixel area.

30. The solid state emitter panel of claim 28, wherein each pixel comprises an emitter that provides red light, an emitter that provides green light, and an emitter that provides blue light.

31. The solid state emitter panel of claim 28, wherein said barrier is defined by recesses in said submount such that said mount surface is sunken into said submount, said pixel areas being in said recesses.

32. The solid state emitter panel of claim 28, wherein said barrier comprises a mask on said submount.

33. The solid state emitter panel of claim 28, wherein said barrier comprises a molded encapsulant.

34. The solid state emitter panel of claim 28, further comprising an adhesive between said barrier and said submount.

35. The solid state emitter panel of claim of 28, further comprising filler material on said submount between said pixels.

36. The solid state emitter panel of claim 28, wherein portions of said submount have been removed to define grooves running between said pixels.

37. The solid state emitter panel of claim 28, wherein said pixels are arranged into at least one 4×

4 array.