Thermoforming a substrate bearing LEDs into a curved bulb enclosure

• US 9,528,667 B1
• Filed: 09/03/2015
• Issued: 12/27/2016
• Est. Priority Date: 09/03/2015
• Status: Active Grant

• Current Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Original Assignee: OSRAM Sylvania Inc. (Ams-Osram AG)
• Inventors: Pereyra, Rodrigo M.
• Primary Examiner(s): Santiago, Mariceli
• Application Number:
  US14/844,796
• Time in Patent Office: 481 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/90 Methods of manufacture
• CPC Class Codes: F21V 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21Y 2107/20 on convex supports or substrates, e.g. on the outer surface of spheres
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05K 2201/0129 Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
• CPC Class Codes: H05K 2201/09018 Rigid curved substrate
• CPC Class Codes: H05K 2201/09027 Non-rectangular flat PCB, e.g. circular
• CPC Class Codes: H05K 2201/09118 Moulded substrate
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2203/085 Using vacuum or low pressure
• CPC Class Codes: H05K 2203/1453 Applying the circuit pattern before another process, e.g. before filling of vias with conductive paste, before making printed resistors
• CPC Class Codes: H05K 3/0014 Shaping of the substrate, e.g. by moulding

Abstract

A method of manufacturing a lamp comprising forming a first sheet segment (48) into a first shell portion (110) after forming a first electrically conductive trace (70) on the first sheet segment (48) and after placing a first plurality of LEDs (90) on the first sheet segment (48); forming a second sheet segment (50) into a second shell portion (120) after forming a second electrically conductive trace (80) on the second plastic segment (50) and after placing a second plurality of LEDs (90) on the second sheet segment (50); and joining the first shell portion (110) and the second shell portion (120) into a bulb enclosure (40) defining an interior region (42) therein. The first and second sheet segments (48, 50) are preferably thermoformed and may be connected by a web (60).

Claims

1. A method of manufacturing a lamp (10) comprising:

forming a first electrically conductive trace (70) on a first sheet segment (48), wherein the first sheet segment is a plastics material;

forming a second electrically conductive trace (80) on a second sheet segment (50), wherein the second sheet segment is a plastics material;

placing a first plurality of solid-state light sources (90) on the first sheet segment (48) such that each of the solid-state light sources of the first plurality of solid-state light sources (90) is in electrical communication with the first electrically conductive trace (70), wherein the first plurality of solid-state light sources (90) is a first plurality of light-emitting diodes, and wherein the first plurality of light-emitting diodes each comprise at least one light-emitting chip (94);

placing a second plurality of solid-state light sources (100) on the second sheet segment (50) such that each of the solid-state light sources of the second plurality of solid-state light sources (100) is in electrical communication with the second electrically conductive trace (80), wherein the second plurality of solid-state light sources (100) is a second plurality of light-emitting diodes, and wherein the second plurality of light-emitting diodes each comprise at least one light-emitting chip (94);

forming the first sheet segment (48) into a first shell portion (110) after forming the first electrically conductive trace (70) and after placing the first plurality of solid-state light sources (90) on the first sheet segment (48), wherein the first electrically conductive trace (70) and the first plurality of solid-state light sources (90) are located on a first curved region (112) of the first shell portion (110);

forming the second sheet segment (50) into a second shell portion (120) after forming the second electrically conductive trace (80) on the second sheet segment (50) and after placing the second plurality of solid-state light sources (100) on the second sheet segment (50), wherein the second electrically conductive trace (80) and the second plurality of solid-state light sources (100) are located on a second curved region (122) of the second shell portion (120); and

joining the first shell portion (110) and the second shell portion (120), including the first curved region (112) of the first shell portion (110) and the second curved region (122) of the second shell portion (120), in confronting relation into a bulb enclosure (40) defining an interior region (42) therein.

2. The method of claim 1 wherein:

the first curved region (112) of the first shell portion (110) is permanently curved simultaneously about two axes (X, Y) when forming the first sheet segment (48) into the first shell portion (110); and

the second curved region (122) of the second shell portion (120) is permanently curved simultaneously about two axes (X′

, Y′

) when forming the second sheet segment (50) into the second shell portion (120).

3. The method of claim 2 wherein:

the two axes (X, Y) used to form the first sheet segment (48) into the first shell portion (110) are orthogonal to one another; and

the two axes (X′

, Y′

) used to form the second sheet segment (50) into the second shell portion (120) are orthogonal to one another.

4. The method of claim 2 wherein:

the first curved region (112) of the first shell portion (110) comprises a hemi-spherical surface; and

the second curved region (122) of the second shell portion (120) comprises a hemi-spherical surface.

5. The method of claim 1 further comprising:

forming the first shell portion (110) with a first neck (114), wherein the first electrically conductive trace (70) is located on the first neck (114) of the first shell portion (110);

forming the second shell portion (120) with a second neck (124), wherein the second electrically conductive trace (80) is located on the second neck (124) of the second shell portion (120); and

joining the first shell portion (110) and the second shell portion (120) further includes joining the first neck (114) of the first shell portion (110) and the second neck (124) of the second shell portion (120) in confronting relation.

6. The method of claim 5 further comprising:

attaching a lamp base (20) to the first and second necks (114, 124) of the first and second shell portions (110, 120), respectively, of the bulb enclosure (40), wherein the lamp base (20) is configured to be inserted into a conventional socket (160) of a lamp fixture (150).

7. The method of claim 1 further comprising at least one of:

heating the first sheet segment (48) before forming the first sheet segment (48) into the first shell portion (110); and

heating the second sheet segment (50) before forming the second sheet segment (50) into the second shell portion (120).

8. The method of claim 7 further comprising at least one of:

cooling the first shell portion (110) to retain a formed shape of the first shell portion (110) after forming the first sheet segment (48) into the first shell portion (110); and

cooling the second shell portion (120) to retain a formed shape of the second shell portion (120) after forming the second sheet segment (50) into a second shell portion (120).

9. The method of claim 1 further comprising at least one of:

pre-stretching the first sheet segment (48) with vacuum before forming the first sheet segment (48) into the first shell portion (110); and

pre-stretching the second sheet segment (50) with vacuum before forming the second sheet segment (50) into the second shell portion (120).

10. The method of claim 1 further comprising at least one of:

forming the first sheet segment (48) into the first shell portion (110) on a first male mandrel (210); and

forming the second sheet segment (50) into the second shell portion (120) on the first male mandrel (210) or a second male mandrel (230).

11. The method of claim 10 further comprising at least one of:

forming the first sheet segment (48) into the first shell portion (110) on the first male mandrel (210) further includes applying vacuum through the first male mandrel (210) to pull the first sheet segment (48) onto a first shell forming surface (212) of the first male mandrel (210); and

forming the second sheet segment (50) into the second shell portion (120) on the first or second male mandrel (210, 230) further includes applying vacuum through the first or second male mandrel (210, 230) to pull the second sheet segment (120) onto the first shell forming surface (212) of the first male mandrel (210) or a second shell forming surface (232) of the second male mandrel (230), respectively.

12. The method of claim 10 further comprising at least one of:

forming the first sheet segment (48) into the first shell portion (110) on the first male mandrel (210) further includes applying positive air pressure towards the first male mandrel (210) to push the first sheet segment (48) onto a first shell forming surface (212) of the first male mandrel (210); and

forming the second sheet segment (50) into the second shell portion (120) on the first or second male mandrel (210, 230) further includes applying positive air pressure towards the first or second male mandrel (210, 230) to push the second sheet segment (50) onto the first shell forming surface (212) of the first male mandrel (210) or a second shell forming surface (232) of the second male mandrel (230), respectively.

13. The method of claim 1 further comprising at least one of:

the first electrically conductive trace (70) is formed by etching, printing or laminating; and

the second electrically conductive trace (80) is formed by etching, printing or laminating.

14. The method of claim 1 further comprising at least one of:

the first electrically conductive trace (70) is corrugated in a plane; and

the second electrically conductive trace (80) is corrugated in a plane.

15. The method of claim 1 wherein:

the bulb enclosure 40 has an outer surface (52, 54);

the first plurality of solid-state light sources (90) on the first sheet segment (48) are on the outer surface (52) of the bulb enclosure (40); and

the second plurality of solid-state light sources (100) on the second sheet segment (50) are on the outer surface (54) of the bulb enclosure (40).

16. The method of claim 1 wherein:

the bulb enclosure (40) has an enclosure shape corresponding to an A-series lamp.

17. The method of claim 1 further comprising:

joining the first shell portion (110) and the second shell portion (120) at a joint (130), wherein the joint (130) comprises at least one of a butt joint and a lap joint.

18. The method of claim 1 further comprising:

joining the first shell portion (110) and the second shell portion (120) at a connecting web (60), and

folding, during forming the first shell portion (110) and the second shell portion (120) into the bulb enclosure (40), the first shell portion (110) and the second shell portion (120) together with the connecting web (60).

19. The method of claim 1 wherein:

the first sheet segment (48) and the second sheet segment (50) are segments of a single sheet formed of a plastic composition.

20. The method of claim 10 further comprising at least one of:

fixturing the first sheet segment (48) such that the first plurality of solid state light sources (90) is received into a first cavity (222) which does not include a mold forming surface; and

fixturing the second sheet segment (50) such that the second plurality of solid state light sources (100) is received into the first cavity or a second cavity (222) which does not include a mold forming surface.