Light-emitting device and method of packaging the same

Patent metadata

Field	Value
Publication number	US-11600754-B2
Application number	US-201916694735-A
Country	US
Kind code	B2
Filing date	Nov 25, 2019
Priority date	Nov 29, 2018
Publication date	Mar 7, 2023
Grant date	Mar 7, 2023

Abstract

A light-emitting device (100A) includes: a lead frame (110) including a die paddle (111) and a lead (112) spaced apart from each other; a light-emitting die (120) attached on the die paddle (111); a wire (130) bonding the light-emitting die (120) to the lead (112), wherein a first end (131) of the wire (130) and a region of the light-emitting die (120) to which the first end (131) of the wire (130) is bonded form a first necking area (141); a first resin cover (150a) covering the first necking area (141); and a second resin cover (160) covering the first resin cover (150a), the light-emitting die (120), and the wire (130). The first resin cover (150a) has a hardness lower than a hardness of the second resin cover (160).

First claim

The invention claimed is:

1. A light-emitting device comprising:
a lead frame including a die paddle and a lead spaced apart from each other;
a light-emitting die attached on the die paddle;
a wire connecting the light-emitting die to the lead, a first end of the wire and a region of the light-emitting die to which the first end of the wire is bonded forming a first necking area, a second end of the wire and a region of the lead to which the second end of the wire is bonded forming a second necking area;
a first resin cover covering only the first necking area of the wire and the light-emitting die while leaving a majority of a light emitting area of the light-emitting die free of the first resin cover; and
a second resin cover directly covering the first resin cover, the majority of the light emitting area of the light-emitting die that is free of the first resin cover, and the wire,
the first resin cover having a hardness lower than a hardness of the second resin cover.

2. The light-emitting device of claim 1 , the first resin cover including a silicone resin.

3. The light-emitting device of claim 2 , the silicone resin having a dynamic viscosity in a range of 1 to 8 Pa·s when uncured.

4. The light-emitting device of claim 2 , the silicone resin having a hardness of 30 A to 70 D in Shore hardness scales when cured.

5. The light-emitting device of claim 1 , the second resin cover including an epoxy resin.

6. The light-emitting device of claim 1 , the light-emitting die comprising a light-emitting diode die.

7. The light-emitting device of claim 1 , the first resin cover having a transmissivity lower than a transmissivity of the second resin cover.

8. A method for packaging a light-emitting device, the light-emitting device comprising a lead frame and a light-emitting die, the lead frame comprising a die paddle and a lead spaced apart from each other, the light-emitting die being attached on the die paddle, the method comprising:
connecting the light-emitting die to the lead with a wire, a first end of the wire and a region of the light-emitting die to which the first end of the wire is bonded forming a first necking area, a second end of the wire and a region of the lead to which the second end of the wire is bonded forming a second necking area;
covering only the first necking area of the wire and the light-emitting die with a first resin cover while leaving a majority of a light emitting area of the light-emitting die free of the first resin cover; and
forming a second resin cover directly on and to seal the first resin cover, the majority of the light emitting area of the light-emitting die that is free of the first resin cover, and the wire,
the first resin cover having a hardness lower than a hardness of the second resin cover.

9. The method of claim 8 , the covering of the first necking area comprising dispensing a silicone resin at the first necking area.

10. The method of claim 9 , the silicone resin being uncured during the dispensing and having a dynamic viscosity in a range of 1 to 8 Pa·s when uncured.

11. The method of claim 9 , further comprising curing the silicone resin after the dispensing.

12. The method of claim 11 , the silicone resin having a hardness of 30 A to 70 D in Shore hardness scales after the curing.

13. The method of claim 8 , the forming of the second resin cover comprising molding or casting an epoxy resin on the first resin cover, the light-emitting die, and the wire.

14. The method of claim 8 , the light-emitting die comprising a light-emitting diode die.

15. The method of claim 8 , the first resin cover having a transmissivity lower than a transmissivity of the second resin cover.

16. The method of claim 8 , further comprising covering only the second necking area of the wire and the lead with an additional first resin cover that is separated from the first resin cover, the additional first resin cover having a hardness lower than a hardness of the second resin cover, the second resin cover being formed directly on and to seal the additional first resin cover.

17. The method of claim 8 , the first resin cover being arranged so as to relieve stress on the first end of the wire and the first necking area.

18. The light-emitting device of claim 1 , further comprising an additional first resin cover, separated from the first resin cover, covering only the second necking area of the wire and the lead, the additional first resin cover having a hardness lower than a hardness of the second resin cover, the second resin cover directly covering the additional first resin cover.

19. The light-emitting device of claim 1 , the first resin cover being arranged so as to relieve stress on the first end of the wire and the first necking area.

Assignees

• Lumileds Llc

Inventors

• Yew Hua Sin
• Pan hui ling
• Yan Xinping

Classifications

• H10H20/0364

  of interconnections · CPC title

• H10H20/0362

  of encapsulations · CPC title

• H10H20/854

  characterised by their material, e.g. epoxy or silicone resins · CPC title

• H10H20/01

  Manufacture or treatment · CPC title

• H10H20/857 Primary

  Interconnections, e.g. lead-frames, bond wires or solder balls · CPC title