LFCC package with a reflector cup surrounded by a single encapsulant

• US 8,089,075 B2
• Filed: 04/17/2009
• Issued: 01/03/2012
• Est. Priority Date: 04/17/2009
• Status: Active Grant

• Current Assignee: Bench Walk Lighting, LLC
• Original Assignee: Avago Technologies ECBU IP Singapore Pte Limited (Broadcom, Inc.)
• Inventors: Leng, Tan Kheng, Chuan, Ng Keat, Yi, Yong Lig, Loo, Keh Kean
• Primary Examiner(s): Tran, Minh-Loan T.
• Assistant Examiner(s): HARRISTON, WILLIAM A
• Application Number:
  US12/426,104
• Publication Number:
  US 20100264436A1
• Time in Patent Office: 991 Days
• Field of Search: 257 98-100
• US Class Current: 257/81
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

In an embodiment, the invention provides a LFCC package comprising first, second and third lead frames, a light source, and an encapsulant. The first lead frame comprises two tongues and a reflector cup. The first, second and third lead frames are attached to the encapsulant. The light source is mounted at the bottom of the inside of the reflector cup. The light source is electrically connected to the second and third lead frames by wire bonds. The reflector cup is surrounded on at least four sides by the encapsulant, the encapsulant being an integral single piece structure.

Claims

1. A LFCC package comprising:

a first lead frame comprising;

a reflector cup incorporated within the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

a second lead frame comprising;

at least one lead;

a third lead frame comprising;

at least one lead;

a light source;

an encapsulant;

wherein the first, the second and the third lead frames are attached to the encapsulant;

wherein a bottom surface of the light source is physically attached at the bottom of the inside of the reflector cup of the first lead frame and wherein a top surface of the reflector cup of the first lead frame extends beyond a top surface of the light source;

wherein the light source is electrically connected to the second lead frame and the third lead frame by wire bonds;

wherein at least four sides of the reflector cup of the first lead frame are surrounded by the encapsulant, the encapsulant being an integral single piece structure.

2. The LFCC package of claim 1 wherein the light source is an LED.

3. The LFCC package of claim 1 wherein the light source is a semiconductor laser.

4. The LFCC package of claim 1 wherein the encapsulant includes a material selected from a group consisting of epoxy, silicone, a hybrid of silicone and epoxy, amorphous polyamide resin or fluorocarbon, glass and plastic.

5. The LFCC package of claim 1 wherein the encapsulant hermetically seals the light source.

6. The LFCC package of claim 1 wherein the first and second tongues are substantially rigid so as to reduce movement of the reflector cup, wherein the first and second tongues comprises at least one of J leads and SOJ leads and wherein the encapsulant at least partially fills a portion inside a bend of the first and second tongues.

7. The LFCC package of claim 1 wherein the leads of the first, second and third lead frames include leads selected from a group consisting of J leads, SOJ leads, gull wing leads, reverse gull wing leads and straight cut leads.

8. The LFCC package of claim 1 wherein the first lead frame comprises a bent piece of metal having a first major top surface, a second major bottom surface that opposes the first major top surface, a third side surface that abuts the first and second major top surface, and a fourth side surface that opposes the third side surface and also abuts the first and second major top surface, and wherein the at least four sides of the reflector cup that are surrounded by the encapsulant include at least a portion of the first major top surface, at least a portion of the second major bottom surface, at least a portion of the third side surface, and at least a portion of the fourth side surface.

9. The LFCC package of claim 1 wherein an optical lens is formed as an integral part of the encapsulant.

10. The LFCC package of claim 1 wherein the encapsulant has dimensions that conforms to the PLCC-4 standard.

11. A method of manufacturing a LFCC package, the method comprising:

providing a first lead frame, the first lead frame comprising;

a cavity defined in the first lead frame, the cavity at least partially establishing a reflector cup;

a first tongue;

a second tongue; and

at least two leads;

providing a second lead frame, the second lead frame comprising;

at least one lead;

providing a third lead frame, the third lead frame comprising;

at least one lead;

mounting a light source at a bottom of the reflector cup such that a top surface of the light source is positioned below a top surface of the reflector cup;

electrically connecting the light source to the second lead frame and the third lead frame;

forming an encapsulant that surrounds at least four sides of the reflector cup.

12. The method of claim 11 wherein the electrical connections between the light source and the second and the third lead frames are wire bonds.

13. The method of claim 11 wherein forming the encapsulant is selected from a group consisting of transfer molding, compression molding and injection molding.

14. The method of claim 11 wherein the reflector cup is formed by stamping the first lead frame.

15. The method of claim 11 wherein forming encapsulant includes forming the encapsulant such that the dimensions of the encapsulant conform to the PLCC-4 standard.

16. The method of claim 11 wherein the first and second tongues are substantially rigid so as to reduce movement of the reflector cup, wherein the first and second tongues comprises at least one of J leads and SOJ leads, and wherein the encapsulant at least partially fills a space inside a bend of the first and second tongues.

17. A device comprising:

at least one LFCC package;

the at least one LFCC package comprising;

a first lead frame comprising;

a reflector cup defined as a recess in the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

a second lead frame comprising;

at least one lead;

a third lead frame comprising;

at least one lead;

a light source;

an encapsulant;

wherein the first, the second and the third lead frames are attached to the encapsulant;

wherein the light source is physically attached at the bottom of the inside of the reflector cup of the first lead frame and is positioned within the reflector cup of the first lead frame such that a top surface of the light source is below a top surface of the reflector cup of the first lead frame;

wherein the light source is electrically connected to the second lead frame and the third lead frame by wire bonds;

wherein at least four sides of the reflector cup are surrounded by the encapsulant, the encapsulant being an integral single piece structure.

18. The device of claim 17 wherein the leads of the first, second, and third lead frames includes leads selected from a group consisting of J leads, SOJ leads, gull wing leads, and reverse gull wing leads.

19. The device of claim 17 wherein an optical lens is attached to the at least one LFCC package.

20. The device of claim 17 wherein an optical lens is formed as an integral part of the encapsulant.