PLCC package with a reflector cup surrounded by an encapsulant

• US 8,101,955 B2
• Filed: 04/17/2009
• Issued: 01/24/2012
• 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: Keh, Kean Loo, Yong, Lig Yi, Wong, Kum Soon
• Primary Examiner(s): Mandala, Victor A
• Assistant Examiner(s): HARRISTON, WILLIAM A
• Application Number:
  US12/426,114
• Publication Number:
  US 20100264437A1
• Time in Patent Office: 1,012 Days
• Field of Search: 257 98-100
• US Class Current: 257/81
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements
• 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 PLCC package comprising first and second lead frames, a plastic structural body, a light source, an encapsulant, and an optical lens. The first lead frame comprises two tongues and a reflector cup. The first and second lead frames are attached to the plastic structural body. The light source is mounted and electrically connected at the bottom of the inside of the reflector cup. The light source is also electrically connected to the second lead frame by a wire bond. The reflector cup is surrounded on at least four sides by the encapsulant, the encapsulant having a domed portion that functions as the optical lens, the encapsulant being an integral single piece structure.

Claims

1. A PLCC package comprising:

a first lead frame comprising;

a reflector cup formed in the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

a second lead frame comprising;

at least two leads;

a plastic structural body;

a light source;

an encapsulant;

an optical lens;

wherein the first and the second lead frames are attached to the plastic structural body;

wherein the light source is physically attached at the bottom of the inside of the reflector cup;

wherein the light source is electrically connected to the reflector cup;

wherein the light source is electrically connected to the second lead frame by a wire bond;

wherein at least four sides of the reflector cup are surrounded by the encapsulant, the encapsulant having a domed portion that functions as the optical lens, the encapsulant being an integral single piece structure that comprises at least one material that is not included in the plastic structural body.

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

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

4. The PLCC 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, and glass and wherein the plastic structural body includes plastic.

5. The PLCC package of claim 1 wherein the encapsulant hermetically seals the light source and wherein the plastic structural body comprises a different coefficient of thermal expansion than the encapsulant.

6. The PLCC package of claim 1 wherein the first and second tongues are substantially rigid so as to reduce movement of the reflector cup.

7. The PLCC package of claim 1 wherein the at least two leads of the first and second lead frames includes leads selected from a group consisting of J leads, SOJ leads, gull wing leads, reverse gull wing leads and straight cut leads.

9. The PLCC package of claim 1 wherein the plastic structural body has dimensions that conforms to the PLCC-4 standard.

10. The PLCC package of claim 1 wherein the plastic structural body comprises a white plastic material.

11. The PLCC package of claim 1 wherein the plastic structural body comprises a black plastic material.

8. A PLCC package comprising:

a first lead frame comprising;

a reflector cup formed in the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

a second lead frame comprising;

at least two leads;

a plastic structural body;

a light source;

an encapsulant;

an optical lens;

wherein the first and the second lead frames are attached to the plastic structural body;

wherein the light source is physically attached at the bottom of the inside of the reflector cup;

wherein the light source is electrically connected to the reflector cup;

wherein the light source is electrically connected to the second lead frame by a wire bond;

wherein at least four sides of the reflector cup are surrounded by the encapsulant, the encapsulant having a domed portion that functions as the optical lens, the encapsulant being an integral single piece structure; and

wherein the plastic structural body is an integral single piece structure having a cavity that serves as a container for containing a portion of the encapsulant.

12. A method of manufacturing a PLCC package, the method comprising:

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

a reflector cup integral to the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

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

at least two leads;

forming a plastic structural body around the first and second lead frames, the plastic structural body containing a cavity and comprising a first material having a first coefficient of thermal expansion;

mounting and electrically connecting a light source at a bottom of the reflector cup;

electrically connecting the light source to the second lead frame;

forming an encapsulant that surrounds at least four sides of the reflector cup while forming an optical lens on the PLCC package, the encapsulant comprising a second material having a second coefficient of thermal expansion different from the first coefficient of thermal expansion.

13. The method of claim 12 wherein the electrical connection between the light source and the second lead frame is a wire bond.

14. The method of claim 12 wherein forming the plastic structural body includes an injection molding process.

15. The method of claim 12 wherein forming the encapsulant is selected from a group consisting of transfer molding, compression molding and injection molding.

16. The method of claim 12 wherein the reflector cup is formed by stamping the first lead frame.

17. A method of manufacturing a PLCC package, the method comprising:

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

a reflector cup integral to the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

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

at least two leads;

forming a plastic structural body around the first and second lead frames, the plastic structural body containing a cavity;

mounting and electrically connecting a light source at a bottom of the reflector cup,

electrically connecting the light source to the second lead frame;

forming an encapsulant that surrounds at least four sides of the reflector cup while forming an optical lens on the PLCC package; and

wherein the plastic structural body is an integral single piece structure having a cavity that serves as a container for containing a portion of the encapsulant.

18. A device comprising:

at least one PLCC package;

the at least one PLCC package comprising;

a first lead frame comprising;

a reflector cup established in the first lead frame;

a first tongue;

a second tongue; and

at least two leads;

a second lead frame comprising;

at least two leads;

a plastic structural body;

a light source;

an encapsulant;

an optical lens;

wherein the first and the second lead frames are attached to the plastic structural body;

wherein the light source is physically attached at the bottom of the inside of the reflector cup;

wherein the light source is electrically connected to the reflector cup;

wherein the light source is electrically connected to the second lead frame by a wire bond;

wherein at least four sides of the reflector cup are surrounded by the encapsulant, the encapsulant having a domed portion that functions as the optical lens, the encapsulant being an integral single piece structure that comprises a different coefficient of thermal expansion as compared to the plastic structural body.

19. The device of claim 18 wherein the at least two leads of the first and second lead frames includes leads selected from a group consisting of J leads, SOJ leads, gull wing leads, reverse gull wing leads and straight cut leads.

20. The device of claim 18 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.