Multiple row exposed leads for MLP high density packages

• US 7,846,774 B2
• Filed: 08/18/2006
• Issued: 12/07/2010
• Est. Priority Date: 06/05/2006
• Status: Active Grant

• Current Assignee: Carsem (M) SDN BHD (Hong Leong Company (Malaysia) Bhd.)
• Original Assignee: Carsem (M) SDN BHD (Hong Leong Company (Malaysia) Bhd.)
• Inventors: Wong, Chee Heng, Lau, Kam Chuan, Yip, Chee Sang, Liew, Voon Joon, Lee, Say Yeow, Choong, Shang Yan, Yee, Mow Lum, Goh, Kok Siang
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Duong; Khanh B
• Application Number:
  US11/465,757
• Publication Number:
  US 20070281392A1
• Time in Patent Office: 1,572 Days
• Field of Search: None
• US Class Current: 438/111
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• 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 2224/49433 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/49541 Geometry of the lead-frame
• CPC Class Codes: H01L 23/49558 Insulating layers on lead frames, e.g. bridging members
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 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 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges

Abstract

A leadframe strip production process provides encapsulated semiconductor chips with more than two annular rows of exposed leads by utilizing two types of frames, a leadframe to which IC devices are mounted, and a ring frame strip that is attached to the leadframe with a non-conductive adhesive. The leadframe includes die pads that receive the IC chip devices, and each die pad is positioned within multiple rows of connecting pads for connection with bonding pads of the device to be encapsulated. The connecting pads of the leadframe are arranged in an annular fashion, with inner rows being closer to the die pad and outer rows being farther from the die pad.

Claims

1. A method of producing integrated circuit chip packages from a leadframe strip, the method comprising:

coating a non-conductive adhesive material onto an attachment surface of a ring member;

attaching the ring member to a multiple row leadframe member of the leadframe strip at the attachment surface such that the adhesive material bonds the multiple row leadframe member and ring member together, wherein the multiple row leadframe member includes connecting pads arranged in two or more rows along at least one side of the leadframe member and the connecting pads of two connecting pad rows are suspended by interconnects;

removing the interconnects of the multiple row leadframe member;

completing final operations to encapsulate integrated circuit chips bonded to the multiple row leadframe member.

2. The method as defined in claim 1, wherein the leadframe strip includes multiple leadframe members.

3. The method as defined in claim 1, wherein the ring member is a member of a ring frame strip that includes a plurality of ring members.

4. The method as defined in claim 3, further including cutting the ring member from the ring frame strip, wherein attaching the ring member further comprises attaching the cut ring member to the multiple row leadframe member.

5. The method as defined in claim 1, wherein the ring member is constructed of a conductive material.

6. The method as defined in claim 1, wherein the ring member is constructed of a non-conductive material.

7. The method as defined in claim 1, wherein the number of rows of connecting pads of the multiple row leadframe is three or more.

8. The method as defined in claim 1, wherein the interconnects are of reduced thickness relative to the connecting pads.

9. The method as defined in claim 1, wherein the ring member includes two or more annular ring structures.

10. The method as defined in claim 1, wherein the ring frame strip includes ring members that are configured to mate with corresponding leadframe members of the leadframe.

11. The method as defined in claim 1, wherein the non-conductive adhesive material is an epoxy material.

12. The method of claim 1, wherein each ring member of the ring frame strip includes one or more annular ring structures such that each annular ring structure is configured to mate with at least one corresponding row of connecting pads of the leadframe.

13. A method of producing integrated circuit chip packages from a leadframe strip, the method comprising:

providing a leadframe strip having one or more multiple row leadframe members, each of which includes connecting pads arranged in two or more rows along at least one side of the leadframe member such that the connecting pads of two connecting pad rows are suspended by interconnects and the interconnects are of reduced thickness relative to the connecting pads;

providing a ring frame strip having at least one ring member;

coating a non-conductive adhesive material onto an attachment surface of the ring frame strip;

cutting the at least one ring member from the ring frame strip;

attaching the cut at least one ring member to a single one of the multiple row leadframe members at the attachment surface such that the adhesive material bonds the multiple row leadframe member and ring member together;

removing the interconnects of the multiple row leadframe member;

completing final operations to encapsulate one or more integrated circuit chips bonded to the multiple row leadframe.

14. The method as defined in claim 13, wherein the ring member is constructed of a conductive material.

15. The method as defined in claim 13, wherein the ring member is constructed of a non-conductive material.

16. The method as defined in claim 13, wherein the number of rows of connecting pads of the multiple row leadframe is three or more.

17. The method as defined in claim 13, wherein the ring member includes two or more annular ring structures.

18. The method as defined in claim 13, wherein the ring frame strip includes ring members that are configured to mate with corresponding leadframe members of the leadframe.

19. The method as defined in claim 13, wherein the non-conductive adhesive material is an epoxy material.