Micro lead frame structure having reinforcing portions and method

• US 9,184,118 B2
• Filed: 05/02/2014
• Issued: 11/10/2015
• Est. Priority Date: 05/02/2013
• Status: Active Grant

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated
• Inventors: Jeon, Hyeong Il, Chung, Hyung Kook, Kim, Hong Bae, Kim, Byong Jin
• Primary Examiner(s): Nguyen, Khiem D
• Application Number:
  US14/268,877
• Publication Number:
  US 20140327122A1
• Time in Patent Office: 557 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/32245 the item being metallic
• 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 2224/49052 Different loop heights
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85 using a wire connector
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49541 Geometry of the lead-frame
• CPC Class Codes: H01L 23/49548 Cross section geometry H01L23/49562 takes precedence
• CPC Class Codes: H01L 23/49568 specifically adapted to facilitate heat dissipation
• CPC Class Codes: H01L 23/49582 Metallic layers on lead frames
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/18301 being an anchoring portion, i.e. mechanical interlocking between the encapsulation resin and another package part

Abstract

In one embodiment, a micro lead frame structure includes one or more stiffness reinforcing structures formed on leads and/or connecting structures. The stiffness reinforcing structures can be formed by leaving predetermined portions of the micro lead frame at full thickness including, for example, portions of an inner lead, portions of an outer lead, and portions of a connecting bar, combinations thereof, and other structures. The stiffness reinforcing structures are configured to reduce deformation defects and electrical short defects caused by assembly processes.

Claims

1. An electronic packaged device, comprising:

a die pad having peripheral edge segments;

a plurality of first leads segregated into at least two sets that extend along respective ones of at least two peripheral edge segments of the die pad in spaced relation thereto, wherein each first lead includes a first bond finger proximate to the die pad and a first support bar extending outward from a distal end of the first bond finger in a direction away from the die pad, and wherein the first support bar includes a recessed bottom surface;

a plurality of second leads segregated into at least two sets that extend along the respective ones of at least two peripheral edge segments of the die pad in spaced relation thereto, wherein each second lead includes a second bond finger proximate to the die pad and a second support bar extending outward from a distal end of the second bond finger in a direction away from the die pad, and wherein the second support bar is shorter than the first support bar, and wherein the second support bar includes a stiffness reinforcing structure extending along a top surface of the second support bar that is configured to reduce movement of the second lead during assembly;

an electronic die attached to the die pad and electrically connected to at least some of the first leads and the second leads; and

a package body defining generally planar bottom and side surfaces, the package body at least partially encapsulating the first leads, the second leads and the electronic die such that at least portions of the first leads and at least portions of the second leads are exposed in the bottom and side surfaces of the package body.

2. The electronic packaged device of claim 1, wherein at least a portion of the stiffness reinforcing structure is exposed in a side surface of the package body.

3. The electronic packaged device of claim 1, wherein the stiffness reinforcing structure comprises an inverted T-shape in a cross-sectional view that is narrow at an upper portion and wide at a lower portion.

4. The electronic packaged device of claim 3, wherein the second support bar having the inverted T-shape is exposed in a side surface of the package body.

5. The electronic packaged device of claim 1, wherein:

the first support bar has a top surface that is devoid of a stiffness reinforcing structure;

the first bond finger has a recessed portion on an end proximate to the die pad; and

the second bond finger has a recessed portion on an end proximate to the die pad.

6. The electronic packaged device of claim 1, wherein:

the first support bar has a first cross-sectional shape in an end view;

the second support bar has a second cross-sectional shape in an end view that is different than the first cross-sectional shape.

7. The electronic packaged device of claim 6, wherein the second cross-sectional shape is other than a square shape or a rectangular shape.

8. The electronic packaged device of claim 1, wherein the first bond finger and the second bond finger reside substantially on the same plane.

9. The electronic packaged device of claim 1, wherein the stiffness reinforcing structure is defined by two opposed and spaced apart recessed portions in the second support bar.

10. The electronic packaged device of claim 1, wherein:

the first bond finger and the second bond finger are spaced having a pitch less than approximately 0.85 millimeters;

the first bond finger and the second bond finger have a thickness less than approximately 0.25 millimeters; and

the electronic packaged device is configured as a near chip scale packaged device.

11. An electronic packaged device, comprising:

a die pad having a peripheral edge segment;

a first lead along the peripheral edge segment in spaced relation thereto, wherein the first lead comprises;

a first bond finger proximate to the die pad, and

a first support bar extending from a distal end of the first bond finger in a direction away the die pad, wherein the first support bar includes a recessed bottom surface;

a second lead along the peripheral edge segment in spaced relation thereto, wherein the second lead comprises;

a second bond finger proximate to the die pad, and

a second support bar extending from a distal end of the second bond finger in a direction away from the die pad, wherein the second support bar is shorter than the first support bar, and wherein the second support bar includes a stiffness reinforcing structure along a top surface of the second support bar that is configured to reduce movement of the second leads during assembly;

an electronic die attached to the die pad and electrically connected to the first lead and to the second lead; and

a package body defining a generally planar bottom surface and side surfaces, the package body at least partially encapsulating the first lead, the second lead, and the electronic die such that at least portions of the first bond finger and at least portions of the second bond finger are exposed in the bottom surface and the side surfaces of the package body, and wherein at least a portion of the stiffness reinforcing structure is exposed in one of the side surfaces.

12. The electronic packaged device of claim 11, wherein the stiffness reinforcing structure is bounded on two sides by recessed regions formed along the top surface of the second support bar.

13. The electronic packaged device of claim 11, wherein:

a distal end of the second support bar is exposed in a side surface of the package body and has a first cross-sectional shape;

a distal end of the first support bar is exposed in the side surface adjacent to the second support bar and has a second cross-sectional shape; and

the first cross-sectional shape is different than the second cross-sectional shape.

14. The electronic packaged device of claim 13, wherein the first cross-sectional shape is an inverted T-shape.

15. The electronic packaged device of claim 13, wherein:

at least a portion of the die pad is exposed in the bottom surface of the package body;

the first cross-sectional shape is a shape other than a square shape or a rectangle shape;

the first support bar has a top surface devoid of a stiffness reinforcing structure;

the first bond finger has a recessed portion on an end proximate to the die pad; and

the second bond finger has a recessed portion on an end proximate to the die pad.

16. A packaged semiconductor device, comprising:

a die pad having a peripheral edge segment;

a first lead along the peripheral edge segment in spaced relation thereto, wherein the first lead comprises;

a first bond finger proximate to the die pad, and

a first support bar extending from a distal end of the first bond finger in a direction away the die pad, wherein the first support bar includes a recessed bottom surface;

a second lead along the peripheral edge segment in spaced relation thereto, wherein the second lead comprises;

a second bond finger proximate to the die pad, and

a second support bar extending from a distal end of the second bond finger in a direction away from the die pad, wherein the second support bar is shorter than the first support bar, and wherein the second support bar includes a reinforcing structure along a top surface of the second support bar that is configured to reduce movement of the second lead during assembly;

at least one semiconductor die attached to the die pad and electrically connected to the first lead and to the second lead; and

a package body defining a generally planar bottom surface and side surfaces, the package body at least partially encapsulating the first lead, the second lead, and the electronic die such that at least portions of the first bond finger and at least portions of the second bond finger are exposed in the bottom surface and the side surfaces of the package body, and wherein at least a portion of the reinforcing structure is exposed in one of the side surfaces.

17. The device of claim 16, wherein:

the reinforcing structure is along a top surface of the second support bar; and

the reinforcing structure is bounded on two sides by recessed regions formed along the top surface of the second support bar.

18. The device of claim 17, wherein:

a distal end of the second support bar is exposed in a side surface of the package body and has a first cross-sectional shape;

a distal end of the first support bar is exposed in one of the side surface adjacent to the second support bar and has a second cross-sectional shape; and

the first cross-sectional shape is different than the second cross-sectional shape.

19. The device of claim 18, wherein:

at least a portion of the die pad is exposed in the bottom surface of the package body; and

the first cross-sectional shape is a shape other than a square shape or a rectangle shape.

20. The device of claim 16, wherein:

the first bond finger and the second bond finger are spaced having a pitch less than approximately 0.85 millimeters;

the first bond finger and the second bond finger have a thickness less than approximately 0.25 millimeters; and

the packaged semiconductor device is configured as a near chip scale packaged device.