Plastic integrated circuit device package and leadframe having partially undercut leads and die pad

• US 6,281,568 B1
• Filed: 10/21/1998
• Issued: 08/28/2001
• Est. Priority Date: 10/21/1998
• Status: Expired due to Term

• Current Assignee: Amkor Technology Singapore Holding Pte., Ltd. (Amkor Technology Incorporated)
• Original Assignee: Amkor Technology Incorporated, ANAM Semiconductor Incorporated (DB HiTek Co., Ltd.)
• Inventors: Roman, David, Glenn, Thomas P., Jewler, Scott J., Moon, D. H., Yee, J. H.
• Primary Examiner(s): Williams, Alexander O.
• Application Number:
  US09/176,614
• Time in Patent Office: 1,042 Days
• Field of Search: 257/666, 257/675, 257/692, 257/693, 257/712, 257/713, 257/717, 257/720, 257/796, 257/730, 257/684, 257/676, 257/706, 257/711, 257/797, 257/788, 257/790
• US Class Current: 257/684
• CPC Class Codes: H01L 2224/05599 Material
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85439 Silver (Ag) as principal constituent
• CPC Class Codes: H01L 2224/85444 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/85455 Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/85464 Palladium (Pd) as principal constituent
• CPC Class Codes: H01L 2224/8547 Zirconium (Zr) as principal constituent
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/4951 Chip-on-leads or leads-on-chip techniques, i.e. inner lead fingers being used as die pad
• 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 23/49555 the bent parts being the outer leads
• 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 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• 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
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49171 : with encapsulating

Abstract

Packages for an integrated circuit device and methods and leadframes for making such packages are disclosed. The package includes a die, a die pad, leads, bond wires, and an encapsulant. The lower surfaces of the die pad and leads are provided with a stepped profile by an etching step that etches partially through the thickness of a peripheral portion of the die pad, and also etches partially through the thickness of portions of the leads. Encapsulant material fills in beneath the recessed, substantially horizontal surfaces of the die pad and leads formed by the above-described etching step, and thereby prevents the die pad and leads from being pulled vertically from the package body. Other portions of the die pad and leads are exposed at the lower surface of the package for connecting the package externally.

A metal leadframe for making an encapsulated package includes an outer frame. A die pad is within and connected to the frame. Leads extend from the frame toward the die pad without contacting the die pad. After an encapsulation step, the die pad and leads are severed from the leadframe, and a completed package is cut from the leadframe. A portion of the severed leads may extend laterally beyond the package sides, and may be bent upwards at an oblique angle to facilitate connection of a solder interconnection to the package.

The packages may be made one at a time, or a plurality of packages may be made simultaneously. Packages may be cut from the leadframe with a punch or saw.

Claims

1. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, and the first portion of the second side of each lead is circular;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

2. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, the second side of a plurality of the leads includes a third portion that is undercut so as to be recessed from the first portion of the second side of the lead, the third portion is covered with the encapsulant material, and the first portion of the second side of the lead is between the second portion and the third portion;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

3. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, the package body has exterior side surfaces adjacent to the first external surface of the package body, and an end of each of the leads terminates in the plane of one of the side surfaces;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

4. The package of claim 3, wherein the exterior side surfaces are orthogonal.

5. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, the package body has tapered exterior side surfaces adjacent to the first external surface of the package body, and a short end portion of each of the leads is bent upwards and terminates along one of said exterior side surfaces;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

6. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, and the integrated circuit device extends over the first side of a plurality of the leads;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad, and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

7. The package of claim 6, wherein the integrated circuit device extends over the first side of all of the leads.

8. The package of claim 6, further comprising an insulative material within said encapsulant material and between the integrated circuit device and the first side of the leads over which the integrated circuit device extends.

9. The package of claim 6, wherein the electrical conductors include bond wires.

10. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, and the first portions of the second sides of a plurality of the leads are fully within a perimeter of the package body;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion of the second side of the die pad is covered by the encapsulant material;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

11. The package of claim 10, wherein the leads are arranged so that the exposed first portions of the second sides of the leads form an array with a plurality of rows and a plurality of columns.

12. The package of claim 11, wherein the first portion of the second side of each lead is circular.

13. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, and the second side of each lead including a planar first portion and a second portion, wherein the planar first portion is exposed at a planar first external surface of the package body, the second portion is undercut so as to be recessed from the first portion, the second portion is covered with the encapsulant material, and the leads are arranged so that the exposed first portions of the second sides of the leads form an array with a plurality of rows and a plurality of columns;

a metal die pad separate from the leads and having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, the peripheral portion is undercut so as to be recessed from the central portion, the peripheral portion of the second side of the die pad is covered by the encapsulant material, and the central portion of the second side of the die pad is exposed at the first external surface of the package body;

an integrated circuit device mounted on the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

14. A package for an integrated circuit device comprising:

a package body formed of a hardened encapsulant material;

a plurality of metal leads having a first side and an opposite second side, wherein the second side of each lead includes a first portion exposed at a planar first external surface of the package body and a second portion that is undercut so as to be recessed from the first portion, the second portion being covered with the encapsulant material;

a metal die pad separate from the leads and having a planar first side having a perimeter;

an integrated circuit device mounted on the first side of the die pad, wherein the integrated circuit device extends over the perimeter of the first side of the die pad; and

a plurality of electrical conductors, wherein an electrical conductor is electrically connected between the integrated circuit device and the first side of each lead.

15. The package of claim 14, wherein the die pad has a second side opposite the first side, and the second side includes a central portion and a peripheral portion surrounding the central portion, wherein the peripheral portion is undercut so as to be recessed from the central portion, and at least the peripheral portion is covered by the encapsulant material.

16. The package of claim 15, wherein the central portion of the second side of the die pad is exposed at the first exterior surface of the package body.

17. The package of claim 14, wherein the die pad has a second side opposite the first side and the second side is fully covered with the encapsulant material.

18. The package of claim 14, wherein the first portion of the second side of each lead is rectangular.

19. The package of claim 14, wherein the first portion of the second side of each lead is circular.

20. The package of claim 14, wherein the second side of a plurality of the leads includes a third portion that is undercut so as to be recessed from the first portion of the second side of the lead, the third portion is covered with the encapsulant material, and the first portion of the second side of the lead is between the second portion and the third portion.

21. The package of claim 14, wherein the package body has exterior side surfaces adjacent to the first external surface of the package body, and an end of each of the leads terminates in the plane of one of the side surfaces.

22. The package of claim 21, wherein the exterior side surfaces are orthogonal.

23. The package of claim 14, wherein the package body has tapered exterior side surfaces adjacent to the first external surface of the package body, and a short end portion of each of the leads is bent upwards and terminates along one of said exterior side surfaces.

24. The package of claim 14, wherein the integrated circuit device extends over the first side of a plurality of the leads.

25. The package of claim 24, wherein the integrated circuit device extends over the first side of all of the leads.

26. The package of claim 24, further comprising an insulative material within the encapsulant material and between the integrated circuit device and the first side of plurality of the leads over which the integrated circuit device extends.

27. The package of claim 14, wherein the first portions of the second sides of the leads are fully within a perimeter of the package body.

28. The package of claim 14, wherein the leads are arranged so that the exposed first portions of the second sides of the leads form an array with a plurality of rows and a plurality of columns.

29. The package of claim 24, wherein the leads are arranged so that the exposed first portions of the second sides of the leads form an array with a plurality of rows and columns.

30. The package of claim 16, wherein the second side of a plurality of the leads includes a third portion that is undercut so as to be recessed from the first portion of the second side of the lead, the third portion is covered with the encapsulant material, and the first portion of the second side of the lead is between the second portion and the third portion.

31. The package of claim 24, where the electrical conductors include bond wires.

32. A leadframe for making a plastic integrated circuit device package comprising:

a disposable metal frame;

a plurality of metal leads integrally connected to the frame, and having a planar first side and an opposite second side, wherein the second side of each lead includes a planar first portion and a second portion, the second portion being undercut so as to be recessed from the first portion, and the leads are arranged so that the first portions of the second sides of the leads form an array with a plurality of rows and a plurality of columns; and

a metal die pad connected to the frame and physically isolated from the leads, said die pad having a planar first side having a perimeter and an opposite second side, wherein the second side of the die pad includes a central portion and peripheral portion surrounding the central portion, and the peripheral portion is undercut so as to be recessed from the central portion.

33. The leadframe of claim 32, wherein the first portion of the second side of each lead is circular.

34. The leadframe of claim 32, wherein the first portion of the second side of each lead is rectangular.

35. The leadframe of claim 32, wherein the second side of a plurality of the leads includes a third portion that is undercut so as to be recessed from the first portion of the second side of the lead, and the first portion of the second side of the lead is between the second portion and the third portion.