IC package with dual heat spreaders

• US 6,518,098 B2
• Filed: 08/29/2001
• Issued: 02/11/2003
• Est. Priority Date: 09/01/1998
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Corisis, David J.
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): Chambliss, Alonzo
• Application Number:
  US09/942,178
• Publication Number:
  US 20020024133A1
• Time in Patent Office: 531 Days
• Field of Search: 438/106, 438/110, 438/111, 438/112, 438/121, 438/122, 438/123, 438/124, 438/125, 438/126, 438/127, 298/25, 298/27, 298/41, 298/50, 298/55, 298/56, 257/675, 257/678, 257/706, 257/707, 257/712, 257/713, 257/717, 257/720, 257/787, 361/709, 361/711, 361/716
• US Class Current: 438/122
• CPC Class Codes: H01L 2224/05599 Material
• 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 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49568 specifically adapted to facilitate heat dissipation
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49147 : Assembling terminal to base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49171 : with encapsulating
• CPC Class Codes: Y10T 29/49172 : by molding of insulating material
• CPC Class Codes: Y10T 29/49174 : Assembling terminal to elongated conductor

Abstract

An integrated circuit device has a heat spreader attached to each of the major outer encapsulant surfaces. One or both of the heat spreaders has a pair of end posts configured for insertion into through-holes in a substrate to position and support the device during and following the outer lead solder reflow step at board assembly. The heat spreaders provide high heat dissipation and EMR shielding, and may be connected to the substrate ground to become ground planes.

Claims

1. A method for forming a semiconductor device comprising:

providing a semiconductor die connected to exterior leads extending therefrom;

encapsulating said semiconductor die in a material to form a package having opposing major surfaces, a peripheral edge having a register apparatus therein and a portion of said exterior leads connected to said semiconductor die projecting therefrom;

forming a pair of heat spreaders, said pair of heat spreaders having at least two posts extending therefrom for contacting at least a portion of a substrate, each heat spreader of said pair of heat spreaders configured to cover a portion of said opposing major surfaces, said pair of heat spreaders providing essentially a sole structural support for at least one of said exterior leads, said pair of heat spreaders comprising register apparatus on at least one peripheral edge thereof for accurate mounting to said opposing major surfaces;

attaching said pair of heat spreaders to said opposing major surfaces of said package formed by said material encapsulating said semiconductor die by aligning each of said register apparatus of said pair of heat spreaders with said register apparatus of said package to form a a recess extending into said opposing major surfaces and each said pair of heat spreaders;

positioning said pair of heat spreaders so as to provide and opening between distal end portions of said pair of heat spreaders; and

performing another encapsulation step for forming a final package having portions of said pair of heat spreaders therein, said exterior leads and portions of said at least two posts extending from said final package.

2. The method of claim 1, further comprising:

providing a substrate having at least one electrical substrate lead formed thereon; and

forming substrate areas in said substrate for insertion of said a least two posts therein to align said exterior leads with said at least one electrical substrate lead.

3. The method of claim 2, further comprising:

inserting said at least two posts into said substrate areas; and

connecting said exterior leads to said at least one electrical substrate lead.

4. The method of claim 3, further comprising:

securing said at least two posts to said substrate area with adhesive material.

5. The method of claim 1, further comprising:

electrically connecting at least one of said pair of heat spreaders to a ground bus.

6. The method of claim 5, wherein a post of said pair of heat spreaders is connected to said ground bus.

7. A method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces, a peripheral edge having a register apparatus therein and a portion of said exterior leads projecting therefrom;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom for contacting a least a portion of a substrate, each heat spreader of said pair of heat spreaders configured substantially cover one of said opposing major surfaces of said package, said pair of heat spreaders comprising register apparatus on at least one peripheral edge thereof for accurate mounting to said two opposing major surfaces;

attaching said pair of heat spreaders to said two opposing major surfaces of said package so as to provide essentially the sole structural support for at least one of said exterior leads, said attaching comprising aligning each of said register apparatus of said pair of heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said pair of heat spreaders;

positioning said pair of heat spreaders so as to provide an opening between distal end portions of said pair of heat spreaders; and

encapsulating portions of said pair heat spreaders and portions of said package forming a final package, said exterior leads and said at least two through-hole posts extending from said final package.

8. The method of claim 7, further comprising:

providing said substrate having a plurality of electrical substrate leads formed thereon; and

forming through-holes in said substrate for insertion of said at least two through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

9. The method of claim 8, further comprising:

inserting said at least two through-holes posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

10. The method of claim 8, further comprising:

securing said at least two through-hole posts in said through-holes with adhesive material.

11. The method of claim 8, further comprising:

conductivity attaching at least one of said pair of heat spreaders to a ground bus.

12. The method of claim 11, further comprising:

connecting said at least two through-hole posts of said pair of heat spreaders to said ground bus located on said substrate.

13. The method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces and a portion of said exterior leads projecting therefrom;

forming register apparatus on at least one peripheral edge of said package;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom, each heat spreader of said pair of heat spreaders configured to substantially cover one of said two opposing major surfaces of said package;

forming register apparatus on said each heat spreader of said pair of heat spreaders, said register apparatus formed on at least one peripheral edge of said each heat spreader for machine positioning and attachment of said each heat spreader on one of said two opposing major surfaces of said package, said forming said register apparatus on said at least one peripheral edge of said each heat spreader comprising cutout portions of said each heat spreader of said pair of heat spreader;

attaching said pair of heat spreaders to said two opposing major surfaces of said package so as to provide essentially a sole structural support for at least one of said exterior leads, wherein said attaching comprises aligning each of said register apparatus of said pair of heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said pair of heat spreaders;

positioning said pair of heat spreaders so as to provide an opening between distal end portions of said pair of heat spreaders; and

encapsulating portions of said pair of heat spreaders and portions of said package forming a final package, said exterior leads and at least two through-hole posts extending from said final package.

14. The method of claim 13, further comprising:

providing a substrate having a plurality of electrical substrate leads formed thereon; and

forming through-holes in said substrate for insertion of said at least two through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

15. The method of claim 14, further comprising:

inserting said at least two through-hole posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

16. The method of claim 15, further comprising:

securing at least two through-hole posts in said through-holes with adhesive material.

17. The method of claim 15, further comprising:

connecting said at least two through-hole post of said pair of heat spreaders to ground bus located on said substrate.

18. The method of claim 13, further comprising:

conductivity attaching at least one of said pair of heat spreaders to a ground bus.

19. The method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces and four minor edge surfaces connecting said two opposing major surfaces, said package having a portion of said exterior leads projecting from one of said four minor edge surfaces, said four minor edge surfaces having no heat dissipating structures thereon;

forming register apparatus on at least one peripheral edge of said package;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom for contacting at least a portion of a substrate, each heat spreader of said pair of heat spreaders configures to substantially cover one of said opposing major surfaces of said package;

forming register apparatus on each heat spreader of said pair of heat spreaders, said register apparatus formed on at least one peripheral edge of said each heat spreader;

attaching said pair of heat spreaders to said two opposing major surfaces of said package so as to provide essentially a sole structural support for at least one of said exterior leads, wherein said attaching comprises aligning each of said register apparatus of said pair of heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said pair of heat spreaders;

positioning said heat spreaders so as to provide an opening between distal end portions of said pair of heat spreaders; and

encapsulating portions of said pair of heat spreaders and portions of said package forming a final package, said exterior leads and said at least two through-hole posts extending from said final package.

20. The method of claim 19, further comprising:

providing a substrate having a plurality of electrical substrate leads formed thereon; and

forming through-holes in said substrate for insertion of said at least two through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

21. The method of claim 20, further comprising:

inserting aid at least two through-hole posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

22. The method of claim 21, further comprising:

securing said at least two through-hole posts in said through-holes with adhesive material.

23. The method of claim 21, further comprising:

connecting a through-hole post of said pair of heat spreaders to a ground bus located on said substrate.

24. The method of claim 19, further comprising:

conductivity attaching at least one of said pair of heat spreaders to a ground bus.

25. The method of claim 19, wherein said forming register apparatus on at least one peripheral edge of said heat spreader of said pair of heat spreaders is for machine positioning and attachment of each pair of heat spreader on one of said two opposing major surfaces of said package.

26. The method of claim 25, wherein said forming register apparatus on at least one peripheral edge of said heat spreader comprises cutout portions of each heat spreader of said pair of heat spreaders.