Pbga package with integrated ball grid

• US 6,384,471 B1
• Filed: 01/04/2001
• Issued: 05/07/2002
• Est. Priority Date: 05/10/1999
• Status: Active Grant

• Current Assignee: Bull Sas (Atos SE)
• Original Assignee: Bull Sas (Atos SE)
• Inventors: Stricot, Yves, Petit, Claude
• Primary Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US09/743,061
• Time in Patent Office: 488 Days
• Field of Search: 257/678, 257/693, 257/737, 257/738, 257/698, 438/106, 438/121
• US Class Current: 257/678
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/49822 Multilayer substrates multilayer metallisation on monolayer substrate H01L23/498
• CPC Class Codes: H01L 24/45 of an individual wire connector
• 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 2924/00014 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 Monolayer substrate
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/1532 the connection portion being formed on the die mounting surface of the substrate

Abstract

The present invention concerns a package for an integrated circuit (3) of the type comprising a cavity (2) in which the integrated circuit (3) is mounted, the active surface (10) of the integrated circuit (3) being electrically connected to the package on the level of connection (Nc) of an array of balls (13i) to the package, providing a mechanical and electrical link between the integrated circuit (3) and a printed circuit card to which the package must be assembled. It is characterized in that it comprises an additional layer (14) that is rigid and electrically neutral, mounted on the level of connection (Nc) of the integrated circuit (3) and the balls (13i) and containing the balls (13i).

It particularly applies to the connections of BGA and PBGA packages.

Claims

1. An integrated circuit package of the “

cavity down”

type, comprising a first cavity (2), an integrated circuit (3) mounted in said first cavity, the integrated circuit having an active surface (10) electrically connected to the package by connecting wires (11i) on a level of connection (Nc) of an array of balls (13i), said ball array providing a mechanical and electrical link between the integrated circuit (3) and a printed circuit card to which the package must be assembled, characterized in that it further comprises a rigid and electrically neutral grid (14) having through holes 15i, said grid (14) being attached to the level of connection (Nc) of the integrated circuit (3) and the balls (13i), and the grid holes (15i) being large enough to contain the balls with a pre-established clearance.

2. A package according to claim 1, characterized in that the grid (14) defines a spacer whose thickness is a function of the diameter of the balls (13i) and a maximum acceptable height of the balls after the assembly of the package to the card.

3. A package according to claim 1, characterized in that the grid (14) defines a positioning grid for the balls (13i) that the grid contains.

4. A package according to claim 1, characterized in that the grid (14) is attached by adhesive during the assembly of the package.

5. A package according to claim 1, characterized in that the grid (14) is integrated into the structure of the package.

6. A package according to claim 2, characterized in that the grid (14) defines a positioning grid for the balls (13i) that the grid contains.

7. A package according to claim 2, characterized in that the grid (14) is attached by adhesive during the assembly of the package.

8. A package according to claim 2, characterized in that the grid (14) is attached by adhesive during the assembly of the package.

9. A package according to claim 3, characterized in that the grid (14) defines a second cavity (18) larger than the first cavity (2) in which the integrated circuit (13) is mounted, and the second cavity having an opening is delimited by a connection area (Zc) of the integrated circuit (3) to the package.

10. A package according to claim 3, characterized in that the grid (14) is attached by adhesive during the assembly of the package.

11. A package according to claim 3, characterized in that the grid (14) is integrated into the structure of the package.

12. A package according to claim 6, characterized in that the grid (14) defines a second cavity (18) larger than the first cavity (2) in which the integrated circuit (13) is mounted, and the second cavity having an opening is delimited by a connection area (Zc) of the integrated circuit (3) to the package.

13. A package according to claim 9, characterized in that the second cavity (18) contains a coating material (17) completely covering an active surface (10) of the integrated circuit (3) and connections (11i) of the integrated circuit to the package.

14. A package according to claim 9, characterized in that the grid (14) is attached by adhesive during the assembly of the package.

15. A package according to claim 9, characterized in that the grid (14) is integrated into the structure of the package.

16. A package according to claim 12, characterized in that the second cavity (18) contains a coating material (17) completely covering an active surface (10) of the integrated circuit (3) and connections (11i) of the integrated circuit to the package.

17. A package according to claim 13, characterized in that the grid (14) defines an obstacle between the connection area (Zc) of the integrated circuit (3) to the package and the ball array (13i).

18. A package according to claim 13, characterized in that grid (14) is attached by adhesive during the assembly of the package.

19. A package according to claim 13, characterized in that the grid (14) is integrated into the structure of the package.

20. A package according to claim 16, characterized in that the grid (14) defines an obstacle between the connection area (Zc) of the integrated circuit (3) to the package and the ball array (13i).