Package structure having accessible chip

• US 5,491,362 A
• Filed: 08/13/1993
• Issued: 02/13/1996
• Est. Priority Date: 04/30/1992
• Status: Expired due to Term

• Current Assignee: Seong Capital Limited Limited Liability Company (Intellectual Ventures LLC)
• Original Assignee: VLSI Technology, Inc. (Koninklijke Philips N.V.)
• Inventors: Hamzehdoost, Ahmad, Mora, Leonard L.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): Wallace, Valencia Martin
• Application Number:
  US08/106,146
• Time in Patent Office: 914 Days
• Field of Search: 257/675, 257/676, 257/680, 257/684, 257/687, 257/712, 257/713, 257/714
• US Class Current: 257/712
• CPC Class Codes: H01L 2224/32014 the layer connector being smaller than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/057 the leads being parallel to the base
• CPC Class Codes: H01L 23/3675 characterised by the shape of the housing
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15312 : being a pin array, e.g. PGA
• CPC Class Codes: H01L 2924/1532 : the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/1815 : Shape
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

A package for an integrated-circuit includes a package body having a die-cavity formed therein. A die-attach pad is formed in the package body adjacent the die-cavity. An opening is formed in the central portion of the die-attach pad for exposing one side of the integrated-circuit die so that an external cooling media can directly contact the exposed side of the integrated-circuit die. The die-attach pad can be formed as a die-mounting ring adjacent the die-attach cavity. The peripheral edge of the integrated-circuit die is fixed to a mounting surface on the die-mounting ring portion to accommodate direct cooling of the exposed side of the integrated-circuit die. The mounting surface of the die-mounting ring extends beyond the peripheral edge of the integrated-circuit die to accommodate a range of sizes of the integrated-circuit die. The exposed surface of the integrated circuit die is cooled, for example, with a cooling fluid, a heatsink, or a thermo-electric refrigeration unit in contact with the exposed side of the die. The exposed side of the die is coated with a film to provide a seal for the exposed side of the integrated-circuit die.

Claims

1. An integrated-circuit package assembly for an integrated-circuit die, comprising:

said integrated-circuit die having a first, front surface on which are formed wire-bonding pads, said integrated-circuit die having a second, back surface, wherein said second, back surface has a mounting area adjacent to a peripheral edge of said integrated-circuit die for mounting said integrated-circuit die;

a package body having a die cavity formed therein for receiving said integrated-circuit die, said package body having a ring portion formed therein adjacent to the die cavity, wherein said ring portion extends from said package body into the die cavity, wherein said ring portion includes a mounting surface to which the mounting area on said second, back surface, of said integrated-circuit die is fixed to provide exposure of the back side of said integrated-circuit die and to accommodate direct cooling of the exposed back side of the integrated-circuit die; and

bonding wires connected between the wire-bonding pads on the front surface of the integrated circuit die and lead fingers of a leadframe for the integrated-circuit package assembly.

2. The integrated-circuit package assembly of claim 1 wherein the mounting surface of the ring portion of the integrated-circuit package extends inwardly beyond the peripheral edge of the integrated-circuit die to accommodate a range of sizes of the integrated-circuit die.

3. The assembly of claim 1 including a refrigeration unit in contact with the exposed back side of the die.

4. The assembly of claim 1, including heatsink means, contacting the exposed back side of the integrated circuit, for cooling said integrated-circuit die.

5. The assembly of claim 1 wherein the exposed side of the die is coated with a film of protective sealing material to provide a seal to protect said exposed back side of the integrated-circuit die from the ambient.

6. The assembly of claim 1 wherein the wire-bonding pads on the first, front surface of the integrated-circuit die are located adjacent to the peripheral edge of said integrated-circuit die.

7. A package structure having an accessible chip comprising:

an integrated-circuit die having front and back surfaces, said front surface having wire-bonding pads peripherally disposed thereon, said back surface having a mounting area peripherally located thereon,

a package body having a die cavity formed therein for receiving said integrated-circuit die, said package body having a ring portion formed therein adjacent to said die cavity, wherein said ring portion extends from said package body into said die cavity, said ring portion including a mounting surface to which said mounting area on said back surface of said integrated-circuit die is fixed such that said integrated-circuit die is secured within said die cavity in a die-down configuration with said back surface of said integrated-circuit die exposed thereby allowing direct cooling of said exposed back surface of said integrated-circuit die; and

bonding wires connected between said wire-bonding pads peripherally located on said front surface of said integrated-circuit die and lead fingers of a leadframe for said integrated-circuit package assembly,

8. The package structure of claim 7 wherein said exposed back surface of said integrated-circuit die is coated with a film of protective sealing material to provide a protective carrier over said exposed back surface of said integrated-circuit die.

9. The package structure of claim 7 wherein said ring portion of said package body extends from said package inwardly into said die cavity such that said mounting surface is able to accommodate mounting thereon of a plurality of sizes of mounting areas corresponding to differing sized integrated-circuit dies, thereby allowing a single package body to accommodate various sizes of integrated-circuit dies.

10. The package structure of claim 7 wherein a refrigeration unit is disposed in contact with said exposed back surface of said integrated-circuit die, thereby providing cooling to said die.

11. The package structure of claim 7 wherein heatsink means is disposed in contact with said exposed back surface of said integrated-circuit die, thereby providing cooling to said die.

12. The package structure of claim 7 wherein ambient air is in contact with said exposed back surface of said integrated-circuit die, thereby providing cooling to said die.

13. An integrated-circuit package structure for housing and exposing an integrated-circuit die comprising:

an integrated-circuit die having front and back surfaces, said front surface having wire-bonding pads peripherally disposed thereon, said back surface having a mounting area peripherally located thereon,

a package body having a die cavity formed therein for receiving said integrated-circuit die, said package body having a ring portion formed therein adjacent to said die cavity, wherein said ring portion extends from said package body into said die cavity, said ring portion including an integrated-circuit die mounting surface to which said mounting area on said back surface of said integrated-circuit die is fixed such that said integrated-circuit die is secured within said die cavity in a die-down configuration with said back surface of said integrated-circuit die exposed thereby allowing direct cooling of said exposed back surface of said integrated-circuit die,

ambient air contacting said exposed back surface of said integrated-circuit die, thereby providing cooling to said die; and

bonding wires connected between said wire-bonding pads peripherally located on said front surface of said integrated circuit die and lead fingers of a leadframe for said integrated-circuit package assembly.

14. The package structure of claim 13 wherein said exposed back surface of said integrated-circuit die is coated with a film of protective sealing material to provide a protective barrier over said exposed back surface of said integrated-circuit die.

15. The package structure of claim 13 wherein said ring portion of said package body extends from said package inwardly into said die cavity such that said mounting surface is able to accommodate mounting thereon of a plurality of sizes of mounting areas corresponding to differing sized integrated-circuit dies, thereby allowing a single package body to accommodate various sizes of integrated-circuit dies.