Method for thinning of integrated circuit chips for lightweight packaged electronic systems

• US 5,324,687 A
• Filed: 10/16/1992
• Issued: 06/28/1994
• Est. Priority Date: 10/16/1992
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: General Electric Company
• Inventors: Wojnarowski, Robert J.
• Primary Examiner(s): Kunemund, Robert
• Assistant Examiner(s): Tsai, H. Jey
• Application Number:
  US07/962,379
• Time in Patent Office: 620 Days
• Field of Search: 437/8, 437/209, 437/207, 437/219, 437/220, 257/668, 257/700, 257/701, 257/671, 257/669, 257/684, 257/693, 257/680, 257/687, 257/688, 257/702, 257/707, 257/709, 257/724, 257/731, 257/752
• US Class Current: 438/107
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2221/68359 used as a support during manufacture of interconnect decals or build up layers
• CPC Class Codes: H01L 2221/68377 with parts of the auxiliary support remaining in the finished device
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/24137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/24226 the HDI interconnect connecting to the same level of the item at which the semiconductor or solid-state body is mounted, e.g. the item being planar
• CPC Class Codes: H01L 2224/24227 the HDI interconnect not connecting to the same level of the item at which the semiconductor or solid-state body is mounted, e.g. the semiconductor or solid-state body being mounted in a cavity or on a protrusion of the item
• 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 2224/73267 Layer and HDI connectors
• CPC Class Codes: H01L 23/5387 Flexible insulating substrates H01L23/5388 takes precedence
• CPC Class Codes: H01L 23/5389 the chips being integrally enclosed by the interconnect and support structures
• CPC Class Codes: H01L 24/24 of an individual high density interconnect connector
• CPC Class Codes: H01L 24/82 by forming build-up interconnects at chip-level, e.g. for high density interconnects [HDI] interconnection structure between a plurality of semiconductor chips H01L23/5389
• CPC Class Codes: H01L 25/0652 the devices being arranged next and on each other, i.e. mixed assemblies
• CPC Class Codes: H01L 25/50 Multistep manufacturing processes of assemblies consisting of devices, each device being of a type provided for in group H01L27/00 or H01L29/00 H01L21/50 takes precedence
• 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 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/05432 : Al2O3
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12042 : LASER
• 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 2924/1517 : Multilayer substrate
• CPC Class Codes: H01L 2924/157 : with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/1579 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2924/18162 : of a chip with build-up interconnect
• CPC Class Codes: Y10S 438/977 : Thinning or removal of substrate

Abstract

A method of thinning dice or integrated circuit chips used in producing lightweight packaged electronic systems, such as HDI circuits and systems produced therefrom provides for positioning dice in a die carrier layer that allows for easy separation from the dice after completion of the die thinning step. A holding layer is then attached to the die carrier layer for ease of attaching it to a material removal device, such as a lapping machine or an ultrasonic milling machine. A portion of the die carrier layer, along its exposed side, is then removed by the material removal device as a consequence of removal, by the material removal device, of an expendable portion of the dice positioned within the die carrier layer. The holding layer and the die carrier layer are then separated from the thinned dice by a conventional method, such as chemical etching, solvent soaking or induction heating. The thinned dice are significantly lighter than their original weight and their uniform thickness makes them well suited for mass produced lightweight electronic systems and flexible assemblies, such as HDI circuits.

Claims

1. A method of thinning dice for use in a packaged electronic system comprising:

positioning a plurality of said dice in a die carrier layer;

bonding a polymer film to said die carrier layer having said plurality of dice positioned therein;

affixing a holding layer to said polymer film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing an expendable portion of at least some of said plurality of dice to decrease thickness of said at least some of said plurality of dice to said desired thickness, while simultaneously removing a portion of said die carrier layer; and

detaching said holding layer from said polymer film.

2. The method of claim 1 wherein said die carrier layer comprises a removable material selected from the group consisting of alumina, polymer, metal and metal alloy.

3. The method of claim 1 wherein said holding layer comprises a material selected from the group consisting of metal, polymer and alumina.

4. The method of claim 3 wherein said metal is magnetic.

15. The method of claim 1 wherein each one of said dice has contact pads and the step of positioning said dice in said die carrier layer comprises pouring material for said die carrier layer around said dice so that said contact pads are coplanar with a face of said die carrier layer.

5. A method of producing a lightweight packaged electronic system comprising:

positioning a plurality of dice in a die carrier layer such that contact pads of said plurality of dice are coplanar with a face of said die carrier layer;

bonding a flexible polymer dielectric film to said face of said die carrier layer and to said plurality of dice;

affixing a holding layer to said flexible polymer dielectric film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing from the exposed side of said die carrier layer an expendable portion of said die carrier layer along with an expendable portion of at least some of said plurality of dice to decrease thickness of both said at least some of said plurality of dice and said die carrier layer to said desired thickness;

bonding a substrate to the thinned side of said die carrier layer;

removing said holding layer from said flexible polymer dielectric film; and

depositing a pattern of flexible conductors on said flexible polymer dielectric film to electrically interconnect at least some of said contact pads of said plurality of dice.

6. A method of producing a lightweight flexible packaged electronic system comprising:

positioning a plurality of dice in a die carrier layer such that contact pads of said plurality of dice are coplanar with a face of said die carrier;

bonding a flexible polymer dielectric film to said face of said die carrier layer and to said plurality of dice;

affixing a holding layer to said flexible polymer dielectric film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing from the exposed side of said die carrier layer an expendable portion of said die carrier layer and an expendable portion of at least some of said plurality of dice to decrease thickness of said at least some of said plurality of dice to said desired thickness;

separating said die carrier layer from said flexible polymer dielectric film and said plurality of dice;

bonding a substrate to said plurality of said dice;

removing said holding layer from said flexible polymer dielectric film; and

depositing a pattern of flexible conductors on said flexible polymer dielectric film to electrically interconnect at least some of said contact pads of said plurality of dice.

7. The method of claim 6 further comprising bonding spacer members to said flexible polymer dielectric film for providing structural strength to said packaged electronic system.

8. The method of claim 6 further comprising mounting on the exposed surface of said flexible polymer dielectric film having said pattern of flexible conductors thereon a temperature-sensitive die.

9. The method of claim 6 wherein said substrate is provided with a curvature.

10. The method of claim 6 wherein at least one of said plurality of dice comprises a dummy spacer die.

11. A method of producing a lightweight flexible packaged electronic system having process temperature-sensitive dice therein comprising;

positioning in a die carrier layer a plurality of dice, some of which comprise dummy spacer dice of the same size as said process temperature-sensitive dice, such that contact pads of said plurality of dice are coplanar with a face of said die carrier layer;

bonding a flexible polymer dielectric film to said face of said die carrier layer and to said plurality of dice positioned in said die carrier layer;

affixing a holding layer to said flexible polymer dielectric film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing from the exposed side of said die carrier layer an expendable portion of said die carrier layer and an expendable portion of at least some of said plurality of dice positioned in said die carrier layer to decrease the thickness of said at least some of said plurality of dice to said desired thickness;

separating said die carrier layer from said flexible polymer dielectric film and said plurality of dice

bonding a substrate to said plurality of dice;

removing said holding layer from said flexible polymer dielectric film;

depositing a pattern of flexible conductors on said flexible polymer dielectric film to electrically interconnect at least some of said contact pads of said plurality of dice; and

replacing said dummy spacer dice in said die carrier layer with said process temperature-sensitive dice.

12. The method of claim 11 wherein said substrate is provided with a curvature.

13. A method of producing a stacked lightweight packaged electronic system comprising;

positioning a plurality of dice in a die carrier layer such that contact pads of said plurality of dice are coplanar with a face of said die carrier layer;

bonding a polymer dielectric film to said face of said die carrier layer and to said plurality of dice;

affixing a holding layer to said polymer dielectric film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing from the exposed side of said die carrier layer an expendable portion of said die carrier layer and an expendable portion of at least some of said plurality of dice to decrease thickness of said at least some of said plurality of dice and said die carrier layer to said desired thickness;

attaching a temporary transfer substrate to the thinned side of said die carrier layer;

removing said holding layer from said polymer dielectric film;

perforating said dielectric film to form via openings therein in alignment with at least some of said contact pads;

depositing on said polymer dielectric film a pattern of conductors having edge contact pads to electrically interconnect at least some of said contact pads of said plurality of dice;

removing said temporary transfer substrate to form a high density interconnect layer;

coating a top and bottom surface of said high density interconnect layer with an adhesive layer;

stacking said high density interconnect layer with at least one additional high density interconnect layer such that for any adjacent pair of said high density interconnect layers, said adhesive layers bond the top surface of one of said high density interconnect layers to the bottom surface of the other of said high density interconnect layers so as to form a unitary stacked module;

bonding a substrate to the bottom surface of the lowermost high density interconnect layer;

bonding a dielectric layer to at least one side of said stacked module having said edge contacts exposed thereon;

perforating said dielectric layer on said at least one side of said stacked module to form apertures therein in alignment with at least some of said edge contact pads; and

depositing a conductive metal track structure on said dielectric layer on said at least one side of said stacked module to provide electrical connection between at least some of said edge contact pads through said apertures in said dielectric layer situated on said at least one side of said stacked module, said metal track structure electrically interconnecting in a predetermined manner said dice positioned in said high density interconnect layers of said stacked module.

14. A method of producing a plurality of dice suitable for use in mass production of a packaged electronic system comprising:

positioning said plurality of dice in a die carrier layer;

bonding a polymer film to said die carrier layer having said plurality of dice positioned therein;

affixing a holding layer to said polymer film;

attaching said holding layer to a material removal device;

selecting a desired thickness less than an initial thickness of at least one of said plurality of dice;

removing a portion of said die carrier layer along with an expendable portion of at least some of said dice to decrease the thickness of said at least some of said dice to said desired thickness;

removing the remaining portion of said die carrier layer; and

detaching said dice having uniform thickness from said polymer film.