Partially etched dielectric film with conductive features

• US 7,012,017 B2
• Filed: 03/03/2004
• Issued: 03/14/2006
• Est. Priority Date: 01/29/2004
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Yang, Rui, Mao, Guoping, Brunner, Dennis M., Kreutter, Nathan P., Buster, David L., Graff, Michael S., Luebbert, Daniel K.
• Primary Examiner(s): Parekh, Nitin
• Application Number:
  US10/791,966
• Publication Number:
  US 20050167829A1
• Time in Patent Office: 741 Days
• Field of Search: 438/613, 438/614, 438/125, 438/652, 438/667, 438/672, 438/713, 257/737, 257/702, 257/692, 257/750
• US Class Current: 438/613
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/4985 Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 24/10 Bump connectors bumps on insulating substrates, e.g. chip carriers, H01L23/49816; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/13 of an individual bump 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01011 Sodium [Na]
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01024 Chromium [Cr]
• 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 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01057 : Lanthanum [La]
• CPC Class Codes: H01L 2924/01061 : Promethium [Pm]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01093 : Neptunium [Np]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 2201/0367 : Metallic bump or raised conductor not used as solder bump
• CPC Class Codes: H05K 2201/0394 : Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/09036 : Recesses or grooves in insulating substrate
• CPC Class Codes: H05K 2201/09563 : Metal filled via
• CPC Class Codes: H05K 2201/09827 : Tapered, e.g. tapered hole, via or groove
• CPC Class Codes: H05K 2203/0369 : Etching selective parts of a metal substrate through part of its thickness, e.g. using etch resist
• CPC Class Codes: H05K 3/002 : by liquid chemical etching
• CPC Class Codes: H05K 3/4007 : Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457

Abstract

Provided are partially etched dielectric films with raised conductive features. Also provided are methods for forming the raised conductive features in the dielectric films, which methods include partially etching the dielectric films.

Claims

1. A process for forming a conductive bump protruding from a dielectric film, said process comprising:

providing a dielectric film having a first side and a second side;

applying a stop layer to at least said first side of said dielectric film, said stop layer having an underside in contact with said first side of said dielectric film;

forming a cavity in the dielectric film that extends through said dielectric film from said second side of said dielectric film to said stop layer;

depositing conductive material to form a conductive plug in said cavity;

removing said stop layer from said first side of said dielectric film to expose a surface of said conductive plug;

controllably etching said dielectric film from around said conductive plug surface to form said conductive bump protruding from said dielectric film.

2. The process of claim 1 further comprising depositing metal on said metallic projection to produce said conductive bump extending out from said metallic projection to cover a portion of said etched surface.

3. The process of claim 1, wherein said controllably etching said dielectric film uses a chemical milling reagent including an alkali metal hydroxide.

4. The process of claim 3, wherein said chemical etching reagent further includes an amine.

5. The process of claim 4, wherein said alkali metal hydroxide is potassium hydroxide and said amine is ethanolamine.

6. The process of claim 1 further comprising depositing metal on said conductive bump such that it extends out in x and y directions to cover a portion of said etched dielectric surface.

7. The process of claim 1 wherein an array of cavities are filled with metal plugs and the controlled etching provides an array of co-planar metallic projections.

8. The process of claim 1 wherein an array of cavities are filled with metal plugs and the controlled etching provides an array of metallic projections surrounded by a dielectric mask.

9. The process of claim 1, wherein said stop layer is a metal layer.

10. The process of claim 1, wherein said stop layer is a flash-plated metal layer.

11. The process of claim 1, wherein said dielectric film comprises a polymer selected from the group consisting of liquid crystal polymers, polycarbonates, and polyimide copolymers including carboxylic ester structural units in the polymeric backbone.

12. The process of claim 11, wherein said liquid crystal polymers are selected from the group consisting of copolymers containing p-phenyleneterephthalamide and copolymers containing p-hydroxybenzoic acid.

13. The process of claim 11, wherein said polyimide copolymers comprise the reaction product of monomers including p-phenylene bis(trimellitic acid monoester anhydride).

14. A process for forming a conductive bump protruding from a dielectric film, said process comprising:

providing a dielectric film having a first side and a second side;

forming an opening in the dielectric film that extends through said dielectric film from said first side to said second side of said dielectric film;

applying a stop layer to said second side of said dielectric film such that said opening is closed off by the stop layer on the side of the opening adjacent the second side, thereby forming a cavity;

depositing conductive material to form a conductive plug in said cavity;

removing said stop layer from said second side of said dielectric film to expose a surface of said conductive plug;

controllably etching said dielectric film from around said conductive plug surface to form said conductive bump protruding from said dielectric film.

15. The process of claim 14 further comprising depositing metal on said conductive bump such that it extends out in x and y directions to cover a portion of said etched dielectric surface.

16. The process of claim 14 wherein an array of cavities are filled with metal plugs and the controlled etching provides an array of co-planar metallic projections.

17. The process of claim 14 wherein an array of cavities are filled with metal plugs and the controlled etching provides an array of metallic projections surrounded by a dielectric mask.

18. The process of claim 14, wherein said stop layer is a polymer resin layer.

19. The process of claim 14, wherein said dielectric film comprises a polymer selected from the group consisting of polycarbonate polymers, liquid crystal polymers, and polyimide polymers including carboxylic ester structural units in the polymeric backbone.

20. The process of claim 19, wherein said liquid crystal polymers are selected from the group consisting of copolymers containing p-phenyleneterephthalamide and copolymers containing p-hydroxybenzoic acid.

21. The process of claim 19, wherein said polyimide copolymers comprise the reaction product of monomers including p-phenylene bis(trimellitic acid monoester anhydride).

22. The process of claim 14 further comprising depositing metal on said metallic projection to produce said conductive bump extending out from said metallic projection to cover a portion of said etched surface.

23. The process of claim 14, wherein said controllably etching said dielectric film uses a chemical milling reagent including an alkali metal hydroxide.

24. The process of claim 23, wherein said chemical etching reagent further includes an amine.

25. The process of claim 24, wherein said alkali metal hydroxide is potassium hydroxide and said amine is ethanolamine.