Method for manufacturing a multilayer wiring substrate

• US 6,261,941 B1
• Filed: 02/12/1999
• Issued: 07/17/2001
• Est. Priority Date: 02/12/1998
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Tummala, Rao R., Li, Weipang
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Ha, Nathan W.
• Application Number:
  US09/249,449
• Time in Patent Office: 886 Days
• Field of Search: 438/618, 438/626, 438/631, 438/645, 438/669, 257/752, 257/753, 257/764, 257/774, 257/776
• US Class Current: 438/618
• CPC Class Codes: H05K 2201/09845 Stepped hole, via, edge, bump or conductor
• CPC Class Codes: H05K 2203/0733 Method for plating stud vias, i.e. massive vias formed by plating the bottom of a hole without plating on the walls
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 3/108 by semi-additive methods; masks therefor characterised by metallic etch mask H05K3/062; electroplating methods or apparatus H05K3/241
• CPC Class Codes: H05K 3/243 characterised by selective plating, e.g. for finish plating of pads selective plating for making the circuit pattern H05K3/108, H05K3/182
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer
• CPC Class Codes: H05K 3/4647 by applying an insulating layer around previously made via studs

Abstract

Generally, the present invention can be viewed as providing a method for manufacturing a multilayer wiring substrate. Briefly described, the method can be broadly conceptualized by the following steps: forming a first conductive connection on a first insulating layer; forming a conductive post on the first conductive connection; forming a second insulating layer on the first conductive connection, the first insulating layer, and the conductive post; exposing the conductive post by removing a portion of the second insulating layer; and forming a second conductive connection on the second insulating layer such that the second conductive connection is electrically connected to the first conductive connection via the conductive post. The second insulating layer can be formed via dry film lamination. In addition, the conductive posts can be exposed by either forming holes in the second insulating layer or by roughening the surface of the second insulating layer.

Claims

1. A method for manufacturing a microfabricated device, comprising the steps of:

forming a first conductive connection on a first insulating layer;

forming a conductive post on said first conductive connection;

forming a second insulating layer via dry film lamination on said first conductive connection, said first insulating layer, and said conductive post;

exposing said conductive post by removing a portion of said second insulating layer; and

forming a second conductive connection on said second insulating layer such that said second conductive connection is electrically coupled to said first conductive connection via said conductive post,

wherein said forming a conductive post step includes the steps of;

forming a sacrificial mask layer on said microfabricated device, said sacrificial mask layer having a hole exposing a portion of said first conductive connection;

applying conductive material to said exposed portion of said first conductive connection subsequent to said forming a sacrificial mask layer step; and

removing said sacrificial mask layer subsequent to said applying step.

2. The method of claim 1, wherein said forming a conductive post step is performed without performing a polishing step.

3. A method for manufacturing a microfabricated device, comprising the steps of:

forming a first conductive connection on a first insulating layer;

forming a conductive post on said first conductive connection;

forming a second insulating layer on said first conductive connection, said first insulating layer, and said conductive post;

exposing said conductive post by removing a portion of said second insulating layer; and

forming a second conductive connection on said second insulating layer such that said second conductive connection is electrically coupled to said first conductive connection via said conductive post,

wherein said exposing step includes the step of roughening a surface of said second insulating layer.

4. The method of claim 3, wherein said forming a second insulating layer step is performed such that said surface of said second insulating layer is less than approximately one micron from said conductive post before said roughening step.

5. The method of claim 3, further comprising the step of planarizing said second insulating layer prior to said roughening step.

6. The method of claim 3, further comprising the step of performing said forming a second insulating layer step via dry film lamination.

7. A method for manufacturing a microfabricated device, comprising the steps of:

forming a first conductive connection on a first insulating layer;

forming a conductive post on said first conductive connection;

forming a second insulating layer on said first conductive connection, said first insulating layer, and said conductive post;

exposing said conductive post by removing a portion of said second insulating layer, said exposing step including the step of forming a hole in a surface of said second insulating layer;

forming a second conductive connection on said second insulating layer such that said second conductive connection is electrically coupled to said first conductive connection via said conductive post; and

inserting conductive material into said hole.

8. The method of claim 7, wherein said forming a second insulating layer step is performed such that a distance between said surface of said second insulating layer and said conductive post is less than approximately one-third of said thickness.

9. The method of claim 7, wherein said forming a second insulating layer step is performed such that a distance between said surface of said second insulating layer and said conductive post is less than approximately one-fourth of said thickness.

10. The method of claim 7, further comprising the step of performing said forming a second insulating layer step via dry film lamination.

11. A method for manufacturing a microfabricated device, comprising the steps of:

forming a first conductive connection on a first insulating layer;

forming a conductive post on said first conductive connection;

forming a second insulating layer on said first conductive connection, said first insulating layer, and said conductive post;

applying a press to a surface of said second insulating layer;

removing said press from said surface;

exposing said conductive post by removing a portion of said second insulating layer; and

forming a second conductive connection on said second insulating layer such that said second conductive connection is electrically coupled to said first conductive connection via said conductive post.

12. The method of claim 11, wherein a surface of said press is comprised of polytetrafloruoethylene (PTFE).

13. The method of claim 11, wherein said exposing step includes the step of forming a hole in said surface of said second insulating layer and wherein said method further includes the step of inserting conductive material into said hole.

14. The method of claim 13, wherein said second insulating layer is formed via dry film lamination.

15. The method of claim 13, wherein said forming a second insulating layer step is performed such that a distance between said surface of said second insulating layer and said conductive post is less than approximately one-third of a distance between said first insulating layer and said second insulating layer subsequent to said applying step.

16. The method of claim 13, wherein said forming a second insulating layer step is performed such that a distance between said surface of said second insulating layer and said conductive post is less than approximately one-fourth of a distance between said first insulating layer and said second insulating layer subsequent to said applying step.

17. The method of claim 11, wherein said exposing step includes the step of roughening a surface of said second insulating layer.

18. The method of claim 17, wherein said applying step planarizes said surface of said second insulating layer such that said surface of said second insulating is less than approximately one micron from said conductive post before said roughening step.

19. A method for manufacturing a microfabricated device, comprising the steps of:

forming a first conductive connection on a first insulating layer;

forming a conductive post on said first conductive connection;

forming a second insulating layer on said first conductive connection, said first insulating layer, and said conductive post;

exposing said conductive post by roughening a surface of said second insulating layer; and

forming a second conductive connection on said second insulating layer such that said second conductive connection is electrically coupled to said first conductive connection via said conductive post.

20. The method of claim 19, wherein said forming a second insulating layer step is performed such that a surface of said second insulating layer is less than approximately one micron from said conductive post before said roughening step.

21. The method of claim 19, further including the step of planarizing a surface of said second insulating layer by applying pressure to said surface.

22. The method of claim 21, wherein said forming a second insulating layer step is performed such that said surface of said second insulating layer is less than approximately one micron from said conductive post subsequent to said planarizing step.