Roughened printed circuit board

• US 7,521,779 B2
• Filed: 11/16/2005
• Issued: 04/21/2009
• Est. Priority Date: 11/26/2004
• Status: Expired due to Fees

• Current Assignee: Nitto Denko Corporation
• Original Assignee: Nitto Denko Corporation
• Inventors: Ookawa, Tadao, Honjo, Mitsuru, Oda, Takashi
• Primary Examiner(s): Williams; Alexander O
• Application Number:
  US11/280,624
• Publication Number:
  US 20060113669A1
• Time in Patent Office: 1,252 Days
• Field of Search: 257/668, 257/E23.009, 257/E23.113, 257/753, 257/752, 257/758, 257/600, 257/601, 361/766, 361/793, 361/761, 361/762, 174/257, 174/260, 298/14
• US Class Current: 257/668
• CPC Class Codes: H05K 1/0393 Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 2203/025 Abrading, e.g. grinding or sand blasting
• CPC Class Codes: H05K 2203/095 Plasma, e.g. for treating a substrate to improve adhesion with a conductor or for cleaning holes
• CPC Class Codes: H05K 3/002 by liquid chemical etching
• CPC Class Codes: H05K 3/0041 by plasma etching
• 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 3/22 Secondary treatment of printed circuits H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107
• CPC Class Codes: H05K 3/281 by means of a preformed insulating foil H05K3/284 takes precedence
• CPC Class Codes: H05K 3/381 by special treatment of the substrate
• CPC Class Codes: H05K 3/386 by the use of an organic polymeric bonding layer, e.g. adhesive
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/53504 One work part comprising paper clip

Abstract

A multi-layer structure including a base insulating layer and a thin metal film layer (seed layer) is prepared. A plating resist layer is formed to have a prescribed pattern on the upper surface of the thin metal film layer. A metal plating layer is formed on the thin metal film layer exposed by electroplating. Then, the plating resist layer is removed, and the thin metal film layer in the region having the plating resist layer is removed. In this way, a conductive pattern including the thin metal film layer and the metal plating layer is formed. The upper surface of the base insulating layer in the region without the conductive pattern is subjected to roughening treatment. A cover insulating layer is formed on the upper surfaces of the base insulating layer and the conductive pattern. In this way, a printed circuit board is completed.

Claims

1. A printed circuit board, comprising:

a first insulating layer; and

a conductive layer comprising a conductive material, provided on one or both surfaces of said first insulating layer and having a prescribed pattern, the one or both surfaces of said first insulating layer comprising at least one area where the conductive material is present and at least one area where the conductive material is not present, wherein the area where the conductive material is not present has a surface roughness of at least 0.1 μ

m, and wherein the surface roughness Ra of the first insulating layer in the area where the conductive material is not present is greater than the surface roughness Ra of the first insulating layer in the area where the conductive material is present and the surface roughness of the conductive layer.

2. The printed circuit board according to claim 1, wherein said conductive layer comprises a thin metal film layer provided in contact with said first insulating layer.

3. The printed circuit board according to claim 1, wherein said first insulating layer has flexibility.

4. The printed circuit board according to claim 1, further comprising a second insulating layer covering the first insulating layer and the conductive layer.

5. A printed circuit board, comprising:

a first insulating layer,

a conductive layer provided on at least one surface of said first insulating layer, and having a prescribed pattern, and

a second insulating layer provided on said one surface of said first insulating layer so as to cover said conductive layer, wherein

said conductive layer has a first surface being in contact with said one surface of said first insulating layer, and a second surface being in contact with said second insulating layer,

said one surface of said first insulating layer includes a first region where said conductive layer is present, and a second region where said conductive layer is not present, and

said second region is roughened to have a surface roughness of at least 0.1 μ

m such that the surface roughness Ra of said first insulating layer in said second region is greater than the surface roughness Ra of said first insulating layer in said first region and the surface roughness of the first and second surfaces of said conductive layer.

6. The printed circuit board according to claim 5, wherein said conductive layer comprises a thin metal film layer provided in contact with said first insulating layer.

7. The printed circuit board according to claim 5, wherein said first and second insulating layers have flexibility.