Printed wiring board having shielding layer

• US 5,220,135 A
• Filed: 03/15/1990
• Issued: 06/15/1993
• Est. Priority Date: 03/15/1989
• Status: Expired due to Term

• Current Assignee: Nippon CMK Corporation
• Original Assignee: Nippon CMK Corporation
• Inventors: Okonogi, Hirotaka, Kawakami, Shin, Haruyama, Satoshi
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Korka, Trinidad
• Application Number:
  US07/493,897
• Time in Patent Office: 1,188 Days
• Field of Search: 174/35 R, 174/265, 174/264, 174/36, 174/250, 174/251, 174/255, 174/257, 174/258, 174/262, 174/263, 174/266, 428/901, 29/830, 427/96, 427/97, 361/397, 361/398
• US Class Current: 174/264
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 2201/0715 provided by an outer layer of PCB
• CPC Class Codes: H05K 2201/09536 Buried plated through-holes, i.e. plated through-holes formed in a core before lamination
• CPC Class Codes: H05K 2201/0959 Plated through-holes or plated blind vias filled with insulating material
• CPC Class Codes: H05K 2203/1453 Applying the circuit pattern before another process, e.g. before filling of vias with conductive paste, before making printed resistors
• CPC Class Codes: H05K 3/0094 Filling or covering plated through-holes or blind plated vias, e.g. for masking or for mechanical reinforcement
• CPC Class Codes: H05K 3/4069 for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/42 Plated through-holes or plated via connections
• CPC Class Codes: H05K 3/4602 characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated
• CPC Class Codes: H05K 9/0039 Galvanic coupling of ground layer on printed circuit board [PCB] to conductive casing printed shielding conductors, ground planes or power planes for reduction of cross-talk or noise in printed circuits H05K1/0218
• CPC Class Codes: Y10S 428/901 Printed circuit

Abstract

A printed wiring board having a shielding layer for use in an integrated circuit is disclosed. The printed wiring board comprises an insulating sheet having a connecting through hole portion, a printed wiring circuit provided on one or both surfaces of the insulating sheet, an insulating layer having a thickness of 20˜50 μm which is provided on the printed wiring circuit, and an electromagnetic shielding layer provided on the insulating layer.

Claims

1. A printed wiring board comprising:

an insulating sheet having a connecting through hole portion, a printed wiring circuit provided on at least one surface of the insulating sheet, an insulating layer having a thickness of 20˜

50 μ

m provided on the printed wiring circuit, and an electromagnetic shielding layer provided on the insulating layer.

2. A printed wiring board as claimed in claim 1, further comprising a sealing member composed of heat-resistant material disposed in the connecting through hole portion of the printed wiring circuit and covered by the insulating layer.

3. A printed wiring board as claimed in claim 2, wherein the sealing member is composed of a thermosetting synthetic resin.

4. A printed wiring board as claimed in claim 2, further comprising a printed wiring circuit on top and bottom surfaces of the insulating sheet, and wherein the sealing member is a conductive synthetic resin including one of carbon, silver and copper for connecting the printed wiring circuits on both the top and bottom surfaces of the insulating sheet.

5. A printed wiring board as claimed in claim 1, further comprising a sealing member composed of weather resistant material disposed on the connecting through hole portion of the printed wiring circuit and covered by the insulating layer.

6. A printed wiring board as claimed in claim 2, wherein the sealing member is composed of a photosetting synthetic resin.

7. A printed circuit board comprising:

an insulating substrate;

a printed circuit on at least one surface of the substrate;

an insulating layer on the printed circuit having a thickness of 20 to 50 μ

m; and

an electromagnetic shielding layer on the insulating layer.

8. The printed circuit board according to claim 7, further comprising a hole in the substrate and a sealing member filling the hole and covered by the insulating layer.

9. The printed circuit board according to claim 8, wherein the sealing member comprises a thermosetting synthetic resin.

10. The printed circuit board according to claim 8, further comprising printed circuits on top and bottom surfaces of the substrate and wherein the sealing member comprises a conductive synthetic resin for connecting the printed circuits.

11. The printed circuit board according to claim 8, wherein the sealing member comprises a photosetting synthetic resin.