Multilayer circuit board

• US 5,136,123 A
• Filed: 03/23/1988
• Issued: 08/04/1992
• Est. Priority Date: 07/17/1987
• Status: Expired due to Term

• Current Assignee: Junkosha Company Limited
• Original Assignee: Junkosha Company Limited
• Inventors: Hirose, Tetsuya, Kobayashi, Satoru, Suzuki, Masahiro, Tanaka, Satoshi
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US07/172,256
• Time in Patent Office: 1,595 Days
• Field of Search: 361/397, 361/414, 174/68.5, 174/110 F, 174/110 FC, 174/117 F, 174/117 FF, 174/255, 174/256, 174/258, 174/268, 333/1, 333/161, 333/236, 333/238, 333/243
• US Class Current: 174/258
• CPC Class Codes: H05K 1/024 Dielectric details, e.g. changing the dielectric material around a transmission line
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 1/034 containing halogen
• CPC Class Codes: H05K 2201/0116 Porous, e.g. foam
• CPC Class Codes: H05K 2201/015 Fluoropolymer, e.g. polytetrafluoroethylene [PTFE]
• CPC Class Codes: H05K 2201/0154 Polyimide
• CPC Class Codes: H05K 2201/09309 Core having two or more power planes; Capacitive laminate of two power planes
• CPC Class Codes: H05K 3/4611 by laminating two or more circuit boards H05K3/4652 takes precedence
• CPC Class Codes: H05K 3/4688 Composite multilayer circuits, i.e. comprising insulating layers having different properties having a special base or central core H05K3/4602

Abstract

A multilayer circuit board is provided having an inner porous fluororesin layer containing electrical circuits, a ground conductor layer located adjacent the fluororesin layer on one side thereof and a power supply conductor layer located adjacent the fluororesin layer on the other side thereof, and a reinforcing, solid plastic dielectric layer adjacent each conductor layer and being external to the inner fluororesin layer. In an alternate embodiment, the multilayer circuit board may have a plurality of inner porous fluororesin layers, at least one fluororesin layer containing electrical circuits, and may have ground conductors and power supply conductors adjacent each fluororesin layer, and reinforcing, solid plastic dielectric layers on the outermost surfaces of the circuit board assembly. The ground and power supply conductor layers extend over the entire surfaces, respectively, of the inner fluororesin layers.

Claims

1. A multilayer circuit board comprising a plurality of inner, porous fluororesin layers, at least one said inner, porous fluororesin layer containing electrical circuits, ground conductors and power supply conductors in contact with and immediately adjacent each fluororesin layer, and reinforcing, solid plastic dielectric layers on the outermost surfaces of the circuit board assembly.

3. The circuit board of claim 1 wherein said reinforcing, solid plastic dielectric layers are of a polyimide resin.

4. The circuit board of claim 1 wherein said reinforcing, solid plastic dielectric layers are of a glass epoxy.

2. The circuit board of claim 21 wherein said reinforcing, solid plastic dielectric layers are of a thermosetting resin.