Reinforced flexible printed wiring board

• US 4,103,102 A
• Filed: 07/01/1976
• Issued: 07/25/1978
• Est. Priority Date: 07/01/1976
• Status: Expired due to Term

• Current Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Original Assignee: Bell Telephone Laboratories, Inc. (Nokia Corporation)
• Inventors: Klein, Theodore Harold
• Primary Examiner(s): Reynolds, Bruce A.
• Application Number:
  US05/701,591
• Time in Patent Office: 754 Days
• Field of Search: 174/68.5, 361/397, 361/398, 361/400, 361/404, 361/408, 29/625, 29/626, 428/901, 428/251, 428/252, 428/268, 428/273, 139/420 C, 57/140 G, 156/148, 427/96
• US Class Current: 174/254
• CPC Class Codes: H05K 1/0353 consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
• CPC Class Codes: H05K 1/0366 reinforced, e.g. by fibres, fabrics H05K1/036 takes precedence
• CPC Class Codes: H05K 2201/0145 Polyester, e.g. polyethylene terephthalate [PET], polyethylene naphthalate [PEN]
• CPC Class Codes: H05K 2201/0278 Polymeric fibers
• CPC Class Codes: H05K 2201/029 Woven fibrous reinforcement or textile textile substrates H05K1/038
• CPC Class Codes: H05K 2203/127 Lubricants, e.g. during drilling of holes

Abstract

An improved reinforced flexible printed wiring board is disclosed. The reinforcement in this printed wiring board is composed of a fabric woven from a yarn of plied continuous filaments of polyester and glass. The fabric is impregnated with an appropriate resin which is subsequently cured. This printed wiring board is found to have improved mechanical and thermal characteristics with little degradation in electrical properties.

Claims

1. A reinforced flexible printed wiring board comprising a resin impregnated woven fabric upon which a metallic circuit configuration is defined:

(a) said woven fabric comprising a yarn of at least one continuous glass fiber twisted relatively about at least one continuous polyester fiber with a periodicity between 0.1 and 10 twists per inch, said glass fiber coated with a lubricant;

(b) said resin being a flexible resin which is at least partially cured, said resin impregnated fabric having insulation resistance greater than 1 ×

10⁹ ohms, propagation tear strength greater than 0.5 pounds, and dimensional stability greater than 2 mils per inch; and

(c) said metallic circuit configuration having a peel strength greater than three pounds per inch of conductor width.

2. The product of claim 1 wherein the ratio of polyester-to-glass surface area is greater than 1/10.

3. The product of claim 1 wherein the resin composition is given by the following values:

space="preserve" listing-type="tabular">______________________________________ Epoxy Resin 100.0 Antimony Oxide 0-80 Chlorinated Hydrocarbon Flame Retardant 0-160 Maleic Anhydride Adduct of Methylcyclopentadiene 68-95 Carboxy Terminated Butadiene-Acrylonitrile 69-107 2,4,6-Tri(dimethylaminomethyl) Phenol 0.5-3.0 Antioxidant 0.1-6.0. ______________________________________

4. The product of claim 1 wherein the resin composition is given by the following values:

space="preserve" listing-type="tabular">______________________________________ Epoxy Resin 100.0 Antimony Oxide 55.4±

6.0 Chlorinated Hydrocarbon Flame Retardant 110.9 ±

11.0 Maleic Anhydride Adduct of Methylcyclopentadiene 86.7 ±

5.0 Carboxy Terminated Butadiene-Acrylonitrile 90.4 ±

3.0 2,4,6-Tri(dimethylaminomethyl) Phenol 1.5 ±

0.5 Antioxidant 0.5 ±

3.0 ______________________________________