Printed circuit board

• US 5,006,397 A
• Filed: 01/30/1990
• Issued: 04/09/1991
• Est. Priority Date: 02/06/1987
• Status: Expired due to Fees

• Current Assignee: Poly-Flex Circuits Incorporated
• Original Assignee: Key-Tech, Inc.
• Inventors: Durand, David
• Primary Examiner(s): Ryan, Patrick J.
• Application Number:
  US07/472,310
• Time in Patent Office: 434 Days
• Field of Search: 428/209, 428/323, 428/325, 428/331, 428/357, 428/397, 428/402, 428/403, 428/901, 430/311, 361/397
• US Class Current: 428/209
• CPC Class Codes: C09D 11/101 Inks specially adapted for printing processes involving curing by wave energy or particle radiation, e.g. with UV-curing following the printing
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01F 41/16 the magnetic material being applied in the form of particles, e.g. by serigraphy , to form thick magnetic films or precursors therefor H01F41/18 -H01F41/24 take precedence
• CPC Class Codes: H05K 1/095 for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 2201/083 Magnetic materials
• CPC Class Codes: H05K 2203/104 Using magnetic force, e.g. to align particles or for a temporary connection during processing
• CPC Class Codes: H05K 3/10 in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
• CPC Class Codes: H05K 3/1283 After-treatment of the printed patterns, e.g. sintering or curing methods
• CPC Class Codes: H05K 3/245 Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing other conductive patterns by such techniques
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/252 Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/259 Silicic material
• CPC Class Codes: Y10T 428/29 Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/2973 Particular cross section
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 Coated

Abstract

A method for producing a circuit board involves printing a U.V. curable ink onto a substrate in a desired cirucit pattern and curing the ink by exposing it to a pulsed U.V. source or subjecting the circuit pattern prepared from a U.V. curable ink containing magnetite particles to a magnetic field to move the magnetite particles to the upper surface of the U.V. curable ink. Other embodiments include circuit boards made in accordance with these methods and the use of the U.V. curable ink as a shielding composition for enclosures housing electronic equipment.

Claims

1. A printed circuit board comprising a substrate and at least one conductive line printed on said substrate, said line comprising a U.V. cured ink comprising from about 33 to 38 weight percent of a thermosetting resin binder and 67 to 62 weight percent of spherical or spheroidal conductive particles having a particle size distribution ranging from 1 to 30 microns, said line having been cured by exposure to U.V. radiation emanating from an electrodeless source having an output in the region between 360 nm and 420 nm in a pulsed manner comprising 5 to 8 one-half second exposure periods, each exposure period followed by a non-exposure period of about 2 to 3 seconds.

2. The printed circuit board of claim 1 wherein said conductive particles comprise silver coated glass spheres wherein the silver comprises about 8 to 12 weight percent based on the total weight of said silver coated glass spheres.

3. The printed circuit board of claim 1 wherein said U.V. curable ink also includes an effective amount of a ketone-amine curing agent.

4. The printed circuit board of claim 3 wherein said ketone-amine curing agent is Michler'"'"'s ketone.

5. The printed circuit board of claim 3 wherein said ketone-amine curing agent comprises a mixture of benzophenone and Michler'"'"'s ketone.

6. The printed circuit board of claim 1 wherein said silver coated glass spheres have an average particle size of about 15 microns.