Flexible printed circuits, prepared by augmentation replacement process

• US 4,670,351 A
• Filed: 02/12/1986
• Issued: 06/02/1987
• Est. Priority Date: 02/12/1986
• Status: Expired due to Fees

• Current Assignee: Insulating Materials Incorporated One Campbell RD Schenectady NY 12306
• Original Assignee: General Electric Company
• Inventors: Keane, John J., Wacker, Thomas P.
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Application Number:
  US06/828,939
• Time in Patent Office: 475 Days
• Field of Search: 361/398, 361/402, 361/411, 29/846, 174/68.5, 428/901, 428/549, 428/210, 428/447, 428/551, 427/96, 427/98, 156/297, 430/315, 430/319
• US Class Current: 428/549
• CPC Class Codes: H05K 1/0313 Organic insulating material
• CPC Class Codes: H05K 1/095 for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 3/246 Reinforcing conductive paste, ink or powder patterns by other methods, e.g. by plating
• CPC Class Codes: Y10S 428/901 Printed circuit
• CPC Class Codes: Y10T 156/1089 of discrete laminae to single face of additional lamina
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 428/12035 Fiber, asbestos, or cellulose in or next to particulate component
• CPC Class Codes: Y10T 428/12049 Nonmetal component
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

The present invention provides flexible printed circuits prepared by (i) applying a design on a silicone-impregnated fabric substrate with a printing ink comprising a mixture of (a) a curable silicone composition and (b) an effective amount of at least one finely divided metal powder; (ii) at least partially curing said silicone composition; and (iii) depositing a conductive metal on the surface of said printing ink.

Claims

1. A flexible printed circuit prepared by a method comprising:

(i) applying a design on the silicone-impregnated fabric substrate with a printing ink comprising a mixture of (a) a curable silicone composition and (b) an effective amount of at least one finely divided metal powder;

(ii) at least partially curing said silicone composition; and

(iii) depositing a conductive metal on the surface of said printing ink.

2. A flexible printed circuit as in claim 1, wherein the substrate is silicone-impregnated glass cloth.

3. A flexible printed circuit as in claim 1 or 2, wherein the curable silicone composition of the printing ink is an addition curable silicone composition.

4. A flexible printed circuit as in claim 1 or 2, wherein the curable silicone composition of the printing ink is a heat curable silicone composition.

5. A flexible printed circuit as in claim 1 or 2, wherein the curable silicone composition of the printing ink is a condensation curable silicone composition.

6. A flexible printed circuit as in claim 3, wherein the finely divided metal powder has a particle size less than about 50 microns.

7. A flexible printed circuit as in claim 4, wherein the finely divided metal powder has a particle size less than about 50 microns.

8. A flexible printed circuit as in claim 5, wherein the finely divided metal powder has a particle size less than about 50 microns.

9. A flexible printed circuit as in claim 6, wherein the finely divided metal powder is iron, nickel, or zinc or a mixture thereof.

10. A flexible printed circuit as in claim 7, wherein the finely divided metal powder is iron, nickel, or zinc or a mixture thereof.

11. A flexible printed circuit as in claim 8, wherein the finely divided metal powder is iron, nickel, or zinc or a mixture thereof.

12. A flexible printed circuit as in claim 9, wherein the conductive metal is copper.

13. A flexible circuit as in claim 10, wherein the conductive metal is copper.

14. A flexible printed circuit as in claim 11, wherein the conductive metal is copper.

15. A flexible printed circuit as in claim 1, wherein the design is applied to the silicone-impregnated fabric substrate by screen printing.

16. A flexible printed circuit as in claim 1, wherein the finely divided metal powder is from about 60% to about 80% by volume of the printing ink mixture.

17. A flexible printed circuit as in claim 1, wherein the conductive metal is deposited on the surface of the printing ink by an augmentation replacement reaction.

18. A flexible printed circuit as in claim 1, wherein the conductive metal is deposited on the surface of the printing ink by an electroless plating process.

19. A flexible printed circuit as in claim 1, wherein the conductive metal is deposited on the surface of the printing ink by an electrodeposition process.

20. A method for making a flexible printed circuit, comprising:

(i) applying a design on a silicone-impregnated fabric substrate with a printing ink comprising a mixture of (a) a curable silicone composition and (b) an effective amount of at least one finely divided metal powder;

(ii) at least partially curing said silicone composition; and

(iii) depositing a conductive metal on the surface of said printing ink.