CONDUCTIVE MATERIAL AND PROCESS

• US 20140178601A1
• Filed: 03/03/2014
• Published: 06/26/2014
• Est. Priority Date: 09/06/2011
• Status: Active Grant

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: Henkel IP & Holding GmbH (Henkel AG & Co KGaA)
• Inventors: Wei, Bin, Xiao, Allison Yue, Huang, Xiaoyan
• Granted Patent: US 10,999,933 B2
• Time in Patent Office: Days
• US Class Current: 427/553
• CPC Class Codes: B41M 5/0023 Digital printing methods characterised by the inks used inks per se C09D11/00
• 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: H05K 1/092 Dispersed materials, e.g. conductive pastes or inks
• CPC Class Codes: H05K 2203/1131 Sintering, i.e. fusing of metal particles to achieve or improve electrical conductivity
• CPC Class Codes: H05K 2203/125 Inorganic compounds, e.g. silver salt
• CPC Class Codes: H05K 3/027 the conductive material being removed by irradiation, e.g. by photons, alpha or beta particles
• CPC Class Codes: H05K 3/105 by conversion of non-conductive material on or in the support into conductive material, e.g. by using an energy beam
• CPC Class Codes: H05K 3/1283 After-treatment of the printed patterns, e.g. sintering or curing methods

Abstract

A method for making a conductive network of sintered silver comprises preparing a conductive ink comprising a silver compound and a binder; depositing the conductive ink on a substrate and applying an external energy source to the deposited conductive ink to dry the ink; and applying an external energy source to the dried ink to decompose the ink to elemental silver and to sinter the elemental silver into a conductive network.

Claims

1. A method for making a conductive network of sintered silver comprising:

(a) preparing a conductive ink comprising a silver compound and a binder;

(b) depositing the conductive ink on a substrate and applying an external energy source to dry the deposited conductive ink;

(c) applying an external energy source to the dried conductive ink to decompose the silver compound to elemental silver and to sinter the elemental silver into a conductive network.

2. The method according to claim 1, in which the conductive ink comprises a silver compound selected from the group consisting of silver oxide, silver carbonate, silver carboxylate, silver acetate, silver formate, silver oxalate, silver propionate, silver butanoate, silver ethylhexanoate, silver neodecanoate, silver pentafluoropropionate, silver citrate, silver glycolate, silver benzoate, silver trifluoroacetate, silver phenylacetate, silver acetylacetonate, and silver hexafluoroacetylacetonate,

3. The method according to claim 2, in which the silver compound is silver formate, silver oxalate, or a combination of silver formate and silver oxalate.

4. The method according to claim 1, in which the silver compound is present in an amount from 1 to 70% by weight of the total conductive ink.

5. The method according to claim 1, in which the binder is selected from the group consisting of polypyrrolidone, epoxies, phenolic resins, acrylics, urethanes, silicones, styrene allyl alcohols, polyalkylene carbonates, and polyvinyl acetals.

6. The method according to claim 5, in which the binder is polypyrrolidone.

7. The method according to claim 1, in which the binder is present in an amount from 0.1 to 30% by weight of the total conductive ink.

8. The method according to claim 1, in which the conductive ink further comprises a reducing agent selected from the group consisting of amines, oximes, guanidines, carbazones, alcohols and polyols, hydrazines, hydrazones, hydrazides, aldehydes, and amides.

9. The method according to claim 8 in which the reducing agent is an amine selected from the group consisting of butyl amine, nonylamine, dibutyl amine, tributyl amine, diethylene amine, tetraethylene pentamine, octylamine, triethyl amine, and isopropanolamine.

10. The method according to claim 9 in which the reducing agent is octylamine.

11. The method according to claim 8 in which the reducing agent is an oxime selected from the group consisting of acetoneoxime, methylaldoxime, and methylethylketoxime.

12. The method according to claim 8 in which the reducing agent is selected from the group consisting of methanol, ethanol, isopropanol, terpineol, t-butanol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol diacetate, formaldehyde, octanal, decanal, dodecanal, and dimethylformamide.

13. The method according to claim 1 in which the external energy source to dry the conductive ink is heat at a temperature or within a temperature range from 25°

to 200°

C.

14. The method according to claim 1 in which the external energy source to sinter the silver is pulsed UV irradiation.