Multilayered metal nano and micron particles

Abstract

A sintering powder, wherein a least a portion of the particles making up the sintering powder comprise: a core comprising a first material; and a shell at least partially coating the core, the shell comprising a second material having a lower oxidation potential than the first material.

1 . A sintering film comprising:
 a sintering powder and a binder, wherein particles of the sintering powder comprise:   a core comprising a first material comprising copper; and   a shell at least partially coating the core, the shell comprising a layer of a second material having a lower oxidation potential than the first material, the second material comprising silver; and   a capping agent at least partially coating the shell, and   wherein the particles have a D50 of from 1 to 30 nm.   
     
     
         2 . The sintering film of  claim 1 , wherein the film is on a polymeric substrate. 
     
     
         3 . The sintering film of  claim 1 , wherein the polymeric substrate has a release coating thereon. 
     
     
         4 . The sintering film of  claim 1 , wherein the binder comprises a thermoplastic and/or thermosetting polymer. 
     
     
         5 . The sintering film of  claim 1 , wherein the binder comprises at least one thermoplastic polymer selected from the group consisting of poly(methyl methacrylate), polyamides, polyethylene, polypropylene, and polystyrene. 
     
     
         6 . The sintering film of  claim 1 , wherein the binder comprises at least one thermosetting polymer selected from the group consisting of polyurethanes, polycyanurates, epoxy resin, polyimides, melamine resin, and bismaleimide resin. 
     
     
         7 . The sintering film of  claim 1 , wherein the binder comprises an epoxy-based resin. 
     
     
         8 . The sintering film of  claim 1 , wherein the particles of the sintering powder have a D95 of less than 100 nm. 
     
     
         9 . The sintering film of  claim 1 , wherein the particles of the sintering powder have a D95 of from 0.1 to 10 μm. 
     
     
         10 . The sintering film of  claim 1 , wherein the sintering powder comprises from 0.1 to 15 wt % capping agent. 
     
     
         11 . The sintering film of  claim 1 , wherein the sintering powder comprises from 0.1 to 5 wt % capping agent. 
     
     
         12 . The sintering film of  claim 1 , wherein the capping agent comprises octylamine. 
     
     
         13 . A method for forming a sintered joint comprising:
 sintering a sintering powder, wherein particles of the sintering powder comprise:   a core comprising a first material comprising copper; and   a shell at least partially coating the core, the shell comprising a layer of a second material having a lower oxidation potential than the first material, the second material comprising silver; and   a capping agent at least partially coating the shell, and   wherein the particles have a D50 of from 1 to 30 nm.   
     
     
         14 . The method of  claim 13 , wherein the capping agent comprises octylamine. 
     
     
         15 . The method of  claim 13 , wherein the sintering powder is a component of a sintering film and the sintering film further comprises a binder. 
     
     
         16 . The method of  claim 13 , wherein the sintering powder is a component of a sintering paste and the sintering paste further comprises a binder and a solvent. 
     
     
         17 . The method of  claim 13 , wherein the sintering joint is formed on a LED, MEMS, OLED, PV cell or semiconductor. 
     
     
         18 . The method of  claim 13 , wherein the sintering joint is used for die attachment, wafer-to-wafer bonding, reflective layer printing, hermetic and near hermetic sealing, and dispensing and the production of interconnect lines. 
     
     
         19 . A sintered joint formed by the method of  claim 13 . 
     
     
         20 . A sintering paste comprising:
 a sintering powder;   a solvent; and   
       optionally a binder and/or a rheology modifier and/or an organosilver compound and/or an activator and/or a surfactant and/or wetting agent and/or hydrogen peroxide or organic peroxides,
 wherein particles of the sintering powder comprise: 
 a core comprising a first material comprising copper; and 
 a shell at least partially coating the core, the shell comprising a layer of a second material having a lower oxidation potential than the first material, the second material comprising silver; and 
 a capping agent at least partially coating the shell, and 
 wherein the particles have a D50 of from 1 to 30 nm. 
 
     
     
         21 . The sintering paste of  claim 20 , wherein the capping agent comprises octylamine. 
     
     
         22 . A method of manufacturing a sintering paste of  claim 20  comprising:
 providing a sintering powder, wherein particles of the sintering powder comprise: 
 a core comprising a first material comprising copper; and 
 a shell at least partially coating the core, the shell comprising a layer of a second material having a lower oxidation potential than the first material, the second material comprising silver; and 
 a capping agent at least partially coating the shell, and 
 wherein the particles have a D50 of from 1 to 30 nm; and 
 dispersing the sintering powder in a solvent and optionally together with a binder and/or a rheology modifier and/or an organosilver compound and/or an activator and/or a surfactant and/or wetting agent and/or hydrogen peroxide or organic peroxides. 
 
     
     
         23 . A LED, MEMS, OLED, PV cell or semiconductor comprising the sintering paste of  claim 20  or sintered product thereof. 
     
     
         24 . A LED, MEMS, OLED, PV cell or semiconductor comprising the sintering film of  claim 1  or sintered product thereof.