Low viscosity precursor compositions and methods for the deposition of conductive electronic features
A precursor composition for the deposition and formation of an electrical feature such as a conductive feature. The precursor composition advantageously has a low viscosity enabling deposition using direct-write tools. The precursor composition also has a low conversion temperature, enabling the deposition and conversion to an electrical feature on low temperature substrates. A particularly preferred precursor composition includes silver metal for the formation of highly conductive silver features.
1 . A process for forming a flat panel display conductive feature, comprising:
(a) direct printing a precursor composition onto a substrate, wherein the precursor composition comprises metallic particles;
(b) confining the printed precursor composition to a region of the substrate with a physical barrier; and
(c) heating the precursor composition to form the flat panel display conductive feature on the substrate, the flat panel display conductive feature having a minimum feature size of not greater than 100 μm.
2 . The process of claim 1 , wherein the direct printing comprises syringe printing.
3 . The process of claim 1 , wherein the direct printing comprises aerosol jet deposition.
4 . The process of claim 1 , wherein the direct printing comprises ink jet printing.
5 . The process of claim 4 , wherein the physical barrier comprises trenches.
6 . The process of claim 5 , wherein the trenches are formed by chemical etching or photochemical means.
7 . The process of claim 5 , wherein the trenches are formed with a laser.
8 . The process of claim 5 , wherein the process further comprises the steps of:
(d) forming a layer on the substrate; and
(e) forming the trenches in the layer.
9 . The process of claim 8 , wherein the trenches are formed in the layer with a laser.
10 . The process of claim 8 , wherein the layer comprises a photoresist layer.
11 . The process of claim 10 , wherein the trenches are formed in the photoresist layer through photolithography.
12 . The process of claim 4 , wherein the physical barrier comprises a feature having a porosity that retains the precursor composition by capillary forces.
13 . The process of claim 4 , wherein the physical barrier comprises retaining barriers.
14 . The process of claim 13 , wherein the retaining barriers are formed through a direct write printing process.
15 . The process of claim 13 , wherein the retaining barriers are formed through an ink jet printing process.
16 . The process of claim 15 , wherein the retaining barriers comprise two parallel lines with narrow parallel spacing, and wherein the precursor composition is direct printed between the two lines to confine the precursor composition.
17 . The process of claim 4 , wherein the direct printing comprises directing droplets of the precursor composition toward a surface of the substrate, the droplets having an average droplet size not greater than about 10 μm.
18 . The process of claim 17 , wherein the average droplet size is not greater than about 5 μm.
19 . The process of claim 4 , wherein the direct printing comprises depositing droplets onto the substrate at a rate of 1000 drops per second or higher.
20 . The process of claim 19 , wherein each droplet comprise from about 25 to 100 picoliters of the precursor composition.
21 . The process of claim 4 , wherein the minimum feature size is not greater than 75 μm.
22 . The process of claim 4 , wherein the minimum feature size is not greater than 50 μm.
23 . The process of claim 4 , wherein the minimum feature size is not greater than 25 μm.
24 . The process of claim 4 , wherein the flat panel display conductive feature has a width not greater than 200 μm.
25 . The process of claim 4 , wherein the flat panel display conductive feature has a width not greater than 100 μm.
26 . The process of claim 4 , wherein the flat panel display conductive feature has a width not greater than 75 μm.
27 . The process of claim 4 , wherein the flat panel display conductive feature has a width not greater than 50 μm.
28 . The process of claim 4 , wherein the process further comprises surface modifying a surface of the substrate prior to the direct printing.
29 . The process of claim 28 , wherein the surface modifying comprises laser patterning.
30 . The process of claim 28 , wherein the surface modifying comprises forming trenches in the surface by chemical etching or photochemical means.
31 . The process of claim 28 , wherein the surface modifying increases or decreases hydropholicity.
32 . The process of claim 4 , wherein the precursor composition further comprises metal oxide particles.
33 . The process of claim 4 , wherein the precursor composition further comprises glass particles.
34 . The process of claim 4 , wherein the metallic particles have a volume median particle size of not greater than 100 nm.
35 . The process of claim 4 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
36 . The process of claim 4 , wherein the metallic particles comprise a metal selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
37 . The process of claim 4 , wherein the metallic particles have a volume median particle size of not greater than 100 nanometers.
38 . The process of claim 4 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
39 . The process of claim 38 , wherein the metallic particles comprise a cap or coating thereon.
40 . The process of claim 39 , wherein the cap or coating comprises an inorganic cap or coating.
41 . The process of claim 39 , wherein the cap or coating comprises silica.
42 . The process of claim 39 , wherein the cap or coating comprises glass.
43 . The process of claim 39 , wherein the cap or coating comprises an organic cap or coating.
44 . The process of claim 39 , wherein the cap or coating comprises a polymer.
45 . The process of claim 39 , wherein the cap or coating comprises an intrinsically conductive polymer, a sulfonated perfluorohydrocarbon polymer, polystyrene, polystyrene/methacrylate, sodium bis(2-ethylhexyl) sulfosuccinate, tetra-n-octyl-ammonium bromide or an alkane thiolate.
46 . The process of claim 39 , wherein the cap or coating comprises PVP.
47 . The process of claim 38 , wherein at least 80 volume percent of the silver particles are not larger than twice the average particle size.
48 . The process of claim 4 , wherein the heating comprises heating in air at from about 450° C. to 600° C.
49 . The process of claim 4 , wherein the substrate comprises glass.
50 . The process of claim 4 , wherein the substrate comprises a polymer.
51 . The process of claim 4 , wherein the flat panel display conductive feature comprises an electrode.
52 . The process of claim 4 , wherein the flat panel display conductive feature comprises a bus line.
53 . The process of claim 4 , wherein the flat panel display conductive feature comprises a transparent conductive feature.
54 . The process of claim 4 , wherein the flat panel display conductive feature comprises indium-tin oxide or antimony-tin oxide.
55 . The process of claim 4 , wherein the metalic particles comprise a metal and the conductivity of the flat panel display conductive feature is no less than 10 percent the conductivity of the equivalent pure metal.
56 . The process of claim 4 , wherein the metallic particles comprise a metal and the flat panel display conductive feature has a resistivity that is not greater than 4 times the resistivity of the equivalent pure metal.
57 . The process of claim 4 , wherein the metallic particles comprise a metal and the flat panel display conductive feature has a resistivity that is not greater than 2 times the resistivity of the equivalent pure metal.
58 . The process of claim 4 , wherein the flat panel display conductive feature has a thickness greater than 1 μm.
59 . The process of claim 4 , wherein the flat panel display conductive feature has a thickness greater than 5 μm.
60 . The process of claim 4 , wherein the flat panel display conductive feature comprises a metal-glass composition.
61 . The process of claim 4 , wherein the process further comprises high shear mixing the precursor composition.
62 . A process for forming a flat panel display conductive feature, the process comprising heating an ink jet printed precursor composition to form the flat panel display conductive feature on a substrate, wherein the precursor composition comprises metallic particles and is confined on the substrate by a physical barrier, and wherein the flat panel display conductive feature has a width of not greater than 100 μm.
63 . The process of claim 62 , wherein the physical barrier comprises trenches.
64 . The process of claim 63 , wherein the trenches are formed by chemical etching or photochemical means.
65 . The process of claim 63 , wherein the trenches are formed with a laser.
66 . The process of claim 63 , wherein the process further comprises the steps of:
(d) forming a layer on the substrate; and
(e) forming the trenches in the layer.
67 . The process of claim 66 , wherein the trenches are formed in the layer with a laser.
68 . The process of claim 66 , wherein the layer comprises a photoresist layer.
69 . The process of claim 68 , wherein the trenches are formed in the photoresist layer through photolithography.
70 . The process of claim 62 , wherein the physical barrier comprises a feature having a porosity that retains the precursor composition by capillary forces.
71 . The process of claim 62 , wherein the physical barrier comprises retaining barriers.
72 . The process of claim 71 , wherein the retaining barriers are formed through a direct write printing process.
73 . The process of claim 71 , wherein the retaining barriers are formed through an ink jet printing process.
74 . The process of claim 73 , wherein the retaining barriers comprise two parallel lines with narrow parallel spacing, and wherein the precursor composition is direct printed between the two lines to confine the precursor composition.
75 . The process of claim 62 , wherein the direct printing comprises directing droplets of the precursor composition toward a surface of the substrate, the droplets having an average droplet size not greater than about 10 μm.
76 . The process of claim 75 , wherein the average droplet size is not greater than about 5 μm.
77 . The process of claim 62 , wherein the direct printing comprises depositing droplets onto the substrate at a rate of 1000 drops per second or higher.
78 . The process of claim 77 , wherein each droplet comprise from about 25 to 100 picoliters of the precursor composition.
79 . The process of claim 62 , wherein the minimum feature size is not greater than 75 μm.
80 . The process of claim 62 , wherein the minimum feature size is not greater than 50 μm.
81 . The process of claim 62 , wherein the minimum feature size is not greater than 25 μm.
82 . The process of claim 62 , wherein the flat panel display conductive feature has a width not greater than 200 μm.
83 . The process of claim 62 , wherein the flat panel display conductive feature has a width not greater than 100 μm.
84 . The process of claim 62 , wherein the flat panel display conductive feature has a width not greater than 75 μm.
85 . The process of claim 62 , wherein the flat panel display conductive feature has a width not greater than 50 μm.
86 . The process of claim 62 , wherein the process further comprises surface modifying a surface of the substrate prior to the direct printing.
87 . The process of claim 86 , wherein the surface modifying comprises laser patterning.
88 . The process of claim 86 , wherein the surface modifying comprises forming trenches in the surface by chemical etching or photochemical means.
89 . The process of claim 86 , wherein the surface modifying increases or decreases hydropholicity.
90 . The process of claim 62 , wherein the precursor composition further comprises metal oxide particles.
91 . The process of claim 62 , wherein the precursor composition further comprises glass particles.
92 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 100 nm.
93 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
94 . The process of claim 62 , wherein the metallic particles comprise a metal selected from the group consisting of silver, palladium, copper, gold, platinum and nickel.
95 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 100 nanometers.
96 . The process of claim 62 , wherein the metallic particles have a volume median particle size of not greater than 0.3 μm.
97 . The process of claim 96 , wherein the metallic particles comprise a cap or coating thereon.
98 . The process of claim 97 , wherein the cap or coating comprises an inorganic cap or coating.
99 . The process of claim 97 , wherein the cap or coating comprises silica.
100 . The process of claim 97 , wherein the cap or coating comprises glass.
101 . The process of claim 97 , wherein the cap or coating comprises an organic cap or coating.
102 . The process of claim 97 , wherein the cap or coating comprises a polymer.
103 . The process of claim 97 , wherein the cap or coating comprises an intrinsically conductive polymer, a sulfonated perfluorohydrocarbon polymer, polystyrene, polystyrene/methacrylate, sodium bis(2-ethylhexyl) sulfosuccinate, tetra-n-octyl-ammonium bromide or an alkane thiolate.
104 . The process of claim 97 , wherein the cap or coating comprises PVP.
105 . The process of claim 96 , wherein at least 80 volume percent of the silver particles are not larger than twice the average particle size.
106 . The process of claim 62 , wherein the heating comprises heating in air at from about 450° C. to 600° C.
107 . The process of claim 62 , wherein the substrate comprises glass.
108 . The process of claim 62 , wherein the substrate comprises a polymer.
109 . The process of claim 62 , wherein the flat panel display conductive feature comprises an electrode.
110 . The process of claim 62 , wherein the flat panel display conductive feature comprises a bus line.
111 . The process of claim 62 , wherein the flat panel display conductive feature comprises a transparent conductive feature.
112 . The process of claim 62 , wherein the flat panel display conductive feature comprises indium-tin oxide or antimony-tin oxide.
113 . The process of claim 62 , wherein the metalic particles comprise a metal and the conductivity of the flat panel display conductive feature is no less than 10 percent the conductivity of the equivalent pure metal.
114 . The process of claim 62 , wherein the metallic particles comprise a metal and the flat panel display conductive feature has a resistivity that is not greater than 4 times the resistivity of the equivalent pure metal.
115 . The process of claim 62 , wherein the metallic particles comprise a metal and the flat panel display conductive feature has a resistivity that is not greater than 2 times the resistivity of the equivalent pure metal.
116 . The process of claim 62 , wherein the flat panel display conductive feature has a thickness greater than 1 μm.
117 . The process of claim 62 , wherein the flat panel display conductive feature has a thickness greater than 5 μm.
118 . The process of claim 62 , wherein the flat panel display conductive feature comprises a metal-glass composition.
119 . The process of claim 62 , wherein the process further comprises high shear mixing the precursor composition.