Composition for electrodes comprising aluminum powder having controlled particle size distribution and size, and electrodes made using the same
Disclosed herein is a composition for electrodes that enables a firing process in air at a temperature of 600° C. or less and does not cause an increase in absolute resistance and a substantial variation of the resistance even when the composition is repeatedly subjected to the firing process. The composition for electrodes comprises: about 5 to about 95% by weight of aluminum powder, the aluminum powder having a particle size distribution of about 2.0 or less as expressed by the following Equation (1) and having D 50 in the range of about 0.1 μm≦D 50 ≦about 20 μm; about 3 to about 60% by weight of an organic binder; and the balance of a solvent: Particle size distribution=( D 90 −D 10 )/ D 50 (1) wherein D 10 , D 50 , and D 90 represent particle diameters at 10%, 50% and 90% points on an accumulation curve of a particle size distribution when the total weight is 100%. An electrode and a PDP fabricated using the composition are also disclosed.
1. A composition for electrodes, comprising:
about 5 to about 95% by weight of comprising aluminum powder, the aluminum powder having a particle size distribution of about 2.0 or less as expressed by the following Equation (1)
Particle size distribution=( D 90 −D 10)/ D 50 Equation (1)
wherein D 10 , D 50 , and D 90 represent particle diameters at 10%, 50% and 90% points on an accumulation curve of a particle size distribution when the total weight is 100% D 90 −D 10 is 3.58 μm to 10.42 μm,
and having D 50 in the range of about 0.1 μm≦D 50 ≦ about 20 μm;
about 3 to about 60% by weight of an organic binder; and
the balance of a solvent.
2. The composition according to claim 1 , wherein the aluminum powder is elemental aluminum or an aluminum alloy.
3. The composition according to claim 2 , wherein the aluminum alloy is formed by alloying at least one element selected from silver, copper, silicon, tin, chromium and germanium with aluminum.
4. The composition according to claim 1 , wherein the aluminum powder has a particle size distribution of about 0.5 to about 1.7 as expressed by Equation (1) and having D 50 in the range of about 0.1 μm≦D 50 ≦ about 20 μm.
5. The composition according to claim 1 , wherein the organic binder is at least one selected from celluloses, water soluble cellulose derivatives, and copolymers obtained by copolymerizing a monomer having an ethylenically unsaturated double bond with a carboxyl group monomer.
6. The composition according to claim 5 , wherein the monomer having an ethylenically unsaturated double bond comprises at least one monomer selected from esters of acrylic acid, styrene, acrylic amide and acrylonitrile and wherein the carboxyl group monomer comprises at least one carboxyl group monomer selected from acrylic acid, methacrylic acid and itaconic acid.
7. The composition according to claim 1 , wherein the solvent is at least one selected from methyl cellosolve, ethyl cellosolve, butyl cellosolve, aliphatic alcohol, α-terpineol, β-terpineol, dihydro-terpineol, ethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, dietherethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, glycerol, butyl acetate, ethyl acetate, cyclohexanol, butyl cellosolve acetate, texanol, mineral spirits, organic acids, oleic acid, and combinations thereof.
8. The composition according to claim 1 , further comprising:
a glass frit in an amount of about 1 to about 30 parts by weight based on 100 parts by weight of the composition.
9. The composition according to claim 8 , wherein the glass frit comprises at least one of PbO, Bi 2 O 3 , SiO 2 , B 2 O 3 , P 2 O 5 , ZnO, Or Al 2 O 3 .
10. The composition according to claim 9 , wherein the glass frit has a glass transition temperature Tg of about 300 to about 600° C.
11. The composition according to claim 1 , wherein the organic binder has a decomposition temperature of about 300 to about 500° C.
12. The composition according to claim 1 , further comprising:
a photo-polymerization compound in an amount of about 0.1 to about 20 parts by weight and a photo-polymerization initiator in an amount of about 0.01 to about 10 parts by weight based on 100 parts by weight of the composition.
13. The composition according to claim 1 , further comprising:
at least one additive selected from antifoaming agents, leveling agents, ultraviolet stabilizers, antioxidant agents, viscosity stabilizers, dispersing agents, anti-heat curing agents, and combinations thereof.
14. An electrode formed using a process selected from a dry film resistor (DFR) process, a coater process, a screen printing process, an off-set printing process, and a photolithography process and comprising the step of firing the composition according to claim 1 at about 450 to about 600° C.
15. An electrode formed using a photolithography process and comprising the step of firing the composition according to claim 12 at about 450 to about 600° C.
16. The composition according to claim 1 , wherein the aluminum powder has a particle size distribution of 0.69 to about 2.0 μm as expressed by Equation (1).
17. The composition according to claim 16 , wherein the aluminum powder has a particle size distribution of 1.44 to about 2.0 μm as expressed by Equation (1).