Copper powders methods for producing powders and devices fabricated from same
Copper metal powders, methods for producing copper metal powders and products incorporating the powders. The copper metal powders have a small particle size, narrow size distribution and a spherical morphology. The method includes forming the metal particles in a continuous manner.
1. A powder batch comprising copper metal particles, wherein said metal particles are substantially spherical, have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said metal particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
2. A powder batch as recited in claim 1 , wherein said metal particles comprise at least about 50 weight percent copper metal.
3. A powder batch as recited in claim 1 , wherein said metal particles comprise at least about 80 weight percent copper metal.
4. A powder batch as recited in claim 1 , wherein at least about 95 weight percent of said metal particles are not larger than twice said average particle size.
5. A powder batch as recited in claim 1 , wherein at least about 90 weight percent of said metal particles are not larger than 1.5 times said average particle size.
6. A powder batch as recited in claim 1 , wherein at least about 95 weight percent of said metal particles are not larger than 1.5 times said average particle size.
7. A powder batch as recited in claim 1 , wherein said average crystallite size is at least about 20 percent of said average particle size.
8. A powder batch as recited in claim 1 , wherein said average crystallite size is at least about 30 percent of said average particle size.
9. A powder batch as recited in claim 1 , wherein said average crystallite size is at least about 60 nanometers.
10. A powder batch as recited in claim 1 , wherein said average crystallite size is at least about 80 nanometers.
11. A powder batch as recited in claim 1 , wherein said metal particles have a particle density of at least about 7.1 g/cm 3 .
12. A powder batch as recited in claim 1 , wherein said metal particles have a particle density of at least about 8.0 g/cm 3 .
13. A powder batch as recited in claim 1 , wherein said metal particles have a particle density of at least about 8.5 g/cm 3 .
14. A powder batch as recited in claim 1 , wherein said average particle size is from about 0.1 μm to about 3 μm.
15. A powder batch as recited in claim 1 , wherein said average particle size is from about 0.3 μm to about 1.5 μm.
16. A powder batch as recited in claim 1 , wherein said average particle size is from about 0.3 μm to about 0.8 μm.
17. A powder batch as recited in claim 1 , wherein not greater than about 0.5 weight percent of said metal particles are in the form of hard agglomerates.
18. A powder batch as recited in claim 1 , wherein said metal particles are coated particles comprising a coating substantially encapsulating an outer surface thereof.
19. A powder batch as recited in claim 1 , wherein said metal particles are composite particles comprising a non-metallic phase dispersed throughout a metal phase.
20. A powder batch as recited in claim 1 , wherein said powder batch has a specific surface area of not greater than about 3 m 2 /g.
21. A powder batch as recited in claim 1 , wherein said metal particles comprise no more than about 0.1 atomic percent impurities.
22. A powder batch as recited in claim 1 , wherein said metal particles comprise no more than about 1 weight percent copper oxide impurities.
23. A powder batch comprising copper metal particles, wherein said metal particles comprise at least about 50 weight percent copper metal wherein said metal particles are substantially spherical, have a weight average particle size of from about 0.3 μm to about 3 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than 1.5 times said average particle size and wherein said metal particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
24. A powder batch as recited in claim 23 , wherein said metal particles have a particle density of at least about 8.5 g/cm 3 .
25. A powder batch as recited in claim 23 , wherein said metal particles comprise at least about 80 weight percent copper metal.
26. A powder batch as recited in claim 23 , wherein at least about 95 weight percent of said metal particles are not larger than 1.5 times said average particle size.
27. A powder batch as recited in claim 23 , wherein said average crystallite size is at least about 60 nanometers.
28. A powder batch comprising metal alloy particles, wherein said metal alloy particles comprise at least about 50 weight percent copper metal and at least a first metal alloying element, and wherein said metal alloy particles are substantially spherical, have a weight average particle size of not greater than about 5 μm and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
29. A powder batch as recited in claim 28 , wherein said first metal alloying element is selected from the group consisting of zinc, palladium, silver, gold, nickel, tungsten, molybdenum tin and platinum.
30. A powder batch as recited in claim 28 , wherein said first metal alloying element is zinc.
31. A powder batch as recited in claim 28 , wherein said first metal alloying element is homogeneously alloyed with said copper metal with substantially no phase segregation.
32. A powder batch as recited in claim 28 wherein said metal alloy particles comprise from about 0.1 to about 40 weight percent of said first metal alloying element based on the total amount of metal.
33. A powder batch as recited in claim 28 wherein said metal alloy particles comprise from about 1 to about 15 weight percent of said first metal alloying element based on the total amount of metal.
34. A powder batch as recited in claim 28 wherein said metal alloy particles have an average particle size of not greater than about 3 μm.
35. A powder batch as recited in claim 28 , wherein said metal alloy particles have a lower sintering temperature than pure copper metal particles.
36. A powder batch as recited in claim 28 , wherein said metal alloy particles have a higher sintering temperature than pure copper metal particles.
37. A powder batch as recited in claim 28 , wherein said metal alloy particles have a higher vaporization temperature than pure copper metal particles.
38. A powder batch as recited in claim 28 , wherein said metal alloy particles have increased oxidation resistance compared to pure copper metal particles.
39. A powder batch comprising coated copper metal particles, said coated metal particles comprising at least about 50 weight percent copper metal and having a weight average particle size of not greater than about 5 μm and wherein said particles comprise at least a first coating substantially encapsulating an outer surface of said particles and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
40. A powder batch as recited in claim 39 , wherein said average particle size is not greater than about 3 μm.
41. A powder batch as recited in claim 39 , wherein said coated metal particles have a particle size distribution wherein at least about 95 weight percent of said particles are not larger than twice said average particle size.
42. A powder batch as recited in claim 39 , wherein said coated metal particles are substantially spherical.
43. A powder batch as recited in claim 39 , wherein said first coating has an average thickness of not greater than about 100 nanometers.
44. A powder batch as recited in claim 39 , wherein said first coating has an average thickness of not greater than about 50 nanometers.
45. A powder batch as recited in claim 39 , wherein said first coating comprises a metal oxide.
46. A powder batch as recited in claim 39 , wherein said first coating comprises a metal oxide selected from the group consisting of ZrO 2 , NiO, SiO 2 , B 2 O 5 , TiO 2 , Cu 2 O, CuO, Bi 2 O 3 , V 2 O 5 and Al 2 O 3 .
47. A powder batch as recited in claim 39 , wherein said first coating comprises a metal oxide selected from the group consisting of SiO 2 and Al 2 O 3 .
48. A powder batch as recited in claim 39 , wherein said first coating comprises an organic compound.
49. A powder batch as recited in claim 39 , wherein said first coating is a monolayer coating.
50. A powder batch as recited in claim 39 , wherein said first coating is a particulate coating.
51. A powder batch as recited in claim 39 , wherein said first coating is a non-particulate coating.
52. A powder batch as recited in claim 39 , wherein said first coating inhibits the sintering of said metal particles at elevated temperatures.
53. A powder batch as recited in claim 39 , wherein said first coating enhances the sintering of said metal particles.
54. A powder batch as recited in claim 39 , wherein said first coating improves the dispersibility of said metal particles in a thick film paste.
55. A powder batch as recited in claim 39 , wherein said coating increases the oxidation resistance of said metal particles.
56. A powder batch as recited in claim 39 , wherein said coating comprises a metal.
57. A powder batch as recited in claim 39 , wherein said coating comprises a noble metal.
58. A powder batch as recited in claim 39 , wherein said coating comprises silver metal.
59. A powder batch as recited in claim 39 , wherein said coated metal particles further comprise a second coating substantially encapsulating said first coating.
60. A powder batch comprising metal composite particles, wherein said composite particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size, wherein said particles include a metal phase comprising copper metal and at least a first non-metallic phase and wherein said particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
61. A powder batch as recited in claim 60 , wherein said composite particles comprise at least about 50 weight percent copper metal.
62. A powder batch as recited in claim 60 , wherein said first non-metallic phase is dispersed throughout said metal phase.
63. A powder batch as recited in claim 60 , wherein said average particle size is not greater than about 3 μm.
64. A powder batch as recited in claim 60 , wherein said average particle size is from about 0.3 μm to about 1.5 μm.
65. A powder batch as recited in claim 60 , wherein at least about 90 weight percent of said composite particles are not larger than 1.5 times said average particle size.
66. A powder batch as recited in claim 60 , wherein said first non-metallic phase comprises a metal oxide.
67. A powder batch as recited in claim 60 , wherein said first non-metallic second phase comprises a metal oxide selected from the group consisting of NiO, SiO 2 , Cu 2 O, CuO, B 2 O 3 , TiO 2 , ZrO 2 , Bi 2 O 3 CaO, V 2 O 5 and Al 2 O 3 .
68. A powder batch as recited in claim 60 , wherein said first non-metallic phase is a dielectric compound selected from the group consisting of titanates, zirconates, silicates, aluminates, tantalates and niobates.
69. A powder batch as recited in claim 60 , wherein said first non-metallic phase is a titanate.
70. A powder batch as recited in claim 60 , wherein said first non-metallic phase is selected from the group consisting of barium titanate and neodymium titanate.
71. A powder batch as recited in claim 60 , wherein said first non-metallic phase is carbon.
72. A powder batch as recited in claim 60 , wherein said composite particles comprise at least about 0.1 weight percent of said first non-metallic phase.
73. A powder batch as recited in claim 60 , wherein said composite particles comprise from about 0.2 to about 35 weight percent of said first non-metallic phase.
74. A powder batch as recited in claim 60 , wherein said composite particles comprise from about 0.2 to about 5 weight percent of said first non-metallic phase.
75. A powder batch comprising metal composite particles, said composite particles having a weight average particle size of not greater than about 5 μm, wherein said composite particles include a metal phase comprising copper metal and at least a first non-metallic phase comprising a ceramic dielectric compound and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
76. A powder batch as recited in claim 75 , wherein said metal phase comprises at least about 50 weight percent copper metal.
77. A powder batch as recited in claim 75 , wherein said ceramic dielectric compound is selected from the group consisting of titanates, zirconates, silicates, aluminates, tantalates and niobates.
78. A powder batch as recited in claim 75 , wherein said ceramic dielectric compound is a titanate.
79. A powder batch as recited in claim 75 , wherein said ceramic dielectric compound is selected from the group consisting of barium titanate and neodymium titanate.
80. A powder batch as recited in claim 75 , wherein said weight average particle size is from about 0.3 μm to about 1.5 μm.
81. A powder batch as recited in claim 75 , wherein said first non-metallic phase is homogeneously dispersed throughout said metal phase.
82. A powder batch as recited in claim 75 , wherein said composite particles comprise at least about 0.1 weight percent of said first non-metallic phase.
83. A powder batch as recited in claim 75 , wherein said composite particles comprise from about 0.2 to about 35 weight percent of said first non-metallic phase.
84. A powder batch as recited in claim 75 , wherein said composite particles comprise from about 0.2 to about 5 weight percent of said first non-metallic phase.
85. A thick-film paste composition suitable for screen printing onto a substrate, comprising:
a) a binder phase;
b) an organic vehicle phase; and
c) a functional phase, said functional phase comprising copper metal particles, wherein said copper metal particles are substantially spherical, have a weight average particle size of not greater than about 5 μm and an average crystallite size of at least about 40 nanometers and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
86. A paste composition as recited in claim 85 , wherein said copper metal particles have a particle size distribution wherein at least about 95 weight percent of said metal particles are not larger than twice said average particle size.
87. A paste composition as recited in claim 85 , wherein said average particle size is not greater than about 3 μm.
88. A paste composition as recited in claim 85 , wherein said average particle size is from about 0.3 μm to about 1.5 μm.
89. A paste composition as recited in claim 85 , wherein said copper metal powder is a metal alloy particle comprising an effective amount of an alloying element to increase the oxidation resistance of the copper metal powder.
90. A paste composition as recited in claim 85 , wherein said binder phase comprises a glass frit.
91. A paste composition as recited in claim 85 , wherein said organic vehicle phase comprises a high molecular weight polymer dissolved in a solvent.
92. A paste composition as recited in claim 85 , wherein said organic vehicle phase comprises a polymer dissolved in a solvent, wherein said polymer is selected from the group consisting of ethyl cellulose, polyvinyl acetate, cellulose resin and acrylic resin and said solvent is selected from the group consisting of methanol, ethanol, terpineol, butyl carbitol, butyl carbitol acetate, aliphatic alcohols, esters and acetone.
93. A paste composition as recited in claim 85 , wherein said paste composition comprises from about 5 to about 95 weight percent of said functional phase.
94. A paste composition as recited in claim 85 , wherein said paste composition comprises from about 60 to about 85 weight percent of said copper metal particles.
95. A paste composition as recited in claim 85 , wherein said copper metal particles are composite particles comprising copper metal and a non-metallic phase.
96. A paste composition as recited in claim 85 , wherein said copper metal particles are composite particles comprising copper metal and a non-metallic second phase dispersed throughout said copper metal.
97. A paste composition as recited in claim 85 , wherein said copper metal particles are coated metal particles comprising a coating substantially encapsulating said particles.
98. A paste composition as recited in claim 85 , wherein said copper metal particles are coated metal particles comprising a metal oxide coating substantially encapsulating an outer surface thereof.
99. A thick-film paste composition suitable for screen printing onto a substrate, comprising:
a) a binder phase;
b) an organic vehicle phase; and
c) a functional phase, said functional phase comprising composite copper metal particles having a weight average particle size not greater than about 5 μm, said composite particles including a metal phase comprising copper metal and at least a first non-metallic phase and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said particles comprise metal crystallites having an average crystallite size of at least about 40 nanometers.
100. A paste composition as recited in claim 99 , wherein said composite particles comprise at least about 50 weight percent copper metal.
101. A paste composition as recited in claim 99 , wherein said first non-metallic phase comprises a metal oxide.
102. A paste composition as recited in claim 99 , wherein said first non-metallic phase is dispersed throughout said copper metal phase.
103. A paste composition as recited in claim 99 , wherein said first non-metallic phase is a ceramic dielectric compound.
104. A paste composition as recited in claim 99 , wherein said first non-metallic phase is a ceramic dielectric compound selected from the group consisting of titanates, zirconates, silicates, aluminates, tantalates and niobates.
105. A paste composition as recited in claim 99 , wherein said first non-metallic phase is a ceramic dielectric compound comprising a titanate.
106. A paste composition as recited in claim 99 , wherein said composite particles comprise from about 0.2 to about 5 weight percent of said first non-metallic phase.
107. A paste composition as recited in claim 99 , wherein said composite copper metal particles comprise up to about 75 weight percent copper metal and wherein said first non-metallic phase is a metal oxide selected from the group consisting of alumina and silica.
108. A paste composition as recited in claim 99 , wherein said weight average particle size is from about 0.3 μm to about 1.5 μm.
109. A green body suitable for sintering to form a multilayer ceramic capacitor, comprising:
a) a plurality of stacked green sheets comprising a dielectric ceramic material; and
b) a thick film paste composition disposed between said sheets, wherein said thick film paste composition comprises a binder phase, an organic vehicle phase and a functional phase and wherein said functional phase comprises copper metal particles having a substantially spherical shape and having a weight average particle size of not greater than about 5 μm and an average crystallite size of at least about 40 nanometers and wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
110. A green body as recited in claim 109 , wherein said average particle size is from about 0.3 μm to about 1.5 μm.
111. A green body as recited in claim 109 , wherein said average particle size is from about 0.3 μm to about 0.8 μm.
112. A green body as recited in claim 109 , wherein said copper metal particles are composite particles comprising a copper metal phase and a non-metallic phase.
113. A green body as recited in claim 109 , wherein said copper metal particles are composite particles comprising copper metal and a metal oxide dispersed throughout said copper metal.
114. A green body as recited in claim 109 , wherein said copper metal particles are composite particles comprising copper metal and a dielectric compound selected from the group consisting of titanates, zirconates, silicates, aluminates, tantalates and niobates.
115. A green body as recited in claim 109 , wherein said copper metal particles are composite particles comprising copper metal and a dielectric compound comprising a titanate.
116. A green body as recited in claim 109 , wherein said copper metal particles are coated particles comprising a coating substantially encapsulating said particles.
117. A green body as recited in claim 109 , wherein said copper metal particles are coated particles comprising a metal oxide coating substantially encapsulating said particles.
118. A green body as recited in claim 109 , wherein said copper metal particles are coated particles comprising a noble metal coating.
119. A green body as recited in claim 109 , wherein said copper metal particles are coated particles comprising a silver metal coating.
120. An intermediate component for a microelectronic device, wherein said component comprises an insulative substrate and a thick film paste disposed on said substrate, said thick film paste comprising copper metal particles having a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said copper metal particles comprise crystallites having an average crystallite size of at least about 40 nanometers.
121. An intermediate component as recited in claim 120 , wherein said substrate comprises a ceramic.
122. An intermediate component as recited in claim 120 , wherein said substrate is a green ceramic sheet.
123. An intermediate component as recited in claim 120 , wherein said substrate is a sintered ceramic.
124. An intermediate component as recited in claim 120 , wherein said weight average particle size is from about 0.3 μm to about 1.5 μm.
125. An intermediate component as recited in claim 120 , wherein said thick film paste is adapted to form a plurality of conductive traces disposed in substantially parallel relation and having an average pitch of not greater than about 25 μm.
126. An intermediate component as recited in claim 120 , wherein said microelectronic device is a multichip module.