Dispersible dielectric particles and methods of forming the same
First Claim
1. A method of forming a composite structure comprising:
- forming an aqueous mixture including barium titanate-based particles and water;
replacing at least a portion of the water in the aqueous mixture with a non-aqueous solvent to form a non-aqueous mixture including the non-aqueous solvent and the barium titanate-based particles;
drying the barium titanate-based particles in the non-aqueous mixture;
mixing the dried barium titanate-based particles with a second non-aqueous solvent and a precursor of polymeric material to form a second non-aqueous mixture; and
removing the second non-aqueous solvent from the second non-aqueous mixture to form a composite structure including barium titanate-based particles distributed in the polymeric material.
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Accused Products
Abstract
Methods of forming dispersible dielectric particles, as well as articles and compositions that include the dispersible dielectric particles, are provided. The methods involve forming an aqueous mixture of dielectric (e.g., barium titanate-based) particles and replacing at least a portion of water in the mixture with a non-aqueous solvent (e.g., ethanol). According to one set of methods, the particles are then dried. The limited, or lack, of water present in the mixture during drying reduces capillary forces that otherwise may draw the particles together to cause formation of strong agglomerates. Thus, particle agglomeration during drying may be reduced which increases particle dispersibility. According to another set of methods of the invention, the particles are not dried after non-aqueous solvent replacement, thus, avoiding formation of agglomerates during drying and increasing dispersibility. In both sets of methods, particles (or mixtures thereof) may be further processed, for example, to form composite layers. As a result of the increased particle dispersibility, the particles are relatively uniformly distributed throughout the polymeric material. This uniform distribution improves properties of the composite layers which may be used as an embedded capacitor in electronic applications including printed circuit boards.
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Citations
50 Claims
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1. A method of forming a composite structure comprising:
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forming an aqueous mixture including barium titanate-based particles and water;
replacing at least a portion of the water in the aqueous mixture with a non-aqueous solvent to form a non-aqueous mixture including the non-aqueous solvent and the barium titanate-based particles;
drying the barium titanate-based particles in the non-aqueous mixture;
mixing the dried barium titanate-based particles with a second non-aqueous solvent and a precursor of polymeric material to form a second non-aqueous mixture; and
removing the second non-aqueous solvent from the second non-aqueous mixture to form a composite structure including barium titanate-based particles distributed in the polymeric material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 47)
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26. A method of forming a composite structure comprising:
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forming an aqueous mixture including barium titanate-based particles and water;
replacing at least a portion of the water in the aqueous mixture with a non-aqueous solvent to form a non-aqueous mixture including the non-aqueous solvent and the barium titanate-based particles;
adding a precursor of a polymeric material to the non-aqueous mixture; and
removing the non-aqueous solvent from the non-aqueous mixture to form a composite structure including barium titanate-based particles distributed in the polymeric material. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
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- 48. A composite layer including barium titanate-based particles distributed in a polymeric material, the barium titanate-based particles being present in an amount of at least 50 percent by weight of the total composite layer, the composite layer having a surface roughness of less than about 500 nm.
Specification