ESD dissipative ceramics
AssigneeSaint-Gobain Ceramics & Plastics, Inc.
InventorsOh-Hun Kwon, Matthew A. Simpson, Roger J. Lin
Life of this patent
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Abstract
This invention relates to a dense ceramics having ESD dissipative characteristics, tunable volume and surface resistivities in semi-insulative range (103-1011 Ohm-cm), substantially pore free, high flexural strength, light colors, for desired ESD dissipation characteristics, structural reliability, high vision recognition, low wear and particulate contamination to be used as ESD dissipating tools, fixtures, load bearing elements, work surfaces, containers in manufacturing and assembling electrostatically sensitive microelectronic, electromagnetic, electro-optic components, devices and systems.
Claims70
An ESD dissipative ceramic component formed by sintering a mixture comprising a base material and one or more resistivity modifiers for a sufficient time and at a sufficient temperature to achieve at least 99 percent of the theoretical density,
- wherein the base material comprises a tetragonal zirconia polycrystal (TZP);
- wherein the resistivity modifier comprises from about 5 vol. % to 60 vol. % of the base material and is selected from the group consisting of conductive and semiconductive materials or mixtures thereof;
- and wherein the ESD dissipative ceramic component has the following physical properties;
- (a) volume resistivity ranging from 103-1011 Ohm-cm;
- (b) flexural strength of at least 500 MPa;
- and
- (c) voltage decay time of less than 500 ms.
An ESD dissipative ceramic component formed by sintering a mixture comprising a base material and one or more resistivity modifiers for a sufficient time and at a sufficient temperature to achieve at least 99.5 percent of the theoretical density;
- wherein the base material comprises a tetragonal zirconia polycrystal (TZP);
- wherein the resistivity modifier comprises from about 5 vol. % to 60 vol. % of the base material and is selected from the group consisting of conductive and semiconductive materials or mixtures thereof;
- and wherein the ESD dissipative ceramic component has the following physical properties:
- (a) volume resistivity ranging from 105-109 Ohm-cm;
- (b) flexural strength of at least 500 MPa;
- and
- (c) voltage decay time of less than 500 ms.
An ESD dissipative ceramic component comprising from about 85 to 60 vol. % Y-TZP and from about 15 to 40 vol. % ZnO densified to at least 99% of the theoretical density by primary and secondary heat treatments.
An ESD dissipative ceramic component formed of a sintered composition comprising:
- a base material comprising tetragonal zirconia;
- and
- a resistivity modifier comprising about 5 vol % to about 60 vol % of the base material, the resistivity modifier selected from conductive and semiconductive materials and mixtures thereof, wherein
- the ESD dissipative ceramic component has a density of at least 99% of the theoretical density of the component.
An ESD dissipative ceramic component formed by sintering a mixture comprising a base material and one or more resistivity modifiers;
- wherein the base material comprises a tetragonal zirconia polycrystal (TZP);
- wherein the resistivity modifier comprises from about 5 vol. % to 60 vol. % of the base material and is selected from the group consisting of conductive and semiconductive materials or mixtures thereof;
- and wherein the ESD dissipative ceramic component has the following physical properties:
- (a) volume resistivity ranging from 106-109 Ohm-cm;
- (b) flexural strength of at least 400 MPa;
- and
- (c) voltage decay time of less than 500 ms.
An ESD dissipative ceramic component formed of a sintered composition comprising:
- a base material comprising tetragonal zirconia;
- and
- a resistivity modifier comprising about 5 vol % to about 60 vol % of the base material, the resistivity modifier selected from conductive and semiconductive materials and mixtures thereof, wherein
- the ESD dissipative ceramic component has an L* color measurement of at least 50 using the CIE 1976 L*a*b* scale on an LKE calorimeter, a density not less than 95% of theoretical density, and a volume resistivity within a range of about 103 to about 1011.
An ESD dissipative ceramic component formed of a sintered composition comprising:
- a base material comprising tetragonal zirconia;
- and
- a resistivity modifier comprising about 5 vol % to about 60 vol % of the base material, the resistivity modifier selected from conductive and semiconductive materials and mixtures thereof, wherein the component has less than 600 particles/cm2 in a particle generation test.
An ESD dissipative ceramic integrated circuit fixture formed of a sintered composition comprising:
- a base material comprising tetragonal zirconia;
- and
- a resistivity modifier comprising about 5 vol % to about 60 vol % of the base material, the resistivity modifier selected from conductive and semiconductive materials and mixtures thereof, wherein the fixture has a density of at least 99% of the theoretical density.
An ESD dissipative ceramic integrated circuit fixture formed of a sintered composition comprising:
- a base material comprising tetragonal zirconia;
- and
- a resistivity modifier comprising about 5 vol % to about 60 vol % of the base material, the resistivity modifier selected from conductive and semiconductive materials and mixtures thereof, wherein the fixture has less than 600 particles/cm2 in a particle generation test.
Dependencies are inferred from the claim text.