Thermocouple shield
First Claim
1. A thermocouple shield for shielding a thermocouple device from a radio frequency field at an operating temperature “
- T,”
the thermocouple device having a maximum width “
W” and
having a thermocouple junction with a length “
L,”
the thermocouple shield comprising;
an electrically conductive tube having at least minimal structural integrity at the temperature “
T,”
the electrically conductive tube having—
a substantially cylindrically-shaped section and a closed end and an open end, the cylindrically-shaped section having an outside diameter greater than approximately two times “
W,” and
an un-insulated bore with a bore diameter not less than approximately “
W” and
with a bore length greater than approximately two times “
L.”
3 Assignments
0 Petitions
Accused Products
Abstract
A thermocouple shield for use in radio frequency fields. In some embodiments the shield includes an electrically conductive tube that houses a standard thermocouple having a thermocouple junction. The electrically conductive tube protects the thermocouple from damage by an RF (including microwave) field and mitigates erroneous temperature readings due to the microwave or RF field. The thermocouple may be surrounded by a ceramic sheath to further protect the thermocouple. The ceramic sheath is generally formed from a material that is transparent to the wavelength of the microwave or RF energy. The microwave transparency property precludes heating of the ceramic sheath due to microwave coupling, which could affect the accuracy of temperature measurements. The ceramic sheath material is typically an electrically insulating material. The electrically insulative properties of the ceramic sheath help avert electrical arcing, which could damage the thermocouple junction. The electrically conductive tube is generally disposed around the thermocouple junction and disposed around at least a portion of the ceramic sheath. The concepts of the thermocouple shield may be incorporated into an integrated shielded thermocouple assembly.
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Citations
18 Claims
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1. A thermocouple shield for shielding a thermocouple device from a radio frequency field at an operating temperature “
- T,”
the thermocouple device having a maximum width “
W” and
having a thermocouple junction with a length “
L,”
the thermocouple shield comprising;an electrically conductive tube having at least minimal structural integrity at the temperature “
T,”
the electrically conductive tube having—a substantially cylindrically-shaped section and a closed end and an open end, the cylindrically-shaped section having an outside diameter greater than approximately two times “
W,” andan un-insulated bore with a bore diameter not less than approximately “
W” and
with a bore length greater than approximately two times “
L.” - View Dependent Claims (2, 3, 4, 5, 6)
- T,”
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7. A thermocouple shield for shielding a thermocouple probe from a radio frequency field having a frequency, where the thermocouple probe comprises an electrically conductive jacket having a tip end surrounding a thermocouple junction, and where the thermocouple probe has a maximum diameter “
- D,”
the thermocouple shield comprising;an electrically conductive tube having a tube bore, a generally hemispherical-shaped closed end and an open end, wherein the electrically conductive tube comprises at least one perforation having a size less than a waveguide-beyond-cutoff dimension at the frequency of the radio frequency field; and a ceramic sheath disposed within the tube bore, the ceramic sheath having a sheath bore with a sheath-bore inside diameter not less than “
D;
”
wherein;the thermocouple probe is disposed within the sheath bore. - View Dependent Claims (8, 9, 10, 11)
- D,”
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12. A shielded thermocouple assembly for use in an RF processing chamber having a radio frequency field, the shielded thermocouple assembly comprising:
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a thermocouple having a thermocouple junction; a ceramic sheath surrounding at least a portion of the thermocouple, the ceramic sheath being electrically insulating and substantially transparent to the radio frequency field; an electrically conductive tube disposed around the thermocouple junction and disposed around at least a portion of the ceramic sheath wherein the electrically conductive tube comprises at least one perforation having a size less than a waveguide-beyond-cutoff dimension at the frequency of the radio frequency field; and an electrical connection configured for electrically coupling the electrically conductive tube with the RF processing chamber. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification