Wireless temperature calibration device and method
AssigneeTexas Instruments Incorporated
InventorsMehrdad M. Moslehi, Habib Najm, Lino A. Velo
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Abstract
A device and method for calibrating at least one temperature sensor is disclosed herein. A wafer (30) is provided having a first plurality of calibration islands (36) of a material having a melting point in the range 150.degree.-1150.degree. C. The effective reflectivity of the wafer is measured in operation using the temperature sensor or via a separate light source. A first step change in an output signal of the temperature sensor corresponding to a wafer temperature equal to the melting point of the first calibration islands is detected. Finally, the temperature sensor calibration parameters are calculated.
Claims38
A wireless device for calibrating at least one temperature sensor, wherein said at least one temperature sensor is operable to detect a temperature dependent characteristic of said wireless device and output a signal corresponding to said temperature dependent characteristic, comprising a wafer having a plurality of calibration islands wherein said islands are of a material having a melting point in the range 150.degree. to 1150.degree. C. such that in operation a step change in said temperature dependent characteristic occurs at a wafer temperature equal to said melting point during a ramped-temperature calibration process.
A system for calibrating at least one temperature sensor, wherein said at least one temperature sensor is operable to detect a temperature dependent characteristic of said system, comprising:
- a. a wafer having a plurality of calibration rings wherein each of said rings comprises at least one material having a melting point in the range of 150.degree. to 1150.degree. C. such that in operation a step change in said temperature dependent characteristic occurs at a wafer temperature equal to said melting point of said calibration rings during a ramped-temperature calibration process;
- b. a plurality of light beams each directed at one of said calibration rings on the wafer;
- and
- c. a plurality of detectors for detecting the wafer reflectance values for each of the light beams.
A wireless device having a frontside and a backside for calibrating at least one temperature sensor, wherein said at least one temperature sensor is operable to detect a temperature dependent characteristic of said wireless device and output a signal corresponding to said temperature dependent characteristic, comprising:
- a. a substrate;
- b. a buffer layer located adjacent to and over the substrate for preventing substrate contamination and thermal reactions;
- c. a plurality of first calibration islands located adjacent to said buffer layer, wherein said first calibration islands are of a material having a melting point in the range of 150.degree. to 1150.degree. C. such that in operation a first step change in said temperature dependent characteristic occurs at a wafer temperature equal to said melting point of said first calibration islands during a ramped-temperature calibration process;
- and
- d. a first encapsulation layer adjacent to said calibration islands for sealing and maintaining the form and integrity of said calibration islands during calibration.
A method for calibrating at least one temperature sensor comprising the steps of:
- a. providing a wafer having a first plurality of calibration islands of a material having a melting point in the range 150.degree. to 1150.degree. C.
- b. ramping the temperature of said wafer;
- c. measuring a temperature dependent characteristic of the wafer with said at least one temperature sensor while said wafer temperature is being changed for each temperature sensor being calibrated;
- d. detecting a first step change in said temperature dependent characteristic corresponding to a wafer temperature equal to said melting point of said first calibration islands for each temperature sensor being calibrated;
- e. calculating the calibration parameters for each temperature sensor being calibrated.
A method for calibrating at least one temperature sensor comprising the steps of:
- a. providing a wafer having at least one plurality of calibration structures of a material having a melting point in the range of 150.degree. to 1150.degree. C., wherein said at least one temperature sensor is operable to detect reflectivity of said wafer and output a signal corresponding to said reflectivity;
- b. directing a light beam at the wafer;
- c. measuring the wafer reflectance at the point at which each light beam is directed;
- d. detecting a first step change in the detected wafer reflectance corresponding to a wafer temperature equal to the melting point of said calibration structures;
- e. determining a first current level of said signal corresponding to said first step change;
- and
- f. calculating the calibration parameters for each temperature sensor being calibrated.
A method for calibrating at least one temperature sensor comprising the steps of:
- a. providing a first wafer having a first plurality of calibration islands of a first material having a melting point in the range 150.degree. to 1150.degree. C.;
- b. slowly ramping the temperature of said first wafer;
- c. measuring a temperature dependent characteristic of the first wafer in response to said changing temperature with each temperature sensor;
- d. detecting a first step change in said temperature dependent characteristic corresponding to a first wafer temperature equal to said melting point of said first calibration islands for each temperature sensor;
- e. providing a second wafer having a second plurality of calibration islands of a second material having a melting point in the range 150.degree. to 1150.degree. C., wherein said second material is different from said first material;
- f. slowly ramping the temperature of said second wafer;
- g. measuring said temperature dependent characteristic of said second wafer in response to said increasing temperature with each temperature sensor;
- h. detecting a second step change in said temperature dependent characteristic corresponding to a second wafer temperature equal to said melting point of said second calibration islands for each temperature sensor;
- and
- i. calculating the calibration parameters for each temperature sensor being calibrated.
Dependencies are inferred from the claim text.