US5713666A
Expired / Lapsed
US
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Thermal testing apparatus and method
Assignee: Seelink Technology
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Filing: 1995-08-30
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Granted: 1998-02-03
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Expires: 2015-08-30
Abstract
Abstract A method and apparatus for measuring thermal properties of electronic components (25) encapsulated in packaging is described. The method can be used to measure a junction temperature T j of the electronic component (25), without removing the package (30), and during operation of the electronic component (25) by a power supply. The method comprises the steps of (a) positioning the electronic component (25) in a field of view of an infrared sensor (90), during operation of the electronic component (25) by the power supply; (b) focusing the infrared sensor (90) on the electronic component (25) inside the package (30) to obtain (i) a sharp outline of the component, and (ii) a maximum temperature reading; (c) removing the electronic component (25) from the field of view of the infrared sensor (90); (d) positioning a blackbody source (65) capable of emitting infrared radiation at different wavelengths at substantially the same focal point as the electronic component (25); (e) calibrating the infrared sensor (90) using the blackbody source (65); (f) replacing the blackbody source (65) by the electronic component (25) while continuing to operate the electronic component (25) by the power supply; (g) adjusting the focus of the calibrated infrared sensor (90) by an amount F c sufficient to compensate for a thermal expansion movement of the electronic component (25) and package (30) caused by a rise in temperature of the electronic component (25) resulting from operation of the component by the power supply; and (h) measuring the junction temperature T j of the electronic component (25) to an accuracy of greater than 5% without removing the package (30) of the electronic component (25).
Inventors
- 👤 Kusuma S. Seelin
- 👤 Srikanth N. Seelin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:21
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/52; G01J5/53; G01J5/0003; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N2021/95638
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
230 words
A method for measuring a junction temperature T j of an electronic component encapsulated in a package, without removing the package, and during operation of the electronic component by a power supply, the method comprising the steps of: (a) positioning the electronic component in a field of view of an infrared sensor, during operation of the electronic component by the power supply; (b) focusing the infrared sensor on the electronic component inside the package to obtain (i) a sharp outline of the electronic component, and (ii) a maximum temperature reading; (c) removing the electronic component from the field of view of the sensor; (d) positioning a blackbody source capable of emitting infrared radiation at different wavelengths at substantially the same focal point as the infrared sensor; (e) calibrating the infrared sensor using the blackbody source; (f) replacing the blackbody source with the electronic component while continuing to operate the electronic component by the power supply; (g) adjusting the focus of the calibrated infrared sensor by an amount F c sufficient to compensate for a thermal expansion movement of the electronic component and package caused by a rise in temperature of the electronic component resulting from operation of the component by the power supply; and (h) measuring the junction temperature T j of the electronic component to an accuracy of better than 5% without removing the package of the electronic component.
Claim 2
Independent Claim
230 words
A method for measuring a junction temperature T j of an electronic component encapsulated in a package, without removing the package, and during operation of the electronic component by a power supply, the method comprising the steps of: (a) positioning the electronic component in a field of view of an infrared sensor, during operation of the electronic component by the power supply; (b) focusing the infrared sensor on the electronic component inside the package to obtain (i) a sharp outline of the electronic component, and (ii) a maximum temperature reading; (c) removing the electronic component from the field of view of the sensor; (d) positioning a blackbody source capable of emitting infrared radiation at different wavelengths at substantially the same focal point as the infrared sensor; (e) calibrating the infrared sensor using the blackbody source; (f) replacing the blackbody source with the electronic component while continuing to operate the electronic component by the power supply; (g) adjusting the focus of the calibrated infrared sensor by an amount F c sufficient to compensate for a thermal expansion movement of the electronic component and package caused by a rise in temperature of the electronic component resulting from operation of the component by the power supply; and (h) measuring the junction temperature T j of the electronic component to an accuracy of better than 5% without removing the package of the electronic component.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the junction temperature T j of the electronic component is measured to an accuracy of better than 2%.
Claim 4
Dependent Claim
33 words
The method of claim 1, wherein the junction temperature T j of the electronic component is measured to an accuracy of at least about 1° C. at a temperature of about 50° C.
Claim 5
Dependent Claim
96 words
The method of claim 1, wherein the step of calibrating the infrared sensor comprises the step of deriving a calibration curve for the infrared sensor by the steps of: (i) setting the blackbody source to emit radiation at a temperature T b , (ii) recording the temperature T c measured by the infra-red sensor when the sensor is focused on the blackbody source, (iii) repeating steps (i) to step (ii) for different temperatures T b , and plotting each T b against each T c to obtain a calibration curve for calibration of the infrared sensor.
Claim 6
Dependent Claim
47 words
The method of claim 1, further comprising the step of using the measured junction temperature T j of the electronic component to determine a thermal characteristic of the electronic component and package selected from the group consisting of thermal resistance, power dissipation factor, and thermal response time.
Claim 7
Dependent Claim
30 words
The method of claim 1, wherein the junction temperature T j is the temperature of at least one transition region between portions of the electronic component having different electrical properties.
Claim 8
Dependent Claim
18 words
The method of claim 1, wherein the package of the electronic component comprises an electrically insulative packaging material.
Claim 9
Dependent Claim
33 words
The method of claim 1, wherein the electronic component in the package is a component selected from the group consisting of an integrated circuit chip, resistor, transistor, capacitor, induction coil, and switching devices.
Claim 10
Dependent Claim
82 words
The method of claim 1, comprising the initial steps of: (i) selecting an optical sensor having a field of view substantially aligned with the field of view of the infrared sensor; (ii) positioning the electronic component in the field of view of the optical sensor, during operation of the electronic component by the power supply; and (iii) focusing the optical sensor on the package of the electronic component to obtain a image of the package to facilitate focusing of the infrared sensor.
Claim 11
Independent Claim
340 words
A method for measuring a junction temperature T j of an electronic component in a package, without removing the package, and during operation of the electronic component by a power supply, the method comprising the steps of: (a) selecting a sensor assembly having a field of view, the sensor assembly comprising (i) an optical sensor, and (ii) an infrared sensor; (b) positioning the electronic component in the field of view of the sensor assembly, during operation of the electronic component by the power supply; (c) coarse focusing the optical sensor of the sensor assembly on the package of the electronic component to obtain an image of the package; (d) fine focusing the infrared sensor on the electronic component inside the package to obtain (i) a sharp outline of the electronic component, and (ii) a maximum temperature reading; (e) removing the electronic component from the field of view of the sensor; (f) deriving a calibration curve for the infrared sensor by the steps of: (1) positioning a blackbody source capable of emitting infrared radiation at a temperature T b in the field of view of the infrared sensor; (2) recording the temperature T c measured by the infrared sensor when the sensor is focused on the blackbody source; (3) repeating steps (1) to (2) for different temperatures T b , and plotting each T b against each T c to obtain a calibration curve for calibration of the infrared sensor; (g) replacing the blackbody source with the electronic component while continuing to operate the electronic component by the power supply; (h) adjusting the focus of the infrared sensor by an amount F c sufficient to compensate for a thermal expansion movement of the electronic component and package caused by a rise in temperature of the electronic component resulting from operation of the component by the power supply; and (i) measuring the junction temperature T j of the electronic component, wherein the temperature T j is measured to an accuracy of better than 5% without removing the package of the electronic component.
Claim 12
Independent Claim
340 words
A method for measuring a junction temperature T j of an electronic component in a package, without removing the package, and during operation of the electronic component by a power supply, the method comprising the steps of: (a) selecting a sensor assembly having a field of view, the sensor assembly comprising (i) an optical sensor, and (ii) an infrared sensor; (b) positioning the electronic component in the field of view of the sensor assembly, during operation of the electronic component by the power supply; (c) coarse focusing the optical sensor of the sensor assembly on the package of the electronic component to obtain an image of the package; (d) fine focusing the infrared sensor on the electronic component inside the package to obtain (i) a sharp outline of the electronic component, and (ii) a maximum temperature reading; (e) removing the electronic component from the field of view of the sensor; (f) deriving a calibration curve for the infrared sensor by the steps of: (1) positioning a blackbody source capable of emitting infrared radiation at a temperature T b in the field of view of the infrared sensor; (2) recording the temperature T c measured by the infrared sensor when the sensor is focused on the blackbody source; (3) repeating steps (1) to (2) for different temperatures T b , and plotting each T b against each T c to obtain a calibration curve for calibration of the infrared sensor; (g) replacing the blackbody source with the electronic component while continuing to operate the electronic component by the power supply; (h) adjusting the focus of the infrared sensor by an amount F c sufficient to compensate for a thermal expansion movement of the electronic component and package caused by a rise in temperature of the electronic component resulting from operation of the component by the power supply; and (i) measuring the junction temperature T j of the electronic component, wherein the temperature T j is measured to an accuracy of better than 5% without removing the package of the electronic component.
Claim 13
Dependent Claim
19 words
The method of claim 10, further comprising the step of verifying calibration of the infrared sensor after step (i).
Claim 14
Independent Claim
142 words
An apparatus for measuring a junction temperature of an electronic component in a package, without removing the package, and during operation of the electronic component, the apparatus comprising: (a) a sensor assembly having a field of view, the sensor assembly comprising an infrared sensor; (b) an adjustable platform in the field of view of the sensor assembly; (c) a blackbody source mounted on the platform, the blackbody source having a emitter capable of emitting infrared radiation at different temperatures T b for calibration of the infrared sensor; and (d) a holder mounted on the platform for holding the package with the electronic component therein, wherein the blackbody source and holder are mounted on the platform so that the package of the electronic component when held in the holder is substantially in the same focal plane as the emitter of the blackbody source.
Claim 15
Independent Claim
142 words
An apparatus for measuring a junction temperature of an electronic component in a package, without removing the package, and during operation of the electronic component, the apparatus comprising: (a) a sensor assembly having a field of view, the sensor assembly comprising an infrared sensor; (b) an adjustable platform in the field of view of the sensor assembly; (c) a blackbody source mounted on the platform, the blackbody source having a emitter capable of emitting infrared radiation at different temperatures T b for calibration of the infrared sensor; and (d) a holder mounted on the platform for holding the package with the electronic component therein, wherein the blackbody source and holder are mounted on the platform so that the package of the electronic component when held in the holder is substantially in the same focal plane as the emitter of the blackbody source.
Claim 16
Dependent Claim
21 words
The apparatus of claim 12, further comprising means for determining a calibration curve for the infrared sensor using the blackbody source.
Claim 17
Dependent Claim
93 words
The apparatus of claim 13, wherein the means for determining a calibration curve for the infrared sensor comprises: (i) means for setting the emitter of the blackbody source to emit radiation at different temperatures T b ; (ii) a recorder for recording the temperatures T c measured by the infrared sensor for each of the temperatures T b , when the infrared sensor is focused on the blackbody source; and (iii) means for generating a calibration curve for the infrared sensor by plotting each T b temperature against the corresponding T c temperature.
Claim 18
Dependent Claim
50 words
The apparatus of claim 12, further comprising means for adjusting a focus of the infrared sensor by an amount F c sufficient to compensate for thermal expansion movement of the electronic component and package caused by a rise in temperature of the electronic component resulting from operation of the component.
Claim 19
Dependent Claim
32 words
The apparatus of claim 15, wherein the means for adjusting the focus of the infrared sensor comprises an adjustable gimbal mechanism that allows rotation of the infrared sensor in a fixed plane.
Claim 20
Dependent Claim
34 words
The apparatus of claim 12, further comprising a positioning mechanism assembly for moving the platform so that the blackbody source or holder can be positioned in the field of view of the sensor assembly.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-02-02 | 2001-08-04 | 2002-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-02-02 | 2005-08-04 | 2006-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-02-02 | 2009-08-04 | 2010-02-03 | $7700.00 | Window Closed / Lapsed |