Abstract: A system employing thermographic techniques is provided for inspecting materials and detecting defects therein such as void, inclusions, interlaminar disbonds, or porosity. The system utilizes a composite material and a source of pulsed current which is delivered to conductive elements within the composite material which, in turn, heats the material being inspected allowing thermographic techniques to be employed to measure the temperature distributions related to the application of the heat source and indicative of the defects of the material being measured.

Abstract: The invention is a synchronized electronic shutter system (SESS) and method for same side and through transmission thermal analysis and inspection of a material for finding defects, corrosion, disbond defects, integrity of a weld and determination of paint thickness. The system comprises an infrared detector that acquires background images of the sample. A shutter then covers the detector and lamps rapidly heat the sample above ambient temperature. Shutters cover all lamps at the same time the shutter over the infrared detector is opened. The infrared detector acquires a series of temperature images over time radiated from the sample as the sample cools down. After collecting a series of temperature images taken by the SESS, a processed image is developed using one of the group comprising time derivative calculation, temperature normalization data reduction routine, thermal diffusivity curve fitting and averaging the series of temperature images.

Abstract: A method and apparatus for mapping the character and location of small surface variations on a planar surface. Energy in the form of pulses is supplied to an object in close proximity to the planar surface to thereby raise the temperature of the object and at part of the surface. A change in temperature of the object is detected when it is in proximity to the variation to define the location and character of the variation. By supplying the energy in the form of pulses, the size of the thermal signature produced in the planar surface is limited wherein a more accurate and more sensitive mapping method and apparatus are provided. The energy supply may be thermal energy or optical energy but preferably is electrical energy which heats a resistive element. Preferably, the object is a magnetoresistive head of a disk drive assembly and the surface may be that of a magnetic recording material. The change in temperature is detected by monitoring the resistance of the magnetoresistive coil of the head.

Abstract: Heat is applied to a conductive structure that includes one or more vias, and the temperature at or near the point of heat application is measured. The measured temperature indicates the integrity or the defectiveness of various features (e.g. vias and/or traces) in the conductive structure, near the point of heat application. Specifically, a higher temperature measurement (as compared to a measurement in a reference structure) indicates a reduced heat transfer from the point of heat application, and therefore indicates a defect. The reference structure can be in the same die as the conductive structure (e.g. to provide a baseline) or outside the die but in the same wafer (e.g. in a test structure) or outside the wafer (e.g. in a reference wafer), depending on the embodiment.

Abstract: An accelerated thermal stress cycle test which can be conducted in a significantly reduced test time compared to the conventional test is provided. The test is carried out in a cluster of reaction chambers that includes a CVD chamber and a cool-down chamber such that a pre-processed wafer can be heated from room temperature to at least 350° C. in an inert gas in about 2 min., and then cooled down to not higher than 70° C. in a cool-down chamber in less than 30 sec. The heating and cooling steps can be repeated between 3 and 7 times to reveal any defect formation caused by the thermal stress cycle test. Typical defects are metal film peeling from insulating dielectric material layer or void formation.

Abstract: In a system (10) for evaluating a structure (20), the structure (20) has a predetermined baseline thermal signature. The system (10) includes a thermal source (30) located at least partially inside the structure (20). The thermal source (30) is operable to generate a predetermined amount of heat, which heats the structure (20). The system (10) also includes a detection device (40) that is operable to determine the temperature at various points of the structure (20). The system (10) further includes a computer (50) that is coupled to the detection device (40). The computer (50) is operable to generate a thermal signature of the structure (20) based on the temperature at the various points. The generated thermal signature of the structure (20) is compared to the baseline thermal signature of the structure (20) to determine whether anomalies exist in the structure (20).

Abstract: An apparatus and method for evaluating thermal barrier coating material on a surface of a part or component that is subjected to transient heat/thermal cycles. A pulsed laser heating apparatus that preferably uses lenses and optical fiber focusing components simulates conditions of brief heating on the test specimen. In the method of the invention, the temporal shape, spatial distribution, and total energy of the laser pulse are designed to produce a spot of uniform illumination and heat absorption on the test specimen that closely approximates the thermal loading that the specimen is expected to receive during use. The test specimen is then examined for thermally induced changes.

Abstract: An accelerated thermal stress cycle test which can be conducted in a significantly reduced test time compared to the conventional test is provided. The test is carried out in a cluster of reaction chambers that includes a CVD chamber and a cool-down chamber such that a pre-processed wafer can be heated from room temperature to at least 350° C. in an inert gas in about 2 min., and then cooled down to not higher than 70° C. in a cool-down chamber in less than 30 sec. The heating and cooling steps can be repeated between 3 and 7 times to reveal any defect formation caused by the thermal stress cycle test. Typical defects are metal film peeling from insulating dielectric material layer or void formation.

Abstract: An accelerated weathering test apparatus for concentrating solar irradiance upon and immersing at least one test specimen including at least one support member and an operative portion operatively connected to the at least one support member. The operative portion includes a mirror bed, at least one standard and a channel. The operative portion is moveable relative to the at least one support member from a first operative position to a second operative position. A target board is disposed in the channel for supporting the at least one test specimen for exposure to concentrated solar radiation when the operative portion is disposed in the first operative position and immersion in a fluid when the operative portion is disposed in the second operative position.

Abstract: A method to accurately evaluate a thermal cycle life of an article with a restraint rate as an evaluating parameter without providing a thermal cycle under actual service conditions to the article subjected to the thermal cycle.

Abstract: A method and apparatus are provided for automated non-destructive evaluation (NDE) thermal imaging tests of combustor liners and other products. The apparatus for automated NDE thermal imaging testing of a sample includes a flash lamp positioned at a first side of the sample. An infrared camera is positioned near a second side of the sample. A linear positioning system supports the sample. A data acquisition and processing computer is coupled to the flash lamp for triggering the flash lamp. The data acquisition and processing computer is coupled to the infrared camera for acquiring and processing image data. The data acquisition and processing computer is coupled to the linear positioning system for positioning the sample for sequentially acquiring image data.

Abstract: A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

Abstract: A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film.

Abstract: A method and apparatus for mapping the character and location of small surface variations on a planar surface. Energy in the form of pulses is supplied to an object in close proximity to the planar surface to thereby raise the temperature of the object and at part of the surface. A change in temperature of the object is detected when it is in proximity to the variation to define the location and character of the variation. By supplying the energy in the form of pulses, the size of the thermal signature produced in the planar surface is limited wherein a more accurate and more sensitive mapping method and apparatus are provided. The energy supply may be thermal energy or optical energy but preferably is electrical energy which heats a resistive element. Preferably, the object is a magnetoresistive head of a disk drive assembly and the surface may be that of a magnetic recording material. The change in temperature is detected by monitoring the resistance of the magnetoresistive coil of the head.

Abstract: A system and method for evaluating the thermal bond between a heat-producing device and a heat-absorbing apparatus. The heat-producing device may be a CPU, such as an INTEL PENTIUM microprocessor, and the heat-absorbing apparatus may be a heat sink. The two may be joined with a heat-conducting substance such as thermal grease or adhesive. In one exemplary embodiment, the heat-producing device is operated at a first power level, a first temperature measurement is then taken, the device is operated at a second power level, and then a second temperature measurement is then taken. The thermal resistance is then calculated, which may involve subtracting the second temperature from the first, and may involve dividing by the power level. The first power level may be full power, and the second power level may be near zero.

Abstract: Defect analysis of a flip chip die having a back side opposite circuitry at a circuit side and a liquid crystal layer is enhanced using a method and system that makes possible the detection of the defect from the back side of the flip chip. According to an example embodiment of the present invention, a flip chip die having a liquid crystal layer is analyzed by detecting a liquid crystal phase change caused by heat generation at a defect in the die. By detecting the phase change associated with a defect, the defect can be located. The defect detection can be used through the back side of the die, and can be used to detect defects located near intrinsic heat sources that make conventional liquid crystal analysis difficult or even impossible.

Abstract: A mechanism is provided for detecting a defect in a populated sample having a thickness dimension substantially smaller than the length and width dimensions thereof, the populated sample having a first side and an opposite second side, at least said first side of said populated sample having one or more Surface Mounted Components.

Abstract: In a method of fabricating a substrate, a substrate is submerged into a chemical bath so that the thickness of the substrate changes. The temperature of the chemical bath is monitored to ascertain a change in the thickness of the substrate.

Abstract: Chemical agent warfare materials and their simulant liquids are identified on terrestrial surfaces at a distance by recognizing the contaminant's infrared fingerprint spectrum brought out in thermal luminescence (TL). Suspect surfaces are irradiated with microwave light that is absorbed into the surface and, subsequently, TL is released by the surface. An optics receiver collects the released TL radiant light, and a data acquisition system searches this TL radiant flux for the contaminant's fingerprint infrared spectrum. A decision on the presence or absence of any-of-N contaminants is done by a neural network system that acts as a filter through real-time pattern recognition of the contaminant's unique infrared absorption or emission spectra.

Abstract: A device for contactless testing of structural and/or surface defects of large-surface bodies, especially of slab-shaped materials includes a conveying device with an unsupported area; a source of heat arranged above the plane of conveyance and extending transversally to the direction of conveyance and which radiates heat in lines or strips onto the plane of conveyance; a thermographic camera having at least one camera line aligned transversally to the direction of conveyance and arranged above the plane of conveyance and after the source of heat in the direction of conveyance; and a computer connected to the camera that has a monitor and generates a separate heat image pattern from every camera line.

Abstract: A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

Abstract: An apparatus and method for determining if a stone mounted in an electrically conductive mounting is a true diamond employs a housing to be held in one hand of a user while the other hand holds the mounting. An electrically and thermally conductive probe extends from the housing. The probe is held against the surface of the stone. Two assemblies connected to the probe measure sequentially to determine the thermal conductivity of the stone and the electrical conductivity of the stone. Displays indicate if the assemblies detect the high thermal conductivity of the stone consistent with diamond and the low electrical conductivity of the stone consistent with diamond. This apparatus distinguishes true diamond over such imitations as cubic zirconia with a lower thermal conductivity and moissanite with a higher electrical conductivity.

Abstract: The thermographic examination of functional surfaces of forming tools in the forming process is important for the selection of an optimal tool material or an optimal coating material for a particular forming process and for a particular workpiece composition, and also for the optimization of process parameters of the forming process. The task of the present invention is comprised therein, to develop a device and a process, which enables the rapid and simple thermographic examination of functional surfaces of forming tools during the forming process. This task is solved by a process and a device, in which the sought after temperature distribution of the functional surfaces during the forming process are conducted, from point of origin, through a channel, in the direction of a temperature measuring device, via thermal radiation or, in certain cases, thermal conductivity.

Abstract: A method and apparatus are provided for automated non-destructive evaluation (NDE) thermal imaging tests of combustor liners and other products. The apparatus for automated NDE thermal imaging testing of a sample includes a flash lamp positioned at a first side of the sample. An infrared camera is positioned near a second side of the sample. A linear positioning system supports the sample. A data acquisition and processing computer is coupled to the flash lamp for triggering the flash lamp. The data acquisition and processing computer is coupled to the infrared camera for acquiring and processing image data. The data acquisition and processing computer is coupled to the linear positioning system for positioning the sample for sequentially acquiring image data.

Abstract: This invention will provide a method of determining nondestructively, the purity or composition of an unknown material sample, such as, for example a sample of gold or silver of unknown purity. Their forms can be a: casting, bullion, coupon or disc (a coin), as well as some jewelry, such as gold or silver rings with signet surfaces. The test specimens are such that their areal dimensions are large compared to their thicknesses, thus qualifying as ‘slabs’. In order to detect a particular adulterant the method may require a dual-test procedure: The first is an application of a pulse of constant heat (or cold) and the second, if necessary, is an application of constant temperature. Furthermore, during the time the conditions are applied the slopes of the time-varying temperature patterns can be determined, the decay curves, after such conditions are removed, and their slopes can also be realized. Such information will provide a further check on the authenticity of the test item.

Abstract: A method for inspecting a connection state of an electronic part and an apparatus for the same which permits judgement of the quality of the connection state at high accuracy without needing structural addition of through holes and pads for use in connection state inspection are provided. The has the steps of: heating a first specific position on the electronic part, measuring a temperature rise of a second specific position thermally coupled to the first specific position, and judging the quality of the connection state of the solder connecting portion by comparing the measured temperature rise and a reference temperature rise.

Abstract: Nondestructive/noncontact evaluation of a material for electrical and magnetic property discontinuities, e.g., a dielectric loss or the presence of a conducting contaminant, is accomplished by using microwaves to heat microwave-absorbing regions of the material caused by such discontinuities; monitoring the change in temperature of the material's surface due to the heating of the microwave-absorbing region as a function of time; and detecting the electrical and magnetic property discontinuities, e.g., the dielectric loss or the conducting contaminant, using the change in the material's surface temperature.

Abstract: A method of manufacturing a display device comprising an air-tight envelope and at least a glass part (3) which forms part of said air-tight envelope, is characterized in that the glass part (3) is warmed up, during a first time period, at a first temperature (T1), whereafter the glass part is immersed, during a second time period, in a fluid (32) at a second temperature (T2), said second temperature being lower than the first temperature (T2<T1). Preferably, 25°≦T1−T2≦85°, and, in particular, T1−T2≈50°. Preferably, 50° C.≦T1≦100° C., and, in particular, T1≈65° C. Preferably, the glass part is a display window (3) or a cone portion of a display window, and the fluid is water (32).

Abstract: A heating zone (22) and a detection zone (23) at the surface (1a) of a part (1) are displaced in such a way as to carry out the scanning of the surface (1a) and a flux radiated in the detection zone (23) is detected by using a line of detectors (21) which is chosen from a matrix of detectors (20). The method makes is possible in particular to reduce the time for scanning the surface (1a) of the part and to be able to adjust the offset, in the direction of displacement (24), between the heating zone (22) and the detection (23), simply by choosing the line (21) of the matrix of detectors (20). The method and the device in accordance with the invention make it possible in particular to carry out thermographic inspections of parts made of any materials and in particular of metal parts which may have considerable dimensions and complex shapes.

Abstract: An infrared inspection system and an induction heating system used in conjunction enable the inspection of rubber coated rolls, such as rolls used in the pulp and paper industry. The system effects non-destructive inspections of rubber coated rolls to detect a debonded condition between the metal core and rubber coating. The method includes supporting a roll for inspection, evenly heating or cooling the roll, and observing a thermal transient of the roll generated by the evenly heating process. Using an infrared camera, observed areas that are not transferring heat uniformly with respect to neighboring areas are suspected debonded areas.

Abstract: An IR transient thermography imaging system includes high-power flash lamps fitted with spectrally tuned optical filters and a focal-plane array camera for IR image data acquisition. The image data processing control computer analyzes acquired IR image data frames and provides a color-keyed display of an imaged object that correlates to object thickness over the imaged surface area. Acquisition of IR data is initiated at a firing of flash lamps used to heat a surface of the object along with a reference standard. A predetermined number of IR image frames are acquired and recorded over a predetermined period of time after firing of the lamps to develop a temperature-time (T-t) history of the object surface and the reference standard. A contrast curve is calculated for each pixel in the image frame, each pixel corresponding to an elemental region on the object surface.

Abstract: A method and a system are disclosed for determining at least one characteristic of a sample that contains a substrate and at least one film disposed on or over a surface of the substrate. The method includes a first step of placing a mask over a free surface of the at least one film, where the mask has a top surface and a bottom surface that is placed adjacent to the free surface of the film. The bottom surface of the mask has formed therein or thereon a plurality of features for forming at least one grating. A next step directs optical pump pulses through the mask to the free surface of the film, where individual ones of the pump pulses are followed by at least one optical probe pulse. The pump pulses are spatially distributed by the grating for launching a plurality of spatially distributed, time varying strain pulses within the film, which cause a detectable change in optical constants of the film.

Abstract: Methods for analyzing temperature characteristics of an integrated circuit. In one embodiment, a beam of laser light is directed at the back side of an integrated circuit. The intensity level of laser light reflected from the integrated circuit is measured and compared to a reference intensity level. The magnitude of the difference between the reference intensity level and the intensity level of the reflected laser light is indicative of a temperature characteristic of the integrated circuit.

Abstract: In an infrared (IR) transient thermography system a sequence of image frames is acquired from an IR sensitive focal-plane array camera. Each sequentially acquired image frame is made up of an array of pixels and has assigned a frame number that corresponds to elapsed time. A method of analyzing thermal imaging data-frames is presented wherein a synthetically generated temperature-time reference curve is used to determine pixel contrast-versus-time data.

Abstract: In an infrared (IR) transient thermography system a sequence of image frames is acquired from an IR sensitive focal-plane array camera. Each sequentially acquired image frame is made up of an array of pixels and has assigned a frame-number that corresponds to elapsed time. Temperature-versus-time (T-t) data corresponding to each pixel is developed from stacks of sequential image-frames. A method of analyzing the stacks of thermal data image-frames is presented wherein either the Real or the Imaginary component portions of a Fast-Fourier Transform of a normalized T-t data curve from each pixel is used to determine the thickness of an object and produce a color-keyed or gray-scale coded thickness map.

Abstract: This invention will provide a method of determining nondestructively, the purity or composition of an unknown material sample, such as, for example a sample of gold or silver of unknown purity. Their forms can be a: casting, bullion, coupon or disc (a coin), as well as some jewelry, such as gold or silver rings with signet surfaces. The method involves subjecting one of the large surfaces of the sample of known thickness to an elevated or a cold temperature, relative to the initial temperature of the sample, and comparing the time-varying temperature pattern during finite lengths of time at the same surface thereof, or at the opposite surface, with that of a known and identically-sized standard subjected to the equivalent conditions. The temperature of said surfaces or opposite surfaces can be monitored during the time the heat or cold pulse, or constant temperature is applied and/or after withdrawal.

Abstract: Method and apparatus for photothermal analysis of a layer of material, especially for thickness measurement thereof. The invention relates to a method of photothermal analysis of a layer of material, especially of measuring the thickness of a layer, wherein the surface of a first layer of material is excited by electromagnetic radiation and heat radiation emitted by said surface and having a first temperature response curve is detected, the surface of a second layer of material is excited and heat radiation emitted by said surface and having a second temperature response curve is detected, the first layer of material being a reference layer and the second layer of material being the layer of material to be analyzed. A stretch factor is determined between the first and second temperature response curves, and the stretch factor is used as a characteristic factor for the ratio between the layer of material to be analyzed and the reference layer.

Abstract: A method for inspecting an object and detecting defects is taught (BGA and Flip-Chip solder joints on a PCB particularly). The method comprises injecting a heat pulse by light beam at a selected point on the object; capturing a sequence of consecutive thermal images of the object to record heat diffusion over time resulting from the heat pulse; comparing the heat diffusion over time at the point on said object to a reference; and determining whether the object comprises any defects.

Abstract: The scanning of a surface of a part is carried out by a means of imparting heat to at least one heating zone at the surface of the part. This occurs by relative displacement of the part and of the means of imparting heat. A detector is used to sense the flux radiated by the surface of the part in a detection zone displaced synchronously with the movement of the heating zone. The detector delivers, for each of the positions of a set of successive positions of the detection zone, a signal representative of the flux radiated. The scanning of the surface of the part is carried out along a determined path, in a first direction, then in a second opposite direction. For each of the successive positions of the detection zone, a differential signal is formulated.

Abstract: The temperature of the tread surface part of a tire is increased by running the tire in contact with a drum. The increase in the temperature of the tread surface part is due to the heat of friction between the tread surface part and the drum. Because large increases in temperature indicate that the friction is causing a large amount of wear, it is possible to forecast with ease the amount of wear of the tire from the increase in temperature of the tread surface part. The temperature of the tread surface part can be measured using a thermography machine, and the wear in the tread can be determined by looking at an image that shows the temperature.

Abstract: There are provided an inline inspection system and inspection method for inspecting the substrate surface on which semiconductors and circuit patterns are formed by radiating thereto white beam, laser beam or electron beam, and reviewing, inspecting and discriminating the detected roughness and figure defect, particle and moreover electrical defect on the surface with higher accuracy within a short period of time with the same instrument. Thereby, automatic movement to the position to be reviewed, acquisition of image and classification can be realized.

Abstract: A method for testing an electronic module to evaluate solder joint failures caused by thermally induced stress includes determining a thermal shock endurance test profile that represents field temperature conditions, estimating time/cycles to failure of solder joints in the module using numerical simulation techniques, selecting a design life duration for the module, comparing the design life duration of the module with the estimated time/cycles to failure of the weakest solder joint in the module, determining between robust, marginal, and non-robust module designs based on the design life duration of the module and the estimated time/cycles to failure of the at least one solder joint in the module, and determining an accelerated thermal shock endurance test specification having a test duration for testing the electronic module upon determining a marginal module design.

Abstract: Nondestructive/noncontact evaluation of a material for electrical and magnetic property discontinuities, e.g., a dielectric loss or the presence of a conducting contaminant, is accomplished by using microwaves to heat microwave-absorbing regions of the material caused by such discontinuities; monitoring the change in temperature of the material's surface due to the heating of the microwave-absorbing region as a function of time; and detecting the electrical and magnetic property discontinuities, e.g., the dielectric loss or the conducting contaminant, using the change in the material's surface temperature.

Abstract: In a method of determining the quality of a bond between layers of a laminated body wherein a laser pulse is applied to one side of the body such that the heat travels from the one side through the bond to the other side, the time-dependent temperature change on the other side is recorded, the delay time to reach, at the other side, a predetermined percentage value of the maximum temperature is determined and this delay time is compared with a calibration curve for quantifying the quality of the bond between the layers.

Abstract: In a method of fabricating a substrate, a substrate is submerged into a chemical bath so that the thickness of the substrate changes. The temperature of the chemical bath is monitored to ascertain a change in the thickness of the substrate.

Abstract: Nondestructive/noncontact evaluation of a material for electrical and magnetic property discontinuities, e.g., a dielectric loss or the presence of a conducting contaminant, is accomplished by using microwaves to heat microwave-absorbing regions of the material caused by such discontinuities; monitoring the change in temperature of the material's surface due to the heating of the microwave-absorbing region as a function of time; and detecting the electrical and magnetic property discontinuities, e.g., the dielectric loss or the conducting contaminant, using the change in the material's surface temperature.

Abstract: A categorization of a particular semiconductor wafer based on void size is obtained from sigma data and T0.1% failure data that has been obtained from wafers subjected to isothermal testing. The sigma data and the T0.1% failure data for the particular wafer is compared to stored data corresponding to ranges for sigma and T0.1% data for each of a plurality of void categories, and the particular wafer is categorized based on the stored data. The T0.1% failure data is computed based on a T50% failure data and the sigma value, so that small sample sizes can be utilized to obtain the stored data.

Abstract: A method of assembling an igniter (24) for a gas generating composition (18) comprises providing a pair of spaced apart electrodes (40 and 42) and providing a heat ignitable material (46). A heating element (44) is spot electrical resistance welded to the electrodes (40 and 42). The heating element (44) has flattened portions (110 and 112) at the spot welds (102 and 104) and a central portion between the spot welds (102 and 104) adapted for contact with the heat ignitable material (46). A test level of electric current is directed between the electrodes (40 and 42) and through the heating element (44) and the spot welds (102 and 104) at a level effective to heat the heating element (44) and the spot welds (102 and 104). The level infrared radiation emitted by the heating element (44) and the spot welds (102 and 104) is sensed, throughout a scanned field which fully encompasses the heating element and the welds, under the influence of the test level of electric current.

Abstract: An apparatus measures a property of a layer (such as the sheet resistance of a conductive layer or thermal conductivity of a dielectric layer that is located underneath the conductive layer) by performing the following method: (1) focusing the heating beam on the heated a region (also called "heated region") of the conductive layer (2) modulating the power of the heating beam at a predetermined frequency that is selected to be sufficiently low to ensure that at least a majority (preferably all) of the generated heat transfers out of the heated region by diffusion, and (3) measuring the power of another beam that is (a) reflected by the heated region, and (b) modulated in phase with modulation of the heating beam. The measurement in act (3) can be used directly as a measure of the resistance (per unit length) of a conductive line formed by patterning the conductive layer.

Abstract: A method of and system for determining the location of hot spots on the surface of an object which has thermotropic material applied to the surface are disclosed. The system is designed to varying the nominal temperature of the object through a range of nominal temperatures between a first nominal temperature limit and a second nominal temperature limit, wherein one temperature limit is below and the other nominal temperature limit is above the temperature at which the thermotropic material changes phase. A sequence of images of the surface are acquired, each of the images depicting a two dimensional temperature representation of the surface at a predetermined nominal temperature within the range of nominal temperatures, wherein each image in the sequence represents an incremental change in nominal temperature than that of a preceding image.