scholarly journals New Developments in IR Lock-In Thermography

2004 ◽  
Author(s):  
O. Breitenstein ◽  
J.P. Rakotoniaina ◽  
M. Hejjo Al Rifai ◽  
M. Gradhand ◽  
F. Altmann ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Spatial Resolution ◽  
Infrared Camera ◽  
Detection Sensitivity ◽  
New Developments ◽  
Technical Developments ◽  
Corrected Image ◽  
Lock In ◽  
Blurring Effect ◽  
Colloidal Bismuth

Abstract Lock-in thermography based on an infrared camera has proven to be a useful tool for failure analysis of integrated circuits (ICs). This article discusses four novel technical developments of lock-in thermography. These developments are blackening the IC surface with colloidal bismuth, the synchronous undersampling technique allowing the use of higher lock-in frequencies, displaying the 0deg/-90deg signal as a novel high resolution emissivity corrected image type, and removing the thermal blurring effect by mathematically deconvoluting the 0deg/-90deg; signal. The effect of these techniques is demonstrated by using a regularly working operational amplifier (pA 741) and a damaged capacitor as test devices. It is shown that blackening the IC surface improves the detection sensitivity in metallized regions by up to a factor of 10, whereas the other methods allow improvement of the effective spatial resolution. The article also discusses which of the spatial resolution improvement techniques is most appropriate in different situations.

Combining Refractive Solid Immersion Lens and Pulsed Laser Induced Techniques for Effective Defect Localization on Microprocessors

2008 ◽  
Author(s):  
A.C.T. Quah ◽  
S.H. Goh ◽  
V.K. Ravikumar ◽  
S.L. Phoa ◽  
V. Narang ◽  
...  
Keyword(s):  
Case Studies ◽  
Spatial Resolution ◽  
Failure Modes ◽  
Pulsed Laser ◽  
Detection Algorithm ◽  
Detection Sensitivity ◽  
Solid Immersion Lens ◽  
Defect Localization ◽  
Lock In

Abstract The spatial resolution and sensitivity of laser induced techniques are significantly enhanced by combining refractive solid immersion lens technology and laser pulsing with lock-in detection algorithm. Laser pulsing and lock-in detection enhances the detection sensitivity and removes the ‘tail’ artifacts due to amplifier ac-coupling response. Three case studies on microprocessor devices with different failure modes are presented to show that the enhancements made a difference between successful and unsuccessful defect localization.

Enhanced Detection Sensitivity with Pulsed Laser Digital Signal Integration Algorithm

2006 ◽  
Author(s):  
A.C.T. Quah ◽  
J.C.H. Phang ◽  
L.S. Koh ◽  
S.H. Tan ◽  
C.M. Chua
Keyword(s):  
Fault Localization ◽  
Pulsed Laser ◽  
Digital Signal ◽  
Detection Sensitivity ◽  
Signal Integration ◽  
Laser Operation ◽  
Frequency Range ◽  
Integration Algorithm ◽  
Detection Systems ◽  
Lock In

Abstract This paper describes a pulsed laser induced digital signal integration algorithm for pulsed laser operation that is compatible with existing ac-coupled and dc-coupled detection systems for fault localization. This algorithm enhances laser induced detection sensitivity without a lock-in amplifier. The best detection sensitivity is achieved at a pulsing frequency range between 500 Hz to 1.5 kHz. Within this frequency range, the algorithm is capable of achieving more than 9 times enhancement in detection sensitivity.

Fault Localization and Functional Testing of ICs by Lock-in Thermography

2002 ◽  
Author(s):  
O. Breitenstein ◽  
J.P. Rakotoniaina ◽  
F. Altmann ◽  
J. Schulz ◽  
G. Linse
Keyword(s):  
Spatial Resolution ◽  
Electronic Device ◽  
Imaging Techniques ◽  
Heat Diffusion ◽  
Acquisition Time ◽  
Temperature Modulation ◽  
Heat Sources ◽  
Ir Camera ◽  
Free Running ◽  
Lock In

Abstract In this paper new thermographic techniques with significant improved temperature and/or spatial resolution are presented and compared with existing techniques. In infrared (IR) lock-in thermography heat sources in an electronic device are periodically activated electrically, and the surface is imaged by a free-running IR camera. By computer processing and averaging the images over a certain acquisition time, a surface temperature modulation below 100 µK can be resolved. Moreover, the effective spatial resolution is considerably improved compared to stead-state thermal imaging techniques, since the lateral heat diffusion is suppressed in this a.c. technique. However, a serious limitation is that the spatial resolution is limited to about 5 microns due to the IR wavelength range of 3 -5 µm used by the IR camera. Nevertheless, we demonstrate that lock-in thermography reliably allows the detection of defects in ICs if their power exceeds some 10 µW. The imaging can be performed also through the silicon substrate from the backside of the chip. Also the well-known fluorescent microthermal imaging (FMI) technique can be be used in lock-in mode, leading to a temperature resolution in the mK range, but a spatial resolution below 1 micron.

New developments in breast thermography.High spatial resolution

Cancer ◽  
1969 ◽  
Vol 24 (6) ◽  
pp. 1212-1221 ◽  
Author(s):  
Gerald D. Dodd ◽  
Alfonso Zermeno ◽  
Lee Marsh ◽  
David Boyd ◽  
John D. Wallace
Keyword(s):  
Spatial Resolution ◽  
New Developments

“Good versus Good Enough?” Empirical Tests of Methane Leak Detection Sensitivity of a Commercial Infrared Camera

2018 ◽  
Vol 52 (4) ◽  
pp. 2368-2374 ◽  
Author(s):  
Arvind P. Ravikumar ◽  
Jingfan Wang ◽  
Mike McGuire ◽  
Clay S. Bell ◽  
Daniel Zimmerle ◽  
...  
Keyword(s):  
Infrared Camera ◽  
Leak Detection ◽  
Detection Sensitivity ◽  
Empirical Tests

Cross-plane Thermoreflectance Imaging of Thermoelectric Elements

2005 ◽  
Vol 886 ◽  
Author(s):  
Peter M. Mayer ◽  
Rajeev J. Ram
Keyword(s):  
Temperature Distribution ◽  
Spatial Resolution ◽  
Quasi Equilibrium ◽  
Thermal Impedance ◽  
Thermal Measurements ◽  
Systems Identification ◽  
Lock In ◽  
Operational Device

ABSTRACTThis paper presents the first cross-plane thermoreflectance image of the temperature distribution in a thermoelectric (TE) element under bias. Using the technique of lock-in CCD thermoreflectance imaging, we can map the temperature distribution of an operational device with submicron spatial resolution and a temperature resolution of 10 mK. As such it offers a complete picture of the quasi-equilibrium transport within the device. The submicron resolution of the thermoreflectance image enables clear determination of localized heating due at interfaces - for example to due contact resistance - and thermal impedance mismatch within samples. The high spatial resolution is ideal for the characterization of thin-film thermoelectric materials where data from conventional techniques (such as the transient Harman method) are difficult to interpret. This paper also presents the first thermoreflectance data we are aware of for BiTe-based material systems. Identification and separation of the Peltier and Joule components of the heating are possible, and finite difference simulations of the devices are presented for comparison with experiment. In this way it is possible to simultaneously acquire information about the Seebeck coefficient, electrical conductivity, and thermal conductivity of the thermoelectric material. The measurements demonstrate the feasibility of non-contact thermal measurements at the sub-micron scale.

scholarly journals Lock-in thermography using a cellphone attachment infrared camera

AIP Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 035305 ◽  
Author(s):  
Marjan Razani ◽  
Artur Parkhimchyk ◽  
Nima Tabatabaei
Keyword(s):  
Infrared Camera ◽  
Lock In
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