Lock-In Thermography : Basics and Applications to Functional Diagnostics of Electronic Components

by Breitenstein, O.; Langenkamp, M.

• ISBN13: 9783540434399
• ISBN10: 3540434399
• Format: Hardcover
• Copyright: 2003-11-01
• Publisher: Springer Verlag

Summary

The book deals with lock-in thermography as a special variant of the well known IR thermography for all applications where the heat of the sample can be pulsed. Compared to steady-state thermography, the lock-in mode enables a much improved signal/noise ratio (up to 1000x) by signal averaging, a far better lateral resolution, and it may provide inherent emissivity correction. Thus, it replaces thermal failure analysis previously carried out by using conventional IR microscopy, liquid crystal imaging, or fluorescent microthermal imaging. Various experimental approaches to lock-in thermography are reviewed with special emphasis on the systems developed by the authors themselves. Thus, the book provides a useful introduction to this technique and a helpful guide for scientists and engineers working in electronic device failure analysis. It concludes with a detailed theoretical treatment of the propagation of thermal waves, which is presented as a basis for various applications, e.g., integrated circuits, MOS structures, solar cells and solar modules.

Author Biography

Otwin Breitenstein studied physics at Leipzig university and graduated there in 1980. After dealing with spatially resolved capacitance spectroscopy of point defects (Scanning-DLTS) at the Institute of Solid State Physics and Electron Microscopy in Halle until 1992, he is a scientific staff member at Max Planck Institute of Microstructure Physics, Halle. His main interest field is electronic device and materials analysis by electron microscopic and IR-based methods.Wilhelm Warta studied Physics at W++rzburg and then Stuttgart University, where he graduated and received his PhD with research on charge transport properties of organic molecular crystals. 1985 he joined Fraunhofer Institute for Solar Energy Systems in Freiburg starting with work on carrier lifetime measurement techniques for semiconductor materials. His fields are the development of measurement techniques for solar cell development, characterization of solar cell material and solar cells, device and process simulation as well as high precision calibration of solar cells.

Table of Contents

1. Introduction	1	(6)
2. Physical and Technical Basics	7	(32)
2.1 IR Thermography Basics	7	(6)
2.2 The Lock-in Principle and its Digital Realization	13	(7)
2.3 Lock-in Thermography	20	(4)
2.4 Influence of Non-harmonic Heating	24	(5)
2.5 Noise Analysis	29	(3)
2.6 Calibration	32	(3)
2.7 Synchronous Undersampling	35	(4)
3. Experimental Technique	39	(30)
3.1 Different (Lock-in) Thermography Realizations	39	(10)
3.2 Dynamic Precision Contact Thermography (DPCT)	49	(6)
3.3 IR-Camera Based Lock-in Thermography, DSP Solution	55	(7)
3.4 The Commercial TDL 384 M 'Lock-in' System	62	(7)
4. Theory	69	(46)
4.1 Influence of the Heat Conduction to the Surrounding	69	(6)
4.2 Temperature Drift Compensation	75	(7)
4.3 Thermal Waves of Point Sources	82	(5)
4.4 Thermal Waves of Extended Sources	87	(8)
4.5 The Quantitative Interpretation of Lock-in Thermograms	95	(20)
4.5.1 The Image Integration Method	98	(7)
4.5.2 Deconvolution of Lock-in Thermograms	105	(10)
5. Measurement Strategies	115	(28)
5.1 Which Signal Should be Displayed?	115	(6)
5.2 Influence of the Lock-in Frequency	121	(4)
5.3 Influence of the IR Emissivity	125	(9)
5.4 Local I-V Characteristics Measured Thermally [LIVT]	134	(4)
5.5 Influence of the Peltier Effect	138	(5)
6. Typical Applications	143	(26)
6.1 Integrated Circuits	143	(7)
6.2 Solar Cells and Modules	150	(10)
6.2.1 Inhomogeneities of Solar Cells	151	(6)
6.2.2 Failure Analysis of Solar Modules	157	(3)
6.3 Gate Oxide Integrity (GOT) Defects	160	(3)
6.4 Bonded Wafers	163	(6)
7. Summary and Outlook	169	(4)
References	173	(8)
A. Thermal and IR Properties of Selected Materials	181	(2)
B. Digital Micrograph Scripts for FFT Deconvolution	183	(2)
List of Symbols	185	(4)
Abbreviations	189	(2)
Index	191