Advanced terahertz techniques for quality control and counterfeit detection (original) (raw)
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In this paper, a comprehensive set of techniques for quality control and authentication of packaged integrated circuits (IC) using terahertz (THz) time-domain spectroscopy (TDS) is developed. By material characterization, the presence of unexpected materials in counterfeit components is revealed. Blacktopping layers are detected using THz time-of-flight tomography, and thickness of hidden layers is measured. Sanded and contaminated components are detected by THz reflection-mode imaging. Differences between inside structures of counterfeit and authentic components are revealed through developing THz transmission imaging. For enabling accurate measurement of features by THz transmission imaging, a novel resolution enhancement technique (RET) has been developed. This RET is based on deconvolution of the THz image and the THz point spread function (PSF). The THz PSF is mathematically modeled through incorporating the spectrum of the THz imaging system, the axis of propagation of the beam, and the intensity extinction coefficient of the object into a Gaussian beam distribution. As a result of implementing this RET, the accuracy of the measurements on THz images has been improved from 2.4 mm to 0.1 mm and bond wires as small as 550 μm inside the packaging of the ICs are imaged.
THz radiation is capable of penetrating most of nonmetallic materials and allows THz spectroscopy to be used to image the interior structures and constituent materials of wide variety of objects including Integrated circuits (ICs). The fact that many materials in THz spectral region have unique spectral fingerprints provides an authentication platform to distinguish between authentic and counterfeit electronic components. Counterfeit and authentic ICs are investigated using a high-speed terahertz spectrometer with laser pulse duration of 90 fs and repetition rate of 250 MHz with spectral range up to 3 THz. Time delays, refractive indices and absorption characteristics are extracted to distinguish between authentic and counterfeit parts. Spot measurements are used to develop THz imaging techniques. In this work it was observed that the packaging of counterfeit ICs, compared to their authentic counterparts, are not made from homogeneous materials. Moreover, THz techniques were used to observe different layers of the electronic components to inspect die and lead geometries. Considerable differences between the geometries of the dies/leads of the counterfeit ICs and their authentic counterparts were observed. Observing the different layers made it possible to distinguish blacktopped counterfeit ICs precisely. According to the best knowledge of authors the reported THz inspection techniques in this paper are reported for the first time for authentication of electronic components.
AlyPOTEC: Analysis of pharmaceutical counterfeits using terahertz technology
2012
The project ‘AlyPOTEC’ aims to improve the citizen security with respect to counterfeit, falsified or poor quality pharmaceutical products. Targeted applications of the project are typically: customs controls, quality control or product authentication by pharmaceutical industrial, or by official medicine control laboratories. The objective of the project is to carry out a comprehensive analysis of these products. A study of the detection capabilities of the THz spectroscopy towards selected samples and counterfeiting criteria will be performed. In fact, this technique could provide a complementary analysis, which will give further information on the counterfeit product origin and “history” (manufacturing process, composition, transport and storage). Comparative analysis with established methods will be achieved to highlight THz technology assets. An innovative, compact and mobile prototype will be developed using fiber coupled components according to the results of the product analy...
SPIE Proceedings, 2008
We report the use of a 160×120 pixel microbolometer camera, under illumination by a milliwatt-scale 3.6 THz quantum cascade laser, for real-time imaging of materials which are exclusively nonmetallic in character. By minimizing diffraction effects suffered by the camera system and operating the laser at bias currents approaching saturation values, an imaging scheme was developed in which overlapping samples of nonmetallic materials can be imaged with high fidelity and long persistence times. Furthermore, an examination of various security features embedded within domestic and foreign currency notes suggests that this imaging scheme could serve a future role in detection of assorted counterfeiting practices.
Teraherz frequencies electromagnetic waves - a new tool for investigating composite defects
2011
In this paper the possibility of using a modern NDT technique THz electromagnetic waves for composite materials defects detection and identification was investigated. Two technological defects were investigated voids and internal delaminating. The composite materials were hand lay up made. Several kinds of reinforcing fibers (glass, basalt, jute) and polyester resin were used. Glass micro spheres and mica plates were placed at different depths in order to simulate technological defects. The specimens were tested using terahertz frequencies electromagnetic waves. The goal was to verify if the NDT method is appropriate to identify technological defects, misuse damage as well as determine parameters such as depth or size.
Comparison of terahertz technologies for detection and identification of explosives
Terahertz Physics, Devices, and Systems VIII: Advanced Applications in Industry and Defense, 2014
We present results on the comparison of different THz technologies for the detection and identification of a variety of explosives from our laboratory tests that were carried out in the framework of NATO SET-193 "THz technology for stand-off detection of explosives: from laboratory spectroscopy to detection in the field" under the same controlled conditions. Several laser-pumped pulsed broadband THz time-domain spectroscopy (TDS) systems as well as one electronic frequency-modulated continuous wave (FMCW) device recorded THz spectra in transmission and/or reflection.
Imagerie et spectroscopie Terahertz: applications aux problématiques de défense et de sécurité
2015
The aim of this work is to demonstrate the potential and capabilities of terahertz technology for parcels screening and inspection to detect threats such as weapons and explosives, without the need to open the parcel.In this study, we first present terahertz time-domain spectroscopy and spectral imaging for explosives detection. Two types of explosives as well as their binary mixture is analyzed. Due to the complexity of extracting information when facing such mixtures of samples, three chemometric tools are used: principal component analysis (PCA), partial least square analysis (PLS) and partial least squares-discriminant analysis (PLS-DA). The analyses are applied to terahertz spectral data and to spectral-images in order to: (i) describe a set of unknown data and identify similarities between samples by PCA; (ii) create a classification model and predict the belonging of unknown samples to each of the classes, by PLS-DA; (iii) create a model able to quantify and predict the explo...
Aeronautics composite material inspection with a terahertz time-domain spectroscopy system
The usability of pulsed broadband terahertz radiation for the inspection of composite materials from the aeronautics industry is investigated, with the goal of developing a mobile time-domain spectroscopy system that operates in reflection geometry. A wide range of samples based on glass and carbon fiber reinforced plastics with various types of defects is examined using an imaging system; the results are evaluated both in time and frequency domain. The conductivity of carbon fibers prevents penetration of the respective samples but also allows analysis of coatings from the reflected THz pulses. Glass fiber composites are, in principle, transparent for THz radiation, but commonly with significant absorption for wavelengths >1 THz. Depending on depth, matrix material, and size, defects like foreign material inserts, delaminations, or moisture contamination can be visu-alized. If a defect is not too deep in the sample, its location can be correctly identified from the delay between partial reflections at the surface and the defect itself. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE) [DOI: 10 .1117/1.OE.53.3.031208]
Inspection of coatings using terahertz time domain spectroscopy system
AIP Conference Proceedings, 2017
There are many methods of examination of coating failures. This paper presents application of a Terahertz Time Domain Spectroscopy for inspection of thin nonconductive coatings. Results of preliminary tests and results of inspection carried for various kinds of coatings were presented. The coatings containing selected kinds of defects were also prepared and evaluated. The presented results show that the terahertz method can be a good alternative in case of coatings testing.