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Non-Line-Of-Sight (NLOS) imaging aims at recovering the 3D geometry of objects that are hidden from the direct line of sight. One major challenge with this technique is the weak available multibounce signal limiting scene size, capture speed, and reconstruction quality. To overcome this obstacle, we introduce a multipixel time-of-flight non-line-of-sight imaging method combining specifically designed Single Photon Avalanche Diode (SPAD) array detectors with a fast reconstruction algorithm that captures and reconstructs live low-latency videos of non-line-of-sight scenes with natural non-retroreflective objects. We develop a model of the signal-to-noise-ratio of non-line-of-sight imaging and use it to devise a method that reconstructs the scene such that signal-to-noise-ratio, motion blur, angular resolution, and depth resolution are all independent of scene depth suggesting that reconstruction of very large scenes may be possible., Non-line-of-sight imaging can recover the 3D geometry of hidden objects, but is limited by weak multibounce signals. Here, the authors introduce a multipixel time-of-flight NLOS imaging approach, combining array detectors and a fast algorithm, for live reconstruction of natural nonretroreflective objects.

The paper reports the mechanical properties of 4H-SiC die with different thicknesses, that have been determined through a 3-point bend (3-PB) test. In particular, it reports 1) the measurement of the failure strength of thin 4H-SiC rectangular die; 2) the Weibull analysis of the failure strength of 4H-SiC die, exploited to determine the maximal load that can be applied to the die, without any breakage; 3) the measure of 244±15 GPa for the effective Young modulus E of SiC die, gained from the 3-PB test elaborations.

The high power demanding in many emerging power electronic applications requires innovative solutions in semiconductor field. One of the possible keys to satisfy this requirement is the use of more paralleled devices. For traction applications, parallel connection of Silicon Carbide (SiC) MOSFETs is widely employed. In this framework, the power devices are housed in module packages. This paper presents a parametric analysis of a SiC power module for traction inverters, with a three-phase topology, containing many paralleled dice for each swich. The scope of the work is to study this phenomenon with a numerical investigation based on a circuit simulation, evaluating the junction temperature in a case study. The parameters varied in the simulations are the threshold voltage and the drain-source on-state resistance.

Nowadays, solder reliability in new power electronic packages is an important research topic. Therefore, it is of paramount importance to properly understand and model the material behaviour and to develop a calculation model to predict reliability performances. This work presents a thermo-mechanical analysis of different solder layers for a low voltage discrete package. The solder joint reliability between package and PCB is also considered in the simulation. This modelling activity is possible by employing the Anand visco-plastic model and by means of a finite element model implemented in COMSOL. The number of cycles to failure can be subsequently computed, with the Darveaux method, for fatigue life estimation purpose.

Innovation on semiconductors technology requires enhancements of all actors like adhesion layers, barriers and metal stacks, beyond of semiconductor materials themselves. In general, metallic layers influence the whole die performances. The composition and the layout of these metal layers are fundamental for the signal transmission from the frame to the die and vice versa, and therefore their improvement contributes to the die development in terms of performances and reliability. In the present work, two pad structures have been benchmarked and analyzed under the structural strength standpoint. The experimental comparison among the different pads has been done through a flat punch nanoindentation to highlight the material strength and the crack propagation phenomena. Testing results have been compared to finite element models to analyze the stress through the different layers. The findings of the work demonstrate the validity of the methodology adopted and show the importance of the metallic connections layouts for the stress concentration and crack formation analysis.

In this work the warpage of a power modules ceramic substrates due to temperature variation has been numerically calculated. It has been used a not linear finite element model, which account the experimentally characterized material properties, including the copper elastoplasticity. Model results have been compared with dedicated interferometric measurements to validate the model. As application example, it has been calculated the benefit in terms of temperature warpage realized with a different substrate design option.

This work has investigated the impact of crystallographic structure on SnAgCu (SAC) solder reliability at print board circuit (PCB) level. A detailed reliability analysis has been performed on packages with different solder thickness. The correlation between experiments and Finite Element Model results explains how NiAu metallization and the reduction of solder thickness improve the solder joint reliability performances.

In this paper an overview on Power Packages challenges and technology approaches is given. These challenges mainly originate from Silicon Carbide MOSFETs superior properties allowing high power, high temperature capability, fast switching transients and high electric field operations. All these features can be obtained in a significant reduced chip area. In order to benefit from the disrupting advantages of these wide band gap semiconductor based power devices, a strong focus on packaging and interconnection technologies is needed to withstand these challenging requirements. In addition one of the major and strong boost for Silicon Carbide technology development is given by the car electrification trend: the strict requirements for the Automotive Market are leading to a design and engineering oriented, since the preliminary stage of development, to optimize the reliability of Power Packages.

In this paper we present a novel single-photon detector specifically designed for Non-Line-Of-Sight (NLOS) imaging applications within the framework of the DARPA REVEAL program. The instrument is based on a linear 16 &times, 1 Complementary Metal-Oxide-Semiconductor (CMOS) Single-Photon Avalanche Diode (SPAD) array operated in fast-gated mode by a novel fast-gating Active Quenching Circuit (AQC) array, which enables the detectors with sub-ns transitions thanks to a SPAD-dummy approach. The detector exhibits a timing resolution better than 50 ps (Full Width at Half Maximum - FWHM) at a measurement repetition rate up to 40 MHz, and provides 16 independent outputs compatible with commercial Time-Correlated Single-Photon Counting (TCSPC) instrumentation. The instrument has been experimentally characterized and operated in preliminary NLOS imaging acquisitions where a 40 &times, 60 cm hidden object is successfully reconstructed by scanning over a grid of 150 &times, 150 positions.

We present the current status of the LUCA project whose aim is to develop an innovative device combining ultrasound and diffuse optics for an improved screening of the thyroid cancer.

We present a new full-custom instrument for time-domain diffuse optical spectroscopy developed within Horizon 2020 LUCA (Laser and Ultrasound Co-Analyzer for thyroid nodules) project. It features eight different picosecond diode lasers (in the 635 - 1050 nm range), two 1.3 × 1.3 mm2 active-area SiPMs (Silicon PhotoMultipliers) working in single-photon mode and two 10 ps resolution time-to-digital converters. A custom FPGA-based control board manages the instrument and communicates with an external computer via USB connection. The instrument proved state-of-the-art performance: an instrument response function narrower than 160 ps (fullwidth at half-maximum), a long-term measurement stability better than 1%, and an output average optical power higher than 1 mW at 40 MHz. The instrument has been validated with phantom measurements.

In the last decades the main focus for improvements in Power Electronics was mainly addressed on chip technology. Therefore, Power Electronic performance depends by a high ratio on package technologies and on their interconnections. In particular, the automotive industry has high requirements regarding cost efficiency, reliability and compactness. Increasing power densities, cost pressure and more stringent reliability target for modern power semiconductors are making thermal system optimization more and more important in relation to electrical optimization. This article will give an overview of the new methodological approach leaded by Finite Element (FE) simulation for new packages and interconnection solution ideas. A viscoplastic creep modelling is adopted for the solder taking into account time, temperature and stress dependences in Thermal Cycle. A parametric study is performed by changing geometrical solutions. The results obtained from the modelling has been used to form design guidelines that were also matched with experimental data.

In this paper, we present an innovative instrument for near-infrared time-resolved spectroscopy. The system is based on eight custom-designed pulsed diode lasers emitting at different wavelengths in the near-infrared region (635–1050 nm), all exhibiting an average optical power higher than 1 mW at 40 MHz pulse repetition rate, two custom-made single-photon detectors based on wide-area silicon photomultipliers and two time-measurement units based on a custom time-to-digital converter with 10 ps timing resolution. The system instrument response function has a width narrower than 160 ps (fullwidth at half-maximum) and stability better than ±1% for several hours for all the wavelengths. All the components of the instrument were designed in order to be compact. The entire system will be hosted in a standard 19 inches, 5U rack case (size 48 × 38 × 20 cm3 ). The system communicates with the external computer through a USB 2.0 link and is designed to be employed in a clinical environment. The proposed instrument, thanks to the reduction of its cost and dimensions, paves the way to a wider diffusion of multiwavelengths near-infrared time-resolved spectroscopy systems.

The presented analysis has been aimed to evaluate the impact of die solder and sintering solution for automotive power modules in terms of thermal behavior. First, dedicated temperature measurements have been performed to evaluate the module thermal impedance in the two cases. Then, a lumped equivalent networks has been calculated, by means of a dedicated numeric, and finally function structures have been extracted