Lista de lucrari publicate in reviste ISI

Evenimente

10.10.2018

Marius Purcar participa la evenimentul „Impactul proiectelor Bridge Grant în colaborarea dintre universităţi şi agenţii economici” organizat de catre UEFISCDI la Biblioteca Universităţii Politehnica din Bucureşti.

24.09-12.10.2018

Adrian Bojita face o vizita de lunga durata la Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania in cadrul careia s-a testat versiunea de simulator UTCN bazată pe rețele de discretizare non-conforme pe platforma de simulare internă Infineon; s-au realizat simulări în vederea comparării simulatorului UTCN cu cel Infineon; s-au fost validat rezultatele simulărilor cu măsurătorile experimentale.

17.09.2018

Ca urmare a derularii proiectului SET4CIP, studentul cercetator Adrian Bojita din partea UTCN, a fost admis la studiile doctorale cu frecventa sub indrumarea Prof. Dr. Ing. Vasile Topa. Titlul temei de doctorat este „Metode optimizate de simulare pentru analiza multiscalara a proceselor termo-mecanice din circuitele integrate de putere”. In urma admiterii la doctorat, IFRO a decis finantarea studentului cu o bursa doctorala.

28-29.08.2018

Marius Purcar prezinta in cadrul conferintei "First International Conference on Numerical Modelling in Engineering, August 2018" organizata de universitatea Ghent din Belgia NME 2018, cu articolul:

A. Bojita, M. Purcar, C. Boianceanu, C. Florea, D. Simon, V. Topa, "A Simple Metal-Semiconductor Substructure Model for the Thermal Induced Fatigue Simulation in Power Integrated Circuits",

16.07 - 14.09.2018

Sunt organizate doua stagii de internship in cadrul Infineon Technologies Romania Scs & Co a doi studenti UTCN. Anchidim Nimigean, student absolvent al ciclului de licenta a Facultatii de Inginerie Electrica (UTCN), face stagiul de internship pe directia de cercetare a fenomenelor termo-mecanice din Circuitele Integrate de Putere. Adrian Stoian, absolvent al Facultatii de Electronica, Telecomunicatii si Tehnologia Informatiei (UTCN), face stagiul de internship pe directia de cercetare in zona de Yield a circuitelor integrate de putere.

11-12.07.2018

Cristian Boianceanu face o vizita de scurta durata la UTCN pentru a asista la prezentarile lucrarilor de disertatie cat si discutii asupra directiilor de cercetare in vederea finalizarii proiectului de cercetare SET4CIP.

12.07.2018

Prezentarea lucrarilor de disertatie a studentilor masteranzi UTCN Adrian Bojita, Marius Lungociu si Razvan Pitu.

22.06.2018

Apare in revista Elsevier Microelectronics Reliability, vol. 87, August 2018, pp. 142.150, lucrarea "A simple metal-semiconductor substructure for the advanced thermo-mechanical numerical modeling of the power integrated circuits" de A. Bojita, C. Boianceanu, M. Purcar, C. Florea, D. Simon, C. Plesa, Link catre lucreare

26.04.2018

Acceptarea lucrarii intitulate "A Simple Metal-Semiconductor Substructure Model for the Thermal Induced Fatigue Simulation in Power Integrated Circuits", autori: A. Bojita, M. Purcar, C. Boianceanu, C. Florea, D. Simon, V. Topa, in cadrul conferintei internationale "1st International Conference on Numerical Modelling in Engineering, 28-29 August 2018, Ghent University, Belgium".

15-16.03.2018

Cristian Boinceanu si Ciprian Florea din partea Infineon Technologies Romania Scs & Co fac o vizita de scurta durata la UTCN. Ca urmare a proiectului SET4CIP,in 15.03.2018 ing. Ciprian Florea incepe programul de cercetare doctorala sub indrumarea Prof. Dr. Ing. Topa Vasile, perioada de desfasurare fiind 2018-2021, teza intitulata "Studiul comutatoarelor integrate de putere cu functionalitati de detectare si izolare a defectelor" ce propune detectia rapida a defectarii circuitului si izolarea efectului pe care defectul il are asupra functionarii sistemului. In 16.03.2018 s-a efectuat o comisie de recrutare a doi studenti pentru efectuarea unui stagiu de internship pe perioada verii in cadrul Infineon Technologies Romania Scs & Co. Deasemenea in cadrul acestei vizite s-a verificat si discutat stadiul lucrarilor de disertatie.

12.02-09.03.2018

Adrian Bojita face o vizita de lunga durata la Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania in cadrul careia s-a dezvoltat o ramura a simulatorului termo-mecanic ce utilizeaza retele de discretizare non-conforme pe interfete. Tot in aceasta vizita s-a efectuat si diseminarea rezultatelor cercetarii in vederea publicarii unei lucrari stiintifice in cadrul conferintei "1st International Conference on Numerical Modelling in Engineering, 28-29 August 2018, Ghent University, Belgium".

4.12.2017

UTCN castiga impreuna cu un consortiu format cu alți 37 de parteneri din 6 țări membre ale Uniunii Europene finantare pentru proiectul Integrated Development 4.0, 783163-iDev40. Coordonatorul proiectului UTCN este conf. dr. ing. Ioan Marius Purcar (director proiect Set4CIP). Astfel obiectivele proiectului Set4CIP vor fi dezvoltate mai departe prin:

• proiectarea și implementarea de algoritmi si tehnici avansate pentru simularea si modelarea proceselor electro-termo-mecanice din circuitele integrate de putere

• tehnici de modelare si simulare multiscalara si multi grid a circuitelor integrate de putere

• integrarea și generarea rețelelor de discretizare (mesh)

• analiza si proiectarea circuitelor integrate analogice, de radio-frecventa si de semnal mixt

• dezvoltarea metodelor de optimizare a circuitelor si sistemelor electronice

• implementarea metodelor pentru analiza si testarea datelor multivariabile

• analiza de yield

• analiza corelațiilor din etapele de verificare pre- si post-siliciu

• dezvoltarea unor metode de identificare a factorilor care cauzează yield loss

• metode de preprocesare a datelor (de ex. Outliers’ detection – identificarea de date anormale)

12.10.2017

Marius Purcar si Adrian Bojita, fac o vizita de scurta durata la: Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania, unde alaturi de Cristian Boinceanu si Dan Simon se propun temele lucrarilor de disertatie a studentilor Adrian Bojita, Marius Lungociu si Razvan Pitu. Obectivul lucrarilor fiind elaborarea unei metodologii de simulare termo-mecanica cat si a evidentierii efectelor varietiei dimensiunilor geometrice a sistemului de metalizare sub actiunea ciclilor repetati de temperatura. Termenul de predare al lucrarilor pentru avizul intern IFRO estimat pe 28.06.2018.

11-14.10.2017

Participare la The 40th edition of the INTERNATIONAL SEMICONDUCTOR CONFERENCE 2017, Sinaia, Romania cu articolul:

Adrian Bojita, Purcar M., Boianceanu C., Tomas E., Topa V., "A Study of Adaptive Mesh Refinement Techniques for an Eficient Capture of the Thermo-Mechanical Phenomena in Power Integrated Circuits"

27-29.09.2017

Participare la 23rd INTERNATIONAL WORKSHOP on Thermal Investigations of ICs and Systems - THERMINIC 2017, Amsterdam, netherlands cu articolul:

Bojita A., Boianceanu C., Purcar M, Plesa C, Florea C., "A Simple Metal-Semiconductor Substructure For The Advanced Thermo-Mechanical Numerical Modeling Of The Power Integrated Circuits"

31.07.2017-1.09.2017

Marius Lungociu si Razvan Pitu, in calitate de studenti practicanti ai UTCN fac un stagiu de pregatire la: Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania. sub coordonarea lui Cristian Boinceanu

31.07.-1.09.2017

Adrian Bojita, in calitate de cercetator UTCN face un stagiu de pregatire la: Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania. sub coordonarea lui Cristian Boinceanu

11-12.07.2017

Cristian Boianceanu si Ciprian Florea, fac o vizita de scurta durata la: Universitatea Tehnica din Cluj-Napoca, Baritiu 26-28, Cluj-Napoca, Romania. cu scopul participarii la prezentarea diplomelor de licenta a absolventilor Edgar Tomás Rucián si David Mangado Salomón

6.07.2017

Marius Purcar, in calitate de director de proiect face o vizita de scurta durata la la: Infineon Technologies Munchen, Germania. unde este intampinat de Johan Massoner

6-9.06.2017

Participare la 7th International Conference on Modern Power Systems 2017, Cluj-Napoca, Romania cu articolul:

Bojita A., Avram A., Purcar M., Munteanu C., Topa V., "Thermo-Mechanical Simulation of the Metal-Semiconductor Structures of Power Integrated Circuits"

5-18.02.2017

Adrian Bojita, in calitate de cercetator UTCN face un stagiu de pregatire la: Infineon Technologies Romania Scs & Co, B-dul Dimitrie Pompeiu Nr. 6, Sector 2, Bucuresti, Romania. sub coordonarea lui Cristian Boinceanu

12.12.2016

Proiectul SET4CIP a fost prezentat in cadrul lansarii oficiale a proiectului P_40_437 Parteneriate pentru transfer de cunostinte si tehnologie in vederea dezvoltarii de circuite integrate specializate pentru cresterea eficientei energetice a noilor generatii de vehicule - PartenerIC din cadrul actiunii Parteneriate pentru transfer de cunostinte POC-A1-A1.2.3-G-2015.

06.12.2016

S-a desfasurat concursul de ocupare a postului vacant de asistent cercetare din cadrul proiectului. Concursul a fost castigat de ing. Adrian Bojita student masterand in cadrul programului de studii "Tehnici Moderne de Proiectare Asistata de Calculator in Inginerie Electrica" al Facultatii de Inginerie Electrica. Dl. ing. Adrian Bojita isi va incepe activitatea in cadrul proiectului la 01.01.2017.

29.11.2016

Vizita personalului UTCN la IFRO. Vizita are ca obiective:

(1) discutarea si stabilirea structurilor de test,

(2) modalitatile de publicare a rezultatelor,

(3) stabilirea subiectelor pentru practica studentilor.

07.11.2016

Inlanirea de lansare oficiala a proiectului in cadrul careia s-au reunit membrii echipei UTCN. S-au discutat si alocat resursele pentru desfasurarea activitatilor proiectului.

Lucrari publicate in reviste ISI

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1. Avram A., Purcar M., Țopa V., Munteanu C., "An XFEM Based Algorithm for Numerical Optimization of Current Density in Electrochemical Applications", Environmental Engineering And Management Journal, ISSN: 1582-9596, eISSN: 1843-3707, DEC 2016, Vol. 15, ISSUE 12, pp. 2587-2594, DOI: 10.30638/eemj.2016.285.

Abstract

This paper presents an advanced numerical algorithm for the optimization of the current density distribution in electrochemical applications. The optimization principle consists in the distortion of the electric field by an insulating shield properly positioned between the electrodes. Such a distortion influences the distribution of current density at the electrodes under consideration. The electrochemical problem is approached by a Laplace equation which is numerically solved using a mesh-free algorithm based on the extended Finite Element Method (XFEM) while the optimal position of the insulating shield is managed by a genetic algorithm (GA). In order to reduce the computational time, two integration techniques were implemented in the XFEM algorithm: Gauss quadrature for the elements intersected by the discontinuity and natural coordinates for the other elements. The computational environment based on XFEM and GA was implemented in MatLab software. It can solve two dimensional (2D) and three dimensional (3D) applications and it was demonstrated on a practical electrochemical application for the optimization of current density distribution at the neighborhood between a cathode electrode in line with an insulator. The standard current density deviation at the cathode electrode is considerably reduced for optimal shield position comparing to the initial shield position. The use of the combined integration technique in the XFEM framework leads to an overall 70% improvement of the computational time compared with the standard XFEM integration technique.

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2. Plesa C.S., Neag M., Boianceanu C., Negoita A., "Design methodology for over-temperature and over-current protection of an LDO voltage regulator by using electro-thermal simulations", Microelectronics Reliability Vol. 79, December, pp 509-516, 2017.

Abstract

This paper presents a methodology for designing over-temperature and over-current protection (OTP and OCP) circuits for lowdrop-out voltage regulators (LDOs). The OTP monitors the die temperature developedwithin the LDO and disables its output stage when the temperature reaches a certain, user-defined, level (the OTP activation point). If the LDO output current reaches a set threshold (the OCP activation point), the OCP takes control of it, keeping the current value to an acceptable level. The proposedmethodology involves running iteratively electrical, thermal and electro-thermal simulations. It addresses threemajor issues: first, it allows the designer to identify the suitable layout placement of the OTP and OCP sensors, based on the temperature distribution within the LDO power-stage. Second, the OTP and OCP activation points can be set accurately by taking into account coupled electro-thermal phenomena and the unavoidable differences between the temperature and current sensed by the protection circuits and those developed within the worst-case LDO section. Finally, the LDO design can be fine-tuned considering complex scenarios of real-life operation and test requirements. An LDO was designed using this methodology and the paper provides a direct comparison between the expected (simulated) results and measurements performed on the silicon implementation.

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3. A. Bojita, C. Boianceanu, M. Purcar, C. Florea, D. Simon, C. Plesa, "A simple metal-semiconductor substructure for the advanced thermo-mechanical numerical modeling of the power integrated circuits", Elsevier Microelectronics Reliability, vol. 87, August 2018, pp. 142.150

Abstract

The metallization of double-diffused metal-oxide semiconductor (DMOS) power devices, which operate under fast thermal cycling (FTC), undergoes thermal induced plastic metal deformation (TPMD). The design of the metallization has a significant impact on the device lifetime and thus requires a thorough understanding of the temperature, stress and strain distribution. A simple three-dimensional (3D) transistor substructure which is commonly found in various high integration Bipolar-CMOS-DMOS (BCD) technologies is analysed. The thermomechanical behaviour is studied with the finite element method (FEM) for investigation of two potential failure mechanisms: delamination of power metal and accumulation of plastic deformation in signal metallization layer (which leads to inter-metal dielectric cracking). These failure mechanisms are analysed on two versions of the structure: the first one has only signal and power metal lines and the second one has vias, in addition to the signal and power metal lines. The target of the paper is to propose an efficient finite element analysis (FEA) model that can be used for a qualitative assessment of thermo-mechanical phenomena in the metal system of high integration BCD technologies.

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