Papers by Bertrand Chambion
HAL (Le Centre pour la Communication Scientifique Directe), Mar 24, 2014
We present high performance imagers based on our current know-how in curved detectors manufacturi... more We present high performance imagers based on our current know-how in curved detectors manufacturing for VIS or NIR applications. These extremely compact systems are preparing the future of curved imagery.
Over the recent years, a huge interest has grown for curved electronics, particularly for opto-el... more Over the recent years, a huge interest has grown for curved electronics, particularly for opto-electronics systems. Indeed, curved sensors help the correction of off-axis aberrations, such as Petzval Field Curvature and astigmatism. In this paper, we describe benefits of curvature and tunable curvature on an existing fish-eye lens. We proposed a new design architecture, compact and with a high resolution, developed specifically for a curved image sensor. We discuss about aberrations and effect of higher sensor curvature on third order aberrations. Besides, we show results of sensors’ mechanical limits and its electro-optical characterization. Finally, all these experiments and optical results demonstrate the feasibility and high performances of systems with curved sensors.
Applied Optics, Mar 13, 2019
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
arXiv (Cornell University), Mar 21, 2019
HAL (Le Centre pour la Communication Scientifique Directe), Sep 6, 2021
Progress in Photovoltaics: Research and Applications
2018 7th Electronic System-Integration Technology Conference (ESTC)
The growing interest for megapixels arrays optical devices (detecting array/emitting array) has h... more The growing interest for megapixels arrays optical devices (detecting array/emitting array) has highlighted the need for high pixel count and fine pitch interconnection. The LA2P laboratory developed different interconnection technologies in order to optimize the assembly process of optical device. First this paper present the different technologies developed by First, and theory is proposed that shows that the size limitation of “emitting” or “imaging” flip-chipped devices depends on ΔCTE and is independent on the pixel’s pitch. Then, mechanical simulation are presented showing the constraint in interconnection technologies. To finish a room-temperature flip-chip consisting on the insertion of Gold capped micro-tubes inside soft Indium pads is presented with mechanical assembly for reliability tests and infrared demonstrator. This assembly process show the possibility to override limitations given by standard or production interconnection assembly process.
2018 7th Electronic System-Integration Technology Conference (ESTC), 2018
TSV first or TSV last are technologies used in 3D packaging, that are now well described in the l... more TSV first or TSV last are technologies used in 3D packaging, that are now well described in the literature. However there is still room for some improvement especially in the field of TSV isolation. Certain applications such as power applications or light emitting diodes serially powered on the 230 Volts-50 Hz network require some trench isolation for wafer level packaging. In this case the breakdown voltage (up to 600 V) of the trench/TSV becomes a critical issue. In this study different organic and mineral passivation layers were tested to classify their resistance to high voltage. The impact of the Temperature process and the deposition method is shown. Some thermal oxides are also tested and the breakdown voltage is found to be around $800\mathrm{V}/ \mu \mathrm{m}$. Some FEM simulations were achieved showing the influence of the trench geometry. The oxide is then implemented on pixelated samples fabricated on 200mm highly doped Si wafers. Experimental measurements show a breakdown voltage location at the trench crossing zone and a value of $400 \mu \mathrm{m} /\mathrm{V}$ in accordance with the FEM simulations.
Imaging and Applied Optics 2017 (3D, AIO, COSI, IS, MATH, pcAOP), 2017
We present high performance imagers based on our current know-how in curved detectors manufacturi... more We present high performance imagers based on our current know-how in curved detectors manufacturing for VIS or NIR applications. These extremely compact systems are preparing the future of curved imagery.
2017 23rd International Workshop on Thermal Investigations of ICs and Systems (THERMINIC), 2017
This work deals with an overall concept of a 3D-stack enabling to produce a directly pluggable hi... more This work deals with an overall concept of a 3D-stack enabling to produce a directly pluggable high voltage power LED. Using a dedicated silicon vehicle test, a thermal study is carried out with an extensive thermal modelling, optimization, assembly process and Infrared thermal characterization. It is shown that the main thermal issues are due to the presence of the flip chip interconnection layer and in particular the interconnect bump distribution leading to hot spots localization when bumps are missing. According to the results and with a two-steps modelling approach, we can conclude on the good model accuracy (within 11% for the worst cases). Consequently, its relevance for further generation of 3D stacked power devices design highlights the packaging strategy importance to target high performance devices.
2017 IEEE 67th Electronic Components and Technology Conference (ECTC), 2017
Several types of interconnects for the finer pitch assembly are currently being investigated acro... more Several types of interconnects for the finer pitch assembly are currently being investigated across the globe. Here in this paper, a new type of interconnect Ni3Sn4 Interconnect is proposed and evaluated for assembly at 10 pitch and below. The proposed interconnect is compared to traditional solder interconnect. The comparison is done on the basis of shape of the joints in interconnects, the electric yield and mechanical properties. Later, Ni3Sn4 IMC interconnect is also compared to known Cu3Sn IMC Interconnect.
Optics, Photonics, and Digital Technologies for Imaging Applications V, 2018
The method of hybridizing a first microelectronic element (100) with a second microelectronic ele... more The method of hybridizing a first microelectronic element (100) with a second microelectronic element (200) comprises a step of approaching the first and second microelectronic elements (100, 200) so as to generate an interaction bonding of first and second second component (104, 202) of a two-component adhesive. At least one first member (103) extends from said first microelectronic element (100), the first component (104) of the two-component adhesive being associated with said first microelectronic element (100), and at least one second member (201) extends from said second microelectronic element (200), the second component (202) of the two-component adhesive being associated with said second microelectronic element (200). The method comprises a step of mixing the first and second components (104, 202) implemented by said at least first and second members (103, 201) during the step of bringing together, and in that at the end of the step of approaching the distance (d1) separati...
2019 IEEE 69th Electronic Components and Technology Conference (ECTC), 2019
Curved sensors is a well-adapted technology solution to enhance the vast majority of optical syst... more Curved sensors is a well-adapted technology solution to enhance the vast majority of optical systems. It helps to remove lenses and simplify optical architectures. These advantages open news challenges such as a specific fabrication process applied to curved sensors and new rules for final system integration. In this paper, we first introduce benefits of curved sensors applied on a compact high-resolution camera to define the sensor shape specifications and to reach high performances and compactness (-50% compared to a benchmark system). Mechanical limits and optical modeling are used. Then, based on these curved specifications, a novel collective curving process is described, developed on 1/1.8" format CMOS image sensors with a radius or curvature target R= 55 mm and R=60 mm. This work includes packaging and assembly steps, optimizations, and morphological characterizations in accordance to optical design requirements. Finally, a dedicated optical test bench is used for Modula...
2016 6th Electronic System-Integration Technology Conference (ESTC), 2016
Flexible device can be viewed as the ultimate extension of 3D packaging, providing new functions ... more Flexible device can be viewed as the ultimate extension of 3D packaging, providing new functions and advantages. In this work, we propose a new packaging development on tunable curvature of Complementary Metal Oxide Semiconductor (CMOS) image sensors and propose new optical functions. Based on a mechanical study, Tunable Curved Focal Plane Array (T-CFPA) prototypes have been realized. Our investigations prove that our packaging approach for T-CFPA is compatible with spherical shape curving down to 280 mm radius of curvature for a 20*23 mm CMOS image sensor without performance loss. Flexible sensors offer several optical advantages. In single aperture camera, the T-CFPA technology can compensate the Petzval Field Curvature aberration, and simplify the optical design of wide field systems with about 30% less lenses. Applied on monocentric systems, a Field of View of 15° can be imaged, and more than 50° for a modified system. For multi-aperture optics, T-CFPA system allows a Field of V...
Disclosed is a method of making a first microelectronic die (P) having a layer (13) of interest h... more Disclosed is a method of making a first microelectronic die (P) having a layer (13) of interest having a face (11) connection, designed to be hybridized to a second microelectronic die (P2), comprising the steps of: depositing a layer of glue (14) on a face (13a) of the layer of interest (13) opposite the first face (11) connection; attaching a layer called handle (15) on the adhesive layer (14); prior to the steps of depositing the adhesive and fixing the handle layer (15), determining a maximum thickness emaxcc and minimum and maximum Emincc Emaxcc values of Young's modulus of the adhesive layer (14) of a part, and the minimum emincc thickness of the handle layer (15) on the other.
2017 21st European Microelectronics and Packaging Conference (EMPC) & Exhibition, 2017
For the need of energy saving, LEDs are taking more and more space in lighting modules. Moreover,... more For the need of energy saving, LEDs are taking more and more space in lighting modules. Moreover, LEDs add several applications to the lighting function, smartness, dimming, bio photonic applications, a lot of fields that none former light sources could reach [1]. The manufacturers of course must keep the target of making a device compatible with the standards in terms of safety first, but moreover the compactness and reliability with the well-known thermal issues, depending on the wall plug efficiency of the component. In order to manage all the mentioned points, as often, packaging is the key point if one seeks to maximize the lifetime of a LED based luminaire. Indeed, because they are aware of the existing technologies and comparison thanks to quick information available on the Internet, today's customers cannot accept to pay a more expensive light source that have lower performance than the former lighting technologies [2]. The paper that we propose describes the manufacturi...
Monitoring the operation of at least one light emitting diode (10) of a lighting device used to e... more Monitoring the operation of at least one light emitting diode (10) of a lighting device used to establish a diagnosis of the status of the diode (10) during the life of the diode (10). Is provided repeated implementation of a cycle of steps comprising the following steps: a step (E1) for measuring at least one electrical magnitude associated with the operation of the diode and a step (E2) of evaluation a state of the diode (10), especially a state of wear, the result is determined from the result of step (E1) of measuring, said step (E2) evaluation being in particular implemented in life during the diode (10).
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Papers by Bertrand Chambion