Background Gas sensing is becoming more and more important driven by the need to increase safety and to reduce the emissions. Sensors must operate in a variety of conditions and are playing a major role in several applications. Sensors based on optical detection offer some advantages with respect to other techniques. The present work deals with NDIR (Non Dispersive Infra Red) sensors and related packaging technology for enhancing the performances. Method Light source and couple of detectors, used for differential reading, are placed on top of DIL. A lid, properly shaped, has been placed on top of them, creating a complete module. 3D optical simulator, has been used for optimizing the shape of the lid. The best solution is a biconical surface. Moreover, a reflector has been added on top of the DIL surface. Using multiple reflections from source to detector, we can enhance the performances of the gas sensor, keeping a small form factor and footprint. Thanks to multiple reflections, the detectors are not constrained to be in the foci. This permits to address easy placement and large tolerance, without any detrimental effect on the performances. The module has been tested and compared with benchmark. Results Discussion Gas sensor module packaged in DIL 24 was inserted to a control board (Figure 1)and then data was acquired. During testing, the CO2 concentration was varied in extensively, ranging from 0 to 10000 ppm, whereas commercial sensors are usually limited to 5000 ppm and its response was then evaluated in terms of resolution and noise. Results are shown in Figure 2; the yellow and red plot are the concentration trend in the controlled chamber and in green and blue the relative sensor responses. The sensor’s response to common disturbances such as temperature and humidity was also evaluated. The temperature in the chamber has been increased from 21ºC to 33ºC. the sensor was exposed to a relative humidity variation from 20% up to 70%. No drift has been detected for humidity variation, while there is a small drift vs temperature, that can be easily compensated through a firmware recalibration procedure since the sensor embeds a temperature-sensing channel. Conclusion, The proper packaging for a CO2 sensor module has been designed and realized. Thanks to selected solution, the module size is kept small, and the detectors are not forced to be in fixed position. The assemble doesn’t required fine alignment of the lid and the placement tolerances are quite high. The module has been tested, and good results have been obtained. Measurements are aligned with the reference commercial sensor. Repeatability and accuracy have been proven. The working range was tested from 0 up to 10.000 ppm, and the sensitivity is 30 ppm. Future work will focus on more extensive testing to refine accuracy, and noise rejection can be improved by working on the hardware components and power supply.

Over the past two decades, additive manufacturing (AM) and 3-D printing have been widely used for producing macroscale industrial components. More recently, researchers have explored their application in fabricating microstructures and micro-electro-mechanical systems (MEMS). This field faces challenges related to accuracy, resolution, repeatability, scalability, and material compatibility. AM processes are classified into seven categories, with various subtypes and acronyms commonly used in industry. This study, conducted in collaboration between the Sant'Anna Institute of Biorobotics and STMicroelectronics, investigates the feasibility of integrating 3-D printing with application-specific integrated circuit fabrication to create fully functional MEMS. The research focuses on developing capacitive particulate sensors, which detect airborne particles through variations in capacitance between electrode pairs. The project involved the development of two different electrode configurations. Due to limitations in 3-D printing conductive materials at microscopic scales, electrodes were fabricated using a two-step process: 3-D printing with dielectric material followed by gold metallization. Electrical characterization was performed to evaluate resistance and capacitance values. Results indicated challenges in adhesion, uniform metallization, and measurement accuracy, particularly for smaller scale designs. While certain challenges remain, this study offers valuable insights into enhancing AM processes for MEMS production, and lays the groundwork for future developments in microscale 3-D printing technologies.

The MEMS Sensor devices are in a very fast development era and the sensor-tile modules with multi-sensing functions are becoming a reality for system monitoring, especially in sensing matrix configurations. In particular, the focus on single package multi-sensing modules with Bluetooth® LE features are increasing their impact on several product areas. In wearable electronics, building management and bio-medical parameters monitoring environments, SiP (System in Package) approach with antenna set inclusion constitutes the leading solution in order to integrate a 2.45 GHz Bluetooth system. In the present paper we describe a novel packaging approach for integrating a plenitude of MEMS based sensors together with wireless connectivity and embedded processing power. The final component is characterized by small size and good RF performances.

MEMS loudspeakers are becoming more and more interesting for a wide variety of applications. Their complete characterization is vital for any practical application. This characterization must take into consideration the interaction with package and should use packaging solution commonly pursued in high volume manufacturing. A packaging approach based on organic substrate combined with 3D printing is presented. The influence of different die attach materials on the performances of loudspeaker is highlighted.

Ceramic substrate coupled to metal lid has been selected for realizing hermetic package for MEMS mirror. The component passed the fine and gross leak tests and show good performance with improved Q-factor.

The Wafer Level Chip Scale Package technology has been applied to a MEMS pressure sensor. In the proposed realization there is no package protecting the sensingelement from the mechanical and environmental stimuli coming from the external world. The prototypes show good results in terms of pressure accuracy, stability and hysteresis.

For the first time the WLCSP approach has been applied to MEMS based pressure sensor. All the wafer level operations have been performed on ASIC wafer, while the MEMS wafer is not modified. The experimental results show good performance of this approach, especially the hysteresis is noticeable small (0.9 hPa).

The paper suggests a simulation flow methodology suitable for MEMS package designers that can help R&D teams to develop industrially feasible products by achieving consistent warpage prediction results, both at unit and strip levels. Strip-level-wise, one of the most important findings of this activity is the direct impact of raw material selection. Unit-level-wise, it allows checking a priori and in different conditions (inside the socket or mounted on a PCB for example) stress distribution on different elements of the assembled MEMS unit.

Applications for optical scanning and 3D sensing, mostly related to the consumer electronics and automotive markets, are becoming more and more demanding in terms of performance and power consumption. When using a MEMS based Laser Beam Scanning, enclosing the mirrors into a hermetic package helps to address these requirements. Two MEMS mirrors with different sizes and performance have been selected for this study. A unique package, suitable for both mirrors, has been properly designed. The package is based on a ceramic chip carrier with a soldering ring on the top surface. A metal cap with a sintered optical window is attached to the ceramic substrate. The optical window is tilted with respect to the mirror to avoid spurious reflections. The MEMS mirrors have been integrated onto the ceramic substrate by standard die attach and wirebonding technologies. Hermetic sealing has been developed under nitrogen atmosphere to guarantee the MEMS stable operation against humidity and contaminants. Flux-less SnAgCu solder preforms have been selected as sealing material. The solder reflow profile has been optimized in order to obtain a uniform solder fillet at the sealing region while minimizing the thermal stress to the mirrors. The hermeticity of the assemblies has been proved by fine and gross leak testing. The packages show a leak rate < 1.5 E-8 atm cc/s and pass the fine and gross leak test, defined accordingly to MIL-STD-883 TM 1014.18.

The development of Silicon Photonics LIDAR (Laser Imaging, Detection, And Ranging) devices for applications such as autonomous driving has been progressing with many different approaches that can be used to achieve the LIDAR transmitter device mostly based on an Optical Phased Array (OPA). In this paper two different approaches at the eye safe 1550nm range are described: - a Silicon Photonics LIDAR based on OPA’s with a simplified electrical driving architecture and an array of Mach-Zehnder (MZ) interferometers, - an only MZ device used to switch the light output between grating devices to provide beam steering of the LIDAR beam. The design for a Test Board of a Silicon Photonics LIDAR device incorporating a control system for controlling the OPA and the matrix of MZ switches is outlined along with the LIDAR packaging, assembly, and the alignment of collimating lenses to enable the angular deflection of the LIDAR device.

In this paper we make a status review of the various applications of Silicon Photonics, focusing on capability of a versatile 300mm Silicon Photonics platform to address data-communication, 3D-sensing and bio-sensing applications.

Silicon based semiconductors are becoming a source of innovation in the field of RF solutions, especially involved in devices used in our everyday life. Wi-Fi and Bluetooth® connections adopted in home-networking, consumer platforms and wearable devices, together with the large spread of the IoT solutions, are more and more requiring very high levels in system integration. In particular, the focus on single-package Blue Tooth Low Energy (BTLE) system is increasing in the last few years. In this scenario, an innovative SiP (System in Package) solution with antenna integration on the top is considered as a possible and reliable alternative to SMD (Surface Mounted Device) antenna assembled on the package substrate. This paper will present a complex SiP composed by multiple stacked organic substrates, integrating a meander antenna that works in the Bluetooth® bandwidth. After describing the structure, the design methodology and the assembly strategy, a particular focus will be put on the antenna integration and dimensioning, supported by full-wave 3D electromagnetic simulations. The influence of the surrounding system on the antenna performance, and consequently the importance of co-design and co-simulation, will be emphasized.

MEMS mirrors are among the most promising devices for the new wave of MEMS actuator devices. The general purpose of the devices(s) is to deviate a laser beam and scan a two-dimensional target. To limit the complexity of design and to maximize performances on both axes of scan, two different mirrors are chosen that then need to be coupled mechanically and optically to perform the dual scanning. This paper presents a low cost, high performance, high mass production process capable solution, for a dual mirror single package system.

A new generation of devices that connects or contains hybrid mechanical-, electrical-, and optical elements on the nano scale are being developed, with potential applications ranging from quantum-enabled hardware to different types of sensors. However, these hybrid optomechanical devices require innovative packaging with not only stress and strain free assembly with high vacuum and hermetic sealing typical of MEMS, but also optical access through windows, fiber alignment and pigtailing. Detailed description of such a module is provided.

The ever-increasing demand for high network capacities and escalating data centers have pushed the boundary from discrete transceivers toward the integration of monolithic electro-optical ICs [1]. Furthermore, complex modulation schemes such as PAM-4 have been introduced to improve the trade-off between circuit bandwidth, power consumption, data-rate and optical-link range compared to NRZ signaling. Therefore, the cost advantage of a fully integrated silicon solution will eventually push classical discrete implementations toward obsolescence.

A large amount of progress has been made in the industrialization of Silicon Photonics fabricated in CMOS Fabs, enabling the adoption of 100G QSFP modules. Further progress has now increased the transmission capacity of Silicon Photonics devices. In this paper, we outline the package design and evaluation of high capacity Silicon Photonics devices from simulation of the package performance to the prototype packaging results.

Industrial implementation of a silicon photonics platform using 300-mm SOI wafers and aiming at 100 Gb/s aggregate data-rate application is demonstrated. The integration strategy of electronic and photonic ICs, 300-mm process flow, and process variability are discussed, and performances of the passive and active optical devices are shown. An example of a low-cost LGA-based package together with a fiber assembly is given. RX and TX circuits operating at 25 Gb/s are demonstrated. Finally, the process evolution toward the integration of the backside reflector and multiple silicon etching level is demonstrated.

Silicon photonics gathered a great amount of investments during the last decade. Both research centres and major industries directed their resources towards this promising technology. As a result, different technological platforms have been proposed [17] and some of them are now accessible through multi-project wafer services. This interest was fuelled by the idea of exploiting CMOS fabs capability to implement a large scale industrialization of low cost and highly integrated electro-optic chips. The amount of digital data exchanged is in fact constantly increasing: by the end of 2020 global IP traffic will reach 2.3 ZB per year, growing at a compound annual growth rate (CAGR) of 22% [8]. This trend is pushing the need for high data-rate optical communication systems toward shorter and shorter distances, from intra-data centers to on-board and on-chip communications [9]. Silicon photonics is seen as the most promising technology to reach the required cost per bit and level of integration and nowadays its evolution is mainly driven by the data centers market.