Microelectronic Equipment Research Articles

Superhydrophobic/Superhydrophilic Hybrid Copper Surface Enhanced Micro Heat Pipe by Using Laser Selective Texturing

The heat transfer performance of Flat micro heat pipe (FMHP) is mainly determined by liquid absorption capacity of the wick. A chemical-free laser selective micro-texture technology is proposed for the fabrication of FMHP. Series of samples with different widths of the superhydrophobic-superhydrophilic spacing stripes were prepared by laser micro texturing, and their transport capacity was tested. Scanning electron microscope, three-dimensional optical profiling, and X-ray photoelectron spectroscope techniques were used to characterize the surfaces, and the mechanism of accelerating liquid reflux was investigated. Two samples with the same spacing width were used to make FMHPs. The heat transfer performance of each group of FMHPs was tested, including the start-up time, steady state temperature, and axial maximum temperature difference, and the corresponding thermal resistances were calculated. The results show that the width of superhydrophobic-superhydrophilic spacing stripes can affect the capillary force and hysteresis force during droplet transport, thereby affecting the droplet transport velocity, and in turn, influencing the heat transfer performance of the FMHP. Compared with most current flat micro heat pipes, the laser selective textured heat pipe with superhydrophobic-superhydrophilic stripes can significantly improve the heat transfer performance, and is promising for heat transfer applications in microelectronic equipment.

Multifunctional fiber-optic sensors for space infrastructure

Sensors used in rocket and space technology are subject to extreme external influences in terms of temperature, vibration, and shock. Therefore, the choice of the type of sensors is justified precisely by the resistance to such factors, as well as the ability to ensure the temporal and parametric stability of measurements. A new type of sensors – fiber-optic ones – meets these conditions. The basis for the selection and further improvement of such sensors were such requirements as minimum power consumption, high accuracy and stability of measurements, the ability to combine several measurements in one sensor. It is noted that for space infrastructure the factor of the possibility of simultaneous measurement of several parameters with one sensor is one of the important quality indicators. This is due to the possibility of reducing the number of sensors themselves, which reduces the mass and size parameters of space technology. This applies, first of all, to measurements of pressure and temperature, since they, in aggregate, account for at least 40 % of all measurements in space products. The path of choos-ing the types of methods and sensor designs led to the combination of the amplitude conversion method and optical communication in one sensor. In this case, amplitude modulation of pressure and temperature is carried out by a microelec-tromechanical unit (module), and the modulated optical signal is transmitted by an optical module. Such a modular composition of the sensor makes it possible to dispense with optical ana-lyzers (interrogators) and carry out further pro-cessing based on standard interfaces. A limitation of the proposed methods and designs is the need for microelectromechanical structures that measure certain physical quantities. Such structures for fiber-optic sensors are not mass-produced; therefore, their manufacture can be established at instrument-making enterprises with microelectronic equipment

Numerical study on the performance of the H-shaped air-breathing microfluidic fuel cell stack

Microfluidic fuel cells (MFCs) are a kind of promising power source for micro-electronic equipment, such as portable electronic devices, biomedicine test and diagnose devices. One of the major constraints on the commercialization of MFC is the insufficient output power and low power density. To meet the power requirements of practical applications, a novel H-shaped air-breathing dual MFC which can be further assembled into cell stack is proposed. Mathematical model has been established to evaluate the performances of the designed H-shaped dual MFC as well as its connected MFC stack. A good agreement between our simulation result and the reported experimental and simulation results is obtained. Comparing with traditional single cell, this H-shaped dual cell presents a higher output voltage and power density. The design of appropriate inlet flow rate, fuel concentration and electrolyte pH value are beneficial to the improve MFC performance. Output voltage and power density of stacks connected in series are increased with larger cell number, while their fuel efficiencies decrease significantly. However, stacks connected in parallel produce high power density without compromising fuel efficiency. These results provide insight for future design and manufacture of MFC stacks.

A Self-Powered Sensor for Body Motion Mechanical Energy Collection and Monitor

A self-powered sensor for the collection and monitor of body motion mechanical energy is manufactured. This sensor is made up of PVDF which is dealt with polarization. According to practical needs, single or multiple sensors could be selected to serve the function. Through piezoelectric voltage signal that produced by tester body motion mechanical energy to achieve body motion monitor and energy collection to charge microelectronic equipment. This kind of study can help collect body motion energy, facilitate sports training, guide exercise rehabilitation, and promote evaluation of human movement ability to prevent potential risks such as falls. It provides new ideas to material science and sports science practical application.

Verification of the method for determining heat fluxes and heat loses in experiments with a shear-driving liquid film

The cooling of microelectronic equipment is currently one of the most difficult problems of thermal physics. To achieve high heat fluxes and reduce the volume of liquid used, the technological solution looks especially promising, where heat is transferred from the fuel element to a thin, intensely evaporating film of liquid moving under the action of friction of a forced gas flow in a mini-or micro-channel. In recent works, the study of heat losses and determination of the true heat flux in experiments with an intensely evaporating liquid film moving under the action of a gas flow in a mini-channel was carried out. In this paper, the task is to verify the method for determining heat losses. Heat transfer in the convective flow regime is investigated. The experimental and calculated Nusselt numbers in convection experiments with complete channel flooding are in good agreement. In addition, the experimental and calculated Nusselt numbers for film flows are in good agreement. This indicates the correctness of the method for determining heat flux and heat losses in previous studies.

Simulation of Radiation Charging of Microelectronic Equipment Cases for Space Applications

A model and a method for mathematical modeling of radiation charging of polymer microelectronic equipment housings with increased conductivity are developed, which are based on the application of the approximation function of the experimental dependence of the housing conductivity on the irradiation time obtained using parametric identification methods. The research results are aimed at developing composite polymer materials for microelectronic equipment housings with a conductivity that ensures the absence of electrostatic discharges and significantly increases the active life of spacecraft.

Preparation, Properties and Mechanisms of Carbon Fiber/Polymer Composites for Thermal Management Applications.

With the increasing integration and miniaturization of electronic devices, heat dissipation has become a major challenge. The traditional printed polymer circuit board can no longer meet the heat dissipation demands of microelectronic equipment. If the heat cannot be removed quickly and effectively, the efficiency of the devices will be decreased and their lifetime will be shortened. In addition, the development of the aerospace, automobiles, light emitting diode (LED{ TA \\1 “LED; lightemitting diode” \\s “LED” \\c 1 }) and energy harvesting and conversion has gradually increased the demand for low-density and high thermal conductive materials. In recent years, carbon fiber (CF{ TA \\1 “CF; carbon fiber” \\c 1 }) has been widely used for the preparation of polymer composites due to its good mechanical property and ultra-high thermal conductivity. CF materials easily form thermal conduction paths through polymer composites to improve the thermal conductivity. This paper describes the research progress, thermal conductivity mechanisms, preparation methods, factors influencing thermal conductivity and provides relevant suggestions for the development of CF composites for thermal management.

Experimental study of heat transfer in two-phase flow regimes in rectangular microchannel

Existing cooling systems do not fulfil modern requirements for heat removal from high-heat dissipating sources in electronic and microelectronic equipment. When reducing the flat channel thickness, the ratio of the surface to the volume increases inversely to the minimal transverse size of the channel, resulting in high intensity of heat transfer in microsystems. Schlieren and infrared methods serve to determine the main characteristics of a two-phase flow. The characteristics of heat and mass transfer and regimes are studied at various values of the heat flux.

Graphene-based micro-supercapacitors manufactured by laser direct writing

The rapid development of micro-electronic equipment has put forward new requirements for multifunctional and miniaturized energy storage devices. Among them, micro-supercapacitors (MSCs) have received widespread attention because of the advantages of long cycle life and fast charge and discharge. As excellent electronic conductor, graphene has high specific surface area and good ductility, showing wide application prospects in micro-supercapacitors. Among the various preparation methods of graphene-based micro-supercapacitors, laser direct writing technology with the features of inexpensive, flexible and fast, sacrificing-free templates and complicated follow-up processing is an efficient and quickly integrated processing method. To this end, we review the research progress of laser direct write graphene-based micro supercapacitors, including the advantages of laser construction of miniature energy storage devices, typical laser direct writing graphene supercapacitors and their electrode materials, and micro-device configuration assembly (symmetrical and asymmetrical). Meanwhile, the future development trends and challenges of laser direct writing graphene-based micro-supercapacitors are also presented.

Study of physisorption phenomena of chemical species on 300 mm Si wafers during controlled mini-environment transfers between microelectronic equipments

In this work we investigate the behavior of the Si wafers top surface chemistry during transfers or storage between steps in the microelectronic production flow. The study uses a unique 300 mm characterization platform that allows vacuum transfers between separate equipments thanks to the use of specific carriers, thus leading to the concept of quasi insitu characterisations.In order to maximize surface sensitivity, pARXPS (parallel Angle Resolved XPS) analyses is widely used to investigate the Si top surface by considering systematically the grazing photoemission angle.In addition, thanks to a rigorous experimental protocol, the unwanted contribution coming from the setup chain itself is subtracted, and the exact C and O amount of physisorbed species coming from the carrier only is extracted.The results shows that using this simple carrier design, industrially compatible and without embedded pumping, a low level of physisorbed species is possible thanks to the preoutgassing step performed before each transfer. More, this low level can be improved significantly by partially filling the carrier with a low gas pressure (a few Torrs) and the physical phenomenoms explaining this behavior are discussed.Then an innovative improvement, based on using a low pressure of pure H2 is proposed and demonstrated for optimizing furthermore the performances.Beyond Si surfaces, the applications of such an optimized design will be of key interest for preserving the chemical surface integrity of highly more air sensitive materials than Si during transfer between separate equipments.

Determination of thermal conductivity of epoxy resin with metallic load

With the increase of technology in the electronics industry, new methods have emerged, resulting in smaller components and higher processing capacity. In contrast, problems related to rate of heat transfer of these components have been increasing and with this reduction in size, the temperature began to be an important variable to be observed in equipment. Normally, performance improvements, such as computers or racks of telephone exchanges, translate directly into greater heat dissipation of electronic devices that make up the device, and consequently, high rates of heat transfer. Thus, the cooling of electronic equipment gained paramount importance as the effect of increased power densities in micro-electronic equipment made available by advances in semiconductor technology. Because of this, whenever we face interesting challenges in finding a technique of removing heat more effectively for these high-tech applications, is one of those challenges, which underpin this research is to determine the properties of the constituent components of a new system cooling is a heat exchanger based on phase change of a fluid inert. There are a few examples: automotive radiator and air conditioning, cooling and optoelectronic LEDs. A heat exchanger is physically designed to enhance and to improve the surface in contact with the cooling fluid around it, like air. Approach air velocity, choice of material and surface treatment are some of the factors that influence the thermal resistance and thermal performance of these components. In this research, the epoxy resin with metallic charge, has lower thermal conductivity than aluminum, for example, however, it does not conduct electricity, getting great importance of electronic devices nowadays.

CFD analysis of heat transfer enhancement in plate-fin heat sinks with fillet profile: Investigation of new designs

In the last decades, attempts have been made on developing more advanced effective cooling technologies of electronic and microelectronic equipment, however, the heat dissipation is still the main challenge for enhancing the cooling efficiency of heat sinks in a highly competitive electronic industry. In current study, the investigation develops a new thermal design for plate-fin heat sinks with fillet profile so that the removed material from the base, to generate fillet, is attached to the plate-fins in the form of half-round pins. To evaluation of thermal performance of the proposed designs, a numerical study has been carried out based on commercially available computational fluid dynamic (CFD) codes. In particular, different arrangements of half-round pins (which are attached to the plate-fins) subject to both parallel and impinging flow have been compared in terms of their thermal efficiency. The study has shown that the plate-fin heat sinks with corrugated half-round pins in vertical arrangement subject to parallel flow and plate-fin heat sinks with symmetrical half-round hollow pins in vertical arrangement subject to impinging flow show superior thermal performance over other configurations. The former design provides approximately 25.1% and 29% reduction in the base temperature and thermal resistance respectively along with approximately 34.48% increase in Nusselt number rather than the conventional plate-fins with fillet profile. For the latter design, approximately 22.6% and 25.7% reduction in the base temperature and thermal resistance were achieved respectively while Nusselt number sees approximately 31.6% higher values. Therefore, these designs have a promising potential to be applied for cooling the electronic devices.

Fundamental issues related to flow boiling and condensation in microchannels – experimental challenges and opportunities

In recent years, application of the microchannels has received considerable attention due to their capability for thermal management of microelectronic equipment, high power devices and development of compact evaporators. The present paper focuses at a discussion of the heat transfer during flow boiling and condensation in microchannels of the heat sink to identify the methods to improve heat transfer performance and select the physically based models for heat transfer prediction. The main purpose of this study is to discuss the mechanisms of heat transfer in microchannels at different aspect ratio for the three-sided heating case using the experimental data were obtained for refrigerant R134a and dielectric fluid.

Development of Software for Measuring the Electrical Characteristics of the Information Storage Micromodule with Increased Radiation Resistance

Development of software for automation of electrical characteristics measurement plays an important role, because this approach contributes to a significant time reduction. This article discusses the development and application of software for the study of electrical characteristics of miniature data storage modules developed by 3D integration technology for aerospace applications. In outer space there are a number of problems affecting the functioning of microelectronic equipment, in particular - heavy charged particles (HCP) that can lead to both single failures and latch-up effect, which is critical for memory chips. Therefore, there is a need to check the electrical parameters, such as the response time of protection against HCP. The software is developed in LabVIEW and can be used in manual and automatic modes, what allows to improve the efficiency of the testing process. The full range of measurements can be done by one operator in a short period of time.

Determination of the positioning accuracy of industrial manipulators using a digital photo/video camera

Purpose of research. The aim of the study is to develop a system for the analysis and evaluation of positioning errors manipulators precision industrial robots used in the production of microelectronic equipment. The positioning accuracy of the manipulator varies depending on the operating modes of the robot and is difficult to predict and difficult to analyze. The accuracy of positioning is influenced by the design features of the robot manipulator, the speed of movement and rotation of the manipulator, intermediate stops and accelerations, vibrations, both own and caused by the location of the robot in production. The positioning accuracy may differ for different points of the robot working area. We need a system of analysis and error estimation that allows us to effectively carry out a series of hundreds and thousands of measurements. One of the promising areas is the use of digital technology with subsequent processing of data on the computer. Materials and methods of research. The construction of effective robotic systems depends on the correct implementation of the certification of industrial robots in order to provide control systems of industrial robots with accurate data for trouble-free and correct operation in conditions specific to a particular production. The solution of the complex problem of certification of precision industrial robots faces difficulties in the selection of measuring equipment. Studies have been conducted aimed at the formation of point light sources of small diameter. A non-contact measurement method based on obtaining an image of point light sources using a digital photo/video camera is proposed. Application of point light sources for calibration of measuring system is described. Possibilities of specification of positions of point sources by means of computer processing of the images received from the digital camera were investigated. The algorithm of image processing of the camera carrying out in several stages definition of accuracy of positioning of the manipulator of the robot is offered.Results. A remote, non-contact method for measuring the positioning errors of industrial robot manipulators has been developed. A method of assessing the positioning accuracy of industrial robot manipulators based on specially formed point light sources installed in the grips of the manipulators and in the working area of the robot. Implemented the use of digital photo/video cameras for monitoring and fixing the space of the resulting spread of the manipulator positions. The software processing the digital image and allowing to make calculations of an error of positioning is developed. The method makes it possible to effectively carry out large series of measurements and meets the following parameters: the absence of physical points of contact between the measuring system and the robot manipulator, satisfying the accuracy of measurements, ease of operation with measuring equipment, low cost of measuring equipment. The work was presented at the XLV International youth scientific conference Gagarin readings, MATI, Moscow, Russia, 2019. and was awarded a diploma. Conclusion. The article presents the results of research on the development of non-contact system of analysis and evaluation of positioning errors of precision industrial robots. The obtained results can be used for certification of industrial robots. It is possible to control the positioning accuracy of manipulators without removing the robot from the production process.

Synthesis of high quality silver nanowires and their applications in ultrafast photonics.

Silver nanowires are widely used in catalysts, surface enhanced Raman scattering, microelectronic equipment, thin film solar cells, microelectrodes and biosensors for their excellent conductivity, heat transfer, low surface resistance, high transparency and good biocompatibility. However, the optical nonlinearity of silver nanowires has not been further explored yet. In this paper, three silver nanowire samples with different concentrations are produced via a typical hydrothermal method. Their applications to fiber lasers are implemented to prove the optical nonlinearity of silver nanowires for the first time. Based on three kinds of silver nanowires, the mode-locked operation of fiber lasers is successfully realized. Moreover, the fiber laser based on the silver nanowire with a concentration of 2 mg/L demonstrates the shortest pulse duration of 149.3 fs. The experiment not only proves the optical nonlinearity of silver nanowires, but also has some enlightenment on the selection of the optimum concentration of silver nanowires in the consideration of ultrashort pulse output.

Безпечний пристрій сполучення з індукційним мажоритарним реле

One of the tasks solved in the development of control systems is the interfacing of microelectronic equipment with actuators. Its complexity is largely determined by the requirements for the reliability of the designed systems, and in particular, functional safety. The most common method of significantly improving the reliability of automation systems is redundancy [1], therefore, control computing systems of critical control systems are designed to be multi-channel. In such systems, interface devices (ID) perform several functions: they implement the control logic adopted in this system, “reducing” the control signals from the outputs of individual redundancy channels to one; carry out direct switching of control circuits of objects. In railway automation systems, in addition, the ODR should with an acceptable probability eliminate the false activation of actuating objects in case of any failure of the elements of the interface device, as well as elements in the output circuits of the control channels [2]. Since the cost of control systems is proportional to the number of backup channels, the search for a compromise between the acceptable performance characteristics of the systems and their price has led to the fact that two-channel and three-channel structures operating according to scheme 2 of 2 and 2 of 3 are most widely used. It is this logic that the most common devices implement. However, the analysis of known circuit engineering, algorithmic solutions that provide both contactless and relay pairing of control computer complexes with objects suggests that they have a number of significant drawbacks, so the task of finding other solutions remains relevant [5]. This article proposes a design, substantiates the possibility and expediency of using three-element induction relays in the ID, functioning on the principle of a three-phase asynchronous motor and capable of implementing control logic 2 of 2, 2 of 3 with high functional safety indicators

Experimental study on the convective heat transfer performance and pressure drop of functionalized graphene nanofluids in electronics cooling system

Cooling of electronic equipment has gained significant importance in thermal management systems as a result of the increase of power densities in micro-electronic equipment. This present work investigates the convective cooling performance of microwave assisted acidic functionalized graphene – deionized water nanofluid. The nanofluid possess high dispersion stability (Zeta potential < −40 mV) in the pH range (6–8) and a thermal conductivity enhancement of 55.38% compared to base fluid. The heat transfer performance of the nanofluid was studied by investigating the effect of volume fraction (0 to 0.2 vol.%) and flow rate (5 ml/s to 10 ml/s) on the convective heat transfer coefficient, processor core temperature, and pressure drop. An increase in the convective heat transfer coefficient of about 78.5%, a decrease in the core temperature of about 15% and an average increase of 5% in pressure drop were obtained for the maximum concentration and flow rate of the nanofluid. The results concluded that acidic functionalization of graphene nanoparticle has a significant influence on the increase in the thermo-fluid properties of nanofluid and thus can be used as an efficient heat transfer fluid, compared to conventional coolants.

Magnetohydrodynamic Ferro-Nano fluid flow in a semi-porous curved tube under the effect of hall current and nonlinear thermal radiative

Abstract Investigation of hall current as well as joule heating effects on the flow and heat transfer characteristics of Ferro-nanofluid flow through a curved tube studied in this work. This work meets a lot of engineering applications such as heat exchangers at low velocity conditions, collectors of solar energy, cooling devices of electronic and micro-electronic equipments and geophysical transport in electrically conducting. The modeling based on the momentum equations by incorporating the hall current effect as well as the energy equation by incorporating the joule heating and thermal radiative effects. Similarity transformation technique has been used to obtain non-linear ordinary differential system which solved analytically as a series solution using Differential Transformation Method (DTM) with associated of Pade approximation technique. The validation of the obtained results has been examined against a previous published works. The results confirm that the hall current has a direct and strong effect on the flow behavior, such that the presence of hall current reduces the flow pressure within the tube as well as increase the heat flux from the inner surface of the tube. Moreover a third component of velocity generates as well as a normal force called Lorentz force due to the presence of the hall current.

Dry spots dynamics in shear-driven thin liquid films under intensive local heating

Development of the modern microelectronic equipment requires the effective cooling solutions because it is necessary to remove high heat fluxes of up to 1 kW/cm2 and higher from the local hot spots of the processor. Thin and ultra-thin (less than 10 μm in thickness) liquid films, moving under the action of a forced gas flow in a mini-channel, are promising for the use in the temperature control systems of the modern semiconductor devices. Here we report results of systematic experimental studies of the flow and rupture of a water film, shear-driven in the channel, under intense heating from a local heat source with size of 1x1 cm2. To carry out high-speed visualization of the process, the FASTCAM SA1.1 CCD camera is used (with the speed of up to 100 000 frames per second). The camera is equipped with an optical system of high spatial resolution (2.5 μm per 1 pixel of the camera sensor). With the help of high-speed imaging, it was found that the maximum intensity of heat removal from the heater is achieved in the mode, when the film flow continuity is broken. The heater is covered with dry spots having typical size on the order of 10-100 μm and typical lifetime on the order of 0.1-1 ms. At that, the number of dry spots that exist simultaneously on 1 cm2 of the heater surface can reach several hundred. During 1 s up to 1 million dry spots appear and disappear at the area of the heater.