Papers by Keyword: Non-Contact

Abstract: In this paper a comparative study regarding the temperature in milling process for some types of aluminum alloys and an austenitic stainless steel is presented. In order to measure the temperature two methods are used, non-contact method, using an infrared thermometer and a contact method with six thermocouples installed along the workpiece. From the point of view of cutting parameters, for the both methods, different rotational speed and depth of cut were used, while feed speed was kept constant.

Abstract: In this work we present the results of a comparison between the non-contact corona-based QUAD (Quality, Uniformity and Defects) technique for inline mapping of electrically active defects in SiC epi and final wafer level electrical device data on merged PiN Schottky diodes. A new defect analysis method for the QUAD mapping is introduced that involves the creation of a die yield bin map using the in-die values of depletion voltage that facilitates the comparison to the wafer level final electrical device data. Excellent correlation of the QUAD wafer bin map results to the final wafer level electrical device data was observed, illustrating that QUAD mapping of defects in SiC epi can provide a powerful and convenient inline complement to UVPL measurements for determining which defects are electrically active and will impact device performance.

Abstract: We report significant advancements in corona-based non-contact capacitance-voltage (CnCV) metrology recently developed for comprehensive C-V characterization of SiC and other wide bandgap semiconductors. The technique answers the industries needs for nondestructive, cost-effective C-V dopant monitoring for material and device development and manufacturing control. Excellent precision and matching to mercury probe CV is demonstrated for SiC, Ga₂O₃, GaN and AlGaN/GaN structures over a concentration range from 10¹⁴cm^-3 to 2x10¹⁹cm^-3. The emphasis in the present work is on improvement of CnCV in dopant depth profiling resolution and measurement throughout. This is achieved with a variable charge method that in-situ adjusts corona charging increments in response to changes in dopant concentration. Results are presented for multi-layer epitaxial SiC and for 2DEG in AlGaN/GaN HEMT structures. The latter represents an extreme case of high-low concentration profiling with a transition from 10²⁰electrons/cm^-3 in the 2D electron gas to a fully depleted well and dopant concentration in the 10¹⁵cm^-3 range.

Abstract: In this work we present novel photo-assisted characterization of dielectric interfaces in SiC using a modified non-contact corona-Kelvin technique. This technique eliminates the cost and time associated with fabrication of electrical test structures. UV illumination in deep depletion is used to generate minority carriers that empty deep interface states too slow to be emptied by thermal emission. After illumination, the interface state charging current is measured with time resolved voltage decay. This enables novel non-contact corona-Kelvin characterization of hole emission and electron capture processes involving slow interface states. This novel application complements standard corona-Kelvin measurement of dielectric, interface and semiconductor parameters.

Abstract: The loose coupling structure of Contactless Electrical Power Transfer System (CEPTS) is the main cause of transmission inefficiency. Compensation capacitors were calculated and mounted on both sides of primary and secondary coils which forming the following four compensation topologies: primary secondary series (SS compensation), primary series-secondary parallel (SP compensation), primary parallel-secondary series (PS compensation) and primary secondary parallel (PP compensation). Experiment results show that the transmission efficiency differs according to different compensation topologies. SP structure is the most efficient among these four topologies and the transmission efficiency of SP structure is about 40% higher than that of basic structure without compensation.

Abstract: In order to superpolish fused silica surface, a non-contact polishing method is applied, which is called as computer numerical-controlled (CNC) micro-jet polishing (MJP) technology developed on the base of the hydrodynamic mechanism. In this paper, both the theory and the techniques about this new polishing technology are introduced in detail, and the curved surface of fused silica was polished. The results demonstrate that no new scratches were produced when the nanoparticles removed the atoms away from the surface. The roughness decreased monotonously with the removal of subsurface damage layer. And ideal Ultrasmooth surface without scratches was achieved by MJP with waveness less than 0.2nmrmsRMS while the high-spatial frequency roughness less than 0.1nmrmsRMS (sub-angstrom).

Abstract: The phenomenon that bubbles or particles are suspended at the node position of a standing wave of sound is known as acoustic levitation and has recently been applied in the fields of semiconductors, aerospace, and biology [1-3]. By using this phenomenon in this study, a new classification method has been proposed, and a device has been developed to sort objects in accordance with their densities. Unlike the conventional methods as such as centrifugal particle separation or magnetic separation, this method can separate fine particles both of metal and non-metal and without contact easily only using acoustic power. First, we derived the acoustic radiation pressure to be applied to the object from King’s theory, and then we designed and developed a twin-transducer system to apply the required levitation force. The distributions of sound pressure and particle velocity were then visualized. Finally, a series of experiments was conducted to show the capability of classifying the fine abrasive SiO₂ particles and fine iron particles (φ = 50 μm).

Abstract: A kind of intelligent prompt temperature measurement system was designed which was based on single chip micocomputer. It used the pyroelectric infrared sensor to collect the emitted infrared from human body and to preprocess the signal output of the sensor.Then it could be the conversion signal by the A/D transformation inside SCM .The AVR SCM could control to realize the temperature operation and processing, and send the temperature value to the LCD to display and the voice prompt. Simultaneously, it was added the clock function and over temperature alarm function which made the design more practical. Theoretical basis and the software platform were used in this design of the hardware production and software debugging, and finally the design requirements were realized. The temperature measurement system had the advantages of short response time, non-contact,no interference by temperature field, convenient operation.

Abstract: In the light of application requirements for non-contact measurement, this paper puts forward a non-contact measuring device. It generates the ultrasonic through electrical way with SCM detecting echo, the timer detecting ultrasonic transmitting and receiving time difference. Then it carries out the non-contact measurement of distance, and displays on LCD. The device can be used in many aspects, such as alarm, data monitoring, etc

Abstract: Orientation adjustment is an important issue in the micromanipulation of cells. A non-contact method based on a swirl for cell orientation control was introduced in this paper. The swirl is produced by a pair of opposite micro-fluids squirting from two parallel tubes. Cell orientation adjustment is realized by cells rotation due to swirl viscous drag, which drives cells to desired configurations. The appropriate distances between the end face of the two tubes and the distance between the axes of them are 1-3 times tube diameter for the cells rotating in the swirl central zone. Especially when the distances are kept double the cell diameter, cells rotate steadily round the swirl central point. By pulsating jetting, fluctuant micro-fluid are generated which make cell rotating a certain angle. Adjusting the pulse duration, pressure and jetting velocity, the cell rotation angle can be controlled which make orientation control more precisely. The method is valid for cells of different shapes and sizes. The effectiveness of the proposed non-contact method for cell configuration control was verified by experiments.