Instrument Design Technology (United Kingdom)

This paper presents a machine vision inspection method for winding high frequency inductors, which affects the reliability and quality of the electronic products. This paper proposes how to quickly and correctly improve the quality of component detection, an important issue for surface mounted device (SMD) inductors manufacturers. SMD components easily damage the phenomenon of the electrode, and the brightness of the brightness of the damaged area of the electrode close to normal, not easy to be precise defect area separated from the electrode area.

This study presents a new method for surface modification of polymeric materials by using pulsed UV laser welding technology. The bonding procedures including ablation treatment, Oxygen plasma treatment, adhesive layer bonding and cured by pulsed UV laser writing system was exhibited. The investigation of various parameters for UV laser writing system was performed and discussed by using water contact angle measurement. This technique has been successfully applied to bond dissimilar polymer substrates (polydimethylsiloxane (PDMS) to polymethylmethacrylate (PMMA)). The scanning electron microscopy (SEM) image reveals clearly that there was no clogging in the microchannel or deformation observed between PDMS and PMMA. The method was straightforward and the integrity of microfluidic features was successfully preserved after bonding.

Technetium-99 (99Tc) is a key nuclide, produced by the fission of uranium-235 (235U) and plutonium-239 (239Pu), through a cascade decay process, and is one kind of target element in environmental analysis due to its long half-life (t1/2 = 2.1 × 105 years).

In this study, the combined technologies of dual-layer photoresist complimentary lithography (DPCL), inductively coupled plasma-reactive ion etching (ICP-RIE) and laser direct-write lithography (LDL) are applied to produce the submicron patterns on sapphire substrates. The inorganic photoresist has almost no resistance for chlorine containing plasma and aqueous acid etching solution. However, the organic photoresist has high resistance for chlorine containing plasma and aqueous acid etching solution. Moreover, the inorganic photoresist is less etched by oxygen plasma etching process. The organic and inorganic photoresists deposit sequentially into a composite photoresist on a substrate. The DPCL takes advantages of the complementary chemical properties of organic and inorganic photoresists. We fabricated two structures with platform and non-platform structure. The non-platform structure featured structural openings, the top and bottom diameters and the depth are approximately 780 nm, 500 nm and 233 nm, respectively. The platform structure featured structural openings, the top and bottom diameters and the depth are approximately 487 nm, 288 nm and 203 nm, respectively. The precision submicron or nanoscale patterns of large etched area and patterns with high aspect ratio can be quickly produced by this technique. This technology features a low cost but high yield production technology. It has the potential applications in fabrication of micro-/nanostructures and devices for the optoelectronic industry, semiconductor industry and energy industry.

The short-circuit phenomenon is one common error in the operation of electronic circuit. Short-circuit will cause the electrical components damage and the incorrect function in PCB. In general, the detection of short-circuit is performed by using the electrode probe to contact each pad in single PCB or the probe card in mass production of PCD. Due to the fast development of circuit layout, the size of IC with pads is getting smaller; therefore, it is much difficult to detect short-circuit in PCB by the pads-contact inspection. This paper presents a method to detect short-circuit area in PCB without the use of electrode probe, which employs the electromagnetic signals to sense and identify the change of electromagnetic induced by short-circuit. We design an electromagnetic sensing probe which comprises of an equivalent circuit to detect the change of electromagnetism in PCB, and employ an X-Y table for automatic positioning. Instead of tiny electrode probe manufacturing, the electromagnetic sensing method (ESM) is able to detect the short-circuit area inside the multi-layer PCB. In addition, the inspective module with ESM can be designed to be a portable instrument without the space limitation. The article shows the verification of proposed system with the scanning pitch is from 5 to 20 mil line width, the working distance of sensing probe is from 1 to 20 mm, and 4 layers PCB measurement. We also experiment the real case detection by using the ESM in PCB and display ESM can successful indicate the probable area of short-circuit.

The present study is aimed at investigating the effect of acid etching durations on the surface roughness and birefringence of lightweight mirrors made of ZERODUR® glass ceramic. Four acid etching durations (15, 20, 25 and 30 min) have been chosen at a fixed concentration. By using the photoelasticity, surface profiler and laser microscope, the results before and after acid etching have been obtained. It is found the maximum value of the retardation for the polished lightweight ZERODUR® mirror is up to 30 nm. In addition, residual stresses induced by the grinding process with an average grain size of 149 μm are relived after removing ZERODUR® material of a thickness of 60 μm.

Fluorescence is widely used to detect the biochemical effect and some substance containing certain dye. In general, the formation of fluorescent reaction is that an organism or dye, excited by UV light, emits a specific frequency of light; the light is usually a visible or near infrared light. Practically, the fluorescence of object can be excited by continued UV light, but the contrast and sharpness of fluorescence image decrease readily with stray light from the surrounding. In this study, we connect a trigger LED light module to a portable camera system and to perform the fluorescence inspection. When the fluorescent object is excited by asynchronous trigger UV-LED light, the extra intensity of fluorescence can be obtained. In the experiment of security organic dye (BL-ORT), the relative intensity of fluorescence acquired by 30 fps CCD can be increased by more than 11 %. In addition, when the fluorescent dye (chlorine e6) is injected into the tail vein of nude mouse, if its tail excited by the 375nm asynchronous trigger and continuous UV-LED are processed, the average relative intensity is 56.5 % and 49 %, respectively. Therefore, an added relative fluorescence of 15.3 % can be obtained from asynchronous triggering method. Furthermore, the ratio of extra intensity increases with the increase of frame rate of camera.

This article reports an approach of light-weighted mirror design and analysis to increase the weight reduction ratio and improve optical performance based on the finite element method and opto-mechanical analysis. The approach is to represent mirror surface deformation derived from finite element analysis (FEA) by Zernike polynomials, such that the impact of deformation on optical system performance can be evaluated by the optical design and analysis program. The experimental modal analysis was also performed to validate the FEA results. The numerical result shows that the light-weighted primary mirror of Cassegrain telescope is obtained by this approach and predicted deformation fulfills the requirements of optical design.

Improved dynamic performance of a turboalternator may be achieved by the use of a 3-term prime-mover governor. Integral-of-speed and derivative-of-speed signals can be generated and combined with the conventional velocity signal, which then controls the input power. Transfer functions for the synchronous machine, turbine and governor mechanism are obtained from linear theory, and the frequency responses of the system operating with different prime-mover controller configurations are given on Bode diagrams. Interaction between the prime-mover steam-flow controller and the terminal-voltage exciter-field regulator is ascertained for a range of system operating conditions.