Results 1 - 10 of 868
Results 1 - 10 of 868. Search took: 0.028 seconds
|Sort by: date | relevance|
[en] A software package for the automatic layout of printed circuit boards is presented. The program permits an interaction of the user during the layout process. The automatic searching of paths can be interrupted at any step and convenient corrections can be inserted. This procedure improves strongly the performance of the program as far as the number of unresolved connections is concerned
[en] Efforts were undertaken to study and select fabrication methods suitable for processing multiple hybrid microcircuits (HMCs) on 3.75- by 4.5-in. (95 by 114 mm) substrates through thin-film metallization and photolithography. Each fabrication method studied was based on its potential for multiple hybrid microcircuit processing. Thin-film deposition parameters were analyzed in terms of thin-film properties necessary to meet HMC electrical and component attachment requirements, and photolithography parameters were analyzed in terms of dimensional requirements on the circuit pattern. The objective of this effort was met, and the techniques developed are being used successfully in the production of multiple HMCs
[en] Microstrip copper lines play an important role in high-speed printed circuit boards. It is necessary to perform appropriate surface finishing on the microstrip copper lines to avoid oxidation and reduce the loss of signal transmission. In this work, the microstrip copper lines after micro etching treatment were finished with immersion silver, immersion tin and electroless nickel immersion gold (ENIG), respectively. Surface microstructures, 3D features and surface contact angle were examined to find the effect of the copper finishing on signal transmission loss. The results indicated that the microstrip copper lines with micro-etching treatment exhibits low signal transmission loss as − 39.9 dB/m at 20 GHz. The tested microstrip copper lines showed that signal transmission loss follows an increasing trend successively with micro etching treatment, immersion silver treatment, immersion tin treatment and ENIG treatment.
[en] We have developed a vacuum chamber and control system for rapid testing of microfabricated surface ion traps. Our system is modular in design and is based on an in-vacuum printed circuit board with integrated filters. We have used this system to successfully trap and cool barium ions and have achieved ion ‘dark' lifetimes of 31.6 s ± 3.4 s with controlled shuttling of ions. We provide a detailed description of the ion trap system including the in-vacuum materials used, control electronics and neutral atom source. We discuss the challenges presented in achieving a system which can work reliably over two years of operations in which the trap under test was changed at least 10 times
[en] A literature search was conducted to support development of in-house diagnostic testing of thick film materials for hybrid microcircuits. A background literature review covered thick film formulation, processing, structure, and performance. Important material properties and tests were identified and several test procedures were obtained. Several tests were selected for thick film diagnosis at Bendix Kansas City. 126 references
[en] The article deals with the problem of minimizing the number of setups for mounting SMT machines. SMT is a device used to assemble components on printed circuit boards (PCB) during the manufacturing of electronics. Each type of PCB has a different set of components, which are obligatory. Components are placed in the SMT tray. The problem consists in the fact that the total number of components used for all products is greater than the size of the tray. Therefore, every change of manufactured product requires a complete change of components in the tray (i.e., a setup change). Currently, the number of setups corresponds to the number of printed circuit board type. Any production change affects the change of setup and stops production on one shift. Many components occur in more products therefore the question arose as to how to deploy the products into groups so as to minimize the number of setups. This would result in a huge increase in efficiency of production
[en] A system employing an array of inductive pick-up coils around the perimeter of a cylinder has been developed for measurements of the rapidly changing field in the new corrector magnets for the Fermilab Booster. The coils are fabricated on printed circuit boards and feature windings which buck dipole, quadrupole, and sextupole fields, allowing sensitive measurements of both strength and higher-order harmonics. The array of coils is simultaneously sampled at data rates of up to 100kHz with 10kHz bandwidth using 24-bit ADC's
[en] A simple 12-digit binary-to-binary decimal decorder the operation of which is based on the principle of consequent scaling is described. Input binary code conversion into pulse sequence is performed by means of binary counter and zero decorder. At the same time the number of pulses in the binary-decimal code are determined by the binary-decimal counter. The digital pulse is fed to the decorder output. The binary code conversion time makes up 0.5 ms. The decorder comprises 12 K 155 series macromircuits and is assem-- bled on a 120x155 mm2 area unified printed plate. The decorder is used in the multichannel system of detection and indication of measurinq data
[en] This report presents the development a TEG-powered WSN prototype that could be used in nuclear applications. Different design considerations that are important in assembling different components of a WSN were carefully taken into consideration. In designed WSN is compatible to operate with low-power generating TEG and high-power generating TEG based on application requirements. Also, to maintain appropriate power level across different sensor node components, direct current-to-direct current converter with maximum peak power tracking algorithm is implemented. Storage device with real-time clock is embedded to enable local data storage and real-time time stamping. The wireless communication module selected and implemented is Zig Bee protocol. To accommodate different operating conditions and any loss of power from TEG due to unforeseen reasons, backup battery system is also implemented. Entire assembly is performed on a 2-layer printed circuit board and tested for operation. The outcome was successful and it also provided data to validate the mathematical model developed to estimate average power consumption of a WSN under different operating conditions.