scholarly journals Development and Production of Hybrid Circuits for Microwave Radio Links

1977 ◽  
Vol 4 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Per Chr. Malmin

During the last few years, the use of hybrid integrated circuits in microwave radio links has increased significantly. This paper reports on a range of microwave hybrid circuits now in production at our plant. These include transistor high power amplifiers, low noise mixers and various other circuits. The hybrid technology has proven to be cost competitive with the more conventional waveguide and coaxial technologies, and gives quite a few other advantages as well. Among these, the standardization of packages and modules is discussed in some detail. The trend is now to use the hybrid technology in VHF circuits as well. This opens up the possibility of integrating related functions in one package. The production cost in this case must be related to printed circuit boards, and it remains to be seen if there is anything to gain in this respect. However the reduction of the size of modules and the time for circuit alignment will certainly give an improvement in the overall system cost. In order to reduce the cost of microwave hybrid circuits, thick film technology is currently being investigated for use up to 15 GHz. There is probably no specific upper frequency for thick film circuits, but the possibility of using conventional thick film technology depends on the actual circuits under consideration. Preliminary results of this work are reported, together with a cost comparison between thick film and thin film microwave hybrid circuits.

1982 ◽  
Vol 1 (1) ◽  
pp. 22-23 ◽  
Author(s):  
F.W. Martin

The electronics industry is facing a situation in which the cost of electronic functions is dropping continuously while the cost of interconnecting the functions by traditional means, especially through the use of printed circuit boards, continues to rise. Polymer thick film is one proven approach to reversing the trend of rising interconnection costs. It is relatively easy for the typical printed circuit board manufacturer to convert to or adapt polymer thick film because he has most of the necessary equipment, technical knowledge and personnel.


Author(s):  
Mahaveer Penna ◽  
Shiva Shankar ◽  
Keshava Murthy ◽  
Jijesh J J

Background: The communication between two Integrated Circuits (IC) of the Printed Circuit Boards (PCB) currently happening through copper traces which allow electric charge to flow. Several limitations being encountered with the copper traces during high data rate communication because of the resistivity factors, which eventually leads to the damage of traces and the system. Methods: The solution for this issue comes with the design of surface wave communication-based waveguide/channel between the IC’s. Surface wave communication over a specified communication fabric/channel performs the propagation of electromagnetic waves effectively even at high frequencies compared to the copper traces using conductor-dielectric combination. This paper deals in revealing suitable conditions through profound analytical models for achieving effective surface wave communication between the pins of integrated circuits. Results: The analysis includes defining the possible wave propagation terms, suitable channel design aspects for PCB application and corresponding analysis for effective communication at frequencies from 50GHz to 500GHz of millimeter range. This study provides the roadmap to explore a deterministic channel/fabric for pin to pin communication between the IC’s as an alternate for the copper traces. Conclusion: In this process, the proposed channel achieves low dispersion compared to the copper traces at millimeter frequency range.


Recycling ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 22
Author(s):  
Benjamin Monneron-Enaud ◽  
Oliver Wiche ◽  
Michael Schlömann

Electronic components (EC) from waste electrical and electronic equipment (WEEE) such as resistors, capacitors, diodes and integrated circuits are a subassembly of printed circuit boards (PCB). They contain a variety of economically valuable elements e.g., tantalum, palladium, gold, and rare earth elements. However, until recently there has been no systematic dismantling and recycling of the EC to satisfy the demand for raw materials. A problem connected with the recycling of the EC is the removal of the components (dismantling) in order to recover the elements in later processing steps. The aim of the present study was to develop a new technique of dismantling using bioleaching technology to lower costs and environmental impact. In triplicate batch experiments, used PCBs were treated by bioleaching using an iron-oxidizing mixed culture largely dominated by Acidithiobacillus ferrooxidans strains supplemented with 20 mM ferrous iron sulfate at pH 1.8 and 30 °C for 20 days. Abiotic controls were treated by similar conditions in two different variations: 20 mM of Fe2+ and 15 mM of Fe3+. After 20 days, successful dismantling was obtained in both the bioleaching and the Fe3+ control batch. The control with Fe2+ did not show a significant effect. The bioleaching condition presented a lower rate of dismantling which can partially be explained by a constantly higher redox potential leading to a competition of solder leaching and copper leaching from the printed copper wires. The results showed that biodismantling—dismantling using bioleaching—is possible and can be a new unit operation of the recycling process to maximize the recovery of valuable metals from PCBs.


2020 ◽  
Vol 17 (3) ◽  
pp. 79-88
Author(s):  
Maarten Cauwe ◽  
Bart Vandevelde ◽  
Chinmay Nawghane ◽  
Marnix Van De Slyeke ◽  
Erwin Bosman ◽  
...  

Abstract High-density interconnect (HDI) printed circuit boards (PCBs) and associated assemblies are essential to allow space projects to benefit from the ever increasing complexity and functionality of modern integrated circuits such as field-programmable gate arrays, digital signal processors and application processors. Increasing demands for functionality translate into higher signal speeds combined with an increasing number of input/outputs (I/Os). To limit the overall package size, the contact pad pitch of the components is reduced. The combination of a high number of I/Os with a reduced pitch places additional demands onto the PCB, requiring the use of laser-drilled microvias, high-aspect ratio core vias, and small track width and spacing. Although the associated advanced manufacturing processes have been widely used in commercial, automotive, medical, and military applications, reconciling these advancements in capability with the reliability requirements for space remains a challenge. Two categories of the HDI technology are considered: two levels of staggered microvias (basic HDI) and (up to) three levels of stacked microvias (complex HDI). In this article, the qualification of the basic HDI technology in accordance with ECSS-Q-ST-70-60C is described. At 1.0-mm pitch, the technology passes all testing successfully. At .8-mm pitch, failures are encountered during interconnection stress testing and conductive anodic filament testing. These failures provide the basis for updating the design rules for HDI PCBs.


2018 ◽  
Vol 7 (3) ◽  
pp. 108-116 ◽  
Author(s):  
Z. Xu ◽  
B. Ravelo ◽  
J. Gantet ◽  
N. Marier

This article describes an extraction technique of input and output impedances of integrated circuits (ICs) implemented onto the printed circuit boards (PCBs). The feasibility of the technique is illustrated with a proof-of-concept (POC) constituted by two ICs operating in a typically transmitter-receiver (Tx-Rx) circuit. The POC system is assumed composed of three different blocks of emitter signal source, load and interconnect passive network. This latter one is assumed defined by its chain matrix known from its electrical and physical characteristics. The proposed impedance extraction method is elaborated from the given signals at the transmitter output and receiver input. The terminal access impedances are formulated in function of the parameters of the interconnect system chain matrix. The feasibility of the method is checked with a passive circuit constituted by transmission lines driven by voltage source with RL-series network internal impedance and loaded at the output by the RC-parallel network. Good correlation between the access impedance reference and calculated is found.


Author(s):  
A. De Luca Pennacchia ◽  
L. G. De la Fraga ◽  
U. Martí­nez Hernández

The progressive implementation of software functions in Integrated Circuits (ICs) has considerably increased the number of transistors and pin connections of ICs. For that reason, Printed Circuit Boards (PCBs) are fabricated with the Surface Mount Technology (SMT) nowadays and IC mounting on PCB is a crucial process that requires high precision. An Automatic Mechanical Montage (AMM) system is used to mount ICs on the sockets using a couple of reference points for every IC in order to find the correct positions for mounting the IC. Due to some factors in the process of PCB development, there are differences between designed and manufactured PCBs, which could generate delays in their production. In this work, a software tool which allows to work with digital images of PCBs is described. This tool finds the differences generated in PCB development, especially the differences in IC reference points using Digital Image Processing (DIP) techniques.


Author(s):  
Anshul Shrivastava ◽  
Ahmed Amin ◽  
Bhanu Sood ◽  
Michael Azarian ◽  
Michael Pecht ◽  
...  

Abstract Thick film resistors are widely used in consumer and industrial products such as timers, motor controls and a broad range of high performance electronic equipment. This article provides information on failures due to copper dendrite growth, silver migration, sulfur atmosphere corrosion, variation of temperature, and crack due to molding compound mechanisms. It presents case studies in which a physical analysis plan was developed and executed to investigate these sites of interest on as-manufactured and failed thick film power resistors. The analysis techniques included X-ray inspection, cross-sectioning, decapsulation, and optical and environmental scanning electron microscopy analysis. A table illustrates different failure modes and mechanisms for thick film resistors, and also potential application and manufacturing factors that cause failure mechanisms, which then describe the failure modes. The article is concluded that by preventing the failure of thick film resistors, printed circuit boards can be kept in service for their full lifetime.


2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000230-000233 ◽  
Author(s):  
L. Rebenklau ◽  
K. Irrgang ◽  
A. Wodtke ◽  
K. Augsburg ◽  
F. Bechtold ◽  
...  

Nearly every industrial application needs temperature measurement. Typical temperature sensors are based on thermocouples or resistance elements. Nevertheless, these sensors are not always desired for every application. For example, temperature sensing of fluids or gases in pipes. A standard sensor inside such a material flow has an influence on the flow itself (flow resistance, turbulences) which would lead to incorrect temperature result. Additionally, application that need periodical cleaning of their pipe system (food or pharmaceutical production) can't use such sensors because of hygienically reasons. Novel thermoelectric temperature sensors, which could reduce the previously demonstrated problems have been developed as part of a research project. The basic idea of the novel sensor concept is to use thick film technology to enable novel sensor geometries. The typical use of thick film technology is realization of ceramic circuit boards, in which metal-based thick film pastes were screen printed and fired as conductive material. The sensor concept uses a combination of different commercially available metal-based pastes (platinum, silver, nickel, gold) to creates thermocouples based on the Seebeck effect.


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