scholarly journals Direct Chip Mounting — A Challenge to the Design Engineer

1982 ◽  
Vol 10 (1) ◽  
pp. 1-6
Author(s):  
J. Lorman ◽  
J. Prochaska

The extrapolation of development trends in the area of technologically complicated electronic equipment shows an ever increasing complexity in semiconductor technology. This development has so concerned the constructors of electronic equipment that progress in the technology of mounting and interconnection has taken a secondary place.This growing divergence between a fast developing microelectronic industry, and a conservative state of the macroelectronics industry, is a driving force with regard to the progress to effective connection technologies at every level of mounting. The technological solution to all systems will then become more coordinated.The mounting of components to printed circuit boards is traditionally a soldering operation. This principle lead to the development of full automation, and is a standard mounting technology. The growth of integration at the chip level has however brought new requirements that are only satisfied with difficulty.Newly developed requirements show that the use of dual-in-line packages will be unsatisfactory. New methods must be designed to connect the chips directly to the printed circuit board, going from the chip as the smallest mounted unit.Requirements for very complex electronic equipment with a high degree of integration (LSI or VLSI) are not satisfied using traditional mounting systems. These require a totally new mounting concept, from the chips to the printed circuit board.In this paper alternatives to printed circuit board technology with insulated wiring (multilayers), and the mounting of chips from film carriers, are evaluated. These principles have a good possibility of further improvement as progress in mounting technology continues.Price reductions cause an extension of application possibilities and an extension of electronic designs. It is harder to make choices for new designs when there are more degrees of freedom. However the function of chips as the basic element is unchangeable and optimum designs need to be based on this concept.

Author(s):  
O. A. Korotky ◽  
A. A. Korneev ◽  
A. Yu. Galkin

The paper considers defects that directly affect the quality of the finished product, which includes printed circuit boards and wiring connections. Current problems lead to failures of electronic equipment, which can lead to the failure of complex technical systems with subsequent downtime. Also methods for increasing the reliability of electronic equipment products are proposed, which exclude premature failures of the equipment as a whole. Such failures include breakage of the metallization column during extreme heating of the printed circuit board, poor connection quality of components on the board, absence of a layer between the component and the board. The method of preventing such problems is presented below in the text. Elimination of the above defects can lead to trouble-free operation throughout the warranty period of operation of the equipment at various facilities, including those in the military.


Author(s):  
P. Singh ◽  
G.T. Galyon ◽  
J. Obrzut ◽  
W.A. Alpaugh

Abstract A time delayed dielectric breakdown in printed circuit boards, operating at temperatures below the epoxy resin insulation thermo-electrical limits, is reported. The safe temperature-voltage operating regime was estimated and related to the glass-rubber transition (To) of printed circuit board dielectric. The TG was measured using DSC and compared with that determined from electrical conductivity of the laminate in the glassy and rubbery state. A failure model was developed and fitted to the experimental data matching a localized thermal degradation of the dielectric and time dependency. The model is based on localized heating of an insulation resistance defect that under certain voltage bias can exceed the TG, thus, initiating thermal degradation of the resin. The model agrees well with the experimental data and indicates that the failure rate and truncation time beyond which the probability of failure becomes insignificant, decreases with increasing glass-rubber transition temperature.


2021 ◽  
Vol 11 (6) ◽  
pp. 2808
Author(s):  
Leandro H. de S. Silva ◽  
Agostinho A. F. Júnior ◽  
George O. A. Azevedo ◽  
Sergio C. Oliveira ◽  
Bruno J. T. Fernandes

The technological growth of the last decades has brought many improvements in daily life, but also concerns on how to deal with electronic waste. Electrical and electronic equipment waste is the fastest-growing rate in the industrialized world. One of the elements of electronic equipment is the printed circuit board (PCB) and almost every electronic equipment has a PCB inside it. While waste PCB (WPCB) recycling may result in the recovery of potentially precious materials and the reuse of some components, it is a challenging task because its composition diversity requires a cautious pre-processing stage to achieve optimal recycling outcomes. Our research focused on proposing a method to evaluate the economic feasibility of recycling integrated circuits (ICs) from WPCB. The proposed method can help decide whether to dismantle a separate WPCB before the physical or mechanical recycling process and consists of estimating the IC area from a WPCB, calculating the IC’s weight using surface density, and estimating how much metal can be recovered by recycling those ICs. To estimate the IC area in a WPCB, we used a state-of-the-art object detection deep learning model (YOLO) and the PCB DSLR image dataset to detect the WPCB’s ICs. Regarding IC detection, the best result was obtained with the partitioned analysis of each image through a sliding window, thus creating new images of smaller dimensions, reaching 86.77% mAP. As a final result, we estimate that the Deep PCB Dataset has a total of 1079.18 g of ICs, from which it would be possible to recover at least 909.94 g of metals and silicon elements from all WPCBs’ ICs. Since there is a high variability in the compositions of WPCBs, it is possible to calculate the gross income for each WPCB and use it as a decision criterion for the type of pre-processing.


2018 ◽  
Vol 10 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Alexander Fricke ◽  
Mounir Achir ◽  
Philippe Le Bars ◽  
Thomas Kürner

AbstractBased on vector network analyzer Measurements, a model for the specular reflection behavior of printed circuit boards in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for integration to ray-tracing-based propagation modeling.


Cryptography ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 11
Author(s):  
Mitchell Martin ◽  
Jim Plusquellic

Physical Unclonable Functions (PUFs) are primitives that are designed to leverage naturally occurring variations to produce a random bitstring. Current PUF designs are typically implemented in silicon or utilize variations found in commercial off-the-shelf (COTS) parts. Because of this, existing designs are insufficient for the authentication of Printed Circuit Boards (PCBs). In this paper, we propose a novel PUF design that leverages board variations in a manufactured PCB to generate unique and stable IDs for each PCB. In particular, a single copper trace is used as a source of randomness for bitstring generation. The trace connects three notch filter structures in series, each of which is designed to reject specific but separate frequencies. The bitstrings generated using data measured from a set of PCBs are analyzed using statistical tests to illustrate that high levels of uniqueness and randomness are achievable.


Author(s):  
Hansang Lim ◽  
Do-Hwan Jung ◽  
Geono Kwon ◽  
Young Jong Lee ◽  
Jun Seo Park

An automotive junction box distributes electric power to electric systems installed in a vehicle with overcurrent protection. As a larger number of electric systems are installed, the junction box is equipped with more components, functionalities and connections. However, owing to the fuse accessibility, its installation space is so restricted that a downsized design is required for the junction box. The junction box is composed of small signal circuitry for control and monitoring, and large current-carrying circuitry for power distribution which includes many parallel traces. Because of these unique features, widely used techniques for downsizing printed-circuit boards are not applicable. Also, there is no rule for designing large current-carrying parallel traces, and it is difficult to optimize the size of the printed-circuit board for the automotive junction box. This paper presents the design rules for a printed-circuit board when downsizing a junction box. First, the layout strategy for the power distribution components is presented, which is determined by the sum of the squares of the currents flowing through connector pairs. Then, the thermal effects of parallel traces are simulated for different conditions by using thermal analysis software. Based on the results, an analytical estimation of the additional temperature rises due to parallel traces and rules for a thermally effective arrangement of the parallel traces are presented.


2014 ◽  
Vol 7 (11) ◽  
pp. 3674-3682 ◽  
Author(s):  
Jingping Liu ◽  
Cheng Yang ◽  
Haoyi Wu ◽  
Ziyin Lin ◽  
Zhexu Zhang ◽  
...  

A multilayer printed circuit board (PCB) can be fabricated using commercially available printing paper, which shows comparable functionalities with the conventional organic PCBs but 100 times lower environmental impact.


1987 ◽  
Vol 108 ◽  
Author(s):  
David Wei Wang

The printed circuit board is an integral part of the electronic packaging hierarchy. Its use began more than 40 years ago, and the demand for printed circuit boards has increased in parallel with the growth of the electronics industry.[1] According to a recent forecast, the worldwide production of printed circuit boards will reach to over 19 billion U.S. dollars' worth by 1990.[2] With continuing demands for more interconnections, the multilayer circuit board industry is experiencing its fastest growth rate. Boards with more than 20 inner planes of circuitry are being manufactured with high reliability.Based on dollar values, more than 90% of the circuit boards produced are in the rigid board category, where starting materials are based on thermosetting prepregs produced by a solution impregnation method. This article is a review of materials currently used in rigid composites.


2019 ◽  
pp. 130-133
Author(s):  
A. Yu. Gladkevich

Describes the process of improving and developing tools in computer‑aided design system Delta Design. Currently, the modern  process of PCB development is quite complex and time‑consuming process. Existing CAD systems make it easier to design a  printed circuit Board model by providing powerful development tools. Along with the increasing complexity of modern printed  circuit boards, the requirements for development tools are also growing, making them constantly improve. Using the example  of  the  Delta  Design  system,  the  process  of  improving  the  tool  for  moving  track  segments  is  described.  The  analysis  of  the  advantages and disadvantages of the existing tool is made, and the decision on the need to develop a new algorithm is justified.  Of the two proposed variants of such an algorithm, the optimal one was chosen in terms of the quality of the result obtained and  the convenience of operation.


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