Printed Circuit Board (PCB) design process and fabrication

This module describes main characteristics of Printed Circuit Boards (PCBs). A brief history of PCBs is introduced in the first chapter. Then, the design processes and the fabrication of PCBs are addressed and finally a study case is presented in the last chapter of the module.Peer ReviewedPostprint (published version

Design requirements for rigid printed wiring boards and assemblies. NASA Handbook

The NASA requirements for assuring reliable rigid printed wiring board design are prescribed. Basic considerations necessary to assure reliable rigid printed wiring board design are described and incorporated

The Single Row Routing Problem Revisited: A Solution Based on Genetic Algorithms

With the advent of VLSI technology, circuits with more than one million transistors have been integrated onto a single chip. As the complexity of ICs grows, the time and money spent on designing the circuits become more important. A large, often dominant, part of the cost and time required to design an IC is consumed in the routing operation. The routing of carriers, such as in IC chips and printed circuit boards, is a classical problem in Computer Aided Design. With the complexity inherent in VLSI circuits, high performance routers are necessary. In this paper, a crucial step in the channel routing technique, the single row routing (SRR) problem, is considered. First, we discuss the relevance of SRR in the context of the general routing problem. Secondly, we show that heuristic algorithms are far from solving the general problem. Next, we introduce evolutionary computation, and, in particular, genetic algorithms (GAs) as a justifiable method in solving the SRR problem. Finally, an efficient O(nk) complexity technique based on GAs heuristic is obtained to solve the general SRR problem containing n nodes. Experimental results show that the algorithm is faster and can often generate better results than many of the leading heuristics proposed in the literature

Printed circuit board design in a school computer laboratory

Printed Circuit Boards replaced conventional wiring in most electronic equipment after World War II, reducing the size and weight of equipment while improving reliability and uniformity. PCBs are used in all kinds of electrical and electronic products because they can be mass-produced with greater circuit density and also enable easier trouble-shooting. Computer Aided Design (CAD) is critical in teaching PCB layout design but it is a challenge for school and college instructors with limited budgets. After discussion of current trends in PCB design and development, as well as basic PCB design criteria, an affordable PCB design using an " educational" microcomputer is presented

Large-area flexible printed circuits for automotive applications

To meet the demands for safety and passenger comfort, modem passenger cars offer more and increasingly sophisticated electrical and electronic systems. The wiring harnesses that support such systems become too large, complex and heavy, when designed for a conventional electrical architecture based on 14 volts, posing several challenges to automotive manufacturers. Alternative electrical architectures based on 42 volts and in-vehicle multiplexing promise to reduce the size and weight of the wiring harness, but these architectures are yet to be fully developed and standardized. In the near term, alternative wiring solutions have gained the interest of automotive manufacturers. Small flexible printed circuits (FPCs) have previously been integrated into automotive instrument clusters. The benefits of reduced weight and space requirements of such FPCs compared to a wire harness has fuelled an interest in much larger FPCs as substitutes for the Instrument Panel and door harnesses in high-volume production cars. This research investigates the materials typically used in FPC manufacture, for applicability within a passenger car. [Continues.

Subassembly for optoelectronic devices

A subassembly for use in packaging an optoelectronic device (e.g., LED or photodiode) includes a semiconductor (e.g., silicon) base and lid having a variety of etched features (e.g., grooves, cavities, alignment detents) and metalization patterns (e.g., contacts, reflectors) which enable the device to be reliably and inexpensively mounted on the base and coupled to the fiber.Published versio

LED array package with internal feedback and control

A packaged LED array for high temperature operation comprises a metal base, the metal base including an underlying thermal connection pad. One or more layers of ceramic overly the metal base. The array includes a plurality of LED dice, each LED die having electrodes. And, the LED thermally coupled to the metal base. A driver circuit is electrically connected to the LED die electrodes and controls the LED array current. An LED driver is mounted within the LED array package, and thermally coupled to the metal base. In a second embodiment, one or more of the LED dice can be switched from the driver to a measurement circuit and used as a photodetector to measure the light output of the LED array. The measured photodetector signal can further be used as a feedback signal to control the LED array light output.Published versio

Advances in electronic packaging technologies by ultra-small microvias, super-fine interconnections and low loss polymer dielectrics

The fundamental motivation for this dissertation is to address the widening interconnect gap between integrated circuit (IC) demands and package substrates specifically for high frequency digital-RF systems applications. Moore's law for CMOS ICs predicts that transistor density on ICs will double approximately every 18 months. The current state-of-the-art in IC package substrates is at 20µm lines/spaces and 50-60µm microvia diameter using epoxy dielectrics with loss tangent above 0.01. The research targets are to overcome the barriers of current technologies and demonstrate a set of advanced materials and process technologies capable of 5-10µm lines and spaces, and 10-30µm diameter microvias in a multilayer 3-D wiring substrate using 10-25µm thin film dielectrics with loss tangent in the <0.005. The research elements are organized as follows with a clear focus on understanding and characterization of fundamental materials structure-processing-property relationships and interfaces to achieve the next generation targets. (a) Low CTE Core Substrate, (b) Low Loss Dielectrics with 25µm and smaller microvias, (c) Sub-10µm Width Cu Conductors, and (d) Integration of the various dielectric and conductor processes.Ph.D.Committee Chair: Tummala, Rao; Committee Member: Iyer, Mahadevan; Committee Member: Saxena, Ashok; Committee Member: Swaminathan, Madhavan; Committee Member: Wong, Chingpin

Materials for high-density electronic packaging and interconnection

Electronic packaging and interconnections are the elements that today limit the ultimate performance of advanced electronic systems. Materials in use today and those becoming available are critically examined to ascertain what actions are needed for U.S. industry to compete favorably in the world market for advanced electronics. Materials and processes are discussed in terms of the final properties achievable and systems design compatibility. Weak points in the domestic industrial capability, including technical, industrial philosophy, and political, are identified. Recommendations are presented for actions that could help U.S. industry regain its former leadership position in advanced semiconductor systems production