Electrical Connectors

Design, Manufacture, Test, and Selection

San Kyeong, Michael G. Pecht, San Kyeong , Michael G. Pecht

• Editore: Wiley-IEEE Press
• Anno: 2020
• ISBN:
  9781119679820
• Edizione: 1
• Argomento: Technology & Engineering
• Categoria: Industrial Engineering

Discover the foundations and nuances of electrical connectors in this comprehensive and insightful resource

Electrical Connectors: Design, Manufacture, Test, and Selection delivers a comprehensive discussion of electrical connectors, from the components and materials that comprise them to their classifications and underwater, power, and high-speed signal applications. Accomplished engineer and author Michael G. Pecht offers readers a thorough explanation of the key performance and reliability concerns and trade-offs involved in electrical connector selection.

Readers, both at introductory and advanced levels, will discover the latest industry standards for performance, reliability, and safety assurance. The book discusses everything a student or practicing engineer might require to design, manufacture, or select a connector for any targeted application. The science of contact physics, contact finishes, housing materials, andthe full connector assembly process are all discussed at length, as are test methods, performance, and guidelines for various applications.

Electrical Connectors covers a wide variety of other relevant and current topics, like:

• A comprehensive description of all electrical connectors, including their materials, components, applications, and classifications
• A discussion of the design and manufacture of all parts of a connector
• Application-specific criteria for contact resistance, signal quality, and temperature rise
• An examination of key suppliers, materials used, and the different types of data provided
• A presentation of guidelines for end-users involved in connector selection and design

Perfect for connector manufacturers who select, design, and assemble connectors for their products or the end users who concern themselves with operational reliability of the systemin which they're installed, Electrical Connectors also belongs on the bookshelves of students learning the basics of electrical contacts and those who seek a general reference with best-practice advice on how to choose and test connectors for targeted applications.

1
What Is an Electrical Connector?

Michael G. Pechtand San Kyeong

Center for Advanced Life Cycle Engineering (CALCE), University of Maryland, College Park, MD, USA

An electrical connector is an electromechanical component that provides a separable interface between two parts of an electronic system without compromising the performance of the system. Separability enables circuits that are manufactured independently to be electrically connected, tested, maintained, and upgraded. For example, in a computer or smartphone, the main circuit board and the display and its electronics are manufactured at different locations and are electrically connected using connectors. These subsystems (assemblies) can be tested and upgraded independently of each other. Connectors thus remove the problems of permanent connection of parts and eliminate issues associated with rewiring interconnects [1], such as damage to circuit board conduction paths due to repeated soldering and de‐soldering.

Connectors provide much more flexibility to optimize electronic systems than permanent connections. For example, there are a variety of connectors on the market to satisfy the needs for testing, burn‐in, and assembly of different kinds of electronic systems. They help in supply‐chain management, avoid direct connections, provide opportunities for part replacement and repair, and, in some cases, offer cost savings.

1.1 Challenges of Separable Connectors

The evolution of microelectronics toward higher speeds and switching frequency enforces stringent requirements on connectors. The challenges that confront connectors are extra electrical length, the need for a larger assembly area, compatibility with new technologies, and reliability concerns [2]. A connector introduces an extra electrical path that can lead to added propagation delay and electrical noise, such as cross talk. A connector also introduces new concerns for reliability, because degradation of the contact interface can lead to an increase in contact resistance, which can lead to signal degradation, joule heating, and power loss [2]. These losses are due to increases in contact resistance, which is dependent on the material properties of the connectors, environmental conditions, and mode of operation. Furthermore, because a connector occupies more area than a simple solder or adhesive, the use of connectors might be difficult in applications that have constraints on area.

In the case of signal connectors, signal transmission quality (STQ) must be maintained. STQ refers to the transmission of high‐speed signals through connectors and interconnects without loss of signal quality. The losses may be due to cross talk, transmission delay, or characteristic impedance variation on signal propagation and reflections. The transmission and preservation of signal waveforms forms the crux of STQ.

Electromagnetic compatibility (EMC) refers to the ability of the system to prevent the degradation of the digital signals from external electromagnetic energy. The mitigation of EMC generally involves shielding, filtering, and grounding practices to control electromagnetic interference (EMI).

1.2 Components of a Connector

The main components of a connector include the contact springs, contact finish, and connector housing, as shown in Figure 1.1 [3]. The contact interface is defined by the physical–electrical connection of the pieces of the connector that are mated, and this determines how well the connector performs.

1.2.1 Contact Springs

The contact spring provides the path for the transmission of a signal, power, and/or ground between the circuits that the connector connects. It also provides the normal force, the component of the force that is perpendicular to the surface of contact, which helps in the formation and maintenance of the separable interface [4].

The key mechanical requirements of the contact spring are insertion and extraction force, contact force, contact retention, and contact wipe. The electrical requirements of the contact spring are contact resistance, current rating, inductance, capacitance, and bandwidth. Chapters 3 and 6 provide more discussion on these requirements.

There are two types of contact springs: a receptacle, which is generally a spring member, and a plug, which in most cases is rigid and provides a means for deflecting the receptacle spring to generate the contact normal force [5]. A receptacle contact spring ensures low insertion force while mating and helps the connector endure overstress during nonaligned insertions. Figure 1.2 shows examples of plug and receptacle contact springs [6].

Figure 1.1 Schematic illustration of a typical connector [3].

Figure 1.2 (a) Plug contact spring and (b) receptacle contact spring [6].

The material properties that influence the performance...

Indice dei contenuti

• Cover
• Table of Contents
• Title Page
• Copyright
• About the Editors
• List of Contributors
• Preface
• 1 What Is an Electrical Connector?
• 2 Connector Housing
• 3 Contact Spring
• 4 Contact Plating
• 5 Insertion and Extraction Forces
• 6 Contact Interface
• 7 The Back‐End Connection
• 8 Loads and Failure Mechanisms
• 9 Fretting in Connectors
• 10 Testing
• 11 Supplier Selection
• 12 Selecting the Right Connector
• 13 Signal Connector Selection
• 14 Advanced Technology Attachment Connectors
• 15 Power Connectors
• 16 Electrical Connectors for Underwater Applications
• 17 Examples of Connectors
• Appendix A: Standards
• Index
• End User License Agreement