Electronic connector

The market for optical fiber worldwide in 1992 was 2.8 billion corresponding to 10 million fiber kilometers (Mfk) (38). This can be broken down into the U.S. market (3.7 Mfk), the rest of North America (0.4 Mfk), northern Europe (4.1 Mfk), eastern Europe (2.6 Mfk), the Pacific Rim (2.8 Mfk), and elsewhere (0.3 Mfk). Most of the optical fiber is manufactured by only a few companies, the largest of which are AT T and Coming. Other producers include Alcatel, Eujikura, Eurakawa, Northern Telecom, Pirelli, and Sumitomo. The market for optical fibers is projected to reach 3.5 biUion by 1998. In addition, according to ElectroniCast (San Mateo, Ca.), the total market for passive optical components, optical electronics, connectors, and fiber-optic cable is predicted to increase from 1.76 billion (U.S.) in 1992 to over 4 billion in 1997, and 10 billion by 2002. 

G. L. Giusberg, ed.. Connectors and Interconnection Handbook, Vols. 1—3, The Electronic Connector Study Group, Inc., Camden, N.J., 1978. 

Electrical Properties. Polysulfones offer excellent electrical insulative capabiUties and other electrical properties as can be seen from the data in Table 7. The resins exhibit low dielectric constants and dissipation factors even in the GH2 (microwave) frequency range. This performance is retained over a wide temperature range and has permitted appHcations such as printed wiring board substrates, electronic connectors, lighting sockets, business machine components, and automotive fuse housings, to name a few. The desirable electrical properties along with the inherent flame retardancy of polysulfones make these polymers prime candidates in many high temperature electrical and electronic appHcations. 

Electronic Connectors. The complexity and size of many electronic systems necessitate constmction from relatively small building blocks which ate then assembled with connectors. An electronic connector is a separable electrical connector used in telecommunications apparatus, computers, and in signal transmission and current transmission <5 A. Separable connectors ate favored over permanent or hard-wired connections because the former facilitate the manufacture of electronic systems also, connectors permit assemblies to be easily demounted and reconnected when inspection, replacement, or addition of new parts is called for. 

Electronic connectors may connect internally or externally. Internal connections may be between a component and a printed circuit board or wire (Fig. la) a printed circuit board and a wire or another printed circuit board which is in a chassis (Fig. lb) and between chassis in the same cabinet (Fig. 

Fig. lab. Some types of electronic connectors, (a) Receptacle for dual-in-line package (DIP) semiconductor integrated circuit, (b) Connectors for printed circuit boards having edge contacts two-piece connectors have male and female connector halves, one of which is attached to the printed circuit board. 

Fig. 4. Contact spring configurations for separable electronic connectors. Examples (a)—(g) ate engaged by sliding the spring contact and its mating member together (a)—(d) ate blade-fork contacts (e), folded cantilever contact for printed circuit boards (f), straight cantilever contact for printed circuit...

Another type of electronic connector joins coaxial conductors. These have a soHd or stranded center-conductor surrounded by a dielectric. The dielectric is covered with a conductive shield made of metal braid or tape and with a layer of insulation. Coaxial cable connectors terminate the center-conductor and the shield. These are used primarily in radio frequency circuits. The shape, dimensions, and materials of an electronic connector shell or stmcture may have to be designed to shield the connection from electromagnetic and radio frequency interferences in many appHcations. 

Base Metal Finishes. The low cost of base metal finishes obviates selective coating. Electro deposition is used for 0.5—5 p.m thick coatings of tin and tin—lead alloy, usually about 50 wt % Sn, 50 wt % Pb, on electronic connector contacts, on contacts at the edges of printed circuit boards, and on terminals. Sheet copper alloys that have been coated with tin—lead alloy are widely used for contacts that are stamped and then formed into the desired shapes, such as pins having a closed end and sockets. Aluminum connectors that have utility—industrial appHcations are more thickly coated, and hot-dipping in molten tin is common. 

Fretting corrosion (36,37) can lead to high contact resistance of base metal contacts, such as tin plate in electronic connectors. Small cycHcal displacements of the connector halves occur because of external vibration or differential thermal expansion and contraction of the mating contacts. The wear debris that is formed remains in the contact zone. The accumulation of oxide debris in the contact region leads to increased contact resistance. Solutions to this problem are stmctures that do not permit movement of contact surfaces with respect to one another, the use of gold as a contact finish, and the appHcation of thick coatings of contact lubricants and greases, which reduce the rate of wear and restrict access of air to the contact surfaces. 

P. Dobrogowski and J. Schroeder, III, Proceedings of the Twelfth Mnnual Connector Symposium, Electronic Connector Study Group, Cherry Hill, N.J., 1979, pp. 233-238. 

Connectors and Interconnection Handbook, 5 vols.. International Institute of Connector and Interconnection Technology, Inc., Anaheim, Calif. emphasis on electronic connector design. 

Electronic connector. The metallic path between the anode and the cathode that conducts electricity outside the electrolyte. In practice, the two... 

With industry proving to be so conservative about binary alloys it is hardly surprising that ternary alloys receive little attention. Nevertheless, two ternary alloys at least have become commercially available iron-chromium-nickel (so-called stainless steel) for both functional and domestic markets and an electronic connector and solderable alloy based on copper-zinc-tin. 

Palladium Advantages have been claimed for new baths (e.g. using chelated complexes ). Antler summarised the use of palladium as coatings, inlays and weldments in electronic connectors . Crosby noted that palladium deposits are of two kinds (1) soft but continuous or (2) hard but porous or cracked. To resist wear and substrate corrosion on contacts, he proposed the application of type 1 (from a bath with tetranitropalladium(ii) anion) over type 2 (from solution containing tetramminepalladium(ii) cation) . 

Sockets, switches, relays, electrical and electronic connectors, fuse holders, closures... Chip carriers... 

Diffusion Barriers. Diffusion barriers are used in the production of various components in the electronic industry. For example, electrochemically deposited nickel is used as a barrier layer between gold and copper in electronic connectors and solder interconnections. In these applications the product is a trilayer of composition Cu/Ni/Au. In another example, Ni and Co are considered as diffusion barriers and cladding materials in the production of integrated circuits and multichip electronic packaging. In this case the barrier metal (BM), Co or Ni, is the diffusion barrier between conductor and insulator (i.e., Cu and insulator), and the product trilayer is of composition Cu/BM/insulator. The common couple in these applications is the Cu/BM bilayer (BM, the diffusion barrier metal Co, Ni, or Ni-Co alloy). 

Aramides, aromatic polyesters, polypenzazoles 25,000 20 500 Electronic connectors and precision thermosplast parts some producers buy advanced intermediates... 

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