Shuichiro Inagaki

Design of a Compliant Press-Fit Pin Connection

A design method for a compliant press-fit pin connection in a plated through hole (PTH) is presented. In this connection, both compliant press-fit pin and PTH cause elastic-plastic deformation. Considering this feature, three fundamental design concepts for this connection are discussed. First, three design conditions are set: 1) the upper limit of pin insertion force to protect the copper plate of the inner PTH, 2) the lower limit of pin retention force to accomplish reliable wire wrapping connection, and 3) acceptable PTH diameter tolerance. Second, the deformation and radial force characteristics were studied for both pin and PTH. These characteristics were numerically analyzed by using the elastic-plastic finite element method (FEM). According to actual connection states, the pin edge indentation effect into the plated copper is taken into consideration for the PTH deformation characteristics. Finally, the design point was determined, where the pin and PTH radial forces balance. This design point should satisfy the above-mentioned three conditions. An example of a compliant press-fit pin with N-shaped cross section was studied. Results from the numerical analysis are compared with those obtained from experiments. The two results compare favor- ably.

High-Density Multipin Connector for High-Speed Pulse Propagation

A Procedure for designing connectors suitable for gigabit per second (Gbit/s) rate pulse propagation is presented. A design chart for a multipin connector satisfying both electrical and mechanical requirements is obtained. The design procedure is as follows. First, the effect of varying the arrangement of ground contact springs on characteristic impedance is investigated using the finite-element method. Next, the effect of varying contact spring size and contact spring pitch is analyzed with respect to characteristic impedance and crosstalk. Finally, a design chart is constructed for the multipin connector by combining the mechanical characteristics of the contact springs with the aforementioned electrical characteristics. Based on the resulting design chart, a prototype multipin connector for a pin grid array is fabricated. The empirically derived electrical characteristics of the prototype connector are in good agreement with those predicted analytically.

High density pin board matrix switches for automated MDF systems

High-density, low-cost pin board matrix switches for automated main distributing frame (MDF) systems are described. The MDF system has two basic functions, cross connection and route setting for line test functions. These two functions can be performed automatically using a robot hand to insert a connecting pin into a crosspoint hole on the matrix board. Each crosspoint hole has four isolated cylindrical contacts that are connected to X/sub A/, Y/sub A/, X/sub B/, and Y/sub B/ conductive patterns, which represent the A and B wires of a telephone set circuit. Corresponding to the four contacts of a crosspoint hole, a connecting pin has two spring contacts, one spring contact to connect X/sub A/ and Y/sub A/ conductive patterns, and the other for connecting X/sub B/ and Y/sub B/ conductive patterns. In addition, arrangements have been made to perform the route setting for line testing. A matrix board with crosspoint holes on a 1.5-mm grid has been attained using the low-contact-force design and minimum insulation spacing between the neighboring conductive patterns. The design also considers requirements for the robot hand interface. These pin board matrix switches allow the MDF system to be automated. >

Design of high density pin board matrix switches for automated main distributing frame systems

High-density pin board matrix switches composed of matrix boards and connecting pins are designed to provide the cross connection function of an automated main distributing frame (AMDF) system. The cross connection is performed by inserting a connecting pin into a through hole on the matrix board. A small economic AMDF system is made possible by using a laminated matrix board structure based on mass production technology for printed circuit boards and the simultaneous connection of a paired line by inserting a single connecting pin. The low normal contact force design and small insulation spacing between the neighboring conductor patterns give a through-hole pitch of 1.5 mm and a connecting pin diameter of about 1 mm. The layer design of the matrix boards based on the high insulation resistance and high withstanding voltage characteristics allows a matrix board thickness of about 4.2 mm and a connecting pin length of about 8.7 mm. Evaluations of the electrical and contact characteristics of the matrix boards and connecting pins satisfy the design requirements. >

Waveguide optical switch for 8:1 standby system of optical line terminals

Summary form only given. Summary form only given. To reduce the cost of the optical access network without sacrificing system reliability, instead of using a fully duplex standby system, we are planning to allow a single reserve to be shared among several pieces of equipment. We show the planned configuration of a standby system to share a reserved optical subscriber unit (OSU) in an optical line terminal (OLT) for NTTs passive double star (PDS) optical access network. This solution, however, requires an optical switch to have high reliability and low insertion loss and be independent of both wavelength and polarization, inexpensive and self-latching. None of the switches proposed so far meet all these requirements. In this paper we propose an 8:1 optical switch that is suitable for sharing a reserve OSU to reduce the standby cost. Our switch is an intersecting waveguide switch, whose operating principle is based on thermo-capillarity.