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