Contact sheet

Abstract

A contact sheet used with a socket for connecting an integrated circuit having spherical terminals to a board. The contact sheet has protruding contact springs in some or all of numerous through holes provided in a sheet composed of an insulative elastic material, wherein the contact springs are composed of a conductive material and constituted by two or more cantilevers fixed onto the sheet by bonding or sandwiching one end thereof. Each cantilever has a lower supporting portion and a spherical terminal holding portion, the lower supporting portion is composed of a linear portion or a planar portion formed adjacently to a portion fixed to the sheet, and the spherical terminal holding portion is formed by vertically bending the other end of the cantilever toward one of two openings of a through hole. When an integrated circuit is mounted, the spherical terminal enters into a gap at the spherical terminal holding portion of the two or more cantilevers to cause the lower supporting portion to be flexed toward the other opening, and after the lower supporting portion comes in contact with the board, the spherical terminal holding portions of the two or more cantilevers are pushed and spread in a direction away from the portion of each cantilever that is fixed to the sheet. According to the contact sheet, oxide films are removed and reliable electrical conduction can be secured without crushing distal end portions of spherical terminals. Current passing distances in contact springs are shorter, so that the contact sheet can be ideally used for a high-frequency test board or a mounting board.

Dependencies are inferred from the claim text.