Patent ID: 6655671
Filing Date: 2003-12-02
Classification: H05K,Y10T

Abstract:
An apparatus for holding a printed wiring board, comprising:a holding table which has a flat upper surface and a plurality of negative-pressure-supply holes each of which has an opening in the upper surface; at least one holding member which is attachable to the upper surface of the holding table such that a lower end surface of the holding member is held in close contact with a portion of the upper surface that surrounds the opening of at least one of the negative-pressure-supply holes, the holding member having a negative-pressure passage which is formed therethrough to connect between the lower end surface thereof and an upper end surface thereof, the holding member, attached to the holding table, supporting, at the upper end surface thereof, the printed wiring board, and applying a negative pressure supplied from the at least one negative-pressure-supply hole via the negative-pressure passage thereof, to the printed wiring board and thereby holding the printed wiring board; and a plurality of opening and closing valves which are associated with the plurality of negative-pressure-supply holes, respectively, each of the opening and closing valves closing a corresponding one of the negative-pressure-supply holes in a state in which the holding member is not attached to detached from the portion of the upper surface of the holding table that surrounds the opening of said the corresponding one negative-pressure-supply hole, and opening said corresponding one negative-pressure-supply hole, in a state in which the holding member is attached to said portion of the upper surface, so that said the corresponding one negative-pressure-supply hole is communicated with the negative-pressure passage of the holding member, said each opening and closing valve comprising: a valve hole which is provided at an end portion of said corresponding one negative-pressure-supply hole on a side of the opening thereof in the upper surface of the holding table: a valve seat which is provided by a portion of the holding table and faces upward in the valve hole; a valve member which is provided in the valve hole and which closes the corresponding one negative-pressure-supply hole in a state in which the valve member is seated on the valve seat: one of the valve member and a portion of the holding member in a vicinity of the lower end surface thereof being formed of a permanent magnet and the other of the valve member and the portion of the holding member being formed of a ferromagnetic material, and a coming-off preventing portion which prevents the valve member from coming out of the valve hole, while keeping the communication between the corresponding one negative-pressure-supply hole and the negative-pressure passage of the holding member.