In a Y linear driving mechanism 6 for moving an X linear driving mechanism 8 in a direction Y by a linear motor comprising a stator 16 and a moving element 17, there is provided a drive transmission portion which is connected to the moving element 17 so as to transmit a driving force of the moving element 17, acting in the direction Y, through a moving plate 18 and a connecting member 25. A first air gap G1 is formed between the moving element 17 and the moving plate 18, and a second air gap G2 is formed between the moving plate 18 and the connecting member 25. With this construction, the transfer of heat from the moving element 17 is interrupted in an operating condition, so that troubles, caused by the thermal expansion and contraction due to heat generated by the linear motor, can be prevented.
In a linear driving mechanism for electronic component mounting apparatus that performs mounting operation for mounting an electronic component on a substrate and linearly drives a transfer beam 8 in a Y direction using a linear motor, an object to be driven and the linear motor are disposed such that a position P of thrust generated by the linear motor for driving the transfer beam 8 in the Y direction approximately corresponds to a central position D1 of inertial resistance of the object to be driven comprising movable portions such as transfer beam 8, loading head 9, and transfer plate 12. Accordingly, twisting moment applied to the transfer beam 8 due to inertial force is eliminated in acceleration/deceleration, and loading position accuracy is ensured and a component life can be lengthened.
