US Patent No. 9,155,231


Patent No. 9,155,231
Issue Date October 06, 2015
Title Motor-drive Unit Having Heat Radiator
Inventorship Naoki Masuda, Yamanashi (JP)
Kiichi Inaba, Yamanashi (JP)
Assignee Fanuc Corporation, Yamanashi (JP)

Claim of US Patent No. 9,155,231

1. A motor-drive unit comprising:
a first substrate and a second substrate wherein a circuit for driving a motor is divided and divided sections of the circuit
are formed on the first and second substrates;

a connecting part which connects the first and second substrates so that the first and second substrates intersect with each

a semiconductor device mounted on each of the first and second substrates;
a heat radiator having a first heat-transferring surface adjacent to the semiconductor device mounted on the first substrate
and a second heat-transferring surface having a surface direction different from a surface direction of the first heat-transferring
surface; and

a capacitor positioned within a swept area formed by moving the first substrate in a direction perpendicular to the first
heat-transferring surface, the capacitor being separated from the first substrate, wherein the semiconductor devices are positioned
adjacent to at least the first and second heat transferring surfaces, respectively.