Patent ID: 8915693

Claim:
A robot arm configured to transport semiconductor wafers, comprising: a hand configured to hold a semiconductor wafer; a lower arm link connected to the hand via a first joint; and an upper arm link connected to the lower arm link via a second joint, wherein the lower arm link comprises a first lower arm link and a second lower arm link that are kept parallel at all times, wherein the lower arm link is configured to be separable into two parts at a location between the first joint and the second joint, a proximal end portion of the lower arm link connected to the upper arm link and a distal end portion of the lower arm link connected to the hand are overlapping in a direction perpendicular to a longitudinal direction of the lower arm link, a plurality of positioning pins is disposed alongside in the longitudinal direction and is inserted into an overlapping portion of the proximal end portion and the distal end portion, the proximal end portion of the lower arm link and the distal end portion of the lower arm link are fixed by a plurality of bolts, and the plurality of bolts is disposed on opposite sides of the positioning pins that are disposed alongside in the longitudinal direction of the lower arm link.