A chip transfer apparatus includes a first carrier for feeding chips and a
second carrier for carrying works on it. The transfer apparatus also
includes a transfer engine including two or more coaxial revolvers, which
can revolve coaxially with each other. Each of the coaxial revolvers
includes an end-effector for receiving a chip from the first carrier and
transferring the received chip onto a work on the second carrier. The
end-effectors of the coaxial revolvers are arranged in a circle coaxial
with the revolvers. The end-effectors sequentially receive chips from the
first carrier at substantially zero speed relative to the first carrier
and transfer the received chips onto works on the second carrier at
substantially zero speed relative to the second carrier. While the
end-effectors are revolving, they undergo periodic speed change control
for timing adjustment and speed adjustment for the chip reception and
transfer.