Chip transfer method and apparatus

In a chip transferring apparatus a wafer ( 44 ) and a lead frame ( 50 ) are positioned. A first chip ( 42 ) is picked up from the wafer ( 44 ) by a transfer head ( 14; 40 a- 40 d) in a chip pick-up position, while bonding a second chip to the lead frame ( 50 ) by another transfer head in a chip bonding position. The first chip ( 42 ) is then transferred by said one of the transfer heads from the chip pick-up position to the chip bonding position. Next, the first chip ( 42 ) is bonded on the lead frame ( 50 ) by said one of the transfer heads ( 14; 40 a- 40 d) in the chip bonding position, while another one of the transfer heads picks up a third chip from the wafer ( 44 ) in the chip pick-up position. Each transfer head ( 14; 40 a- 40 d) comprises a collet ( 66 a- 66 d) which, through a mechanical coupling, is coupled to another collet for compensating radial forces exerted on the collet relative to said axis of rotation. Vacuum is transferred to the collet from a stationary pressure source by groove sections ( 106 ) in a transfer assembly stator ( 100 ) communicating through a gap ( 104 ) between the rotatable transfer assembly ( 32 ) and the transfer assembly stator ( 100 ) with gas ducts in the transfer head ( 14; 40 a- 40 d) and the corresponding collet ( 66 a- 66 d). A chip ( 42 ) is picked up from a wafer ( 44 ) by a needle mechanism ( 224 ).