Chip transfer method and apparatus

Apparatus for transferring chips from a wafer to a lead frame, comprising:

• a wafer-positioning device for positioning a wafer, the wafer comprising chips surfaces thereof extending in a first plane, the first plane having a front face and a back face, the chips surfaces exposed on the front face of the first plane;
• a lead frame positioning device for positioning a lead frame, the lead frame comprising a bond surface thereof, the bond surface extending in a second plane which is different from the first plane, the second plane having a front face and a back face, the bond surface exposed on the front face of the second plane, the front face of the second plane facing the front face of the first plane, either parallel (180°) or intersecting at an intersection line to form a dihedral angle of greater than 0° and less than 180°;
• a rotatable transfer assembly comprising at least two transfer heads, a first transfer head for picking up a first chip from the wafer in a chip pick-up position, and a second transfer head for bonding a second chip to the lead frame in a chip bonding position;
• wherein the rotatable transfer assembly is configured to concurrently rotate the first transfer head toward the chip pick-up position of the first transfer head and the second transfer head toward the chip bonding position of the second transfer head;
• and
• a transfer assembly motor for driving the rotatable transfer assembly about an axis of rotation, the axis of rotation extending along a line in a third plane, each point of the third plane being both equidistant to and between the front faces of the first and second planes.