A vacuum bonding tool method for pick-and-place and bonding semiconductor chips onto a substrate or onto a previously mounted die to form a die stack includes a shank and a suction part. The shank has a vacuum conduit extending from a first end to a second end of the shank. The shank is adapted for cooperative engagement with the suction part at the second end, and the shank has a plate at the second end to support the suction part. The suction part has a surface for contacting a semiconductor chip during pick-and place operation. According to the invention, the suction part is made of an elastically deformable conductive or non-conductive material. In various embodiments, the chip contacting surface of the elastically deformable suction part flat overall, or is concave, of has a flat central region and concave regions.