Transfer apparatus for transferring electronic devices

The invention discloses a transfer apparatus for transferring electronic devices. The transfer apparatus comprises: i) a conveying track for conveying electronic devices in a row having a leading electronic device located at a front of the row; ii) first and second vacuum passages connected to the conveying track, the first and second vacuum passages being operative to create vacuum forces to hold electronic devices against the conveying track at a first device position and a second device position respectively such that there is no overlapping between the electronic devices; and iii) first and second sensors arranged with respect to the conveying track, the first sensor being operative to detect a presence or absence of the leading electronic device at the first device position for removal of the leading electronic device from the conveying track, and the second sensor being operative to detect a presence or absence of the leading electronic device at a sensor position between the first and second device pos