Use of converging beams for transmitting electromagnetic energy to power devices for die testing

Abstract

The described method and apparatus wirelessly test individual integrated circuit die on a wafer containing multiple die. The method incorporates activating a selected die on the wafer by wirelessly impacting the die with at least two beams of electromagnetic radiation so that the die receives radiation energy having at least a first energy level, thereby activating the die by causing a current to flow in the die. Each beam of electromagnetic energy individually has less than the first energy level required to activate the die. The beams of electromagnetic energy are directed so that they at least partially overlap on the selected die. In the region of overlap, the two beams together impact the die with an energy level at least equal to the first energy level required to activate the die. The method may additionally include detecting electromagnetic radiation emitted by the die in response to the electromagnetic energy received from the beams of electromagnetic energy. The apparatus includes an integrated circuit wafer and test apparatus. The integrated circuit wafer contains a plurality of individual die. Each die can be activated by directing electromagnetic energy having at least a first energy level onto that die. The test apparatus includes first and second sources of electromagnetic energy. Each source directs to a selected die on the wafer a beam of electromagnetic energy having an energy level less than the first energy level. The beams at least partially overlap on the selected die so that together they couple to the die energy of at least the first energy level.