LED array alignment

摘要

An alignment mark on a light-emitting diode (LED) array chip is formed together with the light-emitting areas (13) of the diodes in the array, by use of a combined mask having a first part and a second part. An impurity is introduced through windows in the first part to form the light-emitting areas. Next the windows are covered with an etching resist, and the chip substrate is etched to create a topographic relief feature (20) defined by the second part of the mask. This topographic relief feature is used as an alignment mark. When LED array chips having these alignment marks are mounted on a supporting surface, they are aligned by recognizing patterns of light reflected from the topographic relief, thereby detecting the positions of the alignment marks.