BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a traditional lighting board;
FIG. 2A is a top view of a cassette light unit used in the present invention;
FIG. 2B is a side view of FIG. 2A;
FIG. 3 is a top view of a first embodiment of the present invention with a single light unit;
FIG. 4A is a top view of a lighting board of the present invention before insertion of a light unit;
FIG. 4B is a side view of FIG. 4A;
FIG. 5 is a top view of a lighting board of a second embodiment of the present invention with multiple light unit slots;
FIG. 6 is a top view of a third embodiment of the present invention with a matrix light unit slots.