Rack-type backlight light emitting element (LEE) printed circuit boards (PCBs) with at least two layers to provide redundant current paths. This enables a PCB strip to be broken at designated perforations in the field in order to accommodate pipes or fixtures that require formation of a gap in the rack array. The entire length and width of an array can be sized in the field. A plurality of PCB arrays can be serially chained together with the system. A chain of PCB strips is snapped into clips, which in turn snap into rails that are fastened to a surface. The mounting system includes various types of clips, such as end clips, clips for different LEE patterns on the PCBs, and mounting clips to secure the rails to a surface.