An electronic device includes display layers such as liquid crystal display layers and a backlight unit that provides illumination for the display layers. The backlight unit includes light-emitting diodes that emit light into the edge of a light guide film. To minimize the inactive area of the display, the light-emitting diodes are tightly spaced to approximate a line light source instead of point light sources. Color and/or luminance compensation layers are incorporated at various locations within the backlight structures to ensure that the backlight provided to the display layers is homogenous. A thin-film transistor layer of the display is coupled to a printed circuit board by a flexible printed circuit. The flexible printed circuit has additional solder mask layers to improve robustness, encapsulation, and traces with a varying pitch.