FIG. 6B is an enlarged plan view illustrating an embodiment of a portion of the main circuit board;

FIG. 7A is a plan view illustrating an embodiment of an area at which the main circuit board and the connection circuit board are connected to each other; and

FIG. 7B is a cross-sectional view illustrating the area at which the main circuit board and the connection circuit board are connected to each other.

The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which various embodiments are shown. This invention may, however, be embodied in many different forms, and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. Also, in the figures, the thickness, ratio, and dimensions of components are exaggerated for clarity of illustration.

Hereinafter, embodiments will be described with reference to the accompanying drawings. It will be understood that when an element such as a region, layer, or portion is referred to as being related to another element such as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element such as a region, layer, or portion is referred to as being related to another element such as being “directly on” another element, no other element or intervening element is present.