Component assembly structure

A component assembly structure comprising:

• a component to be assembled in which a positioning pin is provided on a base, the base including a first side and a second side and a step formed along the second side of the base, the step having a top surface;
• a first component with a first hole to be fitted to the positioning pin, the first component having a top surface;
• and
• a second component with a second hole to be fitted to the positioning pin, wherein
• the positioning pin includes a first shaft portion in a side on the base and a second shaft portion, having a diameter smaller than that of the first shaft portion, in a side on a tip end,
• the first component is positioned on the component to be assembled by fitting the first hole to the first shaft portion,
• the second component is positioned on the component to be assembled by fitting the second hole to the second shaft portion, and wherein the top surface of the step is co-planer with the top surface of the first component.