I am trying to draw 2D artwork for a game but when I import the artwork it is not the same size.

Hello I am new to unity and I understand that 100 pixels per unit means a sprite that’s 100 pixels would equal 1 unit in the scene. What I am trying to do is draw a vector background in illustrator. I am drawing on a canvas that is 640 x 1136 I phone 5 screen size and I have unity set up for the I phone 5 but when I pull in the .png it is bigger than the screen size. I am wondering if I should be drawing the artwork to a different size or should I change PPU in unity? I am not sure where to start any help would be appreciated.

Add canvas

Inspector Canvas > Renderer mode > Screen Space - Camera > Render Camera link your camera

Inspector Canvas > Canvas Scaler > Scale Mode > X - 640 Y - 1136

Add Image in Canvas > Add sprite to image > Set Native Size