Electronic – PCB Footprint Design Dimensions

datasheetfootprintpcb

I am trying to make a Eagle library for a Micro USB B connector. The library is unavailable and I decided to make one with the datasheet dimensions provided.
But it is rather confusing.

The units are in mm
Please check the attached image.

The Dimensions are shown as subtracted from another. Like A-B
I thought that was a tolerance.

I have marked the rear pin. As the top view the size of the pin is 4-1.00
But as Y the size is 2-2.00!! So the error is like 4mm??

Please advice me how to read this dimensions in the datasheet. I do not get that 2-2.00 notation. enter image description here

Best Answer

The 2-2.00 dimension (your Y) is 2.00mm, but it applies to two identical holes (2-) on the datasheet. Only one of those holes is dimensioned for length, the other is dimensioned for width, to avoid an excess of lines and dimensions cluttering the drawing. You are expected to figure out which pair of holes are the same size from the symmetry of the drawing.

Similarly, the socket has 4 tabs 1mm wide, X, shown as 4-1.00