Bow V.S. Twist

You should know three factors of Bow

The bow is a deviation.
Usually the deviation from the flatness of the board characterized.
And the characterized is about foughtly cylindrical or spherical curvature.
Above three factors are basic points of Bow.

Then, if the board is rectangular, the bow calculus method is different.
Because its four corners are in the same plane.
Go deep rectangular bow, continues reading Twist definition below.

The definition of Twist

Three board form of a twist, include the rectangular sheet, panel board and the printed board.
Those three boards have similar deformation effective.
The deformation of a rectangular sheet, panel or printed board, that occurs parallel to a diagonal across its surface in such a way that one of the corners of the sheet is not in the plane formed by the other three corners.

If you want more detail Bow or twist info, please mail to our PCB experts.