How much is the warpage of the circuit board, and how to detect the warpage of the FPC?
Method for detecting warpage is put on the printed circuit board by the test platform, the test needle to warp the largest local, in order to test the diameter of the needle, divided by the PCB curved edge length, we can calculate the soft board warpage.
At present, the degree of warpage of the electronic assembly plant license, whether double-sided or multilayer, 1.6mm thickness, usually 0.70 ~ 0.75%, many SMT, BGA board, the requirement is 0.5%.
According to the United States IPC-6012 (1996 edition) rigid printed board identification and performance specification, flexible circuit board for surface mount printed board to allow maximum warpage and distortion of 0.75%, the other various boards allow for the use of 1.5%.
