What to check in PCB manufacturing quality control

Any PCB manufacturer should conduct a DFM inspection before putting the circuit board into production to find potential quality problems. DFM inspection is very important to ensure high yield, but there are other points of attention in the inspection and testing process, including:
 

(1)Electrical test

This includes needle bed and needle flying test. Both are non-invasive tests and can be used to check for open circuits and short circuits on critical networks during the manufacturing process.
 

(2)Manual or automatic optical inspection

The circuit board should be inspected automatically or manually after manufacturing. Some of the defects that can be identified through automatic inspection include trace size and spacing violations, missing or short-circuited pads, and incomplete or damaged drill holes.
 

(3)BGA inspection

Use X-ray imaging system to inspect BGA devices.
 

(4)TDR test
This test is used to measure the characteristics or differential impedance of the transmission line in the impedance control wiring. This can be done by placing the transmission line on a panel or board-side sample, and then comparing the expected impedance with the reference impedance.

(5)Special standard manufacturing requirements

If you are manufacturing in accordance with IPC Class 3 or Class 3/A, your circuit board must meet important reliability standards. The manufacturer should check these points before and during the manufacturing process to ensure compliance and reliability.